From: Kees Cook &lt;keescook(a)chromium.org&gt; stable inclusion from stable-5.10 category: feature commit:9ee85b8bd3cab1a151850b6648cab7ed2e0d8192 issue: #I4919J -------------------------------- With both ram.c and ram_core.c built into ramoops.ko, it doesn't make sense to have differing pr_fmt prefixes. This fixes ram_core.c to use the module name (as ram.c already does). Additionally improves region reservation error to include the region name. Signed-off-by: Kees Cook &lt;keescook(a)chromium.org&gt; (cherry picked from commit 9ee85b8bd3cab1a151850b6648cab7ed2e0d8192) Signed-off-by: roger &lt;kongzhengrong(a)huawei.com&gt; --- fs/pstore/ram_core.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/fs/pstore/ram_core.c b/fs/pstore/ram_core.c index 79f0e183f135..51185f334589 100644 --- a/fs/pstore/ram_core.c +++ b/fs/pstore/ram_core.c @@ -12,7 +12,7 @@ * */ -#define pr_fmt(fmt) "persistent_ram: " fmt +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include <linux/device.h> #include <linux/err.h> @@ -443,7 +443,8 @@ static void *persistent_ram_iomap(phys_addr_t start, size_t size, void *va; if (!request_mem_region(start, size, label ?: "ramoops")) { - pr_err("request mem region (0x%llx@0x%llx) failed\n", + pr_err("request mem region (%s 0x%llx@0x%llx) failed\n", + label ?: "ramoops", (unsigned long long)size, (unsigned long long)start); return NULL; } -- 2.17.1

From: Kees Cook &lt;keescook(a)chromium.org&gt; stable inclusion from stable-5.10 category: feature commit:0eed84ffb094bbddfb4b9378ef0a2eccf4dda99c issue: #I4919J -------------------------------- This improves and updates some comments: - dump handler comment out of sync from calling convention - fix kern-doc typo and improves status output: - reminder that only kernel crash dumps are compressed - do not be silent about ECC infrastructure failures Signed-off-by: Kees Cook &lt;keescook(a)chromium.org&gt; (cherry picked from commit 0eed84ffb094bbddfb4b9378ef0a2eccf4dda99c) Signed-off-by: roger &lt;kongzhengrong(a)huawei.com&gt; --- fs/pstore/platform.c | 7 +++---- fs/pstore/ram_core.c | 4 +++- include/linux/pstore.h | 2 +- 3 files changed, 7 insertions(+), 6 deletions(-) diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c index 2197bf68f278..ce610b0fb669 100644 --- a/fs/pstore/platform.c +++ b/fs/pstore/platform.c @@ -322,7 +322,7 @@ static void allocate_buf_for_compression(void) big_oops_buf_sz = size; big_oops_buf = buf; - pr_info("Using compression: %s\n", zbackend->name); + pr_info("Using crash dump compression: %s\n", zbackend->name); } static void free_buf_for_compression(void) @@ -374,9 +374,8 @@ void pstore_record_init(struct pstore_record *record, } /* - * callback from kmsg_dump. (s2,l2) has the most recently - * written bytes, older bytes are in (s1,l1). Save as much - * as we can from the end of the buffer. + * callback from kmsg_dump. Save as much as we can (up to kmsg_bytes) from the + * end of the buffer. */ static void pstore_dump(struct kmsg_dumper *dumper, enum kmsg_dump_reason reason) diff --git a/fs/pstore/ram_core.c b/fs/pstore/ram_core.c index 0269fc343ca5..bd95cdfa3384 100644 --- a/fs/pstore/ram_core.c +++ b/fs/pstore/ram_core.c @@ -493,8 +493,10 @@ static int persistent_ram_post_init(struct persistent_ram_zone *prz, u32 sig, bool zap = !!(prz->flags & PRZ_FLAG_ZAP_OLD); ret = persistent_ram_init_ecc(prz, ecc_info); - if (ret) + if (ret) { + pr_warn("ECC failed %s\n", prz->label); return ret; + } sig ^= PERSISTENT_RAM_SIG; diff --git a/include/linux/pstore.h b/include/linux/pstore.h index de9093d6e660..072492f17887 100644 --- a/include/linux/pstore.h +++ b/include/linux/pstore.h @@ -85,7 +85,7 @@ struct pstore_record { /** * struct pstore_info - backend pstore driver structure * - * @owner: module which is repsonsible for this backend driver + * @owner: module which is responsible for this backend driver * @name: name of the backend driver * * @buf_lock: semaphore to serialize access to @buf -- 2.17.1

From: Kees Cook &lt;keescook(a)chromium.org&gt; stable inclusion from stable-5.10 category: feature commit:4af62a6423d0ad98e3eee2bec4305dde8deefefe issue: #I4919J -------------------------------- Minor clean-up to use BIT() (as already done in pstore_ram.h). Signed-off-by: Kees Cook &lt;keescook(a)chromium.org&gt; (cherry picked from commit 4af62a6423d0ad98e3eee2bec4305dde8deefefe) Signed-off-by: roger &lt;kongzhengrong(a)huawei.com&gt; --- include/linux/pstore.h | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/include/linux/pstore.h b/include/linux/pstore.h index 072492f17887..dd8e55742bf9 100644 --- a/include/linux/pstore.h +++ b/include/linux/pstore.h @@ -192,10 +192,10 @@ struct pstore_info { }; /* Supported frontends */ -#define PSTORE_FLAGS_DMESG (1 << 0) -#define PSTORE_FLAGS_CONSOLE (1 << 1) -#define PSTORE_FLAGS_FTRACE (1 << 2) -#define PSTORE_FLAGS_PMSG (1 << 3) +#define PSTORE_FLAGS_DMESG BIT(0) +#define PSTORE_FLAGS_CONSOLE BIT(1) +#define PSTORE_FLAGS_FTRACE BIT(2) +#define PSTORE_FLAGS_PMSG BIT(3) extern int pstore_register(struct pstore_info *); extern void pstore_unregister(struct pstore_info *); -- 2.17.1

From: Thomas Meyer &lt;thomas(a)m3y3r.de&gt; stable inclusion from stable-5.10 category: feature commit:69596433bc28a4642bdc84676f44cfa3b16d0588 issue: #I4919J -------------------------------- Bool initializations should use true and false. Bool tests don't need comparisons. Signed-off-by: Thomas Meyer &lt;thomas(a)m3y3r.de&gt; Signed-off-by: Kees Cook &lt;keescook(a)chromium.org&gt; (cherry picked from commit 69596433bc28a4642bdc84676f44cfa3b16d0588) Signed-off-by: roger &lt;kongzhengrong(a)huawei.com&gt; --- fs/pstore/ftrace.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/pstore/ftrace.c b/fs/pstore/ftrace.c index 06aab07b6bb7..b8a0931568f8 100644 --- a/fs/pstore/ftrace.c +++ b/fs/pstore/ftrace.c @@ -148,7 +148,7 @@ void pstore_unregister_ftrace(void) mutex_lock(&pstore_ftrace_lock); if (pstore_ftrace_enabled) { unregister_ftrace_function(&pstore_ftrace_ops); - pstore_ftrace_enabled = 0; + pstore_ftrace_enabled = false; } mutex_unlock(&pstore_ftrace_lock); -- 2.17.1

From: Yue Hu &lt;huyue2(a)yulong.com&gt; stable inclusion from stable-5.10 category: feature commit:182ca6e0ae23550cf98d05daeab8dcb7fdc0a928 issue: #I4919J -------------------------------- In ramoops_register_dummy() dummy_data is allocated via kzalloc() then it will always occupy the heap space after register platform device via platform_device_register_data(), but it will not be used any more. So let's free it for system usage, replace it with stack memory is better due to small size. Signed-off-by: Yue Hu &lt;huyue2(a)yulong.com&gt; [kees: add required memset and adjust sizeof() argument] Signed-off-by: Kees Cook &lt;keescook(a)chromium.org&gt; (cherry picked from commit 182ca6e0ae23550cf98d05daeab8dcb7fdc0a928) Signed-off-by: roger &lt;kongzhengrong(a)huawei.com&gt; --- fs/pstore/ram.c | 35 ++++++++++++++--------------------- 1 file changed, 14 insertions(+), 21 deletions(-) diff --git a/fs/pstore/ram.c b/fs/pstore/ram.c index 92333953d047..3f7df241e1f9 100644 --- a/fs/pstore/ram.c +++ b/fs/pstore/ram.c @@ -110,7 +110,6 @@ struct ramoops_context { }; static struct platform_device *dummy; -static struct ramoops_platform_data *dummy_data; static int ramoops_pstore_open(struct pstore_info *psi) { @@ -915,13 +914,12 @@ static inline void ramoops_unregister_dummy(void) { platform_device_unregister(dummy); dummy = NULL; - - kfree(dummy_data); - dummy_data = NULL; } static void __init ramoops_register_dummy(void) { + struct ramoops_platform_data pdata; + /* * Prepare a dummy platform data structure to carry the module * parameters. If mem_size isn't set, then there are no module @@ -932,30 +930,25 @@ static void __init ramoops_register_dummy(void) pr_info("using module parameters\n"); - dummy_data = kzalloc(sizeof(*dummy_data), GFP_KERNEL); - if (!dummy_data) { - pr_info("could not allocate pdata\n"); - return; - } - - dummy_data->mem_size = mem_size; - dummy_data->mem_address = mem_address; - dummy_data->mem_type = mem_type; - dummy_data->record_size = record_size; - dummy_data->console_size = ramoops_console_size; - dummy_data->ftrace_size = ramoops_ftrace_size; - dummy_data->pmsg_size = ramoops_pmsg_size; - dummy_data->dump_oops = dump_oops; - dummy_data->flags = RAMOOPS_FLAG_FTRACE_PER_CPU; + memset(&pdata, 0, sizeof(pdata)); + pdata.mem_size = mem_size; + pdata.mem_address = mem_address; + pdata.mem_type = mem_type; + pdata.record_size = record_size; + pdata.console_size = ramoops_console_size; + pdata.ftrace_size = ramoops_ftrace_size; + pdata.pmsg_size = ramoops_pmsg_size; + pdata.dump_oops = dump_oops; + pdata.flags = RAMOOPS_FLAG_FTRACE_PER_CPU; /* * For backwards compatibility ramoops.ecc=1 means 16 bytes ECC * (using 1 byte for ECC isn't much of use anyway). */ - dummy_data->ecc_info.ecc_size = ramoops_ecc == 1 ? 16 : ramoops_ecc; + pdata.ecc_info.ecc_size = ramoops_ecc == 1 ? 16 : ramoops_ecc; dummy = platform_device_register_data(NULL, "ramoops", -1, - dummy_data, sizeof(struct ramoops_platform_data)); + &pdata, sizeof(pdata)); if (IS_ERR(dummy)) { pr_info("could not create platform device: %ld\n", PTR_ERR(dummy)); -- 2.17.1

From: Yue Hu &lt;huyue2(a)yulong.com&gt; stable inclusion from stable-5.10 category: feature commit:4c6c4d34536744f2c9e171ef5bb548a06a525501 issue: #I4919J -------------------------------- Sometimes pstore_console_write() will write records with zero size to persistent ram zone, which is unnecessary. It will only increase resource consumption. Also adjust ramoops_write_kmsg_hdr() to have same logic if memory allocation fails. Signed-off-by: Yue Hu &lt;huyue2(a)yulong.com&gt; Signed-off-by: Kees Cook &lt;keescook(a)chromium.org&gt; (cherry picked from commit 4c6c4d34536744f2c9e171ef5bb548a06a525501) Signed-off-by: roger &lt;kongzhengrong(a)huawei.com&gt; --- fs/pstore/platform.c | 3 +++ fs/pstore/ram.c | 6 ++++-- 2 files changed, 7 insertions(+), 2 deletions(-) diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c index 7a873006d525..2a561728443f 100644 --- a/fs/pstore/platform.c +++ b/fs/pstore/platform.c @@ -520,6 +520,9 @@ static void pstore_console_write(struct console *con, const char *s, unsigned c) { struct pstore_record record; + if (!c) + return; + pstore_record_init(&record, psinfo); record.type = PSTORE_TYPE_CONSOLE; diff --git a/fs/pstore/ram.c b/fs/pstore/ram.c index 2921905cb7e5..bc7af9393d8f 100644 --- a/fs/pstore/ram.c +++ b/fs/pstore/ram.c @@ -354,8 +354,10 @@ static size_t ramoops_write_kmsg_hdr(struct persistent_ram_zone *prz, (time64_t)record->time.tv_sec, record->time.tv_nsec / 1000, record->compressed ? 'C' : 'D'); - WARN_ON_ONCE(!hdr); - len = hdr ? strlen(hdr) : 0; + if (WARN_ON_ONCE(!hdr)) + return 0; + + len = strlen(hdr); persistent_ram_write(prz, hdr, len); kfree(hdr); -- 2.17.1

From: Kees Cook &lt;keescook(a)chromium.org&gt; stable inclusion from stable-5.10 category: feature commit:93ee4b7d9f0632690713aee604c49e298e634094 issue: #I4919J -------------------------------- Since the header is a fixed small maximum size, just use a stack variable to avoid memory allocation in the write path. Signed-off-by: Kees Cook &lt;keescook(a)chromium.org&gt; (cherry picked from commit 93ee4b7d9f0632690713aee604c49e298e634094) Signed-off-by: roger &lt;kongzhengrong(a)huawei.com&gt; --- fs/pstore/ram.c | 10 +++------- 1 file changed, 3 insertions(+), 7 deletions(-) diff --git a/fs/pstore/ram.c b/fs/pstore/ram.c index 5d938d68b2b1..52bf9ba9a139 100644 --- a/fs/pstore/ram.c +++ b/fs/pstore/ram.c @@ -347,19 +347,15 @@ static ssize_t ramoops_pstore_read(struct pstore_record *record) static size_t ramoops_write_kmsg_hdr(struct persistent_ram_zone *prz, struct pstore_record *record) { - char *hdr; + char hdr[36]; /* "===="(4), %lld(20), "."(1), %06lu(6), "-%c\n"(3) */ size_t len; - hdr = kasprintf(GFP_ATOMIC, RAMOOPS_KERNMSG_HDR "%lld.%06lu-%c\n", + len = scnprintf(hdr, sizeof(hdr), + RAMOOPS_KERNMSG_HDR "%lld.%06lu-%c\n", (time64_t)record->time.tv_sec, record->time.tv_nsec / 1000, record->compressed ? 'C' : 'D'); - if (WARN_ON_ONCE(!hdr)) - return 0; - - len = strlen(hdr); persistent_ram_write(prz, hdr, len); - kfree(hdr); return len; } -- 2.17.1

From: Greg Kroah-Hartman &lt;gregkh(a)linuxfoundation.org&gt; stable inclusion from stable-5.10 category: feature commit:fa1af7583e8012c471ee45d5b1703123fe45a9f3 issue: #I4919J -------------------------------- When calling debugfs functions, there is no need to ever check the return value. The function can work or not, but the code logic should never do something different based on this. Cc: Kees Cook &lt;keescook(a)chromium.org&gt; Cc: Anton Vorontsov &lt;anton(a)enomsg.org&gt; Cc: Colin Cross &lt;ccross(a)android.com&gt; Cc: Tony Luck &lt;tony.luck(a)intel.com&gt; Cc: linux-kernel(a)vger.kernel.org Signed-off-by: Greg Kroah-Hartman &lt;gregkh(a)linuxfoundation.org&gt; Signed-off-by: Kees Cook &lt;keescook(a)chromium.org&gt; (cherry picked from commit fa1af7583e8012c471ee45d5b1703123fe45a9f3) Signed-off-by: roger &lt;kongzhengrong(a)huawei.com&gt; --- fs/pstore/ftrace.c | 18 ++---------------- 1 file changed, 2 insertions(+), 16 deletions(-) diff --git a/fs/pstore/ftrace.c b/fs/pstore/ftrace.c index b8a0931568f8..fd9468928bef 100644 --- a/fs/pstore/ftrace.c +++ b/fs/pstore/ftrace.c @@ -120,27 +120,13 @@ static struct dentry *pstore_ftrace_dir; void pstore_register_ftrace(void) { - struct dentry *file; - if (!psinfo->write) return; pstore_ftrace_dir = debugfs_create_dir("pstore", NULL); - if (!pstore_ftrace_dir) { - pr_err("%s: unable to create pstore directory\n", __func__); - return; - } - - file = debugfs_create_file("record_ftrace", 0600, pstore_ftrace_dir, - NULL, &pstore_knob_fops); - if (!file) { - pr_err("%s: unable to create record_ftrace file\n", __func__); - goto err_file; - } - return; -err_file: - debugfs_remove(pstore_ftrace_dir); + debugfs_create_file("record_ftrace", 0600, pstore_ftrace_dir, NULL, + &pstore_knob_fops); } void pstore_unregister_ftrace(void) -- 2.17.1

From: Al Viro &lt;viro(a)zeniv.linux.org.uk&gt; stable inclusion from stable-5.10 category: feature commit:ff847781049c37dff9ad4af2bf2d7aad02622f96 issue: #I4919J -------------------------------- don't bother trying to do bulk access_ok() Signed-off-by: Al Viro &lt;viro(a)zeniv.linux.org.uk&gt; (cherry picked from commit ff847781049c37dff9ad4af2bf2d7aad02622f96) Signed-off-by: roger &lt;kongzhengrong(a)huawei.com&gt; --- fs/pstore/ram_core.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/fs/pstore/ram_core.c b/fs/pstore/ram_core.c index a908ed97a24c..4a947bb60210 100644 --- a/fs/pstore/ram_core.c +++ b/fs/pstore/ram_core.c @@ -282,7 +282,7 @@ static int notrace persistent_ram_update_user(struct persistent_ram_zone *prz, const void __user *s, unsigned int start, unsigned int count) { struct persistent_ram_buffer *buffer = prz->buffer; - int ret = unlikely(__copy_from_user(buffer->data + start, s, count)) ? + int ret = unlikely(copy_from_user(buffer->data + start, s, count)) ? -EFAULT : 0; persistent_ram_update_ecc(prz, start, count); return ret; @@ -347,8 +347,6 @@ int notrace persistent_ram_write_user(struct persistent_ram_zone *prz, int rem, ret = 0, c = count; size_t start; - if (unlikely(!access_ok(VERIFY_READ, s, count))) - return -EFAULT; if (unlikely(c > prz->buffer_size)) { s += c - prz->buffer_size; c = prz->buffer_size; -- 2.17.1

