Hello. On 19-01-2011 22:28, Wu Zhangjin wrote:
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 expects.
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@xxxxxxx> Signed-off-by: Wu Zhangjin<wuzhangjin@xxxxxxxxx> --- 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 bc91e4a..62775d7 100644 --- a/arch/mips/kernel/ftrace.c +++ b/arch/mips/kernel/ftrace.c
[...]
@@ -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);
Unneeded parens.
+ trace.func = self_ra - (MCOUNT_INSN_SIZE * insns);
Here too. WBR, Sergei
