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authorLin Yongting <linyongting@gmail.com>2014-11-26 14:33:49 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2014-11-27 16:00:23 +0000
commit20cb6abfe0062693183eb2a85f7c73792e96407f (patch)
tree8a1989fcfd9b1233d8aeed734e0e1e66147eb22b /arch/arm/lib
parent296630c9c8c6ff5f116b417fafa6067d4c7a786e (diff)
downloadlinux-linaro-stable-20cb6abfe0062693183eb2a85f7c73792e96407f.tar.gz
ARM: 8223/1: Add unwinding support for __memzero function
The __memzero function never had unwinding annotations added. Currently, when accessing invalid pointer by __memzero occurs the backtrace shown will stop at __memzero or some completely unrelated function. Add unwinding annotations in hopes of getting a more useful backtrace in following cases: 1. die on accessing invalid pointer by __memzero 2. kprobe trapped at any instruction within __memzero 3. interrupted at any instruction within __memzero Signed-off-by: Lin Yongting <linyongting@gmail.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/lib')
-rw-r--r--arch/arm/lib/memzero.S12
1 files changed, 12 insertions, 0 deletions
diff --git a/arch/arm/lib/memzero.S b/arch/arm/lib/memzero.S
index 385ccb306fa2..0eded952e089 100644
--- a/arch/arm/lib/memzero.S
+++ b/arch/arm/lib/memzero.S
@@ -9,6 +9,7 @@
*/
#include <linux/linkage.h>
#include <asm/assembler.h>
+#include <asm/unwind.h>
.text
.align 5
@@ -18,6 +19,7 @@
* mis-aligned by, and r1 is the number of bytes. If r1 < 4, then we
* don't bother; we use byte stores instead.
*/
+UNWIND( .fnstart )
1: subs r1, r1, #4 @ 1 do we have enough
blt 5f @ 1 bytes to align with?
cmp r3, #2 @ 1
@@ -47,6 +49,9 @@ ENTRY(__memzero)
* use the LR
*/
str lr, [sp, #-4]! @ 1
+UNWIND( .fnend )
+UNWIND( .fnstart )
+UNWIND( .save {lr} )
mov ip, r2 @ 1
mov lr, r2 @ 1
@@ -66,6 +71,7 @@ ENTRY(__memzero)
tst r1, #16 @ 1 16 bytes or more?
stmneia r0!, {r2, r3, ip, lr} @ 4
ldr lr, [sp], #4 @ 1
+UNWIND( .fnend )
#else
@@ -75,6 +81,9 @@ ENTRY(__memzero)
*/
stmfd sp!, {r4-r7, lr}
+UNWIND( .fnend )
+UNWIND( .fnstart )
+UNWIND( .save {r4-r7, lr} )
mov r4, r2
mov r5, r2
mov r6, r2
@@ -105,9 +114,11 @@ ENTRY(__memzero)
tst r1, #16
stmneia r0!, {r4-r7}
ldmfd sp!, {r4-r7, lr}
+UNWIND( .fnend )
#endif
+UNWIND( .fnstart )
4: tst r1, #8 @ 1 8 bytes or more?
stmneia r0!, {r2, r3} @ 2
tst r1, #4 @ 1 4 bytes or more?
@@ -122,4 +133,5 @@ ENTRY(__memzero)
tst r1, #1 @ 1 a byte left over
strneb r2, [r0], #1 @ 1
ret lr @ 1
+UNWIND( .fnend )
ENDPROC(__memzero)