From: Kees Cook &lt;keescook(a)chromium.org&gt; stable inclusion from stable-5.10 category: feature commit:47af61ffb19baa8df2b109582f87f7622fbe85cc issue: #I4919J -------------------------------- The name "allpstore" doesn't carry much meaning, so rename it to what it actually is: the list of all records present in the filesystem. The lock is also renamed accordingly. Link: https://lore.kernel.org/lkml/20200506152114.50375-5-keescook@chromium.org/ Signed-off-by: Kees Cook &lt;keescook(a)chromium.org&gt; (cherry picked from commit 47af61ffb19baa8df2b109582f87f7622fbe85cc) Signed-off-by: roger &lt;kongzhengrong(a)huawei.com&gt; --- fs/pstore/inode.c | 20 ++++++++++---------- 1 file changed, 10 insertions(+), 10 deletions(-) diff --git a/fs/pstore/inode.c b/fs/pstore/inode.c index d49fb7a8b664..73a57fec03fb 100644 --- a/fs/pstore/inode.c +++ b/fs/pstore/inode.c @@ -41,8 +41,8 @@ #define PSTORE_NAMELEN 64 -static DEFINE_SPINLOCK(allpstore_lock); -static LIST_HEAD(allpstore); +static DEFINE_SPINLOCK(records_list_lock); +static LIST_HEAD(records_list); struct pstore_private { struct list_head list; @@ -208,9 +208,9 @@ static void pstore_evict_inode(struct inode *inode) clear_inode(inode); if (p) { - spin_lock_irqsave(&allpstore_lock, flags); + spin_lock_irqsave(&records_list_lock, flags); list_del(&p->list); - spin_unlock_irqrestore(&allpstore_lock, flags); + spin_unlock_irqrestore(&records_list_lock, flags); free_pstore_private(p); } } @@ -314,8 +314,8 @@ int pstore_mkfile(struct dentry *root, struct pstore_record *record) WARN_ON(!inode_is_locked(d_inode(root))); - spin_lock_irqsave(&allpstore_lock, flags); - list_for_each_entry(pos, &allpstore, list) { + spin_lock_irqsave(&records_list_lock, flags); + list_for_each_entry(pos, &records_list, list) { if (pos->record->type == record->type && pos->record->id == record->id && pos->record->psi == record->psi) { @@ -323,7 +323,7 @@ int pstore_mkfile(struct dentry *root, struct pstore_record *record) break; } } - spin_unlock_irqrestore(&allpstore_lock, flags); + spin_unlock_irqrestore(&records_list_lock, flags); if (rc) return rc; @@ -356,9 +356,9 @@ int pstore_mkfile(struct dentry *root, struct pstore_record *record) d_add(dentry, inode); - spin_lock_irqsave(&allpstore_lock, flags); - list_add(&private->list, &allpstore); - spin_unlock_irqrestore(&allpstore_lock, flags); + spin_lock_irqsave(&records_list_lock, flags); + list_add(&private->list, &records_list); + spin_unlock_irqrestore(&records_list_lock, flags); return 0; -- 2.17.1

From: Kees Cook &lt;keescook(a)chromium.org&gt; stable inclusion from stable-5.10 category: feature commit:7a0ad546847a23f92f5e227fa8e4578eaa3a8d0a issue: #I4919J -------------------------------- The "unlink" handling should perform list removal (which can also make sure records don't get double-erased), and the "evict" handling should be responsible only for memory freeing. Link: https://lore.kernel.org/lkml/20200506152114.50375-8-keescook@chromium.org/ Signed-off-by: Kees Cook &lt;keescook(a)chromium.org&gt; (cherry picked from commit 7a0ad546847a23f92f5e227fa8e4578eaa3a8d0a) Signed-off-by: roger &lt;kongzhengrong(a)huawei.com&gt; --- fs/pstore/inode.c | 19 +++++++++++++------ 1 file changed, 13 insertions(+), 6 deletions(-) diff --git a/fs/pstore/inode.c b/fs/pstore/inode.c index d5760195a0ad..7bec953e2dbc 100644 --- a/fs/pstore/inode.c +++ b/fs/pstore/inode.c @@ -189,10 +189,21 @@ static int pstore_unlink(struct inode *dir, struct dentry *dentry) { struct pstore_private *p = d_inode(dentry)->i_private; struct pstore_record *record = p->record; + int rc = 0; if (!record->psi->erase) return -EPERM; + /* Make sure we can't race while removing this file. */ + mutex_lock(&records_list_lock); + if (!list_empty(&p->list)) + list_del_init(&p->list); + else + rc = -ENOENT; + mutex_unlock(&records_list_lock); + if (rc) + return rc; + mutex_lock(&record->psi->read_mutex); record->psi->erase(record); mutex_unlock(&record->psi->read_mutex); @@ -205,12 +216,7 @@ static void pstore_evict_inode(struct inode *inode) struct pstore_private *p = inode->i_private; clear_inode(inode); - if (p) { - mutex_lock(&records_list_lock); - list_del(&p->list); - mutex_unlock(&records_list_lock); - free_pstore_private(p); - } + free_pstore_private(p); } static const struct inode_operations pstore_dir_inode_operations = { @@ -430,6 +436,7 @@ static void pstore_kill_sb(struct super_block *sb) { kill_litter_super(sb); pstore_sb = NULL; + INIT_LIST_HEAD(&records_list); } static struct file_system_type pstore_fs_type = { -- 2.17.1

From: Pavel Tatashin &lt;pasha.tatashin(a)soleen.com&gt; stable inclusion from stable-5.10 category: feature commit:3524e688b8ee50b0edc76f0e020727eb6c684dbc issue: #I4919J -------------------------------- Add a new member to struct pstore_info for passing information about kmesg dump maximum reason. This allows a finer control of what kmesg dumps are sent to pstore storage backends. Those backends that do not explicitly set this field (keeping it equal to 0), get the default behavior: store only Oopses and Panics, or everything if the printk.always_kmsg_dump boot param is set. Signed-off-by: Pavel Tatashin &lt;pasha.tatashin(a)soleen.com&gt; Link: https://lore.kernel.org/lkml/20200515184434.8470-5-keescook@chromium.org/ Co-developed-by: Kees Cook &lt;keescook(a)chromium.org&gt; Signed-off-by: Kees Cook &lt;keescook(a)chromium.org&gt; (cherry picked from commit 3524e688b8ee50b0edc76f0e020727eb6c684dbc) Signed-off-by: roger &lt;kongzhengrong(a)huawei.com&gt; --- fs/pstore/platform.c | 4 +++- include/linux/pstore.h | 7 +++++++ 2 files changed, 10 insertions(+), 1 deletion(-) diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c index 405f714b69d3..78058359b18e 100644 --- a/fs/pstore/platform.c +++ b/fs/pstore/platform.c @@ -630,8 +630,10 @@ int pstore_register(struct pstore_info *psi) pstore_get_records(0); - if (psi->flags & PSTORE_FLAGS_DMESG) + if (psi->flags & PSTORE_FLAGS_DMESG) { + pstore_dumper.max_reason = psinfo->max_reason; pstore_register_kmsg(); + } if (psi->flags & PSTORE_FLAGS_CONSOLE) pstore_register_console(); if (psi->flags & PSTORE_FLAGS_FTRACE) diff --git a/include/linux/pstore.h b/include/linux/pstore.h index b146181e8709..c39f8c873df9 100644 --- a/include/linux/pstore.h +++ b/include/linux/pstore.h @@ -108,6 +108,12 @@ struct pstore_record { * * @read_mutex: serializes @open, @read, @close, and @erase callbacks * @flags: bitfield of frontends the backend can accept writes for + * @max_reason: Used when PSTORE_FLAGS_DMESG is set. Contains the + * kmsg_dump_reason enum value. KMSG_DUMP_UNDEF means + * "use existing kmsg_dump() filtering, based on the + * printk.always_kmsg_dump boot param" (which is either + * KMSG_DUMP_OOPS when false, or KMSG_DUMP_MAX when + * true); see printk.always_kmsg_dump for more details. * @data: backend-private pointer passed back during callbacks * * Callbacks: @@ -191,6 +197,7 @@ struct pstore_info { struct mutex read_mutex; int flags; + int max_reason; void *data; int (*open)(struct pstore_info *psi); -- 2.17.1

From: Kees Cook &lt;keescook(a)chromium.org&gt; stable inclusion from stable-5.10 category: feature commit:d973f7d83dc7360597373536b34e80eea306d15f issue: #I4919J -------------------------------- It is easier to see how module params are used if they're near the variables they use. Link: https://lore.kernel.org/lkml/20200510202436.63222-4-keescook@chromium.org/ Signed-off-by: Kees Cook &lt;keescook(a)chromium.org&gt; (cherry picked from commit d973f7d83dc7360597373536b34e80eea306d15f) Signed-off-by: roger &lt;kongzhengrong(a)huawei.com&gt; --- fs/pstore/platform.c | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-) diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c index 53d59cedef3d..310034809594 100644 --- a/fs/pstore/platform.c +++ b/fs/pstore/platform.c @@ -88,12 +88,17 @@ static DEFINE_SPINLOCK(pstore_lock); struct pstore_info *psinfo; static char *backend; +module_param(backend, charp, 0444); +MODULE_PARM_DESC(backend, "specific backend to use"); + static char *compress = #ifdef CONFIG_PSTORE_COMPRESS_DEFAULT CONFIG_PSTORE_COMPRESS_DEFAULT; #else NULL; #endif +module_param(compress, charp, 0444); +MODULE_PARM_DESC(compress, "compression to use"); /* Compression parameters */ static struct crypto_comp *tfm; @@ -858,11 +863,5 @@ static void __exit pstore_exit(void) } module_exit(pstore_exit) -module_param(compress, charp, 0444); -MODULE_PARM_DESC(compress, "Pstore compression to use"); - -module_param(backend, charp, 0444); -MODULE_PARM_DESC(backend, "Pstore backend to use"); - MODULE_AUTHOR("Tony Luck &lt;tony.luck(a)intel.com&gt;&quot;)>"); MODULE_LICENSE("GPL"); -- 2.17.1

From: Kees Cook &lt;keescook(a)chromium.org&gt; stable inclusion from stable-5.10 category: feature commit:26961d76ff35aecb1af0fefd283fb5170786a812 issue: #I4919J -------------------------------- Refactor device tree size parsing routines to be able to pass a non-zero default value for providing a configurable default for the coming "max_reason" field. Also rename the helpers, since we're not always parsing a size -- we're parsing a u32 and making sure it's not greater than INT_MAX. Link: https://lore.kernel.org/lkml/20200506211523.15077-4-keescook@chromium.org/ Link: https://lore.kernel.org/lkml/20200521205223.175957-1-tyhicks@linux.microsof… Signed-off-by: Kees Cook &lt;keescook(a)chromium.org&gt; (cherry picked from commit 26961d76ff35aecb1af0fefd283fb5170786a812) Signed-off-by: roger &lt;kongzhengrong(a)huawei.com&gt; --- fs/pstore/ram.c | 31 +++++++++++++++++++------------ 1 file changed, 19 insertions(+), 12 deletions(-) diff --git a/fs/pstore/ram.c b/fs/pstore/ram.c index 22a8e1bdc928..44e3823b7354 100644 --- a/fs/pstore/ram.c +++ b/fs/pstore/ram.c @@ -658,19 +658,25 @@ static int ramoops_init_prz(const char *name, return 0; } -static int ramoops_parse_dt_size(struct platform_device *pdev, - const char *propname, u32 *value) +/* Read a u32 from a dt property and make sure it's safe for an int. */ +static int ramoops_parse_dt_u32(struct platform_device *pdev, + const char *propname, + u32 default_value, u32 *value) { u32 val32 = 0; int ret; ret = of_property_read_u32(pdev->dev.of_node, propname, &val32); - if (ret < 0 && ret != -EINVAL) { + if (ret == -EINVAL) { + /* field is missing, use default value. */ + val32 = default_value; + } else if (ret < 0) { dev_err(&pdev->dev, "failed to parse property %s: %d\n", propname, ret); return ret; } + /* Sanity check our results. */ if (val32 > INT_MAX) { dev_err(&pdev->dev, "%s %u > INT_MAX\n", propname, val32); return -EOVERFLOW; @@ -703,21 +709,22 @@ static int ramoops_parse_dt(struct platform_device *pdev, pdata->mem_type = of_property_read_bool(of_node, "unbuffered"); pdata->dump_oops = !of_property_read_bool(of_node, "no-dump-oops"); -#define parse_size(name, field) { \ - ret = ramoops_parse_dt_size(pdev, name, &value); \ +#define parse_u32(name, field, default_value) { \ + ret = ramoops_parse_dt_u32(pdev, name, default_value, \ + &value); \ if (ret < 0) \ return ret; \ field = value; \ } - parse_size("record-size", pdata->record_size); - parse_size("console-size", pdata->console_size); - parse_size("ftrace-size", pdata->ftrace_size); - parse_size("pmsg-size", pdata->pmsg_size); - parse_size("ecc-size", pdata->ecc_info.ecc_size); - parse_size("flags", pdata->flags); + parse_u32("record-size", pdata->record_size, 0); + parse_u32("console-size", pdata->console_size, 0); + parse_u32("ftrace-size", pdata->ftrace_size, 0); + parse_u32("pmsg-size", pdata->pmsg_size, 0); + parse_u32("ecc-size", pdata->ecc_info.ecc_size, 0); + parse_u32("flags", pdata->flags, 0); -#undef parse_size +#undef parse_u32 /* * Some old Chromebooks relied on the kernel setting the -- 2.17.1

From: Kees Cook &lt;keescook(a)chromium.org&gt; stable inclusion from stable-5.10 category: feature commit:16a583079e937f6f5e6274ef7fda6dbf7dcb669f issue: #I4919J -------------------------------- Move the ftrace log merging logic out of pstore/ram into pstore/ftrace so other backends can use it, like pstore/zone. Link: https://lore.kernel.org/lkml/20200510202436.63222-7-keescook@chromium.org/ Signed-off-by: Kees Cook &lt;keescook(a)chromium.org&gt; (cherry picked from commit 16a583079e937f6f5e6274ef7fda6dbf7dcb669f) Signed-off-by: roger &lt;kongzhengrong(a)huawei.com&gt; --- fs/pstore/ftrace.c | 54 +++++++++++++++++++++++++++++++++++++++++ fs/pstore/internal.h | 9 +++++++ fs/pstore/ram.c | 57 +++----------------------------------------- 3 files changed, 66 insertions(+), 54 deletions(-) diff --git a/fs/pstore/ftrace.c b/fs/pstore/ftrace.c index fd9468928bef..8a4f05c27205 100644 --- a/fs/pstore/ftrace.c +++ b/fs/pstore/ftrace.c @@ -24,6 +24,7 @@ #include <linux/debugfs.h> #include <linux/err.h> #include <linux/cache.h> +#include <linux/slab.h> #include <asm/barrier.h> #include "internal.h" @@ -140,3 +141,56 @@ void pstore_unregister_ftrace(void) debugfs_remove_recursive(pstore_ftrace_dir); } + +ssize_t pstore_ftrace_combine_log(char **dest_log, size_t *dest_log_size, + const char *src_log, size_t src_log_size) +{ + size_t dest_size, src_size, total, dest_off, src_off; + size_t dest_idx = 0, src_idx = 0, merged_idx = 0; + void *merged_buf; + struct pstore_ftrace_record *drec, *srec, *mrec; + size_t record_size = sizeof(struct pstore_ftrace_record); + + dest_off = *dest_log_size % record_size; + dest_size = *dest_log_size - dest_off; + + src_off = src_log_size % record_size; + src_size = src_log_size - src_off; + + total = dest_size + src_size; + merged_buf = kmalloc(total, GFP_KERNEL); + if (!merged_buf) + return -ENOMEM; + + drec = (struct pstore_ftrace_record *)(*dest_log + dest_off); + srec = (struct pstore_ftrace_record *)(src_log + src_off); + mrec = (struct pstore_ftrace_record *)(merged_buf); + + while (dest_size > 0 && src_size > 0) { + if (pstore_ftrace_read_timestamp(&drec[dest_idx]) < + pstore_ftrace_read_timestamp(&srec[src_idx])) { + mrec[merged_idx++] = drec[dest_idx++]; + dest_size -= record_size; + } else { + mrec[merged_idx++] = srec[src_idx++]; + src_size -= record_size; + } + } + + while (dest_size > 0) { + mrec[merged_idx++] = drec[dest_idx++]; + dest_size -= record_size; + } + + while (src_size > 0) { + mrec[merged_idx++] = srec[src_idx++]; + src_size -= record_size; + } + + kfree(*dest_log); + *dest_log = merged_buf; + *dest_log_size = total; + + return 0; +} +EXPORT_SYMBOL_GPL(pstore_ftrace_combine_log); diff --git a/fs/pstore/internal.h b/fs/pstore/internal.h index fe5f7ef7323f..7783db28ce4a 100644 --- a/fs/pstore/internal.h +++ b/fs/pstore/internal.h @@ -12,9 +12,18 @@ extern unsigned long kmsg_bytes; #ifdef CONFIG_PSTORE_FTRACE extern void pstore_register_ftrace(void); extern void pstore_unregister_ftrace(void); +ssize_t pstore_ftrace_combine_log(char **dest_log, size_t *dest_log_size, + const char *src_log, size_t src_log_size); #else static inline void pstore_register_ftrace(void) {} static inline void pstore_unregister_ftrace(void) {} +static inline ssize_t +pstore_ftrace_combine_log(char **dest_log, size_t *dest_log_size, + const char *src_log, size_t src_log_size) +{ + *dest_log_size = 0; + return 0; +} #endif #ifdef CONFIG_PSTORE_PMSG diff --git a/fs/pstore/ram.c b/fs/pstore/ram.c index 89bd5d479b33..4c539f5bffa0 100644 --- a/fs/pstore/ram.c +++ b/fs/pstore/ram.c @@ -35,6 +35,7 @@ #include <linux/pstore_ram.h> #include <linux/of.h> #include <linux/of_address.h> +#include "internal.h" #define RAMOOPS_KERNMSG_HDR "====" #define MIN_MEM_SIZE 4096UL @@ -182,59 +183,6 @@ static bool prz_ok(struct persistent_ram_zone *prz) persistent_ram_ecc_string(prz, NULL, 0)); } -static -ssize_t ftrace_log_combine(char **dest_log, size_t *dest_log_size, - const char *src_log, size_t src_log_size) -{ - size_t dest_size, src_size, total, dest_off, src_off; - size_t dest_idx = 0, src_idx = 0, merged_idx = 0; - void *merged_buf; - struct pstore_ftrace_record *drec, *srec, *mrec; - size_t record_size = sizeof(struct pstore_ftrace_record); - - dest_off = *dest_log_size % record_size; - dest_size = *dest_log_size - dest_off; - - src_off = src_log_size % record_size; - src_size = src_log_size - src_off; - - total = dest_size + src_size; - merged_buf = kmalloc(total, GFP_KERNEL); - if (!merged_buf) - return -ENOMEM; - - drec = (struct pstore_ftrace_record *)(*dest_log + dest_off); - srec = (struct pstore_ftrace_record *)(src_log + src_off); - mrec = (struct pstore_ftrace_record *)(merged_buf); - - while (dest_size > 0 && src_size > 0) { - if (pstore_ftrace_read_timestamp(&drec[dest_idx]) < - pstore_ftrace_read_timestamp(&srec[src_idx])) { - mrec[merged_idx++] = drec[dest_idx++]; - dest_size -= record_size; - } else { - mrec[merged_idx++] = srec[src_idx++]; - src_size -= record_size; - } - } - - while (dest_size > 0) { - mrec[merged_idx++] = drec[dest_idx++]; - dest_size -= record_size; - } - - while (src_size > 0) { - mrec[merged_idx++] = srec[src_idx++]; - src_size -= record_size; - } - - kfree(*dest_log); - *dest_log = merged_buf; - *dest_log_size = total; - - return 0; -} - static ssize_t ramoops_pstore_read(struct pstore_record *record) { ssize_t size = 0; @@ -307,7 +255,8 @@ static ssize_t ramoops_pstore_read(struct pstore_record *record) prz_next->corrected_bytes; tmp_prz->bad_blocks += prz_next->bad_blocks; - size = ftrace_log_combine(&tmp_prz->old_log, + size = pstore_ftrace_combine_log( + &tmp_prz->old_log, &tmp_prz->old_log_size, prz_next->old_log, prz_next->old_log_size); -- 2.17.1

