Merge tag 'perf-core-2022-05-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull perf events updates from Ingo Molnar:
 "Platform PMU changes:

   - x86/intel:
      - Add new Intel Alder Lake and Raptor Lake support

   - x86/amd:
      - AMD Zen4 IBS extensions support
      - Add AMD PerfMonV2 support
      - Add AMD Fam19h Branch Sampling support

  Generic changes:

   - signal: Deliver SIGTRAP on perf event asynchronously if blocked

     Perf instrumentation can be driven via SIGTRAP, but this causes a
     problem when SIGTRAP is blocked by a task & terminate the task.

     Allow user-space to request these signals asynchronously (after
     they get unblocked) & also give the information to the signal
     handler when this happens:

       "To give user space the ability to clearly distinguish
        synchronous from asynchronous signals, introduce
        siginfo_t::si_perf_flags and TRAP_PERF_FLAG_ASYNC (opted for
        flags in case more binary information is required in future).

        The resolution to the problem is then to (a) no longer force the
        signal (avoiding the terminations), but (b) tell user space via
        si_perf_flags if the signal was synchronous or not, so that such
        signals can be handled differently (e.g. let user space decide
        to ignore or consider the data imprecise). "

   - Unify/standardize the /sys/devices/cpu/events/* output format.

   - Misc fixes & cleanups"

* tag 'perf-core-2022-05-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (32 commits)
  perf/x86/amd/core: Fix reloading events for SVM
  perf/x86/amd: Run AMD BRS code only on supported hw
  perf/x86/amd: Fix AMD BRS period adjustment
  perf/x86/amd: Remove unused variable 'hwc'
  perf/ibs: Fix comment
  perf/amd/ibs: Advertise zen4_ibs_extensions as pmu capability attribute
  perf/amd/ibs: Add support for L3 miss filtering
  perf/amd/ibs: Use ->is_visible callback for dynamic attributes
  perf/amd/ibs: Cascade pmu init functions' return value
  perf/x86/uncore: Add new Alder Lake and Raptor Lake support
  perf/x86/uncore: Clean up uncore_pci_ids[]
  perf/x86/cstate: Add new Alder Lake and Raptor Lake support
  perf/x86/msr: Add new Alder Lake and Raptor Lake support
  perf/x86: Add new Alder Lake and Raptor Lake support
  perf/amd/ibs: Use interrupt regs ip for stack unwinding
  perf/x86/amd/core: Add PerfMonV2 overflow handling
  perf/x86/amd/core: Add PerfMonV2 counter control
  perf/x86/amd/core: Detect available counters
  perf/x86/amd/core: Detect PerfMonV2 support
  x86/msr: Add PerfCntrGlobal* registers
  ...

2 files changed, 18 insertions, 4 deletions

diff --git a/kernel/events/core.c b/kernel/events/core.c
index 7f1e4c5897e7..950b25c3f210 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -6428,8 +6428,8 @@ static void perf_sigtrap(struct perf_event *event)
 	if (current->flags & PF_EXITING)
 		return;
 
-	force_sig_perf((void __user *)event->pending_addr,
-		       event->attr.type, event->attr.sig_data);
+	send_sig_perf((void __user *)event->pending_addr,
+		      event->attr.type, event->attr.sig_data);
 }
 
 static void perf_pending_event_disable(struct perf_event *event)
diff --git a/kernel/signal.c b/kernel/signal.c
index 30cd1ca43bcd..e43bc2a692f5 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -1805,7 +1805,7 @@ int force_sig_pkuerr(void __user *addr, u32 pkey)
 }
 #endif
 
-int force_sig_perf(void __user *addr, u32 type, u64 sig_data)
+int send_sig_perf(void __user *addr, u32 type, u64 sig_data)
 {
 	struct kernel_siginfo info;
 
@@ -1817,7 +1817,18 @@ int force_sig_perf(void __user *addr, u32 type, u64 sig_data)
 	info.si_perf_data = sig_data;
 	info.si_perf_type = type;
 
-	return force_sig_info(&info);
+	/*
+	 * Signals generated by perf events should not terminate the whole
+	 * process if SIGTRAP is blocked, however, delivering the signal
+	 * asynchronously is better than not delivering at all. But tell user
+	 * space if the signal was asynchronous, so it can clearly be
+	 * distinguished from normal synchronous ones.
+	 */
+	info.si_perf_flags = sigismember(&current->blocked, info.si_signo) ?
+				     TRAP_PERF_FLAG_ASYNC :
+				     0;
+
+	return send_sig_info(info.si_signo, &info, current);
 }
 
 /**
@@ -3432,6 +3443,7 @@ void copy_siginfo_to_external32(struct compat_siginfo *to,
 		to->si_addr = ptr_to_compat(from->si_addr);
 		to->si_perf_data = from->si_perf_data;
 		to->si_perf_type = from->si_perf_type;
+		to->si_perf_flags = from->si_perf_flags;
 		break;
 	case SIL_CHLD:
 		to->si_pid = from->si_pid;
@@ -3509,6 +3521,7 @@ static int post_copy_siginfo_from_user32(kernel_siginfo_t *to,
 		to->si_addr = compat_ptr(from->si_addr);
 		to->si_perf_data = from->si_perf_data;
 		to->si_perf_type = from->si_perf_type;
+		to->si_perf_flags = from->si_perf_flags;
 		break;
 	case SIL_CHLD:
 		to->si_pid    = from->si_pid;
@@ -4722,6 +4735,7 @@ static inline void siginfo_buildtime_checks(void)
 	CHECK_OFFSET(si_pkey);
 	CHECK_OFFSET(si_perf_data);
 	CHECK_OFFSET(si_perf_type);
+	CHECK_OFFSET(si_perf_flags);
 
 	/* sigpoll */
 	CHECK_OFFSET(si_band);