diff options
| author | Marco Elver <elver@google.com> | 2022-01-31 13:34:05 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-02-08 20:34:12 +0300 |
| commit | 64e133ce280b78b3d42d45d348484ac3fe0eb7e5 (patch) | |
| tree | 9e62f16881d092241d32db45c7594f8748826edc /kernel/events | |
| parent | 9a60e92b76d67cdbf9d427dbd3a0c860eaebcab1 (diff) | |
| download | linux-64e133ce280b78b3d42d45d348484ac3fe0eb7e5.tar.xz | |
perf: Copy perf_event_attr::sig_data on modification
[ Upstream commit 3c25fc97f5590060464cabfa25710970ecddbc96 ]
The intent has always been that perf_event_attr::sig_data should also be
modifiable along with PERF_EVENT_IOC_MODIFY_ATTRIBUTES, because it is
observable by user space if SIGTRAP on events is requested.
Currently only PERF_TYPE_BREAKPOINT is modifiable, and explicitly copies
relevant breakpoint-related attributes in hw_breakpoint_copy_attr().
This misses copying perf_event_attr::sig_data.
Since sig_data is not specific to PERF_TYPE_BREAKPOINT, introduce a
helper to copy generic event-type-independent attributes on
modification.
Fixes: 97ba62b27867 ("perf: Add support for SIGTRAP on perf events")
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Link: https://lore.kernel.org/r/20220131103407.1971678-1-elver@google.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'kernel/events')
| -rw-r--r-- | kernel/events/core.c | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c index c7581e3fb8ab..69c70767b5df 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -3234,6 +3234,15 @@ static int perf_event_modify_breakpoint(struct perf_event *bp, return err; } +/* + * Copy event-type-independent attributes that may be modified. + */ +static void perf_event_modify_copy_attr(struct perf_event_attr *to, + const struct perf_event_attr *from) +{ + to->sig_data = from->sig_data; +} + static int perf_event_modify_attr(struct perf_event *event, struct perf_event_attr *attr) { @@ -3256,10 +3265,17 @@ static int perf_event_modify_attr(struct perf_event *event, WARN_ON_ONCE(event->ctx->parent_ctx); mutex_lock(&event->child_mutex); + /* + * Event-type-independent attributes must be copied before event-type + * modification, which will validate that final attributes match the + * source attributes after all relevant attributes have been copied. + */ + perf_event_modify_copy_attr(&event->attr, attr); err = func(event, attr); if (err) goto out; list_for_each_entry(child, &event->child_list, child_list) { + perf_event_modify_copy_attr(&child->attr, attr); err = func(child, attr); if (err) goto out; |