kernel.git/tools/perf/builtin-trace.c, branch linux-5.10.y

perf trace: Fix runtime error of index out of bounds

2025-03-13T11:46:58Z

[ Upstream commit c7b87ce0dd10b64b68a0b22cb83bbd556e28fe81 ] libtraceevent parses and returns an array of argument fields, sometimes larger than RAW_SYSCALL_ARGS_NUM (6) because it includes "__syscall_nr", idx will traverse to index 6 (7th element) whereas sc->fmt->arg holds 6 elements max, creating an out-of-bounds access. This runtime error is found by UBsan. The error message: $ sudo UBSAN_OPTIONS=print_stacktrace=1 ./perf trace -a --max-events=1 builtin-trace.c:1966:35: runtime error: index 6 out of bounds for type 'syscall_arg_fmt [6]' #0 0x5c04956be5fe in syscall__alloc_arg_fmts /home/howard/hw/linux-perf/tools/perf/builtin-trace.c:1966 #1 0x5c04956c0510 in trace__read_syscall_info /home/howard/hw/linux-perf/tools/perf/builtin-trace.c:2110 #2 0x5c04956c372b in trace__syscall_info /home/howard/hw/linux-perf/tools/perf/builtin-trace.c:2436 #3 0x5c04956d2f39 in trace__init_syscalls_bpf_prog_array_maps /home/howard/hw/linux-perf/tools/perf/builtin-trace.c:3897 #4 0x5c04956d6d25 in trace__run /home/howard/hw/linux-perf/tools/perf/builtin-trace.c:4335 #5 0x5c04956e112e in cmd_trace /home/howard/hw/linux-perf/tools/perf/builtin-trace.c:5502 #6 0x5c04956eda7d in run_builtin /home/howard/hw/linux-perf/tools/perf/perf.c:351 #7 0x5c04956ee0a8 in handle_internal_command /home/howard/hw/linux-perf/tools/perf/perf.c:404 #8 0x5c04956ee37f in run_argv /home/howard/hw/linux-perf/tools/perf/perf.c:448 #9 0x5c04956ee8e9 in main /home/howard/hw/linux-perf/tools/perf/perf.c:556 #10 0x79eb3622a3b7 in __libc_start_call_main ../sysdeps/nptl/libc_start_call_main.h:58 #11 0x79eb3622a47a in __libc_start_main_impl ../csu/libc-start.c:360 #12 0x5c04955422d4 in _start (/home/howard/hw/linux-perf/tools/perf/perf+0x4e02d4) (BuildId: 5b6cab2d59e96a4341741765ad6914a4d784dbc6) 0.000 ( 0.014 ms): Chrome_ChildIO/117244 write(fd: 238, buf: !, count: 1) = 1 Fixes: 5e58fcfaf4c6 ("perf trace: Allow allocating sc->arg_fmt even without the syscall tracepoint") Signed-off-by: Howard Chu Link: https://lore.kernel.org/r/20250122025519.361873-1-howardchu95@gmail.com Signed-off-by: Namhyung Kim Signed-off-by: Sasha Levin

perf trace: Avoid garbage when not printing a syscall's arguments

2024-12-14T18:48:02Z

[ Upstream commit 1302e352b26f34991b619b5d0b621b76d20a3883 ] syscall__scnprintf_args may not place anything in the output buffer (e.g., because the arguments are all zero). If that happened in trace__fprintf_sys_enter, its fprintf would receive an unitialized buffer leading to garbage output. Fix the problem by passing the (possibly zero) bounds of the argument buffer to the output fprintf. Fixes: a98392bb1e169a04 ("perf trace: Use beautifiers on syscalls:sys_enter_ handlers") Signed-off-by: Benjamin Peterson Tested-by: Arnaldo Carvalho de Melo Tested-by: Howard Chu Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Ian Rogers Cc: Ingo Molnar Cc: Jiri Olsa Cc: Kan Liang Cc: Mark Rutland Cc: Namhyung Kim Cc: Peter Zijlstra Link: https://lore.kernel.org/r/20241107232128.108981-2-benjamin@engflow.com Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Sasha Levin

