From: Ard Biesheuvel
mainline inclusion
from mainline-5.11-rc1
commit 91580f0dbf24c6d616091526a900213bc7aa48fe
category: feature
issue: #I3ZXZF
CVE: NA
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...
-------------------------------------------------
Replace the open coded PC relative offset calculations with adr_l
and ldr_l invocations. This removes some open coded arithmetic
involving virtual addresses, avoids literal pools on v7+, and slightly
reduces the footprint of the code.
Note that it also removes a stale comment about the contents of r6.
Reviewed-by: Nicolas Pitre
Signed-off-by: Ard Biesheuvel
(cherry picked from commit 91580f0dbf24c6d616091526a900213bc7aa48fe)
Signed-off-by: Zhao Hongjiang
Acked-by: Xie XiuQi
Signed-off-by: Chen Jun
Signed-off-by: Yu Changchun
---
arch/arm/kernel/head.S | 19 ++++---------------
1 file changed, 4 insertions(+), 15 deletions(-)
diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S
index 205881bb0919..fcd998ba9c9a 100644
--- a/arch/arm/kernel/head.S
+++ b/arch/arm/kernel/head.S
@@ -382,10 +382,8 @@ ENTRY(secondary_startup)
/*
* Use the page tables supplied from __cpu_up.
*/
- adr r4, __secondary_data
- ldmia r4, {r5, r7, r12} @ address to jump to after
- sub lr, r4, r5 @ mmu has been enabled
- add r3, r7, lr
+ adr_l r3, secondary_data
+ mov_l r12, __secondary_switched
ldrd r4, r5, [r3, #0] @ get secondary_data.pgdir
ARM_BE8(eor r4, r4, r5) @ Swap r5 and r4 in BE:
ARM_BE8(eor r5, r4, r5) @ it can be done in 3 steps
@@ -400,22 +398,13 @@ ARM_BE8(eor r4, r4, r5) @ without using a temp reg.
ENDPROC(secondary_startup)
ENDPROC(secondary_startup_arm)
- /*
- * r6 = &secondary_data
- */
ENTRY(__secondary_switched)
- ldr sp, [r7, #12] @ get secondary_data.stack
+ ldr_l r7, secondary_data + 12 @ get secondary_data.stack
+ mov sp, r7
mov fp, #0
b secondary_start_kernel
ENDPROC(__secondary_switched)
- .align
-
- .type __secondary_data, %object
-__secondary_data:
- .long .
- .long secondary_data
- .long __secondary_switched
#endif /* defined(CONFIG_SMP) */
--
2.22.0
