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| author | Wu Zhangjin <wuzhangjin@gmail.com> | 2009-11-20 20:34:37 +0800 |
|---|---|---|
| committer | Ralf Baechle <ralf@linux-mips.org> | 2009-12-17 01:57:26 +0000 |
| commit | fc49a3be2be7a0cd44fcd3b37557d6d92cae59b1 (patch) | |
| tree | d216d6b5a23c85ee5bcd3b92dd62a4c6718bd72e /arch/mips/kernel/mcount.S | |
| parent | 046199cae714a7f9e88f5a7940b077f4515f48cb (diff) | |
| download | linux-fc49a3be2be7a0cd44fcd3b37557d6d92cae59b1.tar.gz | |
MIPS: Tracing: Reserve $12(t0) for mcount-ra-address of gcc 4.5
A new option -mmcount-ra-address for gcc 4.5 have been sent by David Daney <ddaney@caviumnetworks.com> in the thread "MIPS: Add option to pass return address location to _mcount", which help to record the location of the return address(ra) for the function graph tracer of MIPS to hijack the return address easier and safer. that option used the $12(t0) register by default, so, we reserve it for it, and use t1,t2,t3 instead of t0,t1,t2. Signed-off-by: Wu Zhangjin <wuzhangjin@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Nicholas Mc Guire <der.herr@hofr.at> Cc: zhangfx@lemote.com Cc: Wu Zhangjin <wuzhangjin@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: linux-kernel@vger.kernel.org Cc: linux-mips@linux-mips.org Patchwork: http://patchwork.linux-mips.org/patch/680/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Diffstat (limited to 'arch/mips/kernel/mcount.S')
| -rw-r--r-- | arch/mips/kernel/mcount.S | 26 |
1 files changed, 13 insertions, 13 deletions
diff --git a/arch/mips/kernel/mcount.S b/arch/mips/kernel/mcount.S index bdfef2c24f16..522e91c688fc 100644 --- a/arch/mips/kernel/mcount.S +++ b/arch/mips/kernel/mcount.S @@ -65,8 +65,8 @@ NESTED(ftrace_caller, PT_SIZE, ra) _mcount: b ftrace_stub nop - lw t0, function_trace_stop - bnez t0, ftrace_stub + lw t1, function_trace_stop + bnez t1, ftrace_stub nop MCOUNT_SAVE_REGS @@ -93,21 +93,21 @@ ftrace_stub: #else /* ! CONFIG_DYNAMIC_FTRACE */ NESTED(_mcount, PT_SIZE, ra) - lw t0, function_trace_stop - bnez t0, ftrace_stub + lw t1, function_trace_stop + bnez t1, ftrace_stub nop - PTR_LA t0, ftrace_stub - PTR_L t1, ftrace_trace_function /* Prepare t1 for (1) */ - bne t0, t1, static_trace + PTR_LA t1, ftrace_stub + PTR_L t2, ftrace_trace_function /* Prepare t2 for (1) */ + bne t1, t2, static_trace nop #ifdef CONFIG_FUNCTION_GRAPH_TRACER - PTR_L t2, ftrace_graph_return - bne t0, t2, ftrace_graph_caller + PTR_L t3, ftrace_graph_return + bne t1, t3, ftrace_graph_caller nop - PTR_LA t0, ftrace_graph_entry_stub - PTR_L t2, ftrace_graph_entry - bne t0, t2, ftrace_graph_caller + PTR_LA t1, ftrace_graph_entry_stub + PTR_L t3, ftrace_graph_entry + bne t1, t3, ftrace_graph_caller nop #endif b ftrace_stub @@ -117,7 +117,7 @@ static_trace: MCOUNT_SAVE_REGS move a0, ra /* arg1: next ip, selfaddr */ - jalr t1 /* (1) call *ftrace_trace_function */ + jalr t2 /* (1) call *ftrace_trace_function */ move a1, AT /* arg2: the caller's next ip, parent */ MCOUNT_RESTORE_REGS |