perf trace: Do not lose last events in a race

2024-12-14T18:48:02Z

[ Upstream commit 3fd7c36973a250e17a4ee305a31545a9426021f4 ] If a perf trace event selector specifies a maximum number of events to output (i.e., "/nr=N/" syntax), the event printing handler, trace__event_handler, disables the event selector after the maximum number events are printed. Furthermore, trace__event_handler checked if the event selector was disabled before doing any work. This avoided exceeding the maximum number of events to print if more events were in the buffer before the selector was disabled. However, the event selector can be disabled for reasons other than exceeding the maximum number of events. In particular, when the traced subprocess exits, the main loop disables all event selectors. This meant the last events of a traced subprocess might be lost to the printing handler's short-circuiting logic. This nondeterministic problem could be seen by running the following many times: $ perf trace -e syscalls:sys_enter_exit_group true trace__event_handler should simply check for exceeding the maximum number of events to print rather than the state of the event selector. Fixes: a9c5e6c1e9bff42c ("perf trace: Introduce per-event maximum number of events property") Signed-off-by: Benjamin Peterson Tested-by: Howard Chu Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Ian Rogers Cc: Ingo Molnar Cc: Jiri Olsa Cc: Kan Liang Cc: Mark Rutland Cc: Namhyung Kim Cc: Peter Zijlstra Link: https://lore.kernel.org/r/20241107232128.108981-1-benjamin@engflow.com Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Sasha Levin

perf trace: avoid garbage when not printing a trace event's arguments

2024-12-14T18:48:02Z

[ Upstream commit 5fb8e56542a3cf469fdf25d77f50e21cbff3ae7e ] trace__fprintf_tp_fields may not print any tracepoint arguments. E.g., if the argument values are all zero. Previously, this would result in a totally uninitialized buffer being passed to fprintf, which could lead to garbage on the console. Fix the problem by passing the number of initialized bytes fprintf. Fixes: f11b2803bb88 ("perf trace: Allow choosing how to augment the tracepoint arguments") Signed-off-by: Benjamin Peterson Tested-by: Howard Chu Tested-by: Arnaldo Carvalho de Melo Link: https://lore.kernel.org/r/20241103204816.7834-1-benjamin@engflow.com Signed-off-by: Namhyung Kim Signed-off-by: Sasha Levin

perf trace: Handle failure when trace point folder is missed

2023-01-14T09:16:02Z

[ Upstream commit 03e9a5d8eb552a1bf692a9c8a5ecd50f4e428006 ] On Arm64 a case is perf tools fails to find the corresponding trace point folder for system calls listed in the table 'syscalltbl_arm64', e.g. the generated system call table contains "lookup_dcookie" but we cannot find out the matched trace point folder for it. We need to figure out if there have any issue for the generated system call table, on the other hand, we need to handle the case when trace point folder is missed under sysfs, this patch sets the flag syscall::nonexistent as true and returns the error from trace__read_syscall_info(). Another problem is for trace__syscall_info(), it returns two different values if a system call doesn't exist: at the first time calling trace__syscall_info() it returns NULL when the system call doesn't exist, later if call trace__syscall_info() again for the same missed system call, it returns pointer of syscall. trace__syscall_info() checks the condition 'syscalls.table[id].name == NULL', but the name will be assigned in the first invoking even the system call is not found. So checking system call's name in trace__syscall_info() is not the right thing to do, this patch simply checks flag syscall::nonexistent to make decision if a system call exists or not, finally trace__syscall_info() returns the consistent result (NULL) if a system call doesn't existed. Fixes: b8b1033fcaa091d8 ("perf trace: Mark syscall ids that are not allocated to avoid unnecessary error messages") Signed-off-by: Leo Yan Acked-by: Ian Rogers Cc: Alexander Shishkin Cc: bpf@vger.kernel.org Cc: Ingo Molnar Cc: Jiri Olsa Cc: Mark Rutland Cc: Namhyung Kim Cc: Peter Zijlstra Link: https://lore.kernel.org/r/20221121075237.127706-4-leo.yan@linaro.org Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Sasha Levin

perf trace: Use macro RAW_SYSCALL_ARGS_NUM to replace number

2023-01-14T09:16:02Z

[ Upstream commit eadcab4c7a66e1df03d32da0db55d89fd9343fcc ] This patch defines a macro RAW_SYSCALL_ARGS_NUM to replace the open coded number '6'. Signed-off-by: Leo Yan Acked-by: Ian Rogers Cc: Alexander Shishkin Cc: Ingo Molnar Cc: Jiri Olsa Cc: Mark Rutland Cc: Namhyung Kim Cc: Peter Zijlstra Cc: bpf@vger.kernel.org Link: https://lore.kernel.org/r/20221121075237.127706-2-leo.yan@linaro.org Signed-off-by: Arnaldo Carvalho de Melo Stable-dep-of: 03e9a5d8eb55 ("perf trace: Handle failure when trace point folder is missed") Signed-off-by: Sasha Levin

