Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
Merge tag 'perf_urgent_for_v6.1_rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf fixes from Borislav Petkov:
"Two more fixes to the perf sigtrap handling:
- output the address in the sample only when it has been requested
- handle the case where user-only events can hit in kernel and thus
upset the sigtrap sanity checking"
* tag 'perf_urgent_for_v6.1_rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf: Consider OS filter fail
perf: Fixup SIGTRAP and sample_flags interaction
+25
-2
+25
-2
kernel/events/core.c
+25
-2
kernel/events/core.c
···
9273
9273
return __perf_event_account_interrupt(event, 1);
9274
9274
}
9275
9275
9276
+
static inline bool sample_is_allowed(struct perf_event *event, struct pt_regs *regs)
9277
+
{
9278
+
/*
9279
+
* Due to interrupt latency (AKA "skid"), we may enter the
9280
+
* kernel before taking an overflow, even if the PMU is only
9281
+
* counting user events.
9282
+
*/
9283
+
if (event->attr.exclude_kernel && !user_mode(regs))
9284
+
return false;
9285
+
9286
+
return true;
9287
+
}
9288
+
9276
9289
/*
9277
9290
* Generic event overflow handling, sampling.
9278
9291
*/
···
9319
9306
}
9320
9307
9321
9308
if (event->attr.sigtrap) {
9309
+
/*
9310
+
* The desired behaviour of sigtrap vs invalid samples is a bit
9311
+
* tricky; on the one hand, one should not loose the SIGTRAP if
9312
+
* it is the first event, on the other hand, we should also not
9313
+
* trigger the WARN or override the data address.
9314
+
*/
9315
+
bool valid_sample = sample_is_allowed(event, regs);
9322
9316
unsigned int pending_id = 1;
9323
9317
9324
9318
if (regs)
···
9333
9313
if (!event->pending_sigtrap) {
9334
9314
event->pending_sigtrap = pending_id;
9335
9315
local_inc(&event->ctx->nr_pending);
9336
-
} else if (event->attr.exclude_kernel) {
9316
+
} else if (event->attr.exclude_kernel && valid_sample) {
9337
9317
/*
9338
9318
* Should not be able to return to user space without
9339
9319
* consuming pending_sigtrap; with exceptions:
···
9348
9328
*/
9349
9329
WARN_ON_ONCE(event->pending_sigtrap != pending_id);
9350
9330
}
9351
-
event->pending_addr = data->addr;
9331
+
9332
+
event->pending_addr = 0;
9333
+
if (valid_sample && (data->sample_flags & PERF_SAMPLE_ADDR))
9334
+
event->pending_addr = data->addr;
9352
9335
irq_work_queue(&event->pending_irq);
9353
9336
}
9354
9337