From 341e0e9f59e26676c88d0aa9a5a9b2d3c44bf21c Mon Sep 17 00:00:00 2001 From: Athira Rajeev Date: Mon, 24 Jul 2023 22:28:15 +0530 Subject: [PATCH] perf callchain powerpc: Fix addr location init during arch_skip_callchain_idx function 'perf record; with callchain recording fails as below in powerpc: ./perf record -a -gR sleep 10 ./perf report perf: Segmentation fault gdb trace points to thread__find_map 0 0x00000000101df314 in atomic_cmpxchg (newval=1818846826, oldval=1818846827, v=0x1001a8f3) at /home/athira/linux/tools/include/asm-generic/atomic-gcc.h:70 1 refcount_sub_and_test (i=1, r=0x1001a8f3) at /home/athira/linux/tools/include/linux/refcount.h:135 2 refcount_dec_and_test (r=0x1001a8f3) at /home/athira/linux/tools/include/linux/refcount.h:148 3 map__put (map=0x1001a8b3) at util/map.c:311 4 0x000000001016842c in __map__zput (map=0x7fffffffa368) at util/map.h:190 5 thread__find_map (thread=0x105b92f0, cpumode=, addr=13835058055283572736, al=al@entry=0x7fffffffa358) at util/event.c:582 6 0x000000001016882c in thread__find_symbol (thread=, cpumode=, addr=, al=0x7fffffffa358) at util/event.c:656 7 0x00000000102e12b4 in arch_skip_callchain_idx (thread=, chain=) at arch/powerpc/util/skip-callchain-idx.c:255 8 0x00000000101d3bf4 in thread__resolve_callchain_sample (thread=0x105b92f0, cursor=0x1053d160, evsel=, sample=0x7fffffffa908, parent=0x7fffffffa778, root_al=0x7fffffffa710, max_stack=) at util/machine.c:2940 9 0x00000000101cd210 in sample__resolve_callchain (sample=, cursor=, parent=, evsel=, al=, max_stack=) at util/callchain.c:1112 10 0x000000001022a9d8 in hist_entry_iter__add (iter=0x7fffffffa750, al=0x7fffffffa710, max_stack_depth=, arg=0x7fffffffbbd0) at util/hist.c:1232 11 0x0000000010056d98 in process_sample_event (tool=0x7fffffffbbd0, event=0x7ffff6223c38, sample=0x7fffffffa908, evsel=, machine=0x10524ef8) at builtin-report.c:332 Here arch_skip_callchain_idx calls thread__find_symbol and which invokes thread__find_map with uninitialised "addr_location". Snippet: thread__find_symbol(thread, PERF_RECORD_MISC_USER, ip, &al); Recent change with commit 0dd5041c9a0eaf8c ("perf addr_location: Add init/exit/copy functions") , introduced "maps__zput" in the function thread__find_map. This could result in segfault while accessing uninitialised map from "struct addr_location". Fix this by adding addr_location__init and addr_location__exit in arch_skip_callchain_idx. Fixes: 0dd5041c9a0eaf8c ("perf addr_location: Add init/exit/copy functions") Reported-by: Aneesh Kumar K.V Signed-off-by: Athira Rajeev Cc: Disha Goel Cc: Ian Rogers Cc: Jiri Olsa Cc: Kajol Jain Cc: Madhavan Srinivasan Cc: Namhyung Kim Cc: linuxppc-dev@lists.ozlabs.org Link: https://lore.kernel.org/r/20230724165815.17810-1-atrajeev@linux.vnet.ibm.com Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/arch/powerpc/util/skip-callchain-idx.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/tools/perf/arch/powerpc/util/skip-callchain-idx.c b/tools/perf/arch/powerpc/util/skip-callchain-idx.c index b7223feec770..5f3edb3004d8 100644 --- a/tools/perf/arch/powerpc/util/skip-callchain-idx.c +++ b/tools/perf/arch/powerpc/util/skip-callchain-idx.c @@ -250,6 +250,7 @@ int arch_skip_callchain_idx(struct thread *thread, struct ip_callchain *chain) if (!chain || chain->nr < 3) return skip_slot; + addr_location__init(&al); ip = chain->ips[1]; thread__find_symbol(thread, PERF_RECORD_MISC_USER, ip, &al); @@ -259,6 +260,7 @@ int arch_skip_callchain_idx(struct thread *thread, struct ip_callchain *chain) if (!dso) { pr_debug("%" PRIx64 " dso is NULL\n", ip); + addr_location__exit(&al); return skip_slot; } @@ -279,5 +281,7 @@ int arch_skip_callchain_idx(struct thread *thread, struct ip_callchain *chain) */ skip_slot = 3; } + + addr_location__exit(&al); return skip_slot; }