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authorLinus Torvalds <torvalds@linux-foundation.org>2022-02-06 21:11:14 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2022-02-06 21:11:14 +0300
commitc3bf8a14408ad2b84fe48246fa66d1459480ee6b (patch)
tree1ec71866638dea3d1e4e7bdbfd9a512ecee02298
parentaeabe1e0744d1794246a909d2c042e9129fe22bd (diff)
parent1d9093457b243061a9bba23543c38726e864a643 (diff)
downloadlinux-c3bf8a14408ad2b84fe48246fa66d1459480ee6b.tar.xz
Merge tag 'perf_urgent_for_v5.17_rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf fixes from Borislav Petkov: - Intel/PT: filters could crash the kernel - Intel: default disable the PMU for SMM, some new-ish EFI firmware has started using CPL3 and the PMU CPL filters don't discriminate against SMM, meaning that CPL3 (userspace only) events now also count EFI/SMM cycles. - Fixup for perf_event_attr::sig_data * tag 'perf_urgent_for_v5.17_rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf/x86/intel/pt: Fix crash with stop filters in single-range mode perf: uapi: Document perf_event_attr::sig_data truncation on 32 bit architectures selftests/perf_events: Test modification of perf_event_attr::sig_data perf: Copy perf_event_attr::sig_data on modification x86/perf: Default set FREEZE_ON_SMI for all
-rw-r--r--arch/x86/events/intel/core.c13
-rw-r--r--arch/x86/events/intel/pt.c5
-rw-r--r--include/uapi/linux/perf_event.h2
-rw-r--r--kernel/events/core.c16
-rw-r--r--tools/testing/selftests/perf_events/sigtrap_threads.c17
5 files changed, 43 insertions, 10 deletions
diff --git a/arch/x86/events/intel/core.c b/arch/x86/events/intel/core.c
index c91434056c29..a3c7ca876aeb 100644
--- a/arch/x86/events/intel/core.c
+++ b/arch/x86/events/intel/core.c
@@ -4703,6 +4703,19 @@ static __initconst const struct x86_pmu intel_pmu = {
.lbr_read = intel_pmu_lbr_read_64,
.lbr_save = intel_pmu_lbr_save,
.lbr_restore = intel_pmu_lbr_restore,
+
+ /*
+ * SMM has access to all 4 rings and while traditionally SMM code only
+ * ran in CPL0, 2021-era firmware is starting to make use of CPL3 in SMM.
+ *
+ * Since the EVENTSEL.{USR,OS} CPL filtering makes no distinction
+ * between SMM or not, this results in what should be pure userspace
+ * counters including SMM data.
+ *
+ * This is a clear privilege issue, therefore globally disable
+ * counting SMM by default.
+ */
+ .attr_freeze_on_smi = 1,
};
static __init void intel_clovertown_quirk(void)
diff --git a/arch/x86/events/intel/pt.c b/arch/x86/events/intel/pt.c
index 7f406c14715f..2d33bba9a144 100644
--- a/arch/x86/events/intel/pt.c
+++ b/arch/x86/events/intel/pt.c
@@ -897,8 +897,9 @@ static void pt_handle_status(struct pt *pt)
* means we are already losing data; need to let the decoder
* know.
*/
- if (!intel_pt_validate_hw_cap(PT_CAP_topa_multiple_entries) ||
- buf->output_off == pt_buffer_region_size(buf)) {
+ if (!buf->single &&
+ (!intel_pt_validate_hw_cap(PT_CAP_topa_multiple_entries) ||
+ buf->output_off == pt_buffer_region_size(buf))) {
perf_aux_output_flag(&pt->handle,
PERF_AUX_FLAG_TRUNCATED);
advance++;
diff --git a/include/uapi/linux/perf_event.h b/include/uapi/linux/perf_event.h
index 1b65042ab1db..82858b697c05 100644
--- a/include/uapi/linux/perf_event.h
+++ b/include/uapi/linux/perf_event.h
@@ -465,6 +465,8 @@ struct perf_event_attr {
/*
* User provided data if sigtrap=1, passed back to user via
* siginfo_t::si_perf_data, e.g. to permit user to identify the event.
+ * Note, siginfo_t::si_perf_data is long-sized, and sig_data will be
+ * truncated accordingly on 32 bit architectures.
