Exercise various mmap(), munmap() and mremap() invocations, which might
cause a perf buffer mapping to be split or truncated.
To avoid hard coding the perf event and having dependencies on
architectures and configuration options, scan through event types in sysfs
and try to open them. On success, try to mmap() and if that succeeds try to
mmap() the AUX buffer.
In case that no AUX buffer supporting event is found, only test the base
buffer mapping. If no mappable event is found or permissions are not
sufficient, skip the tests.
Reserve a PROT_NONE region for both rb and aux tests to allow testing the
case where mremap unmaps beyond the end of a mapped VMA to prevent it from
unmapping unrelated mappings.
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Co-developed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Add a kselftest for testing process-wide perf events with synchronous
SIGTRAP on events (using breakpoints). In particular, we want to test
that changes to the event propagate to all children, and the SIGTRAPs
are in fact synchronously sent to the thread where the event occurred.
Note: The "signal_stress" test case is also added later in the series to
perf tool's built-in tests. The test here is more elaborate in that
respect, which on one hand avoids bloating the perf tool unnecessarily,
but we also benefit from structured tests with TAP-compliant output that
the kselftest framework provides.
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20210408103605.1676875-8-elver@google.com
