kernel/linux.git/tools/perf/util/parse-events.c, branch linux-7.0.y

perf parse-events: Fix big-endian 'overwrite' by writing correct union member

2026-03-17T20:16:09+00:00

The "Read backward ring buffer" test crashes on big-endian (e.g. s390x) due to a NULL dereference when the backward mmap path isn't enabled. Reproducer: # ./perf test -F 'Read backward ring buffer' Segmentation fault (core dumped) # uname -m s390x # Root cause: get_config_terms() stores into evsel_config_term::val.val (u64) while later code reads boolean fields such as evsel_config_term::val.overwrite. On big-endian the 1-byte boolean is left-aligned, so writing evsel_config_term::val.val = 1 is read back as evsel_config_term::val.overwrite = 0, leaving backward mmap disabled and a NULL map being used. Store values in the union member that matches the term type, e.g.: /* for OVERWRITE */ new_term->val.overwrite = 1; /* not new_term->val.val = 1 */ to fix this. Improve add_config_term() and add two more parameters for string and value. Function add_config_term() now creates a complete node element of type evsel_config_term and handles all evsel_config_term::val union members. Impact: Enables backward mmap on big-endian and prevents the crash. No change on little-endian. Output after: # ./perf test -Fv 44 --- start --- Using CPUID IBM,9175,705,ME1,3.8,002f mmap size 1052672B mmap size 8192B ---- end ---- 44: Read backward ring buffer : Ok # Fixes: 159ca97cd97ce8cc ("perf parse-events: Refactor get_config_terms() to remove macros") Reviewed-by: James Clark Reviewed-by: Jan Polensky Signed-off-by: Thomas Richter Acked-by: Ian Rogers Cc: James Clark Signed-off-by: Namhyung Kim Signed-off-by: Arnaldo Carvalho de Melo

perf evlist: Special map propagation for tool events that read on 1 CPU

2026-02-10T12:33:28+00:00

Tool events like duration_time don't need a perf_cpu_map that contains all online CPUs. Having such a perf_cpu_map causes overheads when iterating between events for CPU affinity. During parsing mark events that just read on a single CPU map index as such, then during map propagation set up the evsel's CPUs and thereby the evlists accordingly. The setting cannot be done early in parsing as user CPUs are only fully known when evlist__create_maps is called. Signed-off-by: Ian Rogers Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Andi Kleen Cc: Andres Freund Cc: Dapeng Mi Cc: Dr. David Alan Gilbert Cc: Ingo Molnar Cc: James Clark Cc: Jiri Olsa Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Thomas Falcon Cc: Thomas Richter Cc: Yang Li Signed-off-by: Arnaldo Carvalho de Melo

Revert "perf tool_pmu: More accurately set the cpus for tool events"

2026-02-10T12:32:34+00:00

This reverts commit d8d8a0b3603a9a8fa207cf9e4f292e81dc5d1008. The setting of a user CPU map can cause an empty intersection when combined with CPU 0 and the event removed. This later triggers a segv in the stat-shadow logic. Let's put back a full online CPU map for now by reverting this patch. Closes: https://lore.kernel.org/linux-perf-users/cgja46br2smmznxs7kbeabs6zgv3b4olfqgh2fdp5mxk2yom4v@w6jjgov6hdi6/ Reported-by: Andres Freund Signed-off-by: Ian Rogers Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Andi Kleen Cc: Dapeng Mi Cc: Dr. David Alan Gilbert Cc: Ingo Molnar Cc: James Clark Cc: Jiri Olsa Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Thomas Falcon Cc: Thomas Richter Cc: Yang Li Signed-off-by: Arnaldo Carvalho de Melo

Merge remote-tracking branch 'torvalds/master' into perf-tools-next

2026-01-26T20:03:53+00:00

Merge with upstream to pick up fixes from perf-tools and from other tools/ parts that interact with tools/perf. Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Always uniquify event names