From: WeiXiong Liao &lt;liaoweixiong(a)allwinnertech.com&gt; stable inclusion from stable-5.10 category: feature commit:d26c3321fe18dc74517dc1f518d584aa33b0a851 issue: #I4919J -------------------------------- Implement a common set of APIs needed to support pstore storage zones, based on how ramoops is designed. This will be used by pstore/blk with the intention of migrating pstore/ram in the future. Signed-off-by: WeiXiong Liao &lt;liaoweixiong(a)allwinnertech.com&gt; Link: https://lore.kernel.org/lkml/20200511233229.27745-2-keescook@chromium.org/ Co-developed-by: Kees Cook &lt;keescook(a)chromium.org&gt; Signed-off-by: Kees Cook &lt;keescook(a)chromium.org&gt; (cherry picked from commit d26c3321fe18dc74517dc1f518d584aa33b0a851) Signed-off-by: roger &lt;kongzhengrong(a)huawei.com&gt; --- fs/pstore/Kconfig | 7 + fs/pstore/Makefile | 3 + fs/pstore/platform.c | 2 +- fs/pstore/zone.c | 989 ++++++++++++++++++++++++++++++++++++ include/linux/pstore.h | 1 + include/linux/pstore_zone.h | 44 ++ 6 files changed, 1045 insertions(+), 1 deletion(-) create mode 100644 fs/pstore/zone.c create mode 100644 include/linux/pstore_zone.h diff --git a/fs/pstore/Kconfig b/fs/pstore/Kconfig index 503086f7f7c1..4c01efa459b3 100644 --- a/fs/pstore/Kconfig +++ b/fs/pstore/Kconfig @@ -153,3 +153,10 @@ config PSTORE_RAM "ramoops.ko". For more information, see Documentation/admin-guide/ramoops.rst. + +config PSTORE_ZONE + tristate + depends on PSTORE + help + The common layer for pstore/blk (and pstore/ram in the future) + to manage storage in zones. diff --git a/fs/pstore/Makefile b/fs/pstore/Makefile index 967b5891f325..58a967cbe4af 100644 --- a/fs/pstore/Makefile +++ b/fs/pstore/Makefile @@ -12,3 +12,6 @@ pstore-$(CONFIG_PSTORE_PMSG) += pmsg.o ramoops-objs += ram.o ram_core.o obj-$(CONFIG_PSTORE_RAM) += ramoops.o + +pstore_zone-objs += zone.o +obj-$(CONFIG_PSTORE_ZONE) += pstore_zone.o diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c index 310034809594..216c3247a2c6 100644 --- a/fs/pstore/platform.c +++ b/fs/pstore/platform.c @@ -146,7 +146,7 @@ enum pstore_type_id pstore_name_to_type(const char *name) } EXPORT_SYMBOL_GPL(pstore_name_to_type); -static const char *get_reason_str(enum kmsg_dump_reason reason) +const char *get_reason_str(enum kmsg_dump_reason reason) { switch (reason) { case KMSG_DUMP_PANIC: diff --git a/fs/pstore/zone.c b/fs/pstore/zone.c new file mode 100644 index 000000000000..31c7ce48c0c8 --- /dev/null +++ b/fs/pstore/zone.c @@ -0,0 +1,989 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Provide a pstore intermediate backend, organized into kernel memory + * allocated zones that are then mapped and flushed into a single + * contiguous region on a storage backend of some kind (block, mtd, etc). + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/slab.h> +#include <linux/mount.h> +#include <linux/printk.h> +#include <linux/fs.h> +#include <linux/pstore.h> +#include <linux/pstore_zone.h> +#include <linux/kdev_t.h> +#include <linux/device.h> +#include <linux/namei.h> +#include <linux/fcntl.h> +#include <linux/uio.h> +#include <linux/writeback.h> +#include "internal.h" + +#ifndef SECTOR_SIZE +#define SECTOR_SIZE 512 +#endif + +/** + * struct psz_head - header of zone to flush to storage + * + * @sig: signature to indicate header (PSZ_SIG xor PSZONE-type value) + * @datalen: length of data in @data + * @data: zone data. + */ +struct psz_buffer { +#define PSZ_SIG (0x43474244) /* DBGC */ + uint32_t sig; + atomic_t datalen; + uint8_t data[]; +}; + +/** + * struct psz_kmsg_header - kmsg dump-specific header to flush to storage + * + * @magic: magic num for kmsg dump header + * @time: kmsg dump trigger time + * @compressed: whether conpressed + * @counter: kmsg dump counter + * @reason: the kmsg dump reason (e.g. oops, panic, etc) + * @data: pointer to log data + * + * This is a sub-header for a kmsg dump, trailing after &psz_buffer. + */ +struct psz_kmsg_header { +#define PSTORE_KMSG_HEADER_MAGIC 0x4dfc3ae5 /* Just a random number */ + uint32_t magic; + struct timespec64 time; + bool compressed; + uint32_t counter; + enum kmsg_dump_reason reason; + uint8_t data[]; +}; + +/** + * struct pstore_zone - single stored buffer + * + * @off: zone offset of storage + * @type: front-end type for this zone + * @name: front-end name for this zone + * @buffer: pointer to data buffer managed by this zone + * @oldbuf: pointer to old data buffer + * @buffer_size: bytes in @buffer->data + * @should_recover: whether this zone should recover from storage + * @dirty: whether the data in @buffer dirty + * + * zone structure in memory. + */ +struct pstore_zone { + loff_t off; + const char *name; + enum pstore_type_id type; + + struct psz_buffer *buffer; + struct psz_buffer *oldbuf; + size_t buffer_size; + bool should_recover; + atomic_t dirty; +}; + +/** + * struct psz_context - all about running state of pstore/zone + * + * @kpszs: kmsg dump storage zones + * @kmsg_max_cnt: max count of @kpszs + * @kmsg_read_cnt: counter of total read kmsg dumps + * @kmsg_write_cnt: counter of total kmsg dump writes + * @oops_counter: counter of oops dumps + * @panic_counter: counter of panic dumps + * @recovered: whether finished recovering data from storage + * @on_panic: whether panic is happening + * @pstore_zone_info_lock: lock to @pstore_zone_info + * @pstore_zone_info: information from backend + * @pstore: structure for pstore + */ +struct psz_context { + struct pstore_zone **kpszs; + unsigned int kmsg_max_cnt; + unsigned int kmsg_read_cnt; + unsigned int kmsg_write_cnt; + /* + * These counters should be calculated during recovery. + * It records the oops/panic times after crashes rather than boots. + */ + unsigned int oops_counter; + unsigned int panic_counter; + atomic_t recovered; + atomic_t on_panic; + + /* + * pstore_zone_info_lock protects this entire structure during calls + * to register_pstore_zone()/unregister_pstore_zone(). + */ + struct mutex pstore_zone_info_lock; + struct pstore_zone_info *pstore_zone_info; + struct pstore_info pstore; +}; +static struct psz_context pstore_zone_cxt; + +/** + * enum psz_flush_mode - flush mode for psz_zone_write() + * + * @FLUSH_NONE: do not flush to storage but update data on memory + * @FLUSH_PART: just flush part of data including meta data to storage + * @FLUSH_META: just flush meta data of zone to storage + * @FLUSH_ALL: flush all of zone + */ +enum psz_flush_mode { + FLUSH_NONE = 0, + FLUSH_PART, + FLUSH_META, + FLUSH_ALL, +}; + +static inline int buffer_datalen(struct pstore_zone *zone) +{ + return atomic_read(&zone->buffer->datalen); +} + +static inline bool is_on_panic(void) +{ + return atomic_read(&pstore_zone_cxt.on_panic); +} + +static ssize_t psz_zone_read(struct pstore_zone *zone, char *buf, + size_t len, unsigned long off) +{ + if (!buf || !zone->buffer) + return -EINVAL; + if (off > zone->buffer_size) + return -EINVAL; + len = min_t(size_t, len, zone->buffer_size - off); + memcpy(buf, zone->buffer->data + off, len); + return len; +} + +static int psz_zone_write(struct pstore_zone *zone, + enum psz_flush_mode flush_mode, const char *buf, + size_t len, unsigned long off) +{ + struct pstore_zone_info *info = pstore_zone_cxt.pstore_zone_info; + ssize_t wcnt = 0; + ssize_t (*writeop)(const char *buf, size_t bytes, loff_t pos); + size_t wlen; + + if (off > zone->buffer_size) + return -EINVAL; + + wlen = min_t(size_t, len, zone->buffer_size - off); + if (buf && wlen) { + memcpy(zone->buffer->data + off, buf, wlen); + atomic_set(&zone->buffer->datalen, wlen + off); + } + + /* avoid to damage old records */ + if (!is_on_panic() && !atomic_read(&pstore_zone_cxt.recovered)) + goto dirty; + + writeop = is_on_panic() ? info->panic_write : info->write; + if (!writeop) + goto dirty; + + switch (flush_mode) { + case FLUSH_NONE: + if (unlikely(buf && wlen)) + goto dirty; + return 0; + case FLUSH_PART: + wcnt = writeop((const char *)zone->buffer->data + off, wlen, + zone->off + sizeof(*zone->buffer) + off); + if (wcnt != wlen) + goto dirty; + /* fallthrough */ + case FLUSH_META: + wlen = sizeof(struct psz_buffer); + wcnt = writeop((const char *)zone->buffer, wlen, zone->off); + if (wcnt != wlen) + goto dirty; + break; + case FLUSH_ALL: + wlen = zone->buffer_size + sizeof(*zone->buffer); + wcnt = writeop((const char *)zone->buffer, wlen, zone->off); + if (wcnt != wlen) + goto dirty; + break; + } + + return 0; +dirty: + atomic_set(&zone->dirty, true); + return -EBUSY; +} + +static int psz_flush_dirty_zone(struct pstore_zone *zone) +{ + int ret; + + if (unlikely(!zone)) + return -EINVAL; + + if (unlikely(!atomic_read(&pstore_zone_cxt.recovered))) + return -EBUSY; + + if (!atomic_xchg(&zone->dirty, false)) + return 0; + + ret = psz_zone_write(zone, FLUSH_ALL, NULL, 0, 0); + if (ret) + atomic_set(&zone->dirty, true); + return ret; +} + +static int psz_flush_dirty_zones(struct pstore_zone **zones, unsigned int cnt) +{ + int i, ret; + struct pstore_zone *zone; + + if (!zones) + return -EINVAL; + + for (i = 0; i < cnt; i++) { + zone = zones[i]; + if (!zone) + return -EINVAL; + ret = psz_flush_dirty_zone(zone); + if (ret) + return ret; + } + return 0; +} + +static int psz_move_zone(struct pstore_zone *old, struct pstore_zone *new) +{ + const char *data = (const char *)old->buffer->data; + int ret; + + ret = psz_zone_write(new, FLUSH_ALL, data, buffer_datalen(old), 0); + if (ret) { + atomic_set(&new->buffer->datalen, 0); + atomic_set(&new->dirty, false); + return ret; + } + atomic_set(&old->buffer->datalen, 0); + return 0; +} + +static int psz_kmsg_recover_data(struct psz_context *cxt) +{ + struct pstore_zone_info *info = cxt->pstore_zone_info; + struct pstore_zone *zone = NULL; + struct psz_buffer *buf; + unsigned long i; + ssize_t rcnt; + + if (!info->read) + return -EINVAL; + + for (i = 0; i < cxt->kmsg_max_cnt; i++) { + zone = cxt->kpszs[i]; + if (unlikely(!zone)) + return -EINVAL; + if (atomic_read(&zone->dirty)) { + unsigned int wcnt = cxt->kmsg_write_cnt; + struct pstore_zone *new = cxt->kpszs[wcnt]; + int ret; + + ret = psz_move_zone(zone, new); + if (ret) { + pr_err("move zone from %lu to %d failed\n", + i, wcnt); + return ret; + } + cxt->kmsg_write_cnt = (wcnt + 1) % cxt->kmsg_max_cnt; + } + if (!zone->should_recover) + continue; + buf = zone->buffer; + rcnt = info->read((char *)buf, zone->buffer_size + sizeof(*buf), + zone->off); + if (rcnt != zone->buffer_size + sizeof(*buf)) + return (int)rcnt < 0 ? (int)rcnt : -EIO; + } + return 0; +} + +static int psz_kmsg_recover_meta(struct psz_context *cxt) +{ + struct pstore_zone_info *info = cxt->pstore_zone_info; + struct pstore_zone *zone; + size_t rcnt, len; + struct psz_buffer *buf; + struct psz_kmsg_header *hdr; + struct timespec64 time = { }; + unsigned long i; + /* + * Recover may on panic, we can't allocate any memory by kmalloc. + * So, we use local array instead. + */ + char buffer_header[sizeof(*buf) + sizeof(*hdr)] = {0}; + + if (!info->read) + return -EINVAL; + + len = sizeof(*buf) + sizeof(*hdr); + buf = (struct psz_buffer *)buffer_header; + for (i = 0; i < cxt->kmsg_max_cnt; i++) { + zone = cxt->kpszs[i]; + if (unlikely(!zone)) + return -EINVAL; + + rcnt = info->read((char *)buf, len, zone->off); + if (rcnt != len) { + pr_err("read %s with id %lu failed\n", zone->name, i); + return (int)rcnt < 0 ? (int)rcnt : -EIO; + } + + if (buf->sig != zone->buffer->sig) { + pr_debug("no valid data in kmsg dump zone %lu\n", i); + continue; + } + + if (zone->buffer_size < atomic_read(&buf->datalen)) { + pr_info("found overtop zone: %s: id %lu, off %lld, size %zu\n", + zone->name, i, zone->off, + zone->buffer_size); + continue; + } + + hdr = (struct psz_kmsg_header *)buf->data; + if (hdr->magic != PSTORE_KMSG_HEADER_MAGIC) { + pr_info("found invalid zone: %s: id %lu, off %lld, size %zu\n", + zone->name, i, zone->off, + zone->buffer_size); + continue; + } + + /* + * we get the newest zone, and the next one must be the oldest + * or unused zone, because we do write one by one like a circle. + */ + if (hdr->time.tv_sec >= time.tv_sec) { + time.tv_sec = hdr->time.tv_sec; + cxt->kmsg_write_cnt = (i + 1) % cxt->kmsg_max_cnt; + } + + if (hdr->reason == KMSG_DUMP_OOPS) + cxt->oops_counter = + max(cxt->oops_counter, hdr->counter); + else if (hdr->reason == KMSG_DUMP_PANIC) + cxt->panic_counter = + max(cxt->panic_counter, hdr->counter); + + if (!atomic_read(&buf->datalen)) { + pr_debug("found erased zone: %s: id %lu, off %lld, size %zu, datalen %d\n", + zone->name, i, zone->off, + zone->buffer_size, + atomic_read(&buf->datalen)); + continue; + } + + if (!is_on_panic()) + zone->should_recover = true; + pr_debug("found nice zone: %s: id %lu, off %lld, size %zu, datalen %d\n", + zone->name, i, zone->off, + zone->buffer_size, atomic_read(&buf->datalen)); + } + + return 0; +} + +static int psz_kmsg_recover(struct psz_context *cxt) +{ + int ret; + + if (!cxt->kpszs) + return 0; + + ret = psz_kmsg_recover_meta(cxt); + if (ret) + goto recover_fail; + + ret = psz_kmsg_recover_data(cxt); + if (ret) + goto recover_fail; + + return 0; +recover_fail: + pr_debug("psz_recover_kmsg failed\n"); + return ret; +} + +/** + * psz_recovery() - recover data from storage + * @cxt: the context of pstore/zone + * + * recovery means reading data back from storage after rebooting + * + * Return: 0 on success, others on failure. + */ +static inline int psz_recovery(struct psz_context *cxt) +{ + int ret; + + if (atomic_read(&cxt->recovered)) + return 0; + + ret = psz_kmsg_recover(cxt); + + if (unlikely(ret)) + pr_err("recover failed\n"); + else { + pr_debug("recover end!\n"); + atomic_set(&cxt->recovered, 1); + } + return ret; +} + +static int psz_pstore_open(struct pstore_info *psi) +{ + struct psz_context *cxt = psi->data; + + cxt->kmsg_read_cnt = 0; + return 0; +} + +static inline bool psz_ok(struct pstore_zone *zone) +{ + if (zone && zone->buffer && buffer_datalen(zone)) + return true; + return false; +} + +static inline int psz_kmsg_erase(struct psz_context *cxt, + struct pstore_zone *zone, struct pstore_record *record) +{ + struct psz_buffer *buffer = zone->buffer; + struct psz_kmsg_header *hdr = + (struct psz_kmsg_header *)buffer->data; + + if (unlikely(!psz_ok(zone))) + return 0; + /* this zone is already updated, no need to erase */ + if (record->count != hdr->counter) + return 0; + + atomic_set(&zone->buffer->datalen, 0); + return psz_zone_write(zone, FLUSH_META, NULL, 0, 0); +} + +static int psz_pstore_erase(struct pstore_record *record) +{ + struct psz_context *cxt = record->psi->data; + + switch (record->type) { + case PSTORE_TYPE_DMESG: + if (record->id >= cxt->kmsg_max_cnt) + return -EINVAL; + return psz_kmsg_erase(cxt, cxt->kpszs[record->id], record); + default: + return -EINVAL; + } +} + +static void psz_write_kmsg_hdr(struct pstore_zone *zone, + struct pstore_record *record) +{ + struct psz_context *cxt = record->psi->data; + struct psz_buffer *buffer = zone->buffer; + struct psz_kmsg_header *hdr = + (struct psz_kmsg_header *)buffer->data; + + hdr->magic = PSTORE_KMSG_HEADER_MAGIC; + hdr->compressed = record->compressed; + hdr->time.tv_sec = record->time.tv_sec; + hdr->time.tv_nsec = record->time.tv_nsec; + hdr->reason = record->reason; + if (hdr->reason == KMSG_DUMP_OOPS) + hdr->counter = ++cxt->oops_counter; + else if (hdr->reason == KMSG_DUMP_PANIC) + hdr->counter = ++cxt->panic_counter; + else + hdr->counter = 0; +} + +static inline int notrace psz_kmsg_write_record(struct psz_context *cxt, + struct pstore_record *record) +{ + size_t size, hlen; + struct pstore_zone *zone; + unsigned int zonenum; + + zonenum = cxt->kmsg_write_cnt; + zone = cxt->kpszs[zonenum]; + if (unlikely(!zone)) + return -ENOSPC; + cxt->kmsg_write_cnt = (zonenum + 1) % cxt->kmsg_max_cnt; + + pr_debug("write %s to zone id %d\n", zone->name, zonenum); + psz_write_kmsg_hdr(zone, record); + hlen = sizeof(struct psz_kmsg_header); + size = min_t(size_t, record->size, zone->buffer_size - hlen); + return psz_zone_write(zone, FLUSH_ALL, record->buf, size, hlen); +} + +static int notrace psz_kmsg_write(struct psz_context *cxt, + struct pstore_record *record) +{ + int ret; + + /* + * Explicitly only take the first part of any new crash. + * If our buffer is larger than kmsg_bytes, this can never happen, + * and if our buffer is smaller than kmsg_bytes, we don't want the + * report split across multiple records. + */ + if (record->part != 1) + return -ENOSPC; + + if (!cxt->kpszs) + return -ENOSPC; + + ret = psz_kmsg_write_record(cxt, record); + if (!ret) { + pr_debug("try to flush other dirty zones\n"); + psz_flush_dirty_zones(cxt->kpszs, cxt->kmsg_max_cnt); + } + + /* always return 0 as we had handled it on buffer */ + return 0; +} + +static int notrace psz_pstore_write(struct pstore_record *record) +{ + struct psz_context *cxt = record->psi->data; + + if (record->type == PSTORE_TYPE_DMESG && + record->reason == KMSG_DUMP_PANIC) + atomic_set(&cxt->on_panic, 1); + + switch (record->type) { + case PSTORE_TYPE_DMESG: + return psz_kmsg_write(cxt, record); + default: + return -EINVAL; + } +} + +static struct pstore_zone *psz_read_next_zone(struct psz_context *cxt) +{ + struct pstore_zone *zone = NULL; + + while (cxt->kmsg_read_cnt < cxt->kmsg_max_cnt) { + zone = cxt->kpszs[cxt->kmsg_read_cnt++]; + if (psz_ok(zone)) + return zone; + } + + return NULL; +} + +static int psz_kmsg_read_hdr(struct pstore_zone *zone, + struct pstore_record *record) +{ + struct psz_buffer *buffer = zone->buffer; + struct psz_kmsg_header *hdr = + (struct psz_kmsg_header *)buffer->data; + + if (hdr->magic != PSTORE_KMSG_HEADER_MAGIC) + return -EINVAL; + record->compressed = hdr->compressed; + record->time.tv_sec = hdr->time.tv_sec; + record->time.tv_nsec = hdr->time.tv_nsec; + record->reason = hdr->reason; + record->count = hdr->counter; + return 0; +} + +static ssize_t psz_kmsg_read(struct pstore_zone *zone, + struct pstore_record *record) +{ + ssize_t size, hlen = 0; + + size = buffer_datalen(zone); + /* Clear and skip this kmsg dump record if it has no valid header */ + if (psz_kmsg_read_hdr(zone, record)) { + atomic_set(&zone->buffer->datalen, 0); + atomic_set(&zone->dirty, 0); + return -ENOMSG; + } + size -= sizeof(struct psz_kmsg_header); + + if (!record->compressed) { + char *buf = kasprintf(GFP_KERNEL, "%s: Total %d times\n", + get_reason_str(record->reason), + record->count); + hlen = strlen(buf); + record->buf = krealloc(buf, hlen + size, GFP_KERNEL); + if (!record->buf) { + kfree(buf); + return -ENOMEM; + } + } else { + record->buf = kmalloc(size, GFP_KERNEL); + if (!record->buf) + return -ENOMEM; + } + + size = psz_zone_read(zone, record->buf + hlen, size, + sizeof(struct psz_kmsg_header)); + if (unlikely(size < 0)) { + kfree(record->buf); + return -ENOMSG; + } + + return size + hlen; +} + +static ssize_t psz_pstore_read(struct pstore_record *record) +{ + struct psz_context *cxt = record->psi->data; + ssize_t (*readop)(struct pstore_zone *zone, + struct pstore_record *record); + struct pstore_zone *zone; + ssize_t ret; + + /* before read, we must recover from storage */ + ret = psz_recovery(cxt); + if (ret) + return ret; + +next_zone: + zone = psz_read_next_zone(cxt); + if (!zone) + return 0; + + record->type = zone->type; + switch (record->type) { + case PSTORE_TYPE_DMESG: + readop = psz_kmsg_read; + record->id = cxt->kmsg_read_cnt - 1; + break; + default: + goto next_zone; + } + + ret = readop(zone, record); + if (ret == -ENOMSG) + goto next_zone; + return ret; +} + +static struct psz_context pstore_zone_cxt = { + .pstore_zone_info_lock = + __MUTEX_INITIALIZER(pstore_zone_cxt.pstore_zone_info_lock), + .recovered = ATOMIC_INIT(0), + .on_panic = ATOMIC_INIT(0), + .pstore = { + .owner = THIS_MODULE, + .open = psz_pstore_open, + .read = psz_pstore_read, + .write = psz_pstore_write, + .erase = psz_pstore_erase, + }, +}; + +static void psz_free_zone(struct pstore_zone **pszone) +{ + struct pstore_zone *zone = *pszone; + + if (!zone) + return; + + kfree(zone->buffer); + kfree(zone); + *pszone = NULL; +} + +static void psz_free_zones(struct pstore_zone ***pszones, unsigned int *cnt) +{ + struct pstore_zone **zones = *pszones; + + if (!zones) + return; + + while (*cnt > 0) { + (*cnt)--; + psz_free_zone(&(zones[*cnt])); + } + kfree(zones); + *pszones = NULL; +} + +static void psz_free_all_zones(struct psz_context *cxt) +{ + if (cxt->kpszs) + psz_free_zones(&cxt->kpszs, &cxt->kmsg_max_cnt); +} + +static struct pstore_zone *psz_init_zone(enum pstore_type_id type, + loff_t *off, size_t size) +{ + struct pstore_zone_info *info = pstore_zone_cxt.pstore_zone_info; + struct pstore_zone *zone; + const char *name = pstore_type_to_name(type); + + if (!size) + return NULL; + + if (*off + size > info->total_size) { + pr_err("no room for %s (0x%zx@0x%llx over 0x%lx)\n", + name, size, *off, info->total_size); + return ERR_PTR(-ENOMEM); + } + + zone = kzalloc(sizeof(struct pstore_zone), GFP_KERNEL); + if (!zone) + return ERR_PTR(-ENOMEM); + + zone->buffer = kmalloc(size, GFP_KERNEL); + if (!zone->buffer) { + kfree(zone); + return ERR_PTR(-ENOMEM); + } + memset(zone->buffer, 0xFF, size); + zone->off = *off; + zone->name = name; + zone->type = type; + zone->buffer_size = size - sizeof(struct psz_buffer); + zone->buffer->sig = type ^ PSZ_SIG; + atomic_set(&zone->dirty, 0); + atomic_set(&zone->buffer->datalen, 0); + + *off += size; + + pr_debug("pszone %s: off 0x%llx, %zu header, %zu data\n", zone->name, + zone->off, sizeof(*zone->buffer), zone->buffer_size); + return zone; +} + +static struct pstore_zone **psz_init_zones(enum pstore_type_id type, + loff_t *off, size_t total_size, ssize_t record_size, + unsigned int *cnt) +{ + struct pstore_zone_info *info = pstore_zone_cxt.pstore_zone_info; + struct pstore_zone **zones, *zone; + const char *name = pstore_type_to_name(type); + int c, i; + + *cnt = 0; + if (!total_size || !record_size) + return NULL; + + if (*off + total_size > info->total_size) { + pr_err("no room for zones %s (0x%zx@0x%llx over 0x%lx)\n", + name, total_size, *off, info->total_size); + return ERR_PTR(-ENOMEM); + } + + c = total_size / record_size; + zones = kcalloc(c, sizeof(*zones), GFP_KERNEL); + if (!zones) { + pr_err("allocate for zones %s failed\n", name); + return ERR_PTR(-ENOMEM); + } + memset(zones, 0, c * sizeof(*zones)); + + for (i = 0; i < c; i++) { + zone = psz_init_zone(type, off, record_size); + if (!zone || IS_ERR(zone)) { + pr_err("initialize zones %s failed\n", name); + psz_free_zones(&zones, &i); + return (void *)zone; + } + zones[i] = zone; + } + + *cnt = c; + return zones; +} + +static int psz_alloc_zones(struct psz_context *cxt) +{ + struct pstore_zone_info *info = cxt->pstore_zone_info; + loff_t off = 0; + int err; + size_t size; + + size = info->total_size; + cxt->kpszs = psz_init_zones(PSTORE_TYPE_DMESG, &off, size, + info->kmsg_size, &cxt->kmsg_max_cnt); + if (IS_ERR(cxt->kpszs)) { + err = PTR_ERR(cxt->kpszs); + cxt->kpszs = NULL; + goto fail_out; + } + + return 0; +fail_out: + return err; +} + +/** + * register_pstore_zone() - register to pstore/zone + * + * @info: back-end driver information. See &struct pstore_zone_info. + * + * Only one back-end at one time. + * + * Return: 0 on success, others on failure. + */ +int register_pstore_zone(struct pstore_zone_info *info) +{ + int err = -EINVAL; + struct psz_context *cxt = &pstore_zone_cxt; + + if (info->total_size < 4096) { + pr_warn("total_size must be >= 4096\n"); + return -EINVAL; + } + + if (!info->kmsg_size) { + pr_warn("at least one record size must be non-zero\n"); + return -EINVAL; + } + + if (!info->name || !info->name[0]) + return -EINVAL; + +#define check_size(name, size) { \ + if (info->name > 0 && info->name < (size)) { \ + pr_err(#name " must be over %d\n", (size)); \ + return -EINVAL; \ + } \ + if (info->name & (size - 1)) { \ + pr_err(#name " must be a multiple of %d\n", \ + (size)); \ + return -EINVAL; \ + } \ + } + + check_size(total_size, 4096); + check_size(kmsg_size, SECTOR_SIZE); + +#undef check_size + + /* + * the @read and @write must be applied. + * if no @read, pstore may mount failed. + * if no @write, pstore do not support to remove record file. + */ + if (!info->read || !info->write) { + pr_err("no valid general read/write interface\n"); + return -EINVAL; + } + + mutex_lock(&cxt->pstore_zone_info_lock); + if (cxt->pstore_zone_info) { + pr_warn("'%s' already loaded: ignoring '%s'\n", + cxt->pstore_zone_info->name, info->name); + mutex_unlock(&cxt->pstore_zone_info_lock); + return -EBUSY; + } + cxt->pstore_zone_info = info; + + pr_debug("register %s with properties:\n", info->name); + pr_debug("\ttotal size : %ld Bytes\n", info->total_size); + pr_debug("\tkmsg size : %ld Bytes\n", info->kmsg_size); + + err = psz_alloc_zones(cxt); + if (err) { + pr_err("alloc zones failed\n"); + goto fail_out; + } + + if (info->kmsg_size) { + cxt->pstore.bufsize = cxt->kpszs[0]->buffer_size - + sizeof(struct psz_kmsg_header); + cxt->pstore.buf = kzalloc(cxt->pstore.bufsize, GFP_KERNEL); + if (!cxt->pstore.buf) { + err = -ENOMEM; + goto fail_free; + } + } + cxt->pstore.data = cxt; + + pr_info("registered %s as backend for", info->name); + cxt->pstore.max_reason = info->max_reason; + cxt->pstore.name = info->name; + if (info->kmsg_size) { + cxt->pstore.flags |= PSTORE_FLAGS_DMESG; + pr_cont(" kmsg(%s", get_reason_str(cxt->pstore.max_reason)); + if (cxt->pstore_zone_info->panic_write) + pr_cont(",panic_write"); + pr_cont(")"); + } + pr_cont("\n"); + + err = pstore_register(&cxt->pstore); + if (err) { + pr_err("registering with pstore failed\n"); + goto fail_free; + } + mutex_unlock(&pstore_zone_cxt.pstore_zone_info_lock); + + return 0; + +fail_free: + kfree(cxt->pstore.buf); + cxt->pstore.buf = NULL; + cxt->pstore.bufsize = 0; + psz_free_all_zones(cxt); +fail_out: + pstore_zone_cxt.pstore_zone_info = NULL; + mutex_unlock(&pstore_zone_cxt.pstore_zone_info_lock); + return err; +} +EXPORT_SYMBOL_GPL(register_pstore_zone); + +/** + * unregister_pstore_zone() - unregister to pstore/zone + * + * @info: back-end driver information. See struct pstore_zone_info. + */ +void unregister_pstore_zone(struct pstore_zone_info *info) +{ + struct psz_context *cxt = &pstore_zone_cxt; + + mutex_lock(&cxt->pstore_zone_info_lock); + if (!cxt->pstore_zone_info) { + mutex_unlock(&cxt->pstore_zone_info_lock); + return; + } + + /* Stop incoming writes from pstore. */ + pstore_unregister(&cxt->pstore); + + /* Clean up allocations. */ + kfree(cxt->pstore.buf); + cxt->pstore.buf = NULL; + cxt->pstore.bufsize = 0; + cxt->pstore_zone_info = NULL; + + psz_free_all_zones(cxt); + + /* Clear counters and zone state. */ + cxt->oops_counter = 0; + cxt->panic_counter = 0; + atomic_set(&cxt->recovered, 0); + atomic_set(&cxt->on_panic, 0); + + mutex_unlock(&cxt->pstore_zone_info_lock); +} +EXPORT_SYMBOL_GPL(unregister_pstore_zone); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("WeiXiong Liao &lt;liaoweixiong(a)allwinnertech.com&gt;&quot;)>"); +MODULE_AUTHOR("Kees Cook &lt;keescook(a)chromium.org&gt;&quot;)>"); +MODULE_DESCRIPTION("Storage Manager for pstore/blk"); diff --git a/include/linux/pstore.h b/include/linux/pstore.h index a2755fdd260d..4bc3a674eeeb 100644 --- a/include/linux/pstore.h +++ b/include/linux/pstore.h @@ -57,6 +57,7 @@ enum pstore_type_id { const char *pstore_type_to_name(enum pstore_type_id type); enum pstore_type_id pstore_name_to_type(const char *name); +const char *get_reason_str(enum kmsg_dump_reason reason); struct pstore_info; /** diff --git a/include/linux/pstore_zone.h b/include/linux/pstore_zone.h new file mode 100644 index 000000000000..eb005d9ae40c --- /dev/null +++ b/include/linux/pstore_zone.h @@ -0,0 +1,44 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#ifndef __PSTORE_ZONE_H_ +#define __PSTORE_ZONE_H_ + +#include <linux/types.h> + +typedef ssize_t (*pstore_zone_read_op)(char *, size_t, loff_t); +typedef ssize_t (*pstore_zone_write_op)(const char *, size_t, loff_t); +/** + * struct pstore_zone_info - pstore/zone back-end driver structure + * + * @owner: Module which is responsible for this back-end driver. + * @name: Name of the back-end driver. + * @total_size: The total size in bytes pstore/zone can use. It must be greater + * than 4096 and be multiple of 4096. + * @kmsg_size: The size of oops/panic zone. Zero means disabled, otherwise, + * it must be multiple of SECTOR_SIZE(512 Bytes). + * @max_reason: Maximum kmsg dump reason to store. + * @read: The general read operation. Both of the function parameters + * @size and @offset are relative value to storage. + * On success, the number of bytes should be returned, others + * means error. + * @write: The same as @read. + * @panic_write:The write operation only used for panic case. It's optional + * if you do not care panic log. The parameters and return value + * are the same as @read. + */ +struct pstore_zone_info { + struct module *owner; + const char *name; + + unsigned long total_size; + unsigned long kmsg_size; + int max_reason; + pstore_zone_read_op read; + pstore_zone_write_op write; + pstore_zone_write_op panic_write; +}; + +extern int register_pstore_zone(struct pstore_zone_info *info); +extern void unregister_pstore_zone(struct pstore_zone_info *info); + +#endif -- 2.17.1

