From mboxrd@z Thu Jan 1 00:00:00 1970 From: will.deacon@arm.com (Will Deacon) Date: Mon, 21 Nov 2011 10:23:14 +0000 Subject: [PATCH v2] ARM: unwind: add unwind directives to bitops assembly macros Message-ID: <1321870994-2914-1-git-send-email-will.deacon@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org 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. Cc: Dave Martin Signed-off-by: Will Deacon --- v2: Added function name argument to bitops macros, as suggested by Dave. arch/arm/lib/bitops.h | 26 ++++++++++++++++++++++---- arch/arm/lib/changebit.S | 4 +--- arch/arm/lib/clearbit.S | 4 +--- arch/arm/lib/setbit.S | 4 +--- arch/arm/lib/testchangebit.S | 4 +--- arch/arm/lib/testclearbit.S | 4 +--- arch/arm/lib/testsetbit.S | 4 +--- 7 files changed, 28 insertions(+), 22 deletions(-) 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 + #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 diff --git a/arch/arm/lib/changebit.S b/arch/arm/lib/changebit.S index 68ed5b6..f402786 100644 --- a/arch/arm/lib/changebit.S +++ b/arch/arm/lib/changebit.S @@ -12,6 +12,4 @@ #include "bitops.h" .text -ENTRY(_change_bit) - bitop eor -ENDPROC(_change_bit) +bitop _change_bit, eor diff --git a/arch/arm/lib/clearbit.S b/arch/arm/lib/clearbit.S index 4c04c3b..f6b75fb 100644 --- a/arch/arm/lib/clearbit.S +++ b/arch/arm/lib/clearbit.S @@ -12,6 +12,4 @@ #include "bitops.h" .text -ENTRY(_clear_bit) - bitop bic -ENDPROC(_clear_bit) +bitop _clear_bit, bic diff --git a/arch/arm/lib/setbit.S b/arch/arm/lib/setbit.S index bbee5c6..618feda 100644 --- a/arch/arm/lib/setbit.S +++ b/arch/arm/lib/setbit.S @@ -12,6 +12,4 @@ #include "bitops.h" .text -ENTRY(_set_bit) - bitop orr -ENDPROC(_set_bit) +bitop _set_bit, orr diff --git a/arch/arm/lib/testchangebit.S b/arch/arm/lib/testchangebit.S index 15a4d43..4becdc3 100644 --- a/arch/arm/lib/testchangebit.S +++ b/arch/arm/lib/testchangebit.S @@ -12,6 +12,4 @@ #include "bitops.h" .text -ENTRY(_test_and_change_bit) - testop eor, str -ENDPROC(_test_and_change_bit) +testop _test_and_change_bit, eor, str diff --git a/arch/arm/lib/testclearbit.S b/arch/arm/lib/testclearbit.S index 521b66b..918841d 100644 --- a/arch/arm/lib/testclearbit.S +++ b/arch/arm/lib/testclearbit.S @@ -12,6 +12,4 @@ #include "bitops.h" .text -ENTRY(_test_and_clear_bit) - testop bicne, strne -ENDPROC(_test_and_clear_bit) +testop _test_and_clear_bit, bicne, strne diff --git a/arch/arm/lib/testsetbit.S b/arch/arm/lib/testsetbit.S index 1c98cc2..8d1b2fe 100644 --- a/arch/arm/lib/testsetbit.S +++ b/arch/arm/lib/testsetbit.S @@ -12,6 +12,4 @@ #include "bitops.h" .text -ENTRY(_test_and_set_bit) - testop orreq, streq -ENDPROC(_test_and_set_bit) +testop _test_and_set_bit, orreq, streq -- 1.7.4.1