From 811dd2ae7cd670fefbb3b220b529bb9876edde70 Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Fri, 6 Mar 2015 16:31:22 +0900 Subject: [PATCH] perf probe: Fix --line to handle aliased symbols in glibc Fix perf probe --line to handle aliased symbols correctly in glibc. This makes line_range search failing back to address-based alternative search as same as --add and --vars. Without this patch; ----- # ./perf probe -x /usr/lib64/libc-2.17.so -L malloc Specified source line is not found. Error: Failed to show lines. ----- With this patch; ----- # ./perf probe -x /usr/lib64/libc-2.17.so -L malloc <__libc_malloc@/usr/src/debug/glibc-2.17-c758a686/malloc/malloc.c:0> 0 __libc_malloc(size_t bytes) 1 { mstate ar_ptr; void *victim; __malloc_ptr_t (*hook) (size_t, const __malloc_ptr_t) 6 = force_reg (__malloc_hook); 7 if (__builtin_expect (hook != NULL, 0)) 8 return (*hook)(bytes, RETURN_ADDRESS (0)); 10 arena_lookup(ar_ptr); 12 arena_lock(ar_ptr, bytes); ----- Note that this actually shows __libc_malloc, since it is the real instance of malloc. User can use both __libc_malloc and malloc for --line. Signed-off-by: Masami Hiramatsu Tested-by: Arnaldo Carvalho de Melo Cc: David Ahern Cc: Jiri Olsa Cc: Namhyung Kim Cc: Naohiro Aota Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/20150306073122.6904.18540.stgit@localhost.localdomain Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/probe-event.c | 35 +++++++++++++++++++++++++++++++++-- 1 file changed, 33 insertions(+), 2 deletions(-) diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c index b8f45782126a..4cfd1211a2ae 100644 --- a/tools/perf/util/probe-event.c +++ b/tools/perf/util/probe-event.c @@ -353,6 +353,31 @@ static int get_alternative_probe_event(struct debuginfo *dinfo, return ret; } +static int get_alternative_line_range(struct debuginfo *dinfo, + struct line_range *lr, + const char *target, bool user) +{ + struct perf_probe_point pp = { 0 }, result = { 0 }; + int ret, len = 0; + + pp.function = lr->function; + pp.file = lr->file; + pp.line = lr->start; + if (lr->end != INT_MAX) + len = lr->end - lr->start; + ret = find_alternative_probe_point(dinfo, &pp, &result, + target, user); + if (!ret) { + lr->function = result.function; + lr->file = result.file; + lr->start = result.line; + if (lr->end != INT_MAX) + lr->end = lr->start + len; + clear_perf_probe_point(&pp); + } + return ret; +} + /* Open new debuginfo of given module */ static struct debuginfo *open_debuginfo(const char *module, bool silent) { @@ -734,7 +759,8 @@ static int _show_one_line(FILE *fp, int l, bool skip, bool show_num) * Show line-range always requires debuginfo to find source file and * line number. */ -static int __show_line_range(struct line_range *lr, const char *module) +static int __show_line_range(struct line_range *lr, const char *module, + bool user) { int l = 1; struct int_node *ln; @@ -750,6 +776,11 @@ static int __show_line_range(struct line_range *lr, const char *module) return -ENOENT; ret = debuginfo__find_line_range(dinfo, lr); + if (!ret) { /* Not found, retry with an alternative */ + ret = get_alternative_line_range(dinfo, lr, module, user); + if (!ret) + ret = debuginfo__find_line_range(dinfo, lr); + } debuginfo__delete(dinfo); if (ret == 0 || ret == -ENOENT) { pr_warning("Specified source line is not found.\n"); @@ -819,7 +850,7 @@ int show_line_range(struct line_range *lr, const char *module, bool user) ret = init_symbol_maps(user); if (ret < 0) return ret; - ret = __show_line_range(lr, module); + ret = __show_line_range(lr, module, user); exit_symbol_maps(); return ret; -- 2.20.1