ARM: 7171/1: unwind: add unwind directives to bitops assembly macros
The bitops functions (e.g. _test_and_set_bit) on ARM do not have unwind
annotations and therefore the kernel cannot backtrace out of them on a
fatal error (for example, NULL pointer dereference).
This patch annotates the bitops assembly macros with UNWIND annotations
so that we can produce a meaningful backtrace on error. Callers of the
macros are modified to pass their function name as a macro parameter,
enforcing that the macros are used as standalone function implementations.
Acked-by: Dave Martin <dave.martin@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/lib/bitops.h b/arch/arm/lib/bitops.h
index 10d868a..d6408d1 100644
--- a/arch/arm/lib/bitops.h
+++ b/arch/arm/lib/bitops.h
@@ -1,5 +1,9 @@
+#include <asm/unwind.h>
+
#if __LINUX_ARM_ARCH__ >= 6
- .macro bitop, instr
+ .macro bitop, name, instr
+ENTRY( \name )
+UNWIND( .fnstart )
ands ip, r1, #3
strneb r1, [ip] @ assert word-aligned
mov r2, #1
@@ -13,9 +17,13 @@
cmp r0, #0
bne 1b
bx lr
+UNWIND( .fnend )
+ENDPROC(\name )
.endm
- .macro testop, instr, store
+ .macro testop, name, instr, store
+ENTRY( \name )
+UNWIND( .fnstart )
ands ip, r1, #3
strneb r1, [ip] @ assert word-aligned
mov r2, #1
@@ -34,9 +42,13 @@
cmp r0, #0
movne r0, #1
2: bx lr
+UNWIND( .fnend )
+ENDPROC(\name )
.endm
#else
- .macro bitop, instr
+ .macro bitop, name, instr
+ENTRY( \name )
+UNWIND( .fnstart )
ands ip, r1, #3
strneb r1, [ip] @ assert word-aligned
and r2, r0, #31
@@ -49,6 +61,8 @@
str r2, [r1, r0, lsl #2]
restore_irqs ip
mov pc, lr
+UNWIND( .fnend )
+ENDPROC(\name )
.endm
/**
@@ -59,7 +73,9 @@
* Note: we can trivially conditionalise the store instruction
* to avoid dirtying the data cache.
*/
- .macro testop, instr, store
+ .macro testop, name, instr, store
+ENTRY( \name )
+UNWIND( .fnstart )
ands ip, r1, #3
strneb r1, [ip] @ assert word-aligned
and r3, r0, #31
@@ -73,5 +89,7 @@
moveq r0, #0
restore_irqs ip
mov pc, lr
+UNWIND( .fnend )
+ENDPROC(\name )
.endm
#endif