From: WeiXiong Liao &lt;liaoweixiong(a)allwinnertech.com&gt; stable inclusion from stable-5.10 category: feature commit:17639f67c1d61aba3c05e7703f75cd468f9d484f issue: #I4919J -------------------------------- pstore/blk is similar to pstore/ram, but uses a block device as the storage rather than persistent ram. The pstore/blk backend solves two common use-cases that used to preclude using pstore/ram: - not all devices have a battery that could be used to persist regular RAM across power failures. - most embedded intelligent equipment have no persistent ram, which increases costs, instead preferring cheaper solutions, like block devices. pstore/blk provides separate configurations for the end user and for the block drivers. User configuration determines how pstore/blk operates, such as record sizes, max kmsg dump reasons, etc. These can be set by Kconfig and/or module parameters, but module parameter have priority over Kconfig. Driver configuration covers all the details about the target block device, such as total size of the device and how to perform read/write operations. These are provided by block drivers, calling pstore_register_blkdev(), including an optional panic_write callback used to bypass regular IO APIs in an effort to avoid potentially destabilized kernel code during a panic. Signed-off-by: WeiXiong Liao &lt;liaoweixiong(a)allwinnertech.com&gt; Link: https://lore.kernel.org/lkml/20200511233229.27745-3-keescook@chromium.org/ Co-developed-by: Kees Cook &lt;keescook(a)chromium.org&gt; Signed-off-by: Kees Cook &lt;keescook(a)chromium.org&gt; (cherry picked from commit 17639f67c1d61aba3c05e7703f75cd468f9d484f) Signed-off-by: roger &lt;kongzhengrong(a)huawei.com&gt; --- fs/pstore/Kconfig | 64 ++++++ fs/pstore/Makefile | 3 + fs/pstore/blk.c | 434 +++++++++++++++++++++++++++++++++++++ include/linux/pstore_blk.h | 51 +++++ 4 files changed, 552 insertions(+) create mode 100644 fs/pstore/blk.c create mode 100644 include/linux/pstore_blk.h diff --git a/fs/pstore/Kconfig b/fs/pstore/Kconfig index 4c01efa459b3..57ee251d7b25 100644 --- a/fs/pstore/Kconfig +++ b/fs/pstore/Kconfig @@ -160,3 +160,67 @@ config PSTORE_ZONE help The common layer for pstore/blk (and pstore/ram in the future) to manage storage in zones. + +config PSTORE_BLK + tristate "Log panic/oops to a block device" + depends on PSTORE + depends on BLOCK + select PSTORE_ZONE + default n + help + This enables panic and oops message to be logged to a block dev + where it can be read back at some later point. + + If unsure, say N. + +config PSTORE_BLK_BLKDEV + string "block device identifier" + depends on PSTORE_BLK + default "" + help + Which block device should be used for pstore/blk. + + It accept the following variants: + 1) <hex_major><hex_minor> device number in hexadecimal representation, + with no leading 0x, for example b302. + 2) /dev/<disk_name> represents the device number of disk + 3) /dev/<disk_name><decimal> represents the device number + of partition - device number of disk plus the partition number + 4) /dev/<disk_name>p<decimal> - same as the above, this form is + used when disk name of partitioned disk ends with a digit. + 5) PARTUUID=00112233-4455-6677-8899-AABBCCDDEEFF representing the + unique id of a partition if the partition table provides it. + The UUID may be either an EFI/GPT UUID, or refer to an MSDOS + partition using the format SSSSSSSS-PP, where SSSSSSSS is a zero- + filled hex representation of the 32-bit "NT disk signature", and PP + is a zero-filled hex representation of the 1-based partition number. + 6) PARTUUID=<UUID>/PARTNROFF=<int> to select a partition in relation + to a partition with a known unique id. + 7) <major>:<minor> major and minor number of the device separated by + a colon. + + NOTE that, both Kconfig and module parameters can configure + pstore/blk, but module parameters have priority over Kconfig. + +config PSTORE_BLK_KMSG_SIZE + int "Size in Kbytes of kmsg dump log to store" + depends on PSTORE_BLK + default 64 + help + This just sets size of kmsg dump (oops, panic, etc) log for + pstore/blk. The size is in KB and must be a multiple of 4. + + NOTE that, both Kconfig and module parameters can configure + pstore/blk, but module parameters have priority over Kconfig. + +config PSTORE_BLK_MAX_REASON + int "Maximum kmsg dump reason to store" + depends on PSTORE_BLK + default 2 + help + The maximum reason for kmsg dumps to store. The default is + 2 (KMSG_DUMP_OOPS), see include/linux/kmsg_dump.h's + enum kmsg_dump_reason for more details. + + NOTE that, both Kconfig and module parameters can configure + pstore/blk, but module parameters have priority over Kconfig. diff --git a/fs/pstore/Makefile b/fs/pstore/Makefile index 58a967cbe4af..c270467aeece 100644 --- a/fs/pstore/Makefile +++ b/fs/pstore/Makefile @@ -15,3 +15,6 @@ obj-$(CONFIG_PSTORE_RAM) += ramoops.o pstore_zone-objs += zone.o obj-$(CONFIG_PSTORE_ZONE) += pstore_zone.o + +pstore_blk-objs += blk.o +obj-$(CONFIG_PSTORE_BLK) += pstore_blk.o diff --git a/fs/pstore/blk.c b/fs/pstore/blk.c new file mode 100644 index 000000000000..9b623538fb45 --- /dev/null +++ b/fs/pstore/blk.c @@ -0,0 +1,434 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Implements pstore backend driver that write to block (or non-block) storage + * devices, using the pstore/zone API. + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/kernel.h> +#include <linux/module.h> +#include "../../block/blk.h" +#include <linux/blkdev.h> +#include <linux/string.h> +#include <linux/of.h> +#include <linux/of_address.h> +#include <linux/platform_device.h> +#include <linux/pstore_blk.h> +#include <linux/mount.h> +#include <linux/uio.h> + +static long kmsg_size = CONFIG_PSTORE_BLK_KMSG_SIZE; +module_param(kmsg_size, long, 0400); +MODULE_PARM_DESC(kmsg_size, "kmsg dump record size in kbytes"); + +static int max_reason = CONFIG_PSTORE_BLK_MAX_REASON; +module_param(max_reason, int, 0400); +MODULE_PARM_DESC(max_reason, + "maximum reason for kmsg dump (default 2: Oops and Panic)"); + +/* + * blkdev - the block device to use for pstore storage + * + * Usually, this will be a partition of a block device. + * + * blkdev accepts the following variants: + * 1) <hex_major><hex_minor> device number in hexadecimal representation, + * with no leading 0x, for example b302. + * 2) /dev/<disk_name> represents the device number of disk + * 3) /dev/<disk_name><decimal> represents the device number + * of partition - device number of disk plus the partition number + * 4) /dev/<disk_name>p<decimal> - same as the above, that form is + * used when disk name of partitioned disk ends on a digit. + * 5) PARTUUID=00112233-4455-6677-8899-AABBCCDDEEFF representing the + * unique id of a partition if the partition table provides it. + * The UUID may be either an EFI/GPT UUID, or refer to an MSDOS + * partition using the format SSSSSSSS-PP, where SSSSSSSS is a zero- + * filled hex representation of the 32-bit "NT disk signature", and PP + * is a zero-filled hex representation of the 1-based partition number. + * 6) PARTUUID=<UUID>/PARTNROFF=<int> to select a partition in relation to + * a partition with a known unique id. + * 7) <major>:<minor> major and minor number of the device separated by + * a colon. + */ +static char blkdev[80] = CONFIG_PSTORE_BLK_BLKDEV; +module_param_string(blkdev, blkdev, 80, 0400); +MODULE_PARM_DESC(blkdev, "block device for pstore storage"); + +/* + * All globals must only be accessed under the pstore_blk_lock + * during the register/unregister functions. + */ +static DEFINE_MUTEX(pstore_blk_lock); +static struct block_device *psblk_bdev; +static struct pstore_zone_info *pstore_zone_info; +static pstore_blk_panic_write_op blkdev_panic_write; + +struct bdev_info { + dev_t devt; + sector_t nr_sects; + sector_t start_sect; +}; + +/** + * struct pstore_device_info - back-end pstore/blk driver structure. + * + * @total_size: The total size in bytes pstore/blk can use. It must be greater + * than 4096 and be multiple of 4096. + * @flags: Refer to macro starting with PSTORE_FLAGS defined in + * linux/pstore.h. It means what front-ends this device support. + * Zero means all backends for compatible. + * @read: The general read operation. Both of the function parameters + * @size and @offset are relative value to bock device (not the + * whole disk). + * On success, the number of bytes should be returned, others + * means error. + * @write: The same as @read. + * @panic_write:The write operation only used for panic case. It's optional + * if you do not care panic log. The parameters and return value + * are the same as @read. + */ +struct pstore_device_info { + unsigned long total_size; + unsigned int flags; + pstore_zone_read_op read; + pstore_zone_write_op write; + pstore_zone_write_op panic_write; +}; + +static int psblk_register_do(struct pstore_device_info *dev) +{ + int ret; + + if (!dev || !dev->total_size || !dev->read || !dev->write) + return -EINVAL; + + mutex_lock(&pstore_blk_lock); + + /* someone already registered before */ + if (pstore_zone_info) { + mutex_unlock(&pstore_blk_lock); + return -EBUSY; + } + pstore_zone_info = kzalloc(sizeof(struct pstore_zone_info), GFP_KERNEL); + if (!pstore_zone_info) { + mutex_unlock(&pstore_blk_lock); + return -ENOMEM; + } + + /* zero means not limit on which backends to attempt to store. */ + if (!dev->flags) + dev->flags = UINT_MAX; + +#define verify_size(name, alignsize, enabled) { \ + long _##name_ = (enabled) ? (name) : 0; \ + _##name_ = _##name_ <= 0 ? 0 : (_##name_ * 1024); \ + if (_##name_ & ((alignsize) - 1)) { \ + pr_info(#name " must align to %d\n", \ + (alignsize)); \ + _##name_ = ALIGN(name, (alignsize)); \ + } \ + name = _##name_ / 1024; \ + pstore_zone_info->name = _##name_; \ + } + + verify_size(kmsg_size, 4096, dev->flags & PSTORE_FLAGS_DMESG); +#undef verify_size + + pstore_zone_info->total_size = dev->total_size; + pstore_zone_info->max_reason = max_reason; + pstore_zone_info->read = dev->read; + pstore_zone_info->write = dev->write; + pstore_zone_info->panic_write = dev->panic_write; + pstore_zone_info->name = KBUILD_MODNAME; + pstore_zone_info->owner = THIS_MODULE; + + ret = register_pstore_zone(pstore_zone_info); + if (ret) { + kfree(pstore_zone_info); + pstore_zone_info = NULL; + } + mutex_unlock(&pstore_blk_lock); + return ret; +} + +static void psblk_unregister_do(struct pstore_device_info *dev) +{ + mutex_lock(&pstore_blk_lock); + if (pstore_zone_info && pstore_zone_info->read == dev->read) { + unregister_pstore_zone(pstore_zone_info); + kfree(pstore_zone_info); + pstore_zone_info = NULL; + } + mutex_unlock(&pstore_blk_lock); +} + +/** + * psblk_get_bdev() - open block device + * + * @holder: Exclusive holder identifier + * @info: Information about bdev to fill in + * + * Return: pointer to block device on success and others on error. + * + * On success, the returned block_device has reference count of one. + */ +static struct block_device *psblk_get_bdev(void *holder, + struct bdev_info *info) +{ + struct block_device *bdev = ERR_PTR(-ENODEV); + fmode_t mode = FMODE_READ | FMODE_WRITE; + sector_t nr_sects; + + lockdep_assert_held(&pstore_blk_lock); + + if (pstore_zone_info) + return ERR_PTR(-EBUSY); + + if (!blkdev[0]) + return ERR_PTR(-ENODEV); + + if (holder) + mode |= FMODE_EXCL; + bdev = blkdev_get_by_path(blkdev, mode, holder); + if (IS_ERR(bdev)) { + dev_t devt; + + devt = name_to_dev_t(blkdev); + if (devt == 0) + return ERR_PTR(-ENODEV); + bdev = blkdev_get_by_dev(devt, mode, holder); + if (IS_ERR(bdev)) + return bdev; + } + + nr_sects = part_nr_sects_read(bdev->bd_part); + if (!nr_sects) { + pr_err("not enough space for '%s'\n", blkdev); + blkdev_put(bdev, mode); + return ERR_PTR(-ENOSPC); + } + + if (info) { + info->devt = bdev->bd_dev; + info->nr_sects = nr_sects; + info->start_sect = get_start_sect(bdev); + } + + return bdev; +} + +static void psblk_put_bdev(struct block_device *bdev, void *holder) +{ + fmode_t mode = FMODE_READ | FMODE_WRITE; + + lockdep_assert_held(&pstore_blk_lock); + + if (!bdev) + return; + + if (holder) + mode |= FMODE_EXCL; + blkdev_put(bdev, mode); +} + +static ssize_t psblk_generic_blk_read(char *buf, size_t bytes, loff_t pos) +{ + struct block_device *bdev = psblk_bdev; + struct file file; + struct kiocb kiocb; + struct iov_iter iter; + struct kvec iov = {.iov_base = buf, .iov_len = bytes}; + + if (!bdev) + return -ENODEV; + + memset(&file, 0, sizeof(struct file)); + file.f_mapping = bdev->bd_inode->i_mapping; + file.f_flags = O_DSYNC | __O_SYNC | O_NOATIME; + file.f_inode = bdev->bd_inode; + file_ra_state_init(&file.f_ra, file.f_mapping); + + init_sync_kiocb(&kiocb, &file); + kiocb.ki_pos = pos; + iov_iter_kvec(&iter, READ | ITER_KVEC, &iov, 1, bytes); + + return generic_file_read_iter(&kiocb, &iter); +} + +static ssize_t psblk_generic_blk_write(const char *buf, size_t bytes, + loff_t pos) +{ + struct block_device *bdev = psblk_bdev; + struct iov_iter iter; + struct kiocb kiocb; + struct file file; + ssize_t ret; + struct kvec iov = {.iov_base = (void *)buf, .iov_len = bytes}; + + if (!bdev) + return -ENODEV; + + /* Console/Ftrace backend may handle buffer until flush dirty zones */ + if (in_interrupt() || irqs_disabled()) + return -EBUSY; + + memset(&file, 0, sizeof(struct file)); + file.f_mapping = bdev->bd_inode->i_mapping; + file.f_flags = O_DSYNC | __O_SYNC | O_NOATIME; + file.f_inode = bdev->bd_inode; + + init_sync_kiocb(&kiocb, &file); + kiocb.ki_pos = pos; + iov_iter_kvec(&iter, WRITE | ITER_KVEC, &iov, 1, bytes); + + inode_lock(bdev->bd_inode); + ret = generic_write_checks(&kiocb, &iter); + if (ret > 0) + ret = generic_perform_write(&file, &iter, pos); + inode_unlock(bdev->bd_inode); + + if (likely(ret > 0)) { + const struct file_operations f_op = {.fsync = blkdev_fsync}; + + file.f_op = &f_op; + kiocb.ki_pos += ret; + ret = generic_write_sync(&kiocb, ret); + } + return ret; +} + +static ssize_t psblk_blk_panic_write(const char *buf, size_t size, + loff_t off) +{ + int ret; + + if (!blkdev_panic_write) + return -EOPNOTSUPP; + + /* size and off must align to SECTOR_SIZE for block device */ + ret = blkdev_panic_write(buf, off >> SECTOR_SHIFT, + size >> SECTOR_SHIFT); + return ret ? -EIO : size; +} + +static int __register_pstore_blk(struct pstore_blk_info *info) +{ + char bdev_name[BDEVNAME_SIZE]; + struct block_device *bdev; + struct pstore_device_info dev; + struct bdev_info binfo; + void *holder = blkdev; + int ret = -ENODEV; + + lockdep_assert_held(&pstore_blk_lock); + + /* hold bdev exclusively */ + memset(&binfo, 0, sizeof(binfo)); + bdev = psblk_get_bdev(holder, &binfo); + if (IS_ERR(bdev)) { + pr_err("failed to open '%s'!\n", blkdev); + return PTR_ERR(bdev); + } + + /* only allow driver matching the @blkdev */ + if (!binfo.devt || MAJOR(binfo.devt) != info->major) { + pr_debug("invalid major %u (expect %u)\n", + info->major, MAJOR(binfo.devt)); + ret = -ENODEV; + goto err_put_bdev; + } + + /* psblk_bdev must be assigned before register to pstore/blk */ + psblk_bdev = bdev; + blkdev_panic_write = info->panic_write; + + /* Copy back block device details. */ + info->devt = binfo.devt; + info->nr_sects = binfo.nr_sects; + info->start_sect = binfo.start_sect; + + memset(&dev, 0, sizeof(dev)); + dev.total_size = info->nr_sects << SECTOR_SHIFT; + dev.flags = info->flags; + dev.read = psblk_generic_blk_read; + dev.write = psblk_generic_blk_write; + dev.panic_write = info->panic_write ? psblk_blk_panic_write : NULL; + + ret = psblk_register_do(&dev); + if (ret) + goto err_put_bdev; + + bdevname(bdev, bdev_name); + pr_info("attached %s%s\n", bdev_name, + info->panic_write ? "" : " (no dedicated panic_write!)"); + return 0; + +err_put_bdev: + psblk_bdev = NULL; + blkdev_panic_write = NULL; + psblk_put_bdev(bdev, holder); + return ret; +} + +/** + * register_pstore_blk() - register block device to pstore/blk + * + * @info: details on the desired block device interface + * + * Return: + * * 0 - OK + * * Others - something error. + */ +int register_pstore_blk(struct pstore_blk_info *info) +{ + int ret; + + mutex_lock(&pstore_blk_lock); + ret = __register_pstore_blk(info); + mutex_unlock(&pstore_blk_lock); + + return ret; +} +EXPORT_SYMBOL_GPL(register_pstore_blk); + +static void __unregister_pstore_blk(unsigned int major) +{ + struct pstore_device_info dev = { .read = psblk_generic_blk_read }; + void *holder = blkdev; + + lockdep_assert_held(&pstore_blk_lock); + if (psblk_bdev && MAJOR(psblk_bdev->bd_dev) == major) { + psblk_unregister_do(&dev); + psblk_put_bdev(psblk_bdev, holder); + blkdev_panic_write = NULL; + psblk_bdev = NULL; + } +} + +/** + * unregister_pstore_blk() - unregister block device from pstore/blk + * + * @major: the major device number of device + */ +void unregister_pstore_blk(unsigned int major) +{ + mutex_lock(&pstore_blk_lock); + __unregister_pstore_blk(major); + mutex_unlock(&pstore_blk_lock); +} +EXPORT_SYMBOL_GPL(unregister_pstore_blk); + +static void __exit pstore_blk_exit(void) +{ + mutex_lock(&pstore_blk_lock); + if (psblk_bdev) + __unregister_pstore_blk(MAJOR(psblk_bdev->bd_dev)); + mutex_unlock(&pstore_blk_lock); +} +module_exit(pstore_blk_exit); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("WeiXiong Liao &lt;liaoweixiong(a)allwinnertech.com&gt;&quot;)>"); +MODULE_AUTHOR("Kees Cook &lt;keescook(a)chromium.org&gt;&quot;)>"); +MODULE_DESCRIPTION("pstore backend for block devices"); diff --git a/include/linux/pstore_blk.h b/include/linux/pstore_blk.h new file mode 100644 index 000000000000..4501977b1336 --- /dev/null +++ b/include/linux/pstore_blk.h @@ -0,0 +1,51 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#ifndef __PSTORE_BLK_H_ +#define __PSTORE_BLK_H_ + +#include <linux/types.h> +#include <linux/pstore.h> +#include <linux/pstore_zone.h> + +/** + * typedef pstore_blk_panic_write_op - panic write operation to block device + * + * @buf: the data to write + * @start_sect: start sector to block device + * @sects: sectors count on buf + * + * Return: On success, zero should be returned. Others mean error. + * + * Panic write to block device must be aligned to SECTOR_SIZE. + */ +typedef int (*pstore_blk_panic_write_op)(const char *buf, sector_t start_sect, + sector_t sects); + +/** + * struct pstore_blk_info - pstore/blk registration details + * + * @major: Which major device number to support with pstore/blk + * @flags: The supported PSTORE_FLAGS_* from linux/pstore.h. + * @panic_write:The write operation only used for the panic case. + * This can be NULL, but is recommended to avoid losing + * crash data if the kernel's IO path or work queues are + * broken during a panic. + * @devt: The dev_t that pstore/blk has attached to. + * @nr_sects: Number of sectors on @devt. + * @start_sect: Starting sector on @devt. + */ +struct pstore_blk_info { + unsigned int major; + unsigned int flags; + pstore_blk_panic_write_op panic_write; + + /* Filled in by pstore/blk after registration. */ + dev_t devt; + sector_t nr_sects; + sector_t start_sect; +}; + +int register_pstore_blk(struct pstore_blk_info *info); +void unregister_pstore_blk(unsigned int major); + +#endif -- 2.17.1

