With 0dd5041c9a ("perf addr_location: Add init/exit/copy functions"),
when cpumode is 3 (macro PERF_RECORD_MISC_HYPERVISOR),
thread__find_map() could return with al->maps being NULL.
The path below could add a callchain_cursor_node with NULL ms.maps.
add_callchain_ip()
thread__find_symbol(.., &al)
thread__find_map(.., &al) // al->maps becomes NULL
ms.maps = maps__get(al.maps)
callchain_cursor_append(..., &ms, ...)
node->ms.maps = maps__get(ms->maps)
Then the path below would dereference NULL maps and get segfault.
fill_callchain_info()
maps__machine(node->ms.maps);
Fix it by checking if maps is NULL in fill_callchain_info().
Fixes: 0dd5041c9a ("perf addr_location: Add init/exit/copy functions")
Signed-off-by: Casey Chen <cachen@purestorage.com>
Reviewed-by: Ian Rogers <irogers@google.com>
Reviewed-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: yzhong@purestorage.com
Link: https://lore.kernel.org/r/20240722211548.61455-1-cachen@purestorage.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
4c17736689