Performance events changes for v6.19:

Callchain support:
 
  - Add support for deferred user-space stack unwinding for
    perf, enabled on x86. (Peter Zijlstra, Steven Rostedt)
 
  - unwind_user/x86: Enable frame pointer unwinding on x86
    (Josh Poimboeuf)
 
 x86 PMU support and infrastructure:
 
  - x86/insn: Simplify for_each_insn_prefix() (Peter Zijlstra)
 
  - x86/insn,uprobes,alternative: Unify insn_is_nop()
    (Peter Zijlstra)
 
 Intel PMU driver:
 
  - Large series to prepare for and implement architectural PEBS
    support for Intel platforms such as Clearwater Forest (CWF)
    and Panther Lake (PTL). (Dapeng Mi, Kan Liang)
 
  - Check dynamic constraints (Kan Liang)
 
  - Optimize PEBS extended config (Peter Zijlstra)
 
  - cstates: Remove PC3 support from LunarLake (Zhang Rui)
 
  - cstates: Add Pantherlake support (Zhang Rui)
 
  - cstates: Clearwater Forest support (Zide Chen)
 
 AMD PMU driver:
 
  - x86/amd: Check event before enable to avoid GPF (George Kennedy)
 
 Fixes and cleanups:
 
  - task_work: Fix NMI race condition (Peter Zijlstra)
 
  - perf/x86: Fix NULL event access and potential PEBS record loss
    (Dapeng Mi)
 
  - Misc other fixes and cleanups.
    (Dapeng Mi, Ingo Molnar, Peter Zijlstra)
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'perf-core-2025-12-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull performance events updates from Ingo Molnar:
 "Callchain support:

   - Add support for deferred user-space stack unwinding for perf,
     enabled on x86. (Peter Zijlstra, Steven Rostedt)

   - unwind_user/x86: Enable frame pointer unwinding on x86 (Josh
     Poimboeuf)

  x86 PMU support and infrastructure:

   - x86/insn: Simplify for_each_insn_prefix() (Peter Zijlstra)

   - x86/insn,uprobes,alternative: Unify insn_is_nop() (Peter Zijlstra)

  Intel PMU driver:

   - Large series to prepare for and implement architectural PEBS
     support for Intel platforms such as Clearwater Forest (CWF) and
     Panther Lake (PTL). (Dapeng Mi, Kan Liang)

   - Check dynamic constraints (Kan Liang)

   - Optimize PEBS extended config (Peter Zijlstra)

   - cstates:
      - Remove PC3 support from LunarLake (Zhang Rui)
      - Add Pantherlake support (Zhang Rui)
      - Clearwater Forest support (Zide Chen)

  AMD PMU driver:

   - x86/amd: Check event before enable to avoid GPF (George Kennedy)

  Fixes and cleanups:

   - task_work: Fix NMI race condition (Peter Zijlstra)

   - perf/x86: Fix NULL event access and potential PEBS record loss
     (Dapeng Mi)

   - Misc other fixes and cleanups (Dapeng Mi, Ingo Molnar, Peter
     Zijlstra)"

* tag 'perf-core-2025-12-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (38 commits)
  perf/x86/intel: Fix and clean up intel_pmu_drain_arch_pebs() type use
  perf/x86/intel: Optimize PEBS extended config
  perf/x86/intel: Check PEBS dyn_constraints
  perf/x86/intel: Add a check for dynamic constraints
  perf/x86/intel: Add counter group support for arch-PEBS
  perf/x86/intel: Setup PEBS data configuration and enable legacy groups
  perf/x86/intel: Update dyn_constraint base on PEBS event precise level
  perf/x86/intel: Allocate arch-PEBS buffer and initialize PEBS_BASE MSR
  perf/x86/intel: Process arch-PEBS records or record fragments
  perf/x86/intel/ds: Factor out PEBS group processing code to functions
  perf/x86/intel/ds: Factor out PEBS record processing code to functions
  perf/x86/intel: Initialize architectural PEBS
  perf/x86/intel: Correct large PEBS flag check
  perf/x86/intel: Replace x86_pmu.drain_pebs calling with static call
  perf/x86: Fix NULL event access and potential PEBS record loss
  perf/x86: Remove redundant is_x86_event() prototype
  entry,unwind/deferred: Fix unwind_reset_info() placement
  unwind_user/x86: Fix arch=um build
  perf: Support deferred user unwind
  unwind_user/x86: Teach FP unwind about start of function
  ...

arch/x86/Kconfig

@@ -298,6 +298,7 @@ config X86
 	select HAVE_SYSCALL_TRACEPOINTS
 	select HAVE_UACCESS_VALIDATION		if HAVE_OBJTOOL
 	select HAVE_UNSTABLE_SCHED_CLOCK
+	select HAVE_UNWIND_USER_FP		if X86_64
 	select HAVE_USER_RETURN_NOTIFIER
 	select HAVE_GENERIC_VDSO
 	select VDSO_GETRANDOM			if X86_64

arch/x86/boot/compressed/sev-handle-vc.c

@@ -29,11 +29,10 @@
 bool insn_has_rep_prefix(struct insn *insn)
 {
 	insn_byte_t p;
-	int i;
 
 	insn_get_prefixes(insn);
 
