From 19993b82a571893e661afd90f1d77fa698785cee Mon Sep 17 00:00:00 2001 From: Arnaldo Carvalho de Melo Date: Mon, 13 Nov 2017 16:06:29 -0300 Subject: perf machine: Guard against NULL in machine__exit() A recent fix for 'perf trace' introduced a bug where machine__exit(trace->host) could be called while trace->host was still NULL, so make this more robust by guarding against NULL, just like free() does. The problem happens, for instance, when !root users try to run 'perf trace': [acme@jouet linux]$ trace Error: No permissions to read /sys/kernel/debug/tracing/events/raw_syscalls/sys_(enter|exit) Hint: Try 'sudo mount -o remount,mode=755 /sys/kernel/debug/tracing' perf: Segmentation fault Obtained 7 stack frames. [0x4f1b2e] /lib64/libc.so.6(+0x3671f) [0x7f43a1dd971f] [0x4f3fec] [0x47468b] [0x42a2db] /lib64/libc.so.6(__libc_start_main+0xe9) [0x7f43a1dc3509] [0x42a6c9] Segmentation fault (core dumped) [acme@jouet linux]$ Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Andrei Vagin Cc: David Ahern Cc: Jiri Olsa Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Vasily Averin Cc: Wang Nan Fixes: 33974a414ce2 ("perf trace: Call machine__exit() at exit") Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/machine.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'tools/perf/util/machine.c') diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c index 6a8d03c3d9b7..270f3223c6df 100644 --- a/tools/perf/util/machine.c +++ b/tools/perf/util/machine.c @@ -172,6 +172,9 @@ void machine__exit(struct machine *machine) { int i; + if (machine == NULL) + return; + machine__destroy_kernel_maps(machine); map_groups__exit(&machine->kmaps); dsos__exit(&machine->dsos); -- cgit v1.2.3 From 914eb9ca51117776d83e6761a1c555fb76f0ded2 Mon Sep 17 00:00:00 2001 From: Jiri Olsa Date: Sun, 6 Aug 2017 16:39:39 +0200 Subject: perf callchain: Reset cursor arg instead of callchain_cursor We already pass cursor into thread__resolve_callchain function, so there's no point in resetting the global instance. Signed-off-by: Jiri Olsa Cc: Adrian Hunter Cc: David Ahern Cc: Namhyung Kim Cc: Wang Nan Link: http://lkml.kernel.org/n/tip-puk015qvuppao9m1xtdy9v7j@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/machine.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'tools/perf/util/machine.c') diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c index 270f3223c6df..64d255f6a537 100644 --- a/tools/perf/util/machine.c +++ b/tools/perf/util/machine.c @@ -2204,7 +2204,7 @@ int thread__resolve_callchain(struct thread *thread, { int ret = 0; - callchain_cursor_reset(&callchain_cursor); + callchain_cursor_reset(cursor); if (callchain_param.order == ORDER_CALLEE) { ret = thread__resolve_callchain_sample(thread, cursor, -- cgit v1.2.3 From 935f5a9d4500020879858c9224c98dfabf16101d Mon Sep 17 00:00:00 2001 From: Jin Yao Date: Sat, 30 Dec 2017 00:26:52 +0800 Subject: perf report: Fix a wrong offset issue when using /proc/kcore When a valid vmlinux is not found, 'perf report' falls back to look at /proc/kcore. In this case, it will report the impossible large offset. For example: # perf record -b -e cycles:k find /etc/ > /dev/null # perf report --stdio --branch-history 22.77% _vm_normal_page+18446603336221188162 | ---page_remove_rmap +18446603336221188324 page_remove_rmap +18446603336221188487 (cycles:5) unlock_page_memcg +18446603336221188096 page_remove_rmap +18446603336221188327 (cycles:1) The issue is the value which is passed to parameter 'addr' in __get_srcline() is the objdump address. It's not correct if we calculate the offset by using 'addr - sym->start'. This patch creates a new parameter 'ip' in __get_srcline(). It is not converted to objdump address. With this patch, the perf report output is: 22.77% _vm_normal_page+66 | ---page_remove_rmap +228 page_remove_rmap +391 (cycles:5) unlock_page_memcg +0 page_remove_rmap +231 (cycles:1) page_remove_rmap +236 Committer testing: Make sure you get any valid vmlinux out of the way, using '-v' on the 'perf report' case and deleting it from places where perf searches them, like your kernel build dir and the build-id cache, in ~/.debug/. Reported-by: Arnaldo Carvalho de Melo Signed-off-by: Jin Yao Tested-by: Arnaldo Carvalho de Melo Cc: Alexander Shishkin Cc: Andi Kleen Cc: Jiri Olsa Cc: Kan Liang Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/1514564812-17344-1-git-send-email-yao.jin@linux.intel.com Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/machine.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'tools/perf/util/machine.c') diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c index 64d255f6a537..b05a67464c03 100644 --- a/tools/perf/util/machine.c +++ b/tools/perf/util/machine.c @@ -1726,7 +1726,7 @@ static char *callchain_srcline(struct map *map, struct symbol *sym, u64 ip) bool show_addr = callchain_param.key == CCKEY_ADDRESS; srcline = get_srcline(map->dso, map__rip_2objdump(map, ip), - sym, show_sym, show_addr); + sym, show_sym, show_addr, ip); srcline__tree_insert(&map->dso->srclines, ip, srcline); } -- cgit v1.2.3