* [PATCH] ARM: align the start and end of v7_setup_stack to cache line
@ 2020-04-20 14:50 Cong Zhang
0 siblings, 0 replies; only message in thread
From: Cong Zhang @ 2020-04-20 14:50 UTC (permalink / raw)
To: Russell King; +Cc: linux-arm-kernel, linux-kernel, Cong Zhang
The v7_setup_stack is used when D-cache disabled. When CPU is reading
something nearby with D-cache enabled. It is possible to read
v7_setup_stack to cache line. There is a risk that when cache line write
back the data, v7_setup_stack may already been modified by other CPU with
D-cache disabled.
The change make v7_setup_stack align cache line size and use the whole
cache line to prevent corrupting v7_setup_stack.
Signed-off-by: Cong Zhang <congzhan@codeaurora.org>
---
arch/arm/mm/proc-v7.S | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/arch/arm/mm/proc-v7.S b/arch/arm/mm/proc-v7.S
index 339eb17..587e2eb 100644
--- a/arch/arm/mm/proc-v7.S
+++ b/arch/arm/mm/proc-v7.S
@@ -18,6 +18,7 @@
#include <asm/pgtable-hwdef.h>
#include <asm/pgtable.h>
#include <asm/memory.h>
+#include <asm/cache.h>
#include "proc-macros.S"
@@ -548,10 +549,10 @@ __v7_setup_stack_ptr:
ENDPROC(__v7_setup)
.bss
- .align 2
+ .align L1_CACHE_SHIFT
__v7_setup_stack:
.space 4 * 7 @ 7 registers
-
+ .align L1_CACHE_SHIFT
__INITDATA
.weak cpu_v7_bugs_init
--
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project
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