From: Kees Cook
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.microsoft...
Signed-off-by: Kees Cook
(cherry picked from commit 26961d76ff35aecb1af0fefd283fb5170786a812)
Signed-off-by: roger
---
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
