3.16.82-rc1 review patch. If anyone has any objections, please let me know.
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From: Masami Hiramatsu mhiramat@kernel.org
commit dee36a2abb67c175265d49b9a8c7dfa564463d9a upstream.
Since debuginfo__find_probes() callback function can be called with the location which already passed, the callback function must filter out such overlapped locations.
add_probe_trace_event() has already done it by commit 1a375ae7659a ("perf probe: Skip same probe address for a given line"), but add_available_vars() doesn't. Thus perf probe -v shows same address repeatedly as below:
# perf probe -V vfs_read:18 Available variables at vfs_read:18 @<vfs_read+217> char* buf loff_t* pos ssize_t ret struct file* file @<vfs_read+217> char* buf loff_t* pos ssize_t ret struct file* file @<vfs_read+226> char* buf loff_t* pos ssize_t ret struct file* file
With this fix, perf probe -V shows it correctly:
# perf probe -V vfs_read:18 Available variables at vfs_read:18 @<vfs_read+217> char* buf loff_t* pos ssize_t ret struct file* file @<vfs_read+226> char* buf loff_t* pos ssize_t ret struct file* file
Fixes: cf6eb489e5c0 ("perf probe: Show accessible local variables") Signed-off-by: Masami Hiramatsu mhiramat@kernel.org Tested-by: Arnaldo Carvalho de Melo acme@redhat.com Cc: Jiri Olsa jolsa@redhat.com Cc: Namhyung Kim namhyung@kernel.org Link: http://lore.kernel.org/lkml/157241938927.32002.4026859017790562751.stgit@dev... Signed-off-by: Arnaldo Carvalho de Melo acme@redhat.com Signed-off-by: Ben Hutchings ben@decadent.org.uk --- tools/perf/util/probe-finder.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+)
--- a/tools/perf/util/probe-finder.c +++ b/tools/perf/util/probe-finder.c @@ -1230,6 +1230,18 @@ static int collect_variables_cb(Dwarf_Di return DIE_FIND_CB_SIBLING; }
+static bool available_var_finder_overlap(struct available_var_finder *af) +{ + int i; + + for (i = 0; i < af->nvls; i++) { + if (af->pf.addr == af->vls[i].point.address) + return true; + } + return false; + +} + /* Add a found vars into available variables list */ static int add_available_vars(Dwarf_Die *sc_die, struct probe_finder *pf) { @@ -1239,6 +1251,14 @@ static int add_available_vars(Dwarf_Die Dwarf_Die die_mem; int ret;
+ /* + * For some reason (e.g. different column assigned to same address), + * this callback can be called with the address which already passed. + * Ignore it first. + */ + if (available_var_finder_overlap(af)) + return 0; + /* Check number of tevs */ if (af->nvls == af->max_vls) { pr_warning("Too many( > %d) probe point found.\n", af->max_vls);