diff options
| author | Wu Zhangjin <wuzhangjin@gmail.com> | 2011-01-22 02:01:53 +0800 |
|---|---|---|
| committer | Ralf Baechle <ralf@linux-mips.org> | 2011-03-14 21:07:24 +0100 |
| commit | b9f07eb2f25a64098e2ba223c1a2fe2a8f249e01 (patch) | |
| tree | 1b52def8282e9faa067acb9fc360cbc10ff03fc1 /arch/mips/kernel/ftrace.c | |
| parent | 7f21a60968221eabad5c53fe760db3d094994011 (diff) | |
MIPS, Tracing: Fix set_graph_function of function graph tracer
trace.func should be set to the recorded ip of the mcount calling site
in the __mcount_loc section to filter the function entries configured
through the tracing/set_graph_function interface, but before, this is
set to the self_ra(the return address of mcount), which has made
set_graph_function not work as expected.
This fixes it via calculating the right recorded ip in the __mcount_loc
section and assign it to trace.func.
Reported-by: Zhiping Zhong <xzhong86@163.com>
Signed-off-by: Wu Zhangjin <wuzhangjin@gmail.com>
Cc: Steven Rostedt <srostedt@redhat.com>
Cc: Sergei Shtylyov <sshtylyov@mvista.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/2017/
Signed-off-by: Ralf Baechle <ralf@duck.linux-mips.net>
Diffstat (limited to 'arch/mips/kernel/ftrace.c')
| -rw-r--r-- | arch/mips/kernel/ftrace.c | 11 |
1 files changed, 9 insertions, 2 deletions
diff --git a/arch/mips/kernel/ftrace.c b/arch/mips/kernel/ftrace.c index bc91e4aa08e9..94ca2b018af7 100644 --- a/arch/mips/kernel/ftrace.c +++ b/arch/mips/kernel/ftrace.c @@ -257,7 +257,7 @@ void prepare_ftrace_return(unsigned long *parent_ra_addr, unsigned long self_ra, struct ftrace_graph_ent trace; unsigned long return_hooker = (unsigned long) &return_to_handler; - int faulted; + int faulted, insns; if (unlikely(atomic_read(¤t->tracing_graph_pause))) return; @@ -304,7 +304,14 @@ void prepare_ftrace_return(unsigned long *parent_ra_addr, unsigned long self_ra, return; } - trace.func = self_ra; + /* + * Get the recorded ip of the current mcount calling site in the + * __mcount_loc section, which will be used to filter the function + * entries configured through the tracing/set_graph_function interface. + */ + + insns = in_kernel_space(self_ra) ? 2 : MCOUNT_OFFSET_INSNS + 1; + trace.func = self_ra - (MCOUNT_INSN_SIZE * insns); /* Only trace if the calling function expects to */ if (!ftrace_graph_entry(&trace)) { |