Messages in this thread Patch in this message | | | From | lizf@kernel ... | Subject | [PATCH 3.4 65/91] MIPS: mcount: Adjust stack pointer for static trace in MIPS32 | Date | Wed, 28 Jan 2015 12:08:16 +0800 |
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From: Markos Chandras <markos.chandras@imgtec.com>
3.4.105-rc1 review patch. If anyone has any objections, please let me know.
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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: Zefan Li <lizefan@huawei.com> --- arch/mips/kernel/mcount.S | 12 ++++++++++++ 1 file changed, 12 insertions(+)
diff --git a/arch/mips/kernel/mcount.S b/arch/mips/kernel/mcount.S index 4c968e7..55eca41 100644 --- a/arch/mips/kernel/mcount.S +++ b/arch/mips/kernel/mcount.S @@ -119,7 +119,11 @@ 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 @@ -129,6 +133,9 @@ 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 @@ -177,6 +184,11 @@ 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) -- 1.9.1
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