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 (file)
--- 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

diff --git a/arch/arm/lib/changebit.S b/arch/arm/lib/changebit.S
index 68ed5b6..f402786 100644 (file)
--- 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 (file)
--- 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 (file)
--- 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 (file)
--- 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 (file)
--- 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 (file)
--- 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