perf trace: Return error if a system call doesn't exist

2023-01-14T09:16:02Z

[ Upstream commit d4223e1776c30b2ce8d0e6eaadcbf696e60fca3c ] When a system call is not detected, the reason is either because the system call ID is out of scope or failure to find the corresponding path in the sysfs, trace__read_syscall_info() returns zero. Finally, without returning an error value it introduces confusion for the caller. This patch lets the function trace__read_syscall_info() to return -EEXIST when a system call doesn't exist. Fixes: b8b1033fcaa091d8 ("perf trace: Mark syscall ids that are not allocated to avoid unnecessary error messages") Signed-off-by: Leo Yan Acked-by: Ian Rogers Cc: Alexander Shishkin Cc: bpf@vger.kernel.org Cc: Ingo Molnar Cc: Jiri Olsa Cc: Mark Rutland Cc: Namhyung Kim Cc: Peter Zijlstra Link: https://lore.kernel.org/r/20221121075237.127706-3-leo.yan@linaro.org Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Sasha Levin

perf trace: Fix segfault when trying to trace events by cgroup

2020-11-03T11:31:03Z

# ./perf trace -e sched:sched_switch -G test -a sleep 1 perf: Segmentation fault Obtained 11 stack frames. ./perf(sighandler_dump_stack+0x43) [0x55cfdc636db3] /lib/x86_64-linux-gnu/libc.so.6(+0x3efcf) [0x7fd23eecafcf] ./perf(parse_cgroups+0x36) [0x55cfdc673f36] ./perf(+0x3186ed) [0x55cfdc70d6ed] ./perf(parse_options_subcommand+0x629) [0x55cfdc70e999] ./perf(cmd_trace+0x9c2) [0x55cfdc5ad6d2] ./perf(+0x1e8ae0) [0x55cfdc5ddae0] ./perf(+0x1e8ded) [0x55cfdc5ddded] ./perf(main+0x370) [0x55cfdc556f00] /lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0xe6) [0x7fd23eeadb96] ./perf(_start+0x29) [0x55cfdc557389] Segmentation fault # It happens because "struct trace" in option->value is passed to the parse_cgroups function instead of "struct evlist". Fixes: 9ea42ba4411ac ("perf trace: Support setting cgroups as targets") Signed-off-by: Stanislav Ivanichkin Tested-by: Arnaldo Carvalho de Melo Acked-by: Namhyung Kim Cc: Dmitry Monakhov Link: http://lore.kernel.org/lkml/20201027094357.94881-1-sivanichkin@yandex-team.ru Signed-off-by: Arnaldo Carvalho de Melo

perf trace: Fix off by ones in memset() after realloc() in arches using libaudit

2020-10-13T16:57:41Z

'perf trace ls' started crashing after commit d21cb73a9025 on !HAVE_SYSCALL_TABLE_SUPPORT configs (armv7l here) like this: 0 strlen () at ../sysdeps/arm/armv6t2/strlen.S:126 1 0xb6800780 in __vfprintf_internal (s=0xbeff9908, s@entry=0xbeff9900, format=0xa27160 "]: %s()", ap=..., mode_flags=) at vfprintf-internal.c:1688 ... 5 0x0056ecdc in fprintf (__fmt=0xa27160 "]: %s()", __stream=) at /usr/include/bits/stdio2.h:100 6 trace__sys_exit (trace=trace@entry=0xbeffc710, evsel=evsel@entry=0xd968d0, event=, sample=sample@entry=0xbeffc3e8) at builtin-trace.c:2475 7 0x00566d40 in trace__handle_event (sample=0xbeffc3e8, event=, trace=0xbeffc710) at builtin-trace.c:3122 ... 15 main (argc=2, argv=0xbefff6e8) at perf.c:538 It is because memset in trace__read_syscall_info zeroes wrong memory: 1) when initializing for the first time, it does not reset the last id. 2) in other cases, it resets the last id of previous buffer. ad 1) it causes the crash above as sc->name used in the fprintf above contains garbage. ad 2) it sets nonexistent from true back to false for id 11 here. Not sure, what the consequences are. So fix it by introducing a special case for the initial initialization and do the right +1 in both cases. Fixes: d21cb73a9025 ("perf trace: Grow the syscall table as needed when using libaudit") Signed-off-by: Jiri Slaby Cc: Adrian Hunter Cc: Jiri Olsa Cc: Namhyung Kim Cc: Peter Zijlstra Link: http://lore.kernel.org/lkml/20201001093419.15761-1-jslaby@suse.cz Signed-off-by: Arnaldo Carvalho de Melo

perf record: Extend -D,--delay option with -1 value

2020-08-04T11:50:04Z

Extend -D,--delay option with -1 to start collection with events disabled to be enabled later by 'enable' command provided via control file descriptor. Signed-off-by: Alexey Budankov Acked-by: Jiri Olsa Acked-by: Namhyung Kim Cc: Alexander Shishkin Cc: Andi Kleen Cc: Peter Zijlstra Link: http://lore.kernel.org/lkml/3e7d362c-7973-ee5d-e81e-c60ea22432c3@linux.intel.com Signed-off-by: Arnaldo Carvalho de Melo