From: WeiXiong Liao &lt;liaoweixiong(a)allwinnertech.com&gt; stable inclusion from stable-5.10 category: feature commit:cc9c4d1b5597167f8e8c92f6b61e1cda6d01884d issue: #I4919J -------------------------------- Support backend for console. To enable console backend, just make console_size be greater than 0 and a multiple of 4096. Signed-off-by: WeiXiong Liao &lt;liaoweixiong(a)allwinnertech.com&gt; Link: https://lore.kernel.org/lkml/20200511233229.27745-5-keescook@chromium.org/ Signed-off-by: Kees Cook &lt;keescook(a)chromium.org&gt; (cherry picked from commit cc9c4d1b5597167f8e8c92f6b61e1cda6d01884d) Signed-off-by: roger &lt;kongzhengrong(a)huawei.com&gt; --- fs/pstore/Kconfig | 18 +++++++-- fs/pstore/blk.c | 12 +++++- fs/pstore/zone.c | 81 ++++++++++++++++++++++++++++++++++--- include/linux/pstore_zone.h | 4 +- 4 files changed, 105 insertions(+), 10 deletions(-) diff --git a/fs/pstore/Kconfig b/fs/pstore/Kconfig index 02d75f5a0b18..248264971a30 100644 --- a/fs/pstore/Kconfig +++ b/fs/pstore/Kconfig @@ -180,11 +180,11 @@ config PSTORE_BLK_BLKDEV help Which block device should be used for pstore/blk. - It accept the following variants: + It accepts the following variants: 1) <hex_major><hex_minor> device number in hexadecimal representation, with no leading 0x, for example b302. - 2) /dev/<disk_name> represents the device number of disk - 3) /dev/<disk_name><decimal> represents the device number + 2) /dev/<disk_name> represents the device name of disk + 3) /dev/<disk_name><decimal> represents the device name and number of partition - device number of disk plus the partition number 4) /dev/<disk_name>p<decimal> - same as the above, this form is used when disk name of partitioned disk ends with a digit. @@ -236,3 +236,15 @@ config PSTORE_BLK_PMSG_SIZE NOTE that, both Kconfig and module parameters can configure pstore/blk, but module parameters have priority over Kconfig. + +config PSTORE_BLK_CONSOLE_SIZE + int "Size in Kbytes of console log to store" + depends on PSTORE_BLK + depends on PSTORE_CONSOLE + default 64 + help + This just sets size of console log (console_size) to store via + pstore/blk. The size is in KB and must be a multiple of 4. + + NOTE that, both Kconfig and module parameters can configure + pstore/blk, but module parameters have priority over Kconfig. diff --git a/fs/pstore/blk.c b/fs/pstore/blk.c index 77e8a9a806b6..ff119fc5726c 100644 --- a/fs/pstore/blk.c +++ b/fs/pstore/blk.c @@ -35,6 +35,14 @@ static long pmsg_size = -1; module_param(pmsg_size, long, 0400); MODULE_PARM_DESC(pmsg_size, "pmsg size in kbytes"); +#if IS_ENABLED(CONFIG_PSTORE_CONSOLE) +static long console_size = CONFIG_PSTORE_BLK_CONSOLE_SIZE; +#else +static long console_size = -1; +#endif +module_param(console_size, long, 0400); +MODULE_PARM_DESC(console_size, "console size in kbytes"); + /* * blkdev - the block device to use for pstore storage * @@ -91,7 +99,8 @@ struct bdev_info { * whole disk). * On success, the number of bytes should be returned, others * means error. - * @write: The same as @read. + * @write: The same as @read, but the following error number: + * -EBUSY means try to write again later. * @panic_write:The write operation only used for panic case. It's optional * if you do not care panic log. The parameters and return value * are the same as @read. @@ -142,6 +151,7 @@ static int psblk_register_do(struct pstore_device_info *dev) verify_size(kmsg_size, 4096, dev->flags & PSTORE_FLAGS_DMESG); verify_size(pmsg_size, 4096, dev->flags & PSTORE_FLAGS_PMSG); + verify_size(console_size, 4096, dev->flags & PSTORE_FLAGS_CONSOLE); #undef verify_size pstore_zone_info->total_size = dev->total_size; diff --git a/fs/pstore/zone.c b/fs/pstore/zone.c index 8c40d2126f4c..b5b2a94570cb 100644 --- a/fs/pstore/zone.c +++ b/fs/pstore/zone.c @@ -96,10 +96,12 @@ struct pstore_zone { * * @kpszs: kmsg dump storage zones * @ppsz: pmsg storage zone + * @cpsz: console storage zone * @kmsg_max_cnt: max count of @kpszs * @kmsg_read_cnt: counter of total read kmsg dumps * @kmsg_write_cnt: counter of total kmsg dump writes * @pmsg_read_cnt: counter of total read pmsg zone + * @console_read_cnt: counter of total read console zone * @oops_counter: counter of oops dumps * @panic_counter: counter of panic dumps * @recovered: whether finished recovering data from storage @@ -111,10 +113,12 @@ struct pstore_zone { struct psz_context { struct pstore_zone **kpszs; struct pstore_zone *ppsz; + struct pstore_zone *cpsz; unsigned int kmsg_max_cnt; unsigned int kmsg_read_cnt; unsigned int kmsg_write_cnt; unsigned int pmsg_read_cnt; + unsigned int console_read_cnt; /* * These counters should be calculated during recovery. * It records the oops/panic times after crashes rather than boots. @@ -134,6 +138,9 @@ struct psz_context { }; static struct psz_context pstore_zone_cxt; +static void psz_flush_all_dirty_zones(struct work_struct *); +static DECLARE_DELAYED_WORK(psz_cleaner, psz_flush_all_dirty_zones); + /** * enum psz_flush_mode - flush mode for psz_zone_write() * @@ -242,6 +249,9 @@ static int psz_zone_write(struct pstore_zone *zone, return 0; dirty: atomic_set(&zone->dirty, true); + /* flush dirty zones nicely */ + if (wcnt == -EBUSY && !is_on_panic()) + schedule_delayed_work(&psz_cleaner, msecs_to_jiffies(500)); return -EBUSY; } @@ -298,6 +308,21 @@ static int psz_move_zone(struct pstore_zone *old, struct pstore_zone *new) return 0; } +static void psz_flush_all_dirty_zones(struct work_struct *work) +{ + struct psz_context *cxt = &pstore_zone_cxt; + int ret = 0; + + if (cxt->ppsz) + ret |= psz_flush_dirty_zone(cxt->ppsz); + if (cxt->cpsz) + ret |= psz_flush_dirty_zone(cxt->cpsz); + if (cxt->kpszs) + ret |= psz_flush_dirty_zones(cxt->kpszs, cxt->kmsg_max_cnt); + if (ret && cxt->pstore_zone_info) + schedule_delayed_work(&psz_cleaner, msecs_to_jiffies(1000)); +} + static int psz_kmsg_recover_data(struct psz_context *cxt) { struct pstore_zone_info *info = cxt->pstore_zone_info; @@ -550,6 +575,10 @@ static inline int psz_recovery(struct psz_context *cxt) goto out; ret = psz_recover_zone(cxt, cxt->ppsz); + if (ret) + goto out; + + ret = psz_recover_zone(cxt, cxt->cpsz); out: if (unlikely(ret)) @@ -567,6 +596,7 @@ static int psz_pstore_open(struct pstore_info *psi) cxt->kmsg_read_cnt = 0; cxt->pmsg_read_cnt = 0; + cxt->console_read_cnt = 0; return 0; } @@ -631,8 +661,9 @@ static int psz_pstore_erase(struct pstore_record *record) return psz_kmsg_erase(cxt, cxt->kpszs[record->id], record); case PSTORE_TYPE_PMSG: return psz_record_erase(cxt, cxt->ppsz); - default: - return -EINVAL; + case PSTORE_TYPE_CONSOLE: + return psz_record_erase(cxt, cxt->cpsz); + default: return -EINVAL; } } @@ -695,9 +726,10 @@ static int notrace psz_kmsg_write(struct psz_context *cxt, return -ENOSPC; ret = psz_kmsg_write_record(cxt, record); - if (!ret) { + if (!ret && is_on_panic()) { + /* ensure all data are flushed to storage when panic */ pr_debug("try to flush other dirty zones\n"); - psz_flush_dirty_zones(cxt->kpszs, cxt->kmsg_max_cnt); + psz_flush_all_dirty_zones(NULL); } /* always return 0 as we had handled it on buffer */ @@ -761,9 +793,18 @@ static int notrace psz_pstore_write(struct pstore_record *record) record->reason == KMSG_DUMP_PANIC) atomic_set(&cxt->on_panic, 1); + /* + * if on panic, do not write except panic records + * Fix case that panic_write prints log which wakes up console backend. + */ + if (is_on_panic() && record->type != PSTORE_TYPE_DMESG) + return -EBUSY; + switch (record->type) { case PSTORE_TYPE_DMESG: return psz_kmsg_write(cxt, record); + case PSTORE_TYPE_CONSOLE: + return psz_record_write(cxt->cpsz, record); case PSTORE_TYPE_PMSG: return psz_record_write(cxt->ppsz, record); default: @@ -788,6 +829,13 @@ static struct pstore_zone *psz_read_next_zone(struct psz_context *cxt) return zone; } + if (cxt->console_read_cnt == 0) { + cxt->console_read_cnt++; + zone = cxt->cpsz; + if (psz_old_ok(zone)) + return zone; + } + return NULL; } @@ -898,6 +946,8 @@ static ssize_t psz_pstore_read(struct pstore_record *record) readop = psz_kmsg_read; record->id = cxt->kmsg_read_cnt - 1; break; + case PSTORE_TYPE_CONSOLE: + /* fallthrough */ case PSTORE_TYPE_PMSG: readop = psz_record_read; break; @@ -958,6 +1008,8 @@ static void psz_free_all_zones(struct psz_context *cxt) psz_free_zones(&cxt->kpszs, &cxt->kmsg_max_cnt); if (cxt->ppsz) psz_free_zone(&cxt->ppsz); + if (cxt->cpsz) + psz_free_zone(&cxt->cpsz); } static struct pstore_zone *psz_init_zone(enum pstore_type_id type, @@ -1059,6 +1111,15 @@ static int psz_alloc_zones(struct psz_context *cxt) goto free_out; } + off_size += info->console_size; + cxt->cpsz = psz_init_zone(PSTORE_TYPE_CONSOLE, &off, + info->console_size); + if (IS_ERR(cxt->cpsz)) { + err = PTR_ERR(cxt->cpsz); + cxt->cpsz = NULL; + goto free_out; + } + cxt->kpszs = psz_init_zones(PSTORE_TYPE_DMESG, &off, info->total_size - off_size, info->kmsg_size, &cxt->kmsg_max_cnt); @@ -1093,7 +1154,7 @@ int register_pstore_zone(struct pstore_zone_info *info) return -EINVAL; } - if (!info->kmsg_size && !info->pmsg_size) { + if (!info->kmsg_size && !info->pmsg_size && !info->console_size) { pr_warn("at least one record size must be non-zero\n"); return -EINVAL; } @@ -1116,6 +1177,7 @@ int register_pstore_zone(struct pstore_zone_info *info) check_size(total_size, 4096); check_size(kmsg_size, SECTOR_SIZE); check_size(pmsg_size, SECTOR_SIZE); + check_size(console_size, SECTOR_SIZE); #undef check_size @@ -1142,6 +1204,7 @@ int register_pstore_zone(struct pstore_zone_info *info) pr_debug("\ttotal size : %ld Bytes\n", info->total_size); pr_debug("\tkmsg size : %ld Bytes\n", info->kmsg_size); pr_debug("\tpmsg size : %ld Bytes\n", info->pmsg_size); + pr_debug("\tconsole size : %ld Bytes\n", info->console_size); err = psz_alloc_zones(cxt); if (err) { @@ -1174,6 +1237,10 @@ int register_pstore_zone(struct pstore_zone_info *info) cxt->pstore.flags |= PSTORE_FLAGS_PMSG; pr_cont(" pmsg"); } + if (info->console_size) { + cxt->pstore.flags |= PSTORE_FLAGS_CONSOLE; + pr_cont(" console"); + } pr_cont("\n"); err = pstore_register(&cxt->pstore); @@ -1215,6 +1282,10 @@ void unregister_pstore_zone(struct pstore_zone_info *info) /* Stop incoming writes from pstore. */ pstore_unregister(&cxt->pstore); + /* Flush any pending writes. */ + psz_flush_all_dirty_zones(NULL); + flush_delayed_work(&psz_cleaner); + /* Clean up allocations. */ kfree(cxt->pstore.buf); cxt->pstore.buf = NULL; diff --git a/include/linux/pstore_zone.h b/include/linux/pstore_zone.h index 29c367a3bd80..904ee67f4ba2 100644 --- a/include/linux/pstore_zone.h +++ b/include/linux/pstore_zone.h @@ -18,11 +18,12 @@ typedef ssize_t (*pstore_zone_write_op)(const char *, size_t, loff_t); * it must be multiple of SECTOR_SIZE(512 Bytes). * @max_reason: Maximum kmsg dump reason to store. * @pmsg_size: The size of pmsg zone which is the same as @kmsg_size. + * @console_size:The size of console zone which is the same as @kmsg_size. * @read: The general read operation. Both of the function parameters * @size and @offset are relative value to storage. * On success, the number of bytes should be returned, others * means error. - * @write: The same as @read. + * @write: The same as @read, but -EBUSY means try to write again later. * @panic_write:The write operation only used for panic case. It's optional * if you do not care panic log. The parameters and return value * are the same as @read. @@ -35,6 +36,7 @@ struct pstore_zone_info { unsigned long kmsg_size; int max_reason; unsigned long pmsg_size; + unsigned long console_size; pstore_zone_read_op read; pstore_zone_write_op write; pstore_zone_write_op panic_write; -- 2.17.1