-	for_each_insn_prefix(insn, i, p) {
+	for_each_insn_prefix(insn, p) {
 		if (p == 0xf2 || p == 0xf3)
 			return true;
 	}

arch/x86/events/amd/core.c

@@ -763,6 +763,11 @@ static void amd_pmu_enable_all(int added)
 		if (!test_bit(idx, cpuc->active_mask))
 			continue;
 
+		/*
+		 * FIXME: cpuc->events[idx] can become NULL in a subtle race
+		 * condition with NMI->throttle->x86_pmu_stop().
+		 */
+		if (cpuc->events[idx])
 			amd_pmu_enable_event(cpuc->events[idx]);
 	}
 }

arch/x86/events/core.c

@@ -554,14 +554,22 @@ static inline int precise_br_compat(struct perf_event *event)
 	return m == b;
 }
 
-int x86_pmu_max_precise(void)
+int x86_pmu_max_precise(struct pmu *pmu)
 {
 	int precise = 0;
 
-	/* Support for constant skid */
 	if (x86_pmu.pebs_active && !x86_pmu.pebs_broken) {
+		/* arch PEBS */
+		if (x86_pmu.arch_pebs) {
+			precise = 2;
+			if (hybrid(pmu, arch_pebs_cap).pdists)
 				precise++;
 
+			return precise;
+		}
+
+		/* legacy PEBS - support for constant skid */
+		precise++;
 		/* Support for IP fixup */
 		if (x86_pmu.lbr_nr || x86_pmu.intel_cap.pebs_format >= 2)
 			precise++;
@@ -569,13 +577,14 @@ int x86_pmu_max_precise(void)
 		if (x86_pmu.pebs_prec_dist)
 			precise++;
 	}
+
 	return precise;
 }
 
 int x86_pmu_hw_config(struct perf_event *event)
 {
 	if (event->attr.precise_ip) {
-		int precise = x86_pmu_max_precise();
+		int precise = x86_pmu_max_precise(event->pmu);
 
 		if (event->attr.precise_ip > precise)
 			return -EOPNOTSUPP;
@@ -1344,6 +1353,7 @@ static void x86_pmu_enable(struct pmu *pmu)
 				hwc->state |= PERF_HES_ARCH;
 
 			x86_pmu_stop(event, PERF_EF_UPDATE);
+			cpuc->events[hwc->idx] = NULL;
 		}
 
 		/*
@@ -1365,6 +1375,7 @@ static void x86_pmu_enable(struct pmu *pmu)
 			 * if cpuc->enabled = 0, then no wrmsr as
 			 * per x86_pmu_enable_event()
 			 */
+			cpuc->events[hwc->idx] = event;
 			x86_pmu_start(event, PERF_EF_RELOAD);
 		}
 		cpuc->n_added = 0;
@@ -1531,7 +1542,6 @@ static void x86_pmu_start(struct perf_event *event, int flags)
 
 	event->hw.state = 0;
 
-	cpuc->events[idx] = event;
 	__set_bit(idx, cpuc->active_mask);
 	static_call(x86_pmu_enable)(event);
 	perf_event_update_userpage(event);
@@ -1610,7 +1620,6 @@ void x86_pmu_stop(struct perf_event *event, int flags)
 	if (test_bit(hwc->idx, cpuc->active_mask)) {
 		static_call(x86_pmu_disable)(event);
 		__clear_bit(hwc->idx, cpuc->active_mask);
-		cpuc->events[hwc->idx] = NULL;
 		WARN_ON_ONCE(hwc->state & PERF_HES_STOPPED);
 		hwc->state |= PERF_HES_STOPPED;
 	}
@@ -1648,6 +1657,7 @@ static void x86_pmu_del(struct perf_event *event, int flags)
 	 * Not a TXN, therefore cleanup properly.
 	 */
 	x86_pmu_stop(event, PERF_EF_UPDATE);
+	cpuc->events[event->hw.idx] = NULL;
 
 	for (i = 0; i < cpuc->n_events; i++) {
 		if (event == cpuc->event_list[i])
@@ -2629,7 +2639,9 @@ static ssize_t max_precise_show(struct device *cdev,
 				  struct device_attribute *attr,
 				  char *buf)
 {
-	return snprintf(buf, PAGE_SIZE, "%d\n", x86_pmu_max_precise());
+	struct pmu *pmu = dev_get_drvdata(cdev);
+
+	return snprintf(buf, PAGE_SIZE, "%d\n", x86_pmu_max_precise(pmu));
 }
 
 static DEVICE_ATTR_RO(max_precise);
@@ -2845,46 +2857,6 @@ static unsigned long get_segment_base(unsigned int segment)
 	return get_desc_base(desc);
 }
 