2026-01-20T20:34:12+00:00

evlist__uniquify_evsel_names() only gets called in __parse_events() if verbose is > 0. This means that the auto added "slots" events stay as "slots" rather than being expanded to "cpu_core/slots/" unless Perf is run in verbose mode. This is invisible to users when running Perf stat because evlist__print_counters() always calls it regardless of verbose mode before displaying. The only thing this seems to affect is the test "Parsing of all PMU events from sysfs" which fails when not run in verbose mode. test__checkevent_pmu_events() always expects event names to be prefixed with the pmu name, but this only happens for "slots" events after evlist__uniquify_evsel_names() is called. One fix could be to relax the test to accept the non prefixed name in normal mode. But seeing as Perf stat uniquifies unconditionally, make parse_events() do the same. This fixes the following test failure: $ perf test "Parsing of all PMU events from sysfs" 5.2: Parsing of all PMU events from sysfs : FAILED! $ Reviewed-by: Ian Rogers Signed-off-by: James Clark Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Ingo Molnar Cc: Jiri Olsa Cc: Leo Yan Cc: Mark Rutland Cc: Namhyung Kim Cc: Peter Zijlstra Signed-off-by: Arnaldo Carvalho de Melo

perf parse-events: Always track user config changes

2026-01-15T02:15:37+00:00

Requiring the 'pmu->perf_event_attr_init_default' callback to be set to track user changes is a bit of a trap to fall in. It's hard to see that this is required when depending on the user change tracking. It's possible to want all 0 defaults so not set it, but at the same time still do some programmatic setting of configs with evsel__set_config_if_unset(). Also if a PMU reverts to 0 defaults and deletes its existing callback, it will silently break existing uses of evsel__set_config_if_unset(). One way to fix this would be to assert in evsel__set_config_if_unset() if the changes weren't tracked, but that would be a possibly untested runtime failure. Instead, always track it as it's harmless and simplifies testing too. Reviewed-by: Ian Rogers Signed-off-by: James Clark Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Ingo Molnar Cc: Jiri Olsa Cc: John Garry Cc: Leo Yan Cc: Mark Rutland Cc: Mike Leach Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Suzuki Poulouse Cc: Will Deacon Signed-off-by: Arnaldo Carvalho de Melo

perf parse-events: Track all user changed config bits

2026-01-15T02:14:54+00:00

Currently we only track which bits were set by the user in attr->config. But all configN fields should be treated equally as they can all have default and user overridden values. Track them all by making get_config_chgs() generic and calling it once for each config value. Reviewed-by: Ian Rogers Signed-off-by: James Clark Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Ingo Molnar Cc: Jiri Olsa Cc: John Garry Cc: Leo Yan Cc: Mark Rutland Cc: Mike Leach Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Suzuki Poulouse Cc: Will Deacon Signed-off-by: Arnaldo Carvalho de Melo

perf parse-events: Refactor get_config_terms() to remove macros

2026-01-15T02:13:36+00:00

The ADD_CONFIG_TERM() macros build the __type argument out of a partial EVSEL__CONFIG_TERM_x enum name. This means that they can't be called from a function where __type is a variable and it's also impossible to grep the codebase to find usages of these enums as they're never typed in full. Fix this by removing the macros and replacing them with an add_config_term() function. It seems the main reason these existed in the first place was to avoid type punning and to write to a specific field in the union, but the same thing can be achieved with a single write to a u64 'val' field. Running the Perf tests with "-fsanitize=undefined -fno-sanitize-recover" results in no new issues as a result of this change. Reviewed-by: Ian Rogers Signed-off-by: James Clark Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Ingo Molnar Cc: Jiri Olsa Cc: John Garry Cc: Leo Yan Cc: Mark Rutland Cc: Mike Leach Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Suzuki Poulouse Cc: Will Deacon Signed-off-by: Arnaldo Carvalho de Melo

perf parse-events: Fix evsel allocation failure

2026-01-06T22:54:24+00:00

If evsel__new_idx() returns NULL, the function currently jumps to label 'out_err'. Here, references to `cpus` and `pmu_cpus` are dropped. Also, resources held by evsel->name and evsel->metric_id are freed. But if evsel__new_idx() returns NULL, it can lead to NULL pointer dereference. Fixes: cd63c22168257a0b ("perf parse-events: Minor __add_event refactoring") Signed-off-by: Faisal Bukhari Reviewed-by: Arnaldo Carvalho de Melo Signed-off-by: Namhyung Kim

perf tools: Add support for perf_event_attr::config4

2025-11-24T20:20:06+00:00

perf_event_attr has gained a new field, config4, so add support for it extending the existing configN support. Reviewed-by: Leo Yan Reviewed-by: Ian Rogers Tested-by: Leo Yan Signed-off-by: James Clark Acked-by: Peter Zijlstra (Intel) Signed-off-by: Namhyung Kim