From: WeiXiong Liao &lt;liaoweixiong(a)allwinnertech.com&gt; stable inclusion from stable-5.10 category: feature commit:649304c936cd4d2a2128bb877044772416c7d4f5 issue: #I4919J -------------------------------- Add details on using pstore/blk, the new backend of pstore to record dumps to block devices, in Documentation/admin-guide/pstore-blk.rst Signed-off-by: WeiXiong Liao &lt;liaoweixiong(a)allwinnertech.com&gt; Link: https://lore.kernel.org/lkml/20200511233229.27745-7-keescook@chromium.org/ Signed-off-by: Kees Cook &lt;keescook(a)chromium.org&gt; (cherry picked from commit 649304c936cd4d2a2128bb877044772416c7d4f5) Signed-off-by: roger &lt;kongzhengrong(a)huawei.com&gt; --- Documentation/admin-guide/pstore-blk.rst | 229 +++++++++++++++++++++++ MAINTAINERS | 5 + fs/pstore/Kconfig | 2 + 3 files changed, 236 insertions(+) create mode 100644 Documentation/admin-guide/pstore-blk.rst diff --git a/Documentation/admin-guide/pstore-blk.rst b/Documentation/admin-guide/pstore-blk.rst new file mode 100644 index 000000000000..bef8c7436721 --- /dev/null +++ b/Documentation/admin-guide/pstore-blk.rst @@ -0,0 +1,229 @@ +.. SPDX-License-Identifier: GPL-2.0 + +pstore block oops/panic logger +============================== + +Introduction +------------ + +pstore block (pstore/blk) is an oops/panic logger that writes its logs to a +block device before the system crashes. You can get these log files by +mounting pstore filesystem like:: + + mount -t pstore pstore /sys/fs/pstore + + +pstore block concepts +--------------------- + +pstore/blk provides efficient configuration method for pstore/blk, which +divides all configurations into two parts, configurations for user and +configurations for driver. + +Configurations for user determine how pstore/blk works, such as pmsg_size, +kmsg_size and so on. All of them support both Kconfig and module parameters, +but module parameters have priority over Kconfig. + +Configurations for driver are all about block device, such as total_size +of block device and read/write operations. + +Configurations for user +----------------------- + +All of these configurations support both Kconfig and module parameters, but +module parameters have priority over Kconfig. + +Here is an example for module parameters:: + + pstore_blk.blkdev=179:7 pstore_blk.kmsg_size=64 + +The detail of each configurations may be of interest to you. + +blkdev +~~~~~~ + +The block device to use. Most of the time, it is a partition of block device. +It's required for pstore/blk. + +It accepts the following variants: + +1. <hex_major><hex_minor> device number in hexadecimal represents itself; no + leading 0x, for example b302. +#. /dev/<disk_name> represents the device number of disk +#. /dev/<disk_name><decimal> represents the device number of partition - device + number of disk plus the partition number +#. /dev/<disk_name>p<decimal> - same as the above; this form is used when disk + name of partitioned disk ends with a digit. +#. PARTUUID=00112233-4455-6677-8899-AABBCCDDEEFF represents the unique id of + a partition if the partition table provides it. The UUID may be either an + EFI/GPT UUID, or refer to an MSDOS partition using the format SSSSSSSS-PP, + where SSSSSSSS is a zero-filled hex representation of the 32-bit + "NT disk signature", and PP is a zero-filled hex representation of the + 1-based partition number. +#. PARTUUID=<UUID>/PARTNROFF=<int> to select a partition in relation to a + partition with a known unique id. +#. <major>:<minor> major and minor number of the device separated by a colon. + +kmsg_size +~~~~~~~~~ + +The chunk size in KB for oops/panic front-end. It **MUST** be a multiple of 4. +It's optional if you do not care oops/panic log. + +There are multiple chunks for oops/panic front-end depending on the remaining +space except other pstore front-ends. + +pstore/blk will log to oops/panic chunks one by one, and always overwrite the +oldest chunk if there is no more free chunk. + +pmsg_size +~~~~~~~~~ + +The chunk size in KB for pmsg front-end. It **MUST** be a multiple of 4. +It's optional if you do not care pmsg log. + +Unlike oops/panic front-end, there is only one chunk for pmsg front-end. + +Pmsg is a user space accessible pstore object. Writes to */dev/pmsg0* are +appended to the chunk. On reboot the contents are available in +*/sys/fs/pstore/pmsg-pstore-blk-0*. + +console_size +~~~~~~~~~~~~ + +The chunk size in KB for console front-end. It **MUST** be a multiple of 4. +It's optional if you do not care console log. + +Similar to pmsg front-end, there is only one chunk for console front-end. + +All log of console will be appended to the chunk. On reboot the contents are +available in */sys/fs/pstore/console-pstore-blk-0*. + +ftrace_size +~~~~~~~~~~~ + +The chunk size in KB for ftrace front-end. It **MUST** be a multiple of 4. +It's optional if you do not care console log. + +Similar to oops front-end, there are multiple chunks for ftrace front-end +depending on the count of cpu processors. Each chunk size is equal to +ftrace_size / processors_count. + +All log of ftrace will be appended to the chunk. On reboot the contents are +combined and available in */sys/fs/pstore/ftrace-pstore-blk-0*. + +Persistent function tracing might be useful for debugging software or hardware +related hangs. Here is an example of usage:: + + # mount -t pstore pstore /sys/fs/pstore + # mount -t debugfs debugfs /sys/kernel/debug/ + # echo 1 > /sys/kernel/debug/pstore/record_ftrace + # reboot -f + [...] + # mount -t pstore pstore /sys/fs/pstore + # tail /sys/fs/pstore/ftrace-pstore-blk-0 + CPU:0 ts:5914676 c0063828 c0063b94 call_cpuidle <- cpu_startup_entry+0x1b8/0x1e0 + CPU:0 ts:5914678 c039ecdc c006385c cpuidle_enter_state <- call_cpuidle+0x44/0x48 + CPU:0 ts:5914680 c039e9a0 c039ecf0 cpuidle_enter_freeze <- cpuidle_enter_state+0x304/0x314 + CPU:0 ts:5914681 c0063870 c039ea30 sched_idle_set_state <- cpuidle_enter_state+0x44/0x314 + CPU:1 ts:5916720 c0160f59 c015ee04 kernfs_unmap_bin_file <- __kernfs_remove+0x140/0x204 + CPU:1 ts:5916721 c05ca625 c015ee0c __mutex_lock_slowpath <- __kernfs_remove+0x148/0x204 + CPU:1 ts:5916723 c05c813d c05ca630 yield_to <- __mutex_lock_slowpath+0x314/0x358 + CPU:1 ts:5916724 c05ca2d1 c05ca638 __ww_mutex_lock <- __mutex_lock_slowpath+0x31c/0x358 + +max_reason +~~~~~~~~~~ + +Limiting which kinds of kmsg dumps are stored can be controlled via +the ``max_reason`` value, as defined in include/linux/kmsg_dump.h's +``enum kmsg_dump_reason``. For example, to store both Oopses and Panics, +``max_reason`` should be set to 2 (KMSG_DUMP_OOPS), to store only Panics +``max_reason`` should be set to 1 (KMSG_DUMP_PANIC). Setting this to 0 +(KMSG_DUMP_UNDEF), means the reason filtering will be controlled by the +``printk.always_kmsg_dump`` boot param: if unset, it'll be KMSG_DUMP_OOPS, +otherwise KMSG_DUMP_MAX. + +Configurations for driver +------------------------- + +Only a block device driver cares about these configurations. A block device +driver uses ``register_pstore_blk`` to register to pstore/blk. + +.. kernel-doc:: fs/pstore/blk.c + :identifiers: register_pstore_blk + +Compression and header +---------------------- + +Block device is large enough for uncompressed oops data. Actually we do not +recommend data compression because pstore/blk will insert some information into +the first line of oops/panic data. For example:: + + Panic: Total 16 times + +It means that it's OOPS|Panic for the 16th time since the first booting. +Sometimes the number of occurrences of oops|panic since the first booting is +important to judge whether the system is stable. + +The following line is inserted by pstore filesystem. For example:: + + Oops#2 Part1 + +It means that it's OOPS for the 2nd time on the last boot. + +Reading the data +---------------- + +The dump data can be read from the pstore filesystem. The format for these +files is ``dmesg-pstore-blk-[N]`` for oops/panic front-end, +``pmsg-pstore-blk-0`` for pmsg front-end and so on. The timestamp of the +dump file records the trigger time. To delete a stored record from block +device, simply unlink the respective pstore file. + +Attentions in panic read/write APIs +----------------------------------- + +If on panic, the kernel is not going to run for much longer, the tasks will not +be scheduled and most kernel resources will be out of service. It +looks like a single-threaded program running on a single-core computer. + +The following points require special attention for panic read/write APIs: + +1. Can **NOT** allocate any memory. + If you need memory, just allocate while the block driver is initializing + rather than waiting until the panic. +#. Must be polled, **NOT** interrupt driven. + No task schedule any more. The block driver should delay to ensure the write + succeeds, but NOT sleep. +#. Can **NOT** take any lock. + There is no other task, nor any shared resource; you are safe to break all + locks. +#. Just use CPU to transfer. + Do not use DMA to transfer unless you are sure that DMA will not keep lock. +#. Control registers directly. + Please control registers directly rather than use Linux kernel resources. + Do I/O map while initializing rather than wait until a panic occurs. +#. Reset your block device and controller if necessary. + If you are not sure of the state of your block device and controller when + a panic occurs, you are safe to stop and reset them. + +pstore/blk supports psblk_blkdev_info(), which is defined in +*linux/pstore_blk.h*, to get information of using block device, such as the +device number, sector count and start sector of the whole disk. + +pstore block internals +---------------------- + +For developer reference, here are all the important structures and APIs: + +.. kernel-doc:: fs/pstore/zone.c + :internal: + +.. kernel-doc:: include/linux/pstore_zone.h + :internal: + +.. kernel-doc:: fs/pstore/blk.c + :export: + +.. kernel-doc:: include/linux/pstore_blk.h + :internal: diff --git a/MAINTAINERS b/MAINTAINERS index 1061db6fbc32..032e1d0f681b 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -11801,6 +11801,11 @@ M: Colin Cross &lt;ccross(a)android.com&gt; M: Tony Luck &lt;tony.luck(a)intel.com&gt; S: Maintained T: git git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux.git for-next/pstore +F: Documentation/admin-guide/ramoops.rst +F: Documentation/admin-guide/pstore-blk.rst +F: Documentation/devicetree/bindings/reserved-memory/ramoops.txt +F: drivers/acpi/apei/erst.c +F: drivers/firmware/efi/efi-pstore.c F: fs/pstore/ F: include/linux/pstore* F: drivers/firmware/efi/efi-pstore.c diff --git a/fs/pstore/Kconfig b/fs/pstore/Kconfig index 34e769a06b86..0f5a4bdb3b34 100644 --- a/fs/pstore/Kconfig +++ b/fs/pstore/Kconfig @@ -171,6 +171,8 @@ config PSTORE_BLK This enables panic and oops message to be logged to a block dev where it can be read back at some later point. + For more information, see Documentation/admin-guide/pstore-blk.rst + If unsure, say N. config PSTORE_BLK_BLKDEV -- 2.17.1

