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authorSteven Rostedt <srostedt@redhat.com>2008-11-15 01:21:19 +0100
committerIngo Molnar <mingo@elte.hu>2008-11-16 07:36:42 +0100
commit20e5227e9f55ae1969934821ccbf581563785bbe (patch)
treecac23dc66e00c7667f5c0e7adc72a76bd1041816 /kernel/trace
parentftrace: pass module struct to arch dynamic ftrace functions (diff)
downloadlinux-20e5227e9f55ae1969934821ccbf581563785bbe.tar.xz
linux-20e5227e9f55ae1969934821ccbf581563785bbe.zip
ftrace: allow NULL pointers in mcount_loc
Impact: make ftrace_convert_nops() more permissive Due to the way different architecture linkers combine the data sections of the mcount_loc (the section that lists all the locations that call mcount), there may be zeros added in that section. This is usually due to strange alignments that the linker performs, that pads in zeros. This patch makes the conversion code to nops skip any pointer in the mcount_loc section that is NULL. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/trace')
-rw-r--r--kernel/trace/ftrace.c8
1 files changed, 8 insertions, 0 deletions
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index e9a5fbfce08e..cc4219135dc9 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -1304,6 +1304,14 @@ static int ftrace_convert_nops(struct module *mod,
p = start;
while (p < end) {
addr = ftrace_call_adjust(*p++);
+ /*
+ * Some architecture linkers will pad between
+ * the different mcount_loc sections of different
+ * object files to satisfy alignments.
+ * Skip any NULL pointers.
+ */
+ if (!addr)
+ continue;
ftrace_record_ip(addr);
}