[PATCH RFC v2 6/8] perf/core: Add breakpoint information to siginfo on SIGTRAP
From: Marco Elver <elver@google.com>
Date: 2021-03-10 10:42:59
Also in:
linux-fsdevel, linux-kselftest, lkml
Subsystem:
performance events subsystem, the rest · Maintainers:
Peter Zijlstra, Ingo Molnar, Arnaldo Carvalho de Melo, Namhyung Kim, Linus Torvalds
Encode information from breakpoint attributes into siginfo_t, which helps disambiguate which breakpoint fired. Note, providing the event fd may be unreliable, since the event may have been modified (via PERF_EVENT_IOC_MODIFY_ATTRIBUTES) between the event triggering and the signal being delivered to user space. Signed-off-by: Marco Elver <elver@google.com> --- v2: * Add comment about si_perf==0. --- kernel/events/core.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+)
diff --git a/kernel/events/core.c b/kernel/events/core.c
index e70c411b0b16..aa47e111435e 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c@@ -6336,6 +6336,22 @@ static void perf_sigtrap(struct perf_event *event) info.si_signo = SIGTRAP; info.si_code = TRAP_PERF; info.si_errno = event->attr.type; + + switch (event->attr.type) { + case PERF_TYPE_BREAKPOINT: + info.si_addr = (void *)(unsigned long)event->attr.bp_addr; + info.si_perf = (event->attr.bp_len << 16) | (u64)event->attr.bp_type; + break; + default: + /* + * No additional info set (si_perf == 0). + * + * Adding new cases for event types to set si_perf to a + * non-constant value must ensure that si_perf != 0. + */ + break; + } + force_sig_info(&info); }
--
2.30.1.766.gb4fecdf3b7-goog