From: WeiXiong Liao &lt;liaoweixiong(a)allwinnertech.com&gt; stable inclusion from stable-5.10 category: feature commit:335426c6dcdd338d6b7c939c2da15fc9c5dd4959 issue: #I4919J -------------------------------- One requirement to support MTD devices in pstore/zone is having a way to declare certain regions as broken. Add this support to pstore/zone. The MTD driver should return -ENOMSG when encountering a bad region, which tells pstore/zone to skip and try the next one. Signed-off-by: WeiXiong Liao &lt;liaoweixiong(a)allwinnertech.com&gt; Link: https://lore.kernel.org/lkml/20200511233229.27745-8-keescook@chromium.org/ Co-developed-by: Colin Ian King &lt;colin.king(a)canonical.com&gt; Signed-off-by: Colin Ian King &lt;colin.king(a)canonical.com&gt; Link: //lore.kernel.org/lkml/20200512173801.222666-1-colin.king(a)canonical.com Signed-off-by: Kees Cook &lt;keescook(a)chromium.org&gt; (cherry picked from commit 335426c6dcdd338d6b7c939c2da15fc9c5dd4959) Signed-off-by: roger &lt;kongzhengrong(a)huawei.com&gt; --- fs/pstore/blk.c | 10 ++++-- fs/pstore/zone.c | 65 ++++++++++++++++++++++++++++++------- include/linux/pstore_blk.h | 3 +- include/linux/pstore_zone.h | 12 ++++--- 4 files changed, 71 insertions(+), 19 deletions(-) diff --git a/fs/pstore/blk.c b/fs/pstore/blk.c index 2225a0e6637a..a5d2c1ea3981 100644 --- a/fs/pstore/blk.c +++ b/fs/pstore/blk.c @@ -109,9 +109,12 @@ struct bdev_info { * means error. * @write: The same as @read, but the following error number: * -EBUSY means try to write again later. + * -ENOMSG means to try next zone. * @panic_write:The write operation only used for panic case. It's optional - * if you do not care panic log. The parameters and return value - * are the same as @read. + * if you do not care panic log. The parameters are relative + * value to storage. + * On success, the number of bytes should be returned, others + * excluding -ENOMSG mean error. -ENOMSG means to try next zone. */ struct pstore_device_info { unsigned long total_size; @@ -337,6 +340,9 @@ static ssize_t psblk_blk_panic_write(const char *buf, size_t size, /* size and off must align to SECTOR_SIZE for block device */ ret = blkdev_panic_write(buf, off >> SECTOR_SHIFT, size >> SECTOR_SHIFT); + /* try next zone */ + if (ret == -ENOMSG) + return ret; return ret ? -EIO : size; } diff --git a/fs/pstore/zone.c b/fs/pstore/zone.c index dbbc28cddc72..ead8fbca620d 100644 --- a/fs/pstore/zone.c +++ b/fs/pstore/zone.c @@ -254,6 +254,9 @@ static int psz_zone_write(struct pstore_zone *zone, return 0; dirty: + /* no need to mark dirty if going to try next zone */ + if (wcnt == -ENOMSG) + return -ENOMSG; atomic_set(&zone->dirty, true); /* flush dirty zones nicely */ if (wcnt == -EBUSY && !is_on_panic()) @@ -396,7 +399,11 @@ static int psz_kmsg_recover_meta(struct psz_context *cxt) return -EINVAL; rcnt = info->read((char *)buf, len, zone->off); - if (rcnt != len) { + if (rcnt == -ENOMSG) { + pr_debug("%s with id %lu may be broken, skip\n", + zone->name, i); + continue; + } else if (rcnt != len) { pr_err("read %s with id %lu failed\n", zone->name, i); return (int)rcnt < 0 ? (int)rcnt : -EIO; } @@ -730,24 +737,58 @@ static void psz_write_kmsg_hdr(struct pstore_zone *zone, hdr->counter = 0; } +/* + * In case zone is broken, which may occur to MTD device, we try each zones, + * start at cxt->kmsg_write_cnt. + */ static inline int notrace psz_kmsg_write_record(struct psz_context *cxt, struct pstore_record *record) { size_t size, hlen; struct pstore_zone *zone; - unsigned int zonenum; + unsigned int i; - zonenum = cxt->kmsg_write_cnt; - zone = cxt->kpszs[zonenum]; - if (unlikely(!zone)) - return -ENOSPC; - cxt->kmsg_write_cnt = (zonenum + 1) % cxt->kmsg_max_cnt; + for (i = 0; i < cxt->kmsg_max_cnt; i++) { + unsigned int zonenum, len; + int ret; - pr_debug("write %s to zone id %d\n", zone->name, zonenum); - psz_write_kmsg_hdr(zone, record); - hlen = sizeof(struct psz_kmsg_header); - size = min_t(size_t, record->size, zone->buffer_size - hlen); - return psz_zone_write(zone, FLUSH_ALL, record->buf, size, hlen); + zonenum = (cxt->kmsg_write_cnt + i) % cxt->kmsg_max_cnt; + zone = cxt->kpszs[zonenum]; + if (unlikely(!zone)) + return -ENOSPC; + + /* avoid destroying old data, allocate a new one */ + len = zone->buffer_size + sizeof(*zone->buffer); + zone->oldbuf = zone->buffer; + zone->buffer = kzalloc(len, GFP_KERNEL); + if (!zone->buffer) { + zone->buffer = zone->oldbuf; + return -ENOMEM; + } + zone->buffer->sig = zone->oldbuf->sig; + + pr_debug("write %s to zone id %d\n", zone->name, zonenum); + psz_write_kmsg_hdr(zone, record); + hlen = sizeof(struct psz_kmsg_header); + size = min_t(size_t, record->size, zone->buffer_size - hlen); + ret = psz_zone_write(zone, FLUSH_ALL, record->buf, size, hlen); + if (likely(!ret || ret != -ENOMSG)) { + cxt->kmsg_write_cnt = zonenum + 1; + cxt->kmsg_write_cnt %= cxt->kmsg_max_cnt; + /* no need to try next zone, free last zone buffer */ + kfree(zone->oldbuf); + zone->oldbuf = NULL; + return ret; + } + + pr_debug("zone %u may be broken, try next dmesg zone\n", + zonenum); + kfree(zone->buffer); + zone->buffer = zone->oldbuf; + zone->oldbuf = NULL; + } + + return -EBUSY; } static int notrace psz_kmsg_write(struct psz_context *cxt, diff --git a/include/linux/pstore_blk.h b/include/linux/pstore_blk.h index 4501977b1336..ccba8c068752 100644 --- a/include/linux/pstore_blk.h +++ b/include/linux/pstore_blk.h @@ -14,7 +14,8 @@ * @start_sect: start sector to block device * @sects: sectors count on buf * - * Return: On success, zero should be returned. Others mean error. + * Return: On success, zero should be returned. Others excluding -ENOMSG + * mean error. -ENOMSG means to try next zone. * * Panic write to block device must be aligned to SECTOR_SIZE. */ diff --git a/include/linux/pstore_zone.h b/include/linux/pstore_zone.h index 6f16b0dd834a..e79a18e41064 100644 --- a/include/linux/pstore_zone.h +++ b/include/linux/pstore_zone.h @@ -23,11 +23,15 @@ typedef ssize_t (*pstore_zone_write_op)(const char *, size_t, loff_t); * @read: The general read operation. Both of the function parameters * @size and @offset are relative value to storage. * On success, the number of bytes should be returned, others - * means error. - * @write: The same as @read, but -EBUSY means try to write again later. + * mean error. + * @write: The same as @read, but the following error number: + * -EBUSY means try to write again later. + * -ENOMSG means to try next zone. * @panic_write:The write operation only used for panic case. It's optional - * if you do not care panic log. The parameters and return value - * are the same as @read. + * if you do not care panic log. The parameters are relative + * value to storage. + * On success, the number of bytes should be returned, others + * excluding -ENOMSG mean error. -ENOMSG means to try next zone. */ struct pstore_zone_info { struct module *owner; -- 2.17.1