*/
__u64 sig_data;
};
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 76c754e45d01..57c7197838db 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -3238,6 +3238,15 @@ 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)
{
@@ -3260,10 +3269,17 @@ 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;
diff --git a/tools/testing/selftests/perf_events/sigtrap_threads.c b/tools/testing/selftests/perf_events/sigtrap_threads.c
index 8e83cf91513a..6d849dc2bee0 100644
--- a/tools/testing/selftests/perf_events/sigtrap_threads.c
+++ b/tools/testing/selftests/perf_events/sigtrap_threads.c
@@ -44,9 +44,10 @@ static struct {
} ctx;
/* Unique value to check si_perf_data is correctly set from perf_event_attr::sig_data. */
-#define TEST_SIG_DATA(addr) (~(unsigned long)(addr))
+#define TEST_SIG_DATA(addr, id) (~(unsigned long)(addr) + id)
-static struct perf_event_attr make_event_attr(bool enabled, volatile void *addr)
+static struct perf_event_attr make_event_attr(bool enabled, volatile void *addr,
+ unsigned long id)
{
struct perf_event_attr attr = {
.type = PERF_TYPE_BREAKPOINT,
@@ -60,7 +61,7 @@ static struct perf_event_attr make_event_attr(bool enabled, volatile void *addr)
.inherit_thread = 1, /* ... but only cloned with CLONE_THREAD. */
.remove_on_exec = 1, /* Required by sigtrap. */
.sigtrap = 1, /* Request synchronous SIGTRAP on event. */
- .sig_data = TEST_SIG_DATA(addr),
+ .sig_data = TEST_SIG_DATA(addr, id),
};
return attr;
}
@@ -110,7 +111,7 @@ FIXTURE(sigtrap_threads)
FIXTURE_SETUP(sigtrap_threads)
{
- struct perf_event_attr attr = make_event_attr(false, &ctx.iterate_on);
+ struct perf_event_attr attr = make_event_attr(false, &ctx.iterate_on, 0);
struct sigaction action = {};
int i;
@@ -165,7 +166,7 @@ TEST_F(sigtrap_threads, enable_event)
EXPECT_EQ(ctx.tids_want_signal, 0);
EXPECT_EQ(ctx.first_siginfo.si_addr, &ctx.iterate_on);
EXPECT_EQ(ctx.first_siginfo.si_perf_type, PERF_TYPE_BREAKPOINT);
- EXPECT_EQ(ctx.first_siginfo.si_perf_data, TEST_SIG_DATA(&ctx.iterate_on));
+ EXPECT_EQ(ctx.first_siginfo.si_perf_data, TEST_SIG_DATA(&ctx.iterate_on, 0));
/* Check enabled for parent. */
ctx.iterate_on = 0;
@@ -175,7 +176,7 @@ TEST_F(sigtrap_threads, enable_event)
/* Test that modification propagates to all inherited events. */
TEST_F(sigtrap_threads, modify_and_enable_event)
{
- struct perf_event_attr new_attr = make_event_attr(true, &ctx.iterate_on);
+ struct perf_event_attr new_attr = make_event_attr(true, &ctx.iterate_on, 42);
EXPECT_EQ(ioctl(self->fd, PERF_EVENT_IOC_MODIFY_ATTRIBUTES, &new_attr), 0);
run_test_threads(_metadata, self);
@@ -184,7 +185,7 @@ TEST_F(sigtrap_threads, modify_and_enable_event)
EXPECT_EQ(ctx.tids_want_signal, 0);
EXPECT_EQ(ctx.first_siginfo.si_addr, &ctx.iterate_on);
EXPECT_EQ(ctx.first_siginfo.si_perf_type, PERF_TYPE_BREAKPOINT);
- EXPECT_EQ(ctx.first_siginfo.si_perf_data, TEST_SIG_DATA(&ctx.iterate_on));
+ EXPECT_EQ(ctx.first_siginfo.si_perf_data, TEST_SIG_DATA(&ctx.iterate_on, 42));
/* Check enabled for parent. */
ctx.iterate_on = 0;
@@ -204,7 +205,7 @@ TEST_F(sigtrap_threads, signal_stress)
EXPECT_EQ(ctx.tids_want_signal, 0);
EXPECT_EQ(ctx.first_siginfo.si_addr, &ctx.iterate_on);
EXPECT_EQ(ctx.first_siginfo.si_perf_type, PERF_TYPE_BREAKPOINT);
- EXPECT_EQ(ctx.first_siginfo.si_perf_data, TEST_SIG_DATA(&ctx.iterate_on));
+ EXPECT_EQ(ctx.first_siginfo.si_perf_data, TEST_SIG_DATA(&ctx.iterate_on, 0));
}
TEST_HARNESS_MAIN