mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-18 10:13:57 +08:00
c36ef4b176
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>
96 lines
1.9 KiB
C
96 lines
1.9 KiB
C
#include <asm/unwind.h>
|
|
|
|
#if __LINUX_ARM_ARCH__ >= 6
|
|
.macro bitop, name, instr
|
|
ENTRY( \name )
|
|
UNWIND( .fnstart )
|
|
ands ip, r1, #3
|
|
strneb r1, [ip] @ assert word-aligned
|
|
mov r2, #1
|
|
and r3, r0, #31 @ Get bit offset
|
|
mov r0, r0, lsr #5
|
|
add r1, r1, r0, lsl #2 @ Get word offset
|
|
mov r3, r2, lsl r3
|
|
1: ldrex r2, [r1]
|
|
\instr r2, r2, r3
|
|
strex r0, r2, [r1]
|
|
cmp r0, #0
|
|
bne 1b
|
|
bx lr
|
|
UNWIND( .fnend )
|
|
ENDPROC(\name )
|
|
.endm
|
|
|
|
.macro testop, name, instr, store
|
|
ENTRY( \name )
|
|
UNWIND( .fnstart )
|
|
ands ip, r1, #3
|
|
strneb r1, [ip] @ assert word-aligned
|
|
mov r2, #1
|
|
and r3, r0, #31 @ Get bit offset
|
|
mov r0, r0, lsr #5
|
|
add r1, r1, r0, lsl #2 @ Get word offset
|
|
mov r3, r2, lsl r3 @ create mask
|
|
smp_dmb
|
|
1: ldrex r2, [r1]
|
|
ands r0, r2, r3 @ save old value of bit
|
|
\instr r2, r2, r3 @ toggle bit
|
|
strex ip, r2, [r1]
|
|
cmp ip, #0
|
|
bne 1b
|
|
smp_dmb
|
|
cmp r0, #0
|
|
movne r0, #1
|
|
2: bx lr
|
|
UNWIND( .fnend )
|
|
ENDPROC(\name )
|
|
.endm
|
|
#else
|
|
.macro bitop, name, instr
|
|
ENTRY( \name )
|
|
UNWIND( .fnstart )
|
|
ands ip, r1, #3
|
|
strneb r1, [ip] @ assert word-aligned
|
|
and r2, r0, #31
|
|
mov r0, r0, lsr #5
|
|
mov r3, #1
|
|
mov r3, r3, lsl r2
|
|
save_and_disable_irqs ip
|
|
ldr r2, [r1, r0, lsl #2]
|
|
\instr r2, r2, r3
|
|
str r2, [r1, r0, lsl #2]
|
|
restore_irqs ip
|
|
mov pc, lr
|
|
UNWIND( .fnend )
|
|
ENDPROC(\name )
|
|
.endm
|
|
|
|
/**
|
|
* testop - implement a test_and_xxx_bit operation.
|
|
* @instr: operational instruction
|
|
* @store: store instruction
|
|
*
|
|
* Note: we can trivially conditionalise the store instruction
|
|
* to avoid dirtying the data cache.
|
|
*/
|
|
.macro testop, name, instr, store
|
|
ENTRY( \name )
|
|
UNWIND( .fnstart )
|
|
ands ip, r1, #3
|
|
strneb r1, [ip] @ assert word-aligned
|
|
and r3, r0, #31
|
|
mov r0, r0, lsr #5
|
|
save_and_disable_irqs ip
|
|
ldr r2, [r1, r0, lsl #2]!
|
|
mov r0, #1
|
|
tst r2, r0, lsl r3
|
|
\instr r2, r2, r0, lsl r3
|
|
\store r2, [r1]
|
|
moveq r0, #0
|
|
restore_irqs ip
|
|
mov pc, lr
|
|
UNWIND( .fnend )
|
|
ENDPROC(\name )
|
|
.endm
|
|
#endif
|