diff options
| author | Taras Kondratiuk <taras.kondratiuk@linaro.org> | 2013-11-08 18:29:29 +0000 |
|---|---|---|
| committer | Andrey Konovalov <andrey.konovalov@linaro.org> | 2014-03-17 15:46:02 +0400 |
| commit | 49ccefaf03c07921acd5782f64f68d19f867fe49 (patch) | |
| tree | 8a5a95c07f79e588f1fef3edd0eab7b468a45d50 | |
| parent | 06b4453d9ae4014950435209683f1a983c4c8128 (diff) | |
ARM: kprobes-test: Workaround GAS .align bug
By default if no fill symbol is given to .align directive in a code
section it fills gap with NOPs. If previous fragment is not
instruction-aligned, additional pre-alignment is done by zero bytes
before NOPs. These zero bytes are marked as data by special symbol $d in
symbol table. Unfortunately GAS assumes that there is only code in the
code section so it "puts back" code symbol $a at the end of this
pre-alignment. So if there is some data after alignment it will be
interpreted as code and will be swapped back to LE for BE8 system during
a final linking.
If explicit fill value is given to .align, the NOP-padding code is
skipped and symbol table does not get messed-up.
So the workaround for this issue:
Use explicit fill value if data should be aligned in the code section.
Acked-by: Ben Dooks <ben.dooks@codethink.co.uk>
Acked-by: Jon Medhurst <tixy@linaro.org>
Signed-off-by: Taras Kondratiuk <taras.kondratiuk@linaro.org>
| -rw-r--r-- | arch/arm/kernel/kprobes-test.c | 2 | ||||
| -rw-r--r-- | arch/arm/kernel/kprobes-test.h | 2 |
2 files changed, 2 insertions, 2 deletions
diff --git a/arch/arm/kernel/kprobes-test.c b/arch/arm/kernel/kprobes-test.c index 6e60a349aed9..379639998d5a 100644 --- a/arch/arm/kernel/kprobes-test.c +++ b/arch/arm/kernel/kprobes-test.c @@ -113,7 +113,7 @@ * @ start of inline data... * .ascii "mov r0, r7" @ text title for test case * .byte 0 - * .align 2 + * .align 2, 0 * * @ TEST_ARG_REG * .byte ARG_TYPE_REG diff --git a/arch/arm/kernel/kprobes-test.h b/arch/arm/kernel/kprobes-test.h index e28a869b1ae4..eecc90a0fd91 100644 --- a/arch/arm/kernel/kprobes-test.h +++ b/arch/arm/kernel/kprobes-test.h @@ -115,7 +115,7 @@ struct test_arg_end { /* multiple strings to be concatenated. */ \ ".ascii "#title" \n\t" \ ".byte 0 \n\t" \ - ".align 2 \n\t" + ".align 2, 0 \n\t" #define TEST_ARG_REG(reg, val) \ ".byte "__stringify(ARG_TYPE_REG)" \n\t" \ |