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| author | Markos Chandras <markos.chandras@imgtec.com> | 2014-09-16 15:55:12 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-10-05 14:54:11 -0700 |
| commit | f7feecd70f44ecddb14232de49003a4600482667 (patch) | |
| tree | f9fb3089a81261dcace824a494a82659a9b2b55c /arch | |
| parent | eee78f74dc248ccdcd0e5bc83240a88243407539 (diff) | |
| download | lwn-f7feecd70f44ecddb14232de49003a4600482667.tar.gz lwn-f7feecd70f44ecddb14232de49003a4600482667.zip | |
MIPS: mcount: Adjust stack pointer for static trace in MIPS32
commit 8a574cfa2652545eb95595d38ac2a0bb501af0ae upstream.
Every mcount() call in the MIPS 32-bit kernel is done as follows:
[...]
move at, ra
jal _mcount
addiu sp, sp, -8
[...]
but upon returning from the mcount() function, the stack pointer
is not adjusted properly. This is explained in details in 58b69401c797
(MIPS: Function tracer: Fix broken function tracing).
Commit ad8c396936e3 ("MIPS: Unbreak function tracer for 64-bit kernel.)
fixed the stack manipulation for 64-bit but it didn't fix it completely
for MIPS32.
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/7792/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/mips/kernel/mcount.S | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/arch/mips/kernel/mcount.S b/arch/mips/kernel/mcount.S index 33d067148e61..3efbf0b29c1b 100644 --- a/arch/mips/kernel/mcount.S +++ b/arch/mips/kernel/mcount.S @@ -123,7 +123,11 @@ NESTED(_mcount, PT_SIZE, ra) nop #endif b ftrace_stub +#ifdef CONFIG_32BIT + addiu sp, sp, 8 +#else nop +#endif static_trace: MCOUNT_SAVE_REGS @@ -133,6 +137,9 @@ static_trace: move a1, AT /* arg2: parent's return address */ MCOUNT_RESTORE_REGS +#ifdef CONFIG_32BIT + addiu sp, sp, 8 +#endif .globl ftrace_stub ftrace_stub: RETURN_BACK @@ -181,6 +188,11 @@ NESTED(ftrace_graph_caller, PT_SIZE, ra) jal prepare_ftrace_return nop MCOUNT_RESTORE_REGS +#ifndef CONFIG_DYNAMIC_FTRACE +#ifdef CONFIG_32BIT + addiu sp, sp, 8 +#endif +#endif RETURN_BACK END(ftrace_graph_caller) |