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authorMasami Hiramatsu <mhiramat@kernel.org>2019-10-25 17:46:25 +0900
committerArnaldo Carvalho de Melo <acme@redhat.com>2019-11-06 15:43:06 -0300
commit07d369857808b7e8e471bbbbb0074a6718f89b31 (patch)
tree4b8c798173b40cc45c2d443722d8cc0074b42eea /tools/perf/util/probe-finder.c
parentperf jevents: Fix resource leak in process_mapfile() and main() (diff)
downloadlinux-dev-07d369857808b7e8e471bbbbb0074a6718f89b31.tar.xz
linux-dev-07d369857808b7e8e471bbbbb0074a6718f89b31.zip
perf probe: Fix wrong address verification
Since there are some DIE which has only ranges instead of the combination of entrypc/highpc, address verification must use dwarf_haspc() instead of dwarf_entrypc/dwarf_highpc. Also, the ranges only DIE will have a partial code in different section (e.g. unlikely code will be in text.unlikely as "FUNC.cold" symbol). In that case, we can not use dwarf_entrypc() or die_entrypc(), because the offset from original DIE can be a minus value. Instead, this simply gets the symbol and offset from symtab. Without this patch; # perf probe -D clear_tasks_mm_cpumask:1 Failed to get entry address of clear_tasks_mm_cpumask Error: Failed to add events. And with this patch: # perf probe -D clear_tasks_mm_cpumask:1 p:probe/clear_tasks_mm_cpumask clear_tasks_mm_cpumask+0 p:probe/clear_tasks_mm_cpumask_1 clear_tasks_mm_cpumask+5 p:probe/clear_tasks_mm_cpumask_2 clear_tasks_mm_cpumask+8 p:probe/clear_tasks_mm_cpumask_3 clear_tasks_mm_cpumask+16 p:probe/clear_tasks_mm_cpumask_4 clear_tasks_mm_cpumask+82 Committer testing: I managed to reproduce the above: [root@quaco ~]# perf probe -D clear_tasks_mm_cpumask:1 p:probe/clear_tasks_mm_cpumask _text+919968 p:probe/clear_tasks_mm_cpumask_1 _text+919973 p:probe/clear_tasks_mm_cpumask_2 _text+919976 [root@quaco ~]# But then when trying to actually put the probe in place, it fails if I use :0 as the offset: [root@quaco ~]# perf probe -L clear_tasks_mm_cpumask | head -5 <clear_tasks_mm_cpumask@/usr/src/debug/kernel-5.2.fc30/linux-5.2.18-200.fc30.x86_64/kernel/cpu.c:0> 0 void clear_tasks_mm_cpumask(int cpu) 1 { 2 struct task_struct *p; [root@quaco ~]# perf probe clear_tasks_mm_cpumask:0 Probe point 'clear_tasks_mm_cpumask' not found. Error: Failed to add events. [root@quaco The next patch is needed to fix this case. Fixes: 576b523721b7 ("perf probe: Fix probing symbols with optimization suffix") Reported-by: Arnaldo Carvalho de Melo <acme@kernel.org> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Link: http://lore.kernel.org/lkml/157199318513.8075.10463906803299647907.stgit@devnote2 Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf/util/probe-finder.c')
-rw-r--r--tools/perf/util/probe-finder.c32
1 files changed, 10 insertions, 22 deletions
diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c
index cd9f95e5044e..2b6513e5725c 100644
--- a/tools/perf/util/probe-finder.c
+++ b/tools/perf/util/probe-finder.c
@@ -604,38 +604,26 @@ static int convert_to_trace_point(Dwarf_Die *sp_die, Dwfl_Module *mod,
const char *function,
struct probe_trace_point *tp)
{
- Dwarf_Addr eaddr, highaddr;
+ Dwarf_Addr eaddr;
GElf_Sym sym;
const char *symbol;
/* Verify the address is correct */
- if (dwarf_entrypc(sp_die, &eaddr) != 0) {
- pr_warning("Failed to get entry address of %s\n",
- dwarf_diename(sp_die));
- return -ENOENT;
- }
- if (dwarf_highpc(sp_die, &highaddr) != 0) {
- pr_warning("Failed to get end address of %s\n",
- dwarf_diename(sp_die));
- return -ENOENT;
- }
- if (paddr > highaddr) {
- pr_warning("Offset specified is greater than size of %s\n",
+ if (!dwarf_haspc(sp_die, paddr)) {
+ pr_warning("Specified offset is out of %s\n",
dwarf_diename(sp_die));
return -EINVAL;
}
- symbol = dwarf_diename(sp_die);
+ /* Try to get actual symbol name from symtab */
+ symbol = dwfl_module_addrsym(mod, paddr, &sym, NULL);
if (!symbol) {
- /* Try to get the symbol name from symtab */
- symbol = dwfl_module_addrsym(mod, paddr, &sym, NULL);
- if (!symbol) {
- pr_warning("Failed to find symbol at 0x%lx\n",
- (unsigned long)paddr);
- return -ENOENT;
- }
- eaddr = sym.st_value;
+ pr_warning("Failed to find symbol at 0x%lx\n",
+ (unsigned long)paddr);
+ return -ENOENT;
}
+ eaddr = sym.st_value;
+
tp->offset = (unsigned long)(paddr - eaddr);
tp->address = (unsigned long)paddr;
tp->symbol = strdup(symbol);