From: WeiXiong Liao &lt;liaoweixiong(a)allwinnertech.com&gt; stable inclusion from stable-5.10 category: feature commit:7dcb7848ba110ff192efc917d1a6de66b4c9ca4f issue: #I4919J -------------------------------- Add support for non-block devices (e.g. MTD). A non-block driver calls pstore_blk_register_device() to register iself. In addition, pstore/zone is updated to handle non-block devices, where an erase must be done before a write. Without this, there is no way to remove records stored to an MTD. Signed-off-by: WeiXiong Liao &lt;liaoweixiong(a)allwinnertech.com&gt; Link: https://lore.kernel.org/lkml/20200511233229.27745-10-keescook@chromium.org/ Co-developed-by: Kees Cook &lt;keescook(a)chromium.org&gt; Signed-off-by: Kees Cook &lt;keescook(a)chromium.org&gt; (cherry picked from commit 7dcb7848ba110ff192efc917d1a6de66b4c9ca4f) Signed-off-by: roger &lt;kongzhengrong(a)huawei.com&gt; --- Documentation/admin-guide/pstore-blk.rst | 17 ++++- fs/pstore/blk.c | 93 +++++++++++++----------- fs/pstore/zone.c | 8 +- include/linux/pstore_blk.h | 38 ++++++++++ include/linux/pstore_zone.h | 6 ++ 5 files changed, 114 insertions(+), 48 deletions(-) diff --git a/Documentation/admin-guide/pstore-blk.rst b/Documentation/admin-guide/pstore-blk.rst index bef8c7436721..d45341e55e82 100644 --- a/Documentation/admin-guide/pstore-blk.rst +++ b/Documentation/admin-guide/pstore-blk.rst @@ -7,8 +7,8 @@ Introduction ------------ pstore block (pstore/blk) is an oops/panic logger that writes its logs to a -block device before the system crashes. You can get these log files by -mounting pstore filesystem like:: +block device and non-block device before the system crashes. You can get +these log files by mounting pstore filesystem like:: mount -t pstore pstore /sys/fs/pstore @@ -24,8 +24,8 @@ Configurations for user determine how pstore/blk works, such as pmsg_size, kmsg_size and so on. All of them support both Kconfig and module parameters, but module parameters have priority over Kconfig. -Configurations for driver are all about block device, such as total_size -of block device and read/write operations. +Configurations for driver are all about block device and non-block device, +such as total_size of block device and read/write operations. Configurations for user ----------------------- @@ -152,6 +152,15 @@ driver uses ``register_pstore_blk`` to register to pstore/blk. .. kernel-doc:: fs/pstore/blk.c :identifiers: register_pstore_blk +A non-block device driver uses ``register_pstore_device`` with +``struct pstore_device_info`` to register to pstore/blk. + +.. kernel-doc:: fs/pstore/blk.c + :identifiers: register_pstore_device + +.. kernel-doc:: include/linux/pstore_blk.h + :identifiers: pstore_device_info + Compression and header ---------------------- diff --git a/fs/pstore/blk.c b/fs/pstore/blk.c index 86e943326dfd..383c3dbc5f45 100644 --- a/fs/pstore/blk.c +++ b/fs/pstore/blk.c @@ -105,55 +105,22 @@ struct bdev_info { _##name_; \ }) -/** - * struct pstore_device_info - back-end pstore/blk driver structure. - * - * @total_size: The total size in bytes pstore/blk can use. It must be greater - * than 4096 and be multiple of 4096. - * @flags: Refer to macro starting with PSTORE_FLAGS defined in - * linux/pstore.h. It means what front-ends this device support. - * Zero means all backends for compatible. - * @read: The general read operation. Both of the function parameters - * @size and @offset are relative value to bock device (not the - * whole disk). - * On success, the number of bytes should be returned, others - * means error. - * @write: The same as @read, but the following error number: - * -EBUSY means try to write again later. - * -ENOMSG means to try next zone. - * @panic_write:The write operation only used for panic case. It's optional - * if you do not care panic log. The parameters are relative - * value to storage. - * On success, the number of bytes should be returned, others - * excluding -ENOMSG mean error. -ENOMSG means to try next zone. - */ -struct pstore_device_info { - unsigned long total_size; - unsigned int flags; - pstore_zone_read_op read; - pstore_zone_write_op write; - pstore_zone_write_op panic_write; -}; - -static int psblk_register_do(struct pstore_device_info *dev) +static int __register_pstore_device(struct pstore_device_info *dev) { int ret; + lockdep_assert_held(&pstore_blk_lock); + if (!dev || !dev->total_size || !dev->read || !dev->write) return -EINVAL; - mutex_lock(&pstore_blk_lock); - /* someone already registered before */ - if (pstore_zone_info) { - mutex_unlock(&pstore_blk_lock); + if (pstore_zone_info) return -EBUSY; - } + pstore_zone_info = kzalloc(sizeof(struct pstore_zone_info), GFP_KERNEL); - if (!pstore_zone_info) { - mutex_unlock(&pstore_blk_lock); + if (!pstore_zone_info) return -ENOMEM; - } /* zero means not limit on which backends to attempt to store. */ if (!dev->flags) @@ -179,6 +146,7 @@ static int psblk_register_do(struct pstore_device_info *dev) pstore_zone_info->max_reason = max_reason; pstore_zone_info->read = dev->read; pstore_zone_info->write = dev->write; + pstore_zone_info->erase = dev->erase; pstore_zone_info->panic_write = dev->panic_write; pstore_zone_info->name = KBUILD_MODNAME; pstore_zone_info->owner = THIS_MODULE; @@ -188,20 +156,51 @@ static int psblk_register_do(struct pstore_device_info *dev) kfree(pstore_zone_info); pstore_zone_info = NULL; } + return ret; +} +/** + * register_pstore_device() - register non-block device to pstore/blk + * + * @dev: non-block device information + * + * Return: + * * 0 - OK + * * Others - something error. + */ +int register_pstore_device(struct pstore_device_info *dev) +{ + int ret; + + mutex_lock(&pstore_blk_lock); + ret = __register_pstore_device(dev); mutex_unlock(&pstore_blk_lock); + return ret; } +EXPORT_SYMBOL_GPL(register_pstore_device); -static void psblk_unregister_do(struct pstore_device_info *dev) +static void __unregister_pstore_device(struct pstore_device_info *dev) { - mutex_lock(&pstore_blk_lock); + lockdep_assert_held(&pstore_blk_lock); if (pstore_zone_info && pstore_zone_info->read == dev->read) { unregister_pstore_zone(pstore_zone_info); kfree(pstore_zone_info); pstore_zone_info = NULL; } +} + +/** + * unregister_pstore_device() - unregister non-block device from pstore/blk + * + * @dev: non-block device information + */ +void unregister_pstore_device(struct pstore_device_info *dev) +{ + mutex_lock(&pstore_blk_lock); + __unregister_pstore_device(dev); mutex_unlock(&pstore_blk_lock); } +EXPORT_SYMBOL_GPL(unregister_pstore_device); /** * psblk_get_bdev() - open block device @@ -396,9 +395,10 @@ static int __register_pstore_blk(struct pstore_blk_info *info) dev.flags = info->flags; dev.read = psblk_generic_blk_read; dev.write = psblk_generic_blk_write; + dev.erase = NULL; dev.panic_write = info->panic_write ? psblk_blk_panic_write : NULL; - ret = psblk_register_do(&dev); + ret = __register_pstore_device(&dev); if (ret) goto err_put_bdev; @@ -442,7 +442,7 @@ static void __unregister_pstore_blk(unsigned int major) lockdep_assert_held(&pstore_blk_lock); if (psblk_bdev && MAJOR(psblk_bdev->bd_dev) == major) { - psblk_unregister_do(&dev); + __unregister_pstore_device(&dev); psblk_put_bdev(psblk_bdev, holder); blkdev_panic_write = NULL; psblk_bdev = NULL; @@ -481,6 +481,13 @@ static void __exit pstore_blk_exit(void) mutex_lock(&pstore_blk_lock); if (psblk_bdev) __unregister_pstore_blk(MAJOR(psblk_bdev->bd_dev)); + else { + struct pstore_device_info dev = { }; + + if (pstore_zone_info) + dev.read = pstore_zone_info->read; + __unregister_pstore_device(&dev); + } mutex_unlock(&pstore_blk_lock); } module_exit(pstore_blk_exit); diff --git a/fs/pstore/zone.c b/fs/pstore/zone.c index ead8fbca620d..ce73cd880b5c 100644 --- a/fs/pstore/zone.c +++ b/fs/pstore/zone.c @@ -665,15 +665,21 @@ static inline int psz_kmsg_erase(struct psz_context *cxt, struct psz_buffer *buffer = zone->buffer; struct psz_kmsg_header *hdr = (struct psz_kmsg_header *)buffer->data; + size_t size; if (unlikely(!psz_ok(zone))) return 0; + /* this zone is already updated, no need to erase */ if (record->count != hdr->counter) return 0; + size = buffer_datalen(zone) + sizeof(*zone->buffer); atomic_set(&zone->buffer->datalen, 0); - return psz_zone_write(zone, FLUSH_META, NULL, 0, 0); + if (cxt->pstore_zone_info->erase) + return cxt->pstore_zone_info->erase(size, zone->off); + else + return psz_zone_write(zone, FLUSH_META, NULL, 0, 0); } static inline int psz_record_erase(struct psz_context *cxt, diff --git a/include/linux/pstore_blk.h b/include/linux/pstore_blk.h index 0c40774e71e0..61e914522b01 100644 --- a/include/linux/pstore_blk.h +++ b/include/linux/pstore_blk.h @@ -49,6 +49,44 @@ struct pstore_blk_info { int register_pstore_blk(struct pstore_blk_info *info); void unregister_pstore_blk(unsigned int major); +/** + * struct pstore_device_info - back-end pstore/blk driver structure. + * + * @total_size: The total size in bytes pstore/blk can use. It must be greater + * than 4096 and be multiple of 4096. + * @flags: Refer to macro starting with PSTORE_FLAGS defined in + * linux/pstore.h. It means what front-ends this device support. + * Zero means all backends for compatible. + * @read: The general read operation. Both of the function parameters + * @size and @offset are relative value to bock device (not the + * whole disk). + * On success, the number of bytes should be returned, others + * means error. + * @write: The same as @read, but the following error number: + * -EBUSY means try to write again later. + * -ENOMSG means to try next zone. + * @erase: The general erase operation for device with special removing + * job. Both of the function parameters @size and @offset are + * relative value to storage. + * Return 0 on success and others on failure. + * @panic_write:The write operation only used for panic case. It's optional + * if you do not care panic log. The parameters are relative + * value to storage. + * On success, the number of bytes should be returned, others + * excluding -ENOMSG mean error. -ENOMSG means to try next zone. + */ +struct pstore_device_info { + unsigned long total_size; + unsigned int flags; + pstore_zone_read_op read; + pstore_zone_write_op write; + pstore_zone_erase_op erase; + pstore_zone_write_op panic_write; +}; + +int register_pstore_device(struct pstore_device_info *dev); +void unregister_pstore_device(struct pstore_device_info *dev); + /** * struct pstore_blk_config - the pstore_blk backend configuration * diff --git a/include/linux/pstore_zone.h b/include/linux/pstore_zone.h index e79a18e41064..1e35eaa33e5e 100644 --- a/include/linux/pstore_zone.h +++ b/include/linux/pstore_zone.h @@ -7,6 +7,7 @@ typedef ssize_t (*pstore_zone_read_op)(char *, size_t, loff_t); typedef ssize_t (*pstore_zone_write_op)(const char *, size_t, loff_t); +typedef ssize_t (*pstore_zone_erase_op)(size_t, loff_t); /** * struct pstore_zone_info - pstore/zone back-end driver structure * @@ -27,6 +28,10 @@ typedef ssize_t (*pstore_zone_write_op)(const char *, size_t, loff_t); * @write: The same as @read, but the following error number: * -EBUSY means try to write again later. * -ENOMSG means to try next zone. + * @erase: The general erase operation for device with special removing + * job. Both of the function parameters @size and @offset are + * relative value to storage. + * Return 0 on success and others on failure. * @panic_write:The write operation only used for panic case. It's optional * if you do not care panic log. The parameters are relative * value to storage. @@ -45,6 +50,7 @@ struct pstore_zone_info { unsigned long ftrace_size; pstore_zone_read_op read; pstore_zone_write_op write; + pstore_zone_erase_op erase; pstore_zone_write_op panic_write; }; -- 2.17.1

From: Vasile-Laurentiu Stanimir &lt;vasile-laurentiu.stanimir(a)windriver.com&gt; mainline inclusion from mainline-5.10 category: feature commit:26fecbf7602dd69b649914e61526bd67c557fece issue: #I4919J -------------------------------- While kmsg_bytes can be set for pstore via mount, if a crash occurs before the mount only partial console log will be stored as kmsg_bytes defaults to a potentially different hardcoded value in the kernel (PSTORE_DEFAULT_KMSG_BYTES). This makes it impossible to analyze valuable post-mortem data especially on the embedded development or in the process of bringing up new boards. Change this value to be a Kconfig option with the default of old PSTORE_DEFAULT_KMSG_BYTES Signed-off-by: Vasile-Laurentiu Stanimir &lt;vasile-laurentiu.stanimir(a)windriver.com&gt; Signed-off-by: Kees Cook &lt;keescook(a)chromium.org&gt; (cherry picked from commit 26fecbf7602dd69b649914e61526bd67c557fece) Signed-off-by: roger &lt;kongzhengrong(a)huawei.com&gt; --- fs/pstore/Kconfig | 8 ++++++++ fs/pstore/inode.c | 2 +- fs/pstore/internal.h | 1 - fs/pstore/platform.c | 2 +- 4 files changed, 10 insertions(+), 3 deletions(-) diff --git a/fs/pstore/Kconfig b/fs/pstore/Kconfig index 0f5a4bdb3b34..e0ac6601a928 100644 --- a/fs/pstore/Kconfig +++ b/fs/pstore/Kconfig @@ -13,6 +13,14 @@ config PSTORE If you don't have a platform persistent store driver, say N. +config PSTORE_DEFAULT_KMSG_BYTES + int "Default kernel log storage space" if EXPERT + depends on PSTORE + default "10240" + help + Defines default size of pstore kernel log storage. + Can be enlarged if needed, not recommended to shrink it. + config PSTORE_DEFLATE_COMPRESS tristate "DEFLATE (ZLIB) compression" default y diff --git a/fs/pstore/inode.c b/fs/pstore/inode.c index c29e4d4a3359..b4836705d220 100644 --- a/fs/pstore/inode.c +++ b/fs/pstore/inode.c @@ -276,7 +276,7 @@ static void parse_options(char *options) */ static int pstore_show_options(struct seq_file *m, struct dentry *root) { - if (kmsg_bytes != PSTORE_DEFAULT_KMSG_BYTES) + if (kmsg_bytes != CONFIG_PSTORE_DEFAULT_KMSG_BYTES) seq_printf(m, ",kmsg_bytes=%lu", kmsg_bytes); return 0; } diff --git a/fs/pstore/internal.h b/fs/pstore/internal.h index 7783db28ce4a..b82e074853ec 100644 --- a/fs/pstore/internal.h +++ b/fs/pstore/internal.h @@ -6,7 +6,6 @@ #include <linux/time.h> #include <linux/pstore.h> -#define PSTORE_DEFAULT_KMSG_BYTES 10240 extern unsigned long kmsg_bytes; #ifdef CONFIG_PSTORE_FTRACE diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c index 216c3247a2c6..b0703d0278b4 100644 --- a/fs/pstore/platform.c +++ b/fs/pstore/platform.c @@ -112,7 +112,7 @@ static char *big_oops_buf; static size_t big_oops_buf_sz; /* How much of the console log to snapshot */ -unsigned long kmsg_bytes = PSTORE_DEFAULT_KMSG_BYTES; +unsigned long kmsg_bytes = CONFIG_PSTORE_DEFAULT_KMSG_BYTES; void pstore_set_kmsg_bytes(int bytes) { -- 2.17.1

From: Tetsuo Handa &lt;penguin-kernel(a)I-love.SAKURA.ne.jp&gt; stable inclusion from stable-5.10 category: feature commit:a7acb614287b7de8bf86d6758dac43bbd1d29534 issue: #I4919J -------------------------------- commit 9c7d83ae6ba67d6c6199cce24573983db3b56332 upstream. syzbot is hitting WARN_ON(pstore_sb != sb) at pstore_kill_sb() [1], for the assumption that pstore_sb != NULL is wrong because pstore_fill_super() will not assign pstore_sb = sb when new_inode() for d_make_root() returned NULL (due to memory allocation fault injection). Since mount_single() calls pstore_kill_sb() when pstore_fill_super() failed, pstore_kill_sb() needs to be aware of such failure path. [1] https://syzkaller.appspot.com/bug?id=6abacb8da5137cb47a416f2bef95719ed60508… Reported-by: syzbot &lt;syzbot+d0cf0ad6513e9a1da5df(a)syzkaller.appspotmail.com&gt; Signed-off-by: Tetsuo Handa &lt;penguin-kernel(a)I-love.SAKURA.ne.jp&gt; Signed-off-by: Kees Cook &lt;keescook(a)chromium.org&gt; Link: https://lore.kernel.org/r/20210214031307.57903-1-penguin-kernel@I-love.SAKU… Signed-off-by: Greg Kroah-Hartman &lt;gregkh(a)linuxfoundation.org&gt; (cherry picked from commit a7acb614287b7de8bf86d6758dac43bbd1d29534) Signed-off-by: roger &lt;kongzhengrong(a)huawei.com&gt; --- fs/pstore/inode.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/pstore/inode.c b/fs/pstore/inode.c index b4836705d220..7e45ff1f8a39 100644 --- a/fs/pstore/inode.c +++ b/fs/pstore/inode.c @@ -448,7 +448,7 @@ static struct dentry *pstore_mount(struct file_system_type *fs_type, static void pstore_kill_sb(struct super_block *sb) { mutex_lock(&pstore_sb_lock); - WARN_ON(pstore_sb != sb); + WARN_ON(pstore_sb && pstore_sb != sb); kill_litter_super(sb); pstore_sb = NULL; -- 2.17.1

From: Mukesh Ojha &lt;mojha(a)codeaurora.org&gt; stable inclusion from stable-5.10 category: feature commit:9d843e8fafc7c0b15d8f511d146c0c3d7c816634 issue: #I4919J -------------------------------- There could be a scenario where we define some region in normal memory and use them store to logs which is later retrieved by bootloader during warm reset. In this scenario, we wanted to treat this memory as normal cacheable memory instead of default behaviour which is an overhead. Making it cacheable could improve performance. This commit gives control to change mem_type from Device tree, and also documents the value for normal memory. Signed-off-by: Mukesh Ojha &lt;mojha(a)codeaurora.org&gt; Signed-off-by: Kees Cook &lt;keescook(a)chromium.org&gt; Link: https://lore.kernel.org/r/1616438537-13719-1-git-send-email-mojha@codeauror… (cherry picked from commit 9d843e8fafc7c0b15d8f511d146c0c3d7c816634) Signed-off-by: roger &lt;kongzhengrong(a)huawei.com&gt; --- Documentation/admin-guide/ramoops.rst | 4 +++- .../bindings/reserved-memory/ramoops.txt | 10 ++++++++-- fs/pstore/ram.c | 7 ++++++- fs/pstore/ram_core.c | 18 ++++++++++++++++-- 4 files changed, 33 insertions(+), 6 deletions(-) diff --git a/Documentation/admin-guide/ramoops.rst b/Documentation/admin-guide/ramoops.rst index a60a96218ba9..f1801f480fa3 100644 --- a/Documentation/admin-guide/ramoops.rst +++ b/Documentation/admin-guide/ramoops.rst @@ -3,7 +3,7 @@ Ramoops oops/panic logger Sergiu Iordache &lt;sergiu(a)chromium.org&gt; -Updated: 17 November 2011 +Updated: 10 Feb 2021 Introduction ------------ @@ -30,6 +30,8 @@ mapping to pgprot_writecombine. Setting ``mem_type=1`` attempts to use depends on atomic operations. At least on ARM, pgprot_noncached causes the memory to be mapped strongly ordered, and atomic operations on strongly ordered memory are implementation defined, and won't work on many ARMs such as omaps. +Setting ``mem_type=2`` attempts to treat the memory region as normal memory, +which enables full cache on it. This can improve the performance. The memory area is divided into ``record_size`` chunks (also rounded down to power of two) and each kmesg dump writes a ``record_size`` chunk of diff --git a/Documentation/devicetree/bindings/reserved-memory/ramoops.txt b/Documentation/devicetree/bindings/reserved-memory/ramoops.txt index 0eba562fe5c6..217d72cb21ea 100644 --- a/Documentation/devicetree/bindings/reserved-memory/ramoops.txt +++ b/Documentation/devicetree/bindings/reserved-memory/ramoops.txt @@ -42,8 +42,14 @@ Optional properties: - pmsg-size: size in bytes of log buffer reserved for userspace messages (defaults to 0: disabled) -- unbuffered: if present, use unbuffered mappings to map the reserved region - (defaults to buffered mappings) +- mem-type: if present, sets the type of mapping is to be used to map the + reserved region. mem-type: 0 = write-combined (default), 1 = unbuffered, + 2 = cached. + +- unbuffered: deprecated, use mem_type instead. If present, and mem_type is + not specified, it is equivalent to mem_type = 1 and uses unbuffered mappings + to map the reserved region (defaults to buffered mappings mem_type = 0). If + both are specified -- "mem_type" overrides "unbuffered". - no-dump-oops: if present, only dump panics (defaults to panics and oops) diff --git a/fs/pstore/ram.c b/fs/pstore/ram.c index 9fce181b7042..be6bb96573a0 100644 --- a/fs/pstore/ram.c +++ b/fs/pstore/ram.c @@ -70,7 +70,7 @@ MODULE_PARM_DESC(mem_size, static unsigned int mem_type; module_param(mem_type, uint, 0400); MODULE_PARM_DESC(mem_type, - "set to 1 to try to use unbuffered memory (default 0)"); + "memory type: 0=write-combined (default), 1=unbuffered, 2=cached"); static int ramoops_max_reason = -1; module_param_named(max_reason, ramoops_max_reason, int, 0400); @@ -662,6 +662,10 @@ static int ramoops_parse_dt(struct platform_device *pdev, pdata->mem_size = resource_size(res); pdata->mem_address = res->start; + /* + * Setting "unbuffered" is deprecated and will be ignored if + * "mem_type" is also specified. + */ pdata->mem_type = of_property_read_bool(of_node, "unbuffered"); /* * Setting "no-dump-oops" is deprecated and will be ignored if @@ -680,6 +684,7 @@ static int ramoops_parse_dt(struct platform_device *pdev, field = value; \ } + parse_u32("mem-type", pdata->record_size, pdata->mem_type); parse_u32("record-size", pdata->record_size, 0); parse_u32("console-size", pdata->console_size, 0); parse_u32("ftrace-size", pdata->ftrace_size, 0); diff --git a/fs/pstore/ram_core.c b/fs/pstore/ram_core.c index 66fadf2475b2..65c25b43e464 100644 --- a/fs/pstore/ram_core.c +++ b/fs/pstore/ram_core.c @@ -395,6 +395,10 @@ void persistent_ram_zap(struct persistent_ram_zone *prz) persistent_ram_update_header_ecc(prz); } +#define MEM_TYPE_WCOMBINE 0 +#define MEM_TYPE_NONCACHED 1 +#define MEM_TYPE_NORMAL 2 + static void *persistent_ram_vmap(phys_addr_t start, size_t size, unsigned int memtype) { @@ -408,10 +412,20 @@ static void *persistent_ram_vmap(phys_addr_t start, size_t size, page_start = start - offset_in_page(start); page_count = DIV_ROUND_UP(size + offset_in_page(start), PAGE_SIZE); - if (memtype) + switch (memtype) { + case MEM_TYPE_NORMAL: + prot = PAGE_KERNEL; + break; + case MEM_TYPE_NONCACHED: prot = pgprot_noncached(PAGE_KERNEL); - else + break; + case MEM_TYPE_WCOMBINE: prot = pgprot_writecombine(PAGE_KERNEL); + break; + default: + pr_err("invalid mem_type=%d\n", memtype); + return NULL; + } pages = kmalloc_array(page_count, sizeof(struct page *), GFP_KERNEL); if (!pages) { -- 2.17.1