-#ifdef CONFIG_UPROBES
-/*
- * Heuristic-based check if uprobe is installed at the function entry.
- *
- * Under assumption of user code being compiled with frame pointers,
- * `push %rbp/%ebp` is a good indicator that we indeed are.
- *
- * Similarly, `endbr64` (assuming 64-bit mode) is also a common pattern.
- * If we get this wrong, captured stack trace might have one extra bogus
- * entry, but the rest of stack trace will still be meaningful.
- */
-static bool is_uprobe_at_func_entry(struct pt_regs *regs)
-{
-	struct arch_uprobe *auprobe;
-
-	if (!current->utask)
-		return false;
-
-	auprobe = current->utask->auprobe;
-	if (!auprobe)
-		return false;
-
-	/* push %rbp/%ebp */
-	if (auprobe->insn[0] == 0x55)
-		return true;
-
-	/* endbr64 (64-bit only) */
-	if (user_64bit_mode(regs) && is_endbr((u32 *)auprobe->insn))
-		return true;
-
-	return false;
-}
-
-#else
-static bool is_uprobe_at_func_entry(struct pt_regs *regs)
-{
-	return false;
-}
-#endif /* CONFIG_UPROBES */
-
 #ifdef CONFIG_IA32_EMULATION
 
 #include <linux/compat.h>

arch/x86/events/intel/core.c

@@ -2563,6 +2563,44 @@ static void intel_pmu_disable_fixed(struct perf_event *event)
 	cpuc->fixed_ctrl_val &= ~mask;
 }
 
+static inline void __intel_pmu_update_event_ext(int idx, u64 ext)
+{
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
+	u32 msr;
+
+	if (idx < INTEL_PMC_IDX_FIXED) {
+		msr = MSR_IA32_PMC_V6_GP0_CFG_C +
+		      x86_pmu.addr_offset(idx, false);
+	} else {
+		msr = MSR_IA32_PMC_V6_FX0_CFG_C +
+		      x86_pmu.addr_offset(idx - INTEL_PMC_IDX_FIXED, false);
+	}
+
+	cpuc->cfg_c_val[idx] = ext;
+	wrmsrq(msr, ext);
+}
+
+static void intel_pmu_disable_event_ext(struct perf_event *event)
+{
+	/*
+	 * Only clear CFG_C MSR for PEBS counter group events,
+	 * it avoids the HW counter's value to be added into
+	 * other PEBS records incorrectly after PEBS counter
+	 * group events are disabled.
+	 *
+	 * For other events, it's unnecessary to clear CFG_C MSRs
+	 * since CFG_C doesn't take effect if counter is in
+	 * disabled state. That helps to reduce the WRMSR overhead
+	 * in context switches.
+	 */
+	if (!is_pebs_counter_event_group(event))
+		return;
+
+	__intel_pmu_update_event_ext(event->hw.idx, 0);
+}
+
+DEFINE_STATIC_CALL_NULL(intel_pmu_disable_event_ext, intel_pmu_disable_event_ext);
+
 static void intel_pmu_disable_event(struct perf_event *event)
 {
 	struct hw_perf_event *hwc = &event->hw;
@@ -2571,9 +2609,12 @@ static void intel_pmu_disable_event(struct perf_event *event)
 	switch (idx) {
 	case 0 ... INTEL_PMC_IDX_FIXED - 1:
 		intel_clear_masks(event, idx);
+		static_call_cond(intel_pmu_disable_event_ext)(event);
 		x86_pmu_disable_event(event);
 		break;
 	case INTEL_PMC_IDX_FIXED ... INTEL_PMC_IDX_FIXED_BTS - 1:
+		static_call_cond(intel_pmu_disable_event_ext)(event);
+		fallthrough;
 	case INTEL_PMC_IDX_METRIC_BASE ... INTEL_PMC_IDX_METRIC_END:
 		intel_pmu_disable_fixed(event);
 		break;
@@ -2940,6 +2981,79 @@ static void intel_pmu_enable_acr(struct perf_event *event)
 
 DEFINE_STATIC_CALL_NULL(intel_pmu_enable_acr_event, intel_pmu_enable_acr);
 
+static void intel_pmu_enable_event_ext(struct perf_event *event)
+{
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
+	struct hw_perf_event *hwc = &event->hw;
+	union arch_pebs_index old, new;
+	struct arch_pebs_cap cap;
+	u64 ext = 0;
+
+	cap = hybrid(cpuc->pmu, arch_pebs_cap);
+
+	if (event->attr.precise_ip) {
+		u64 pebs_data_cfg = intel_get_arch_pebs_data_config(event);
+
+		ext |= ARCH_PEBS_EN;
+		if (hwc->flags & PERF_X86_EVENT_AUTO_RELOAD)
+			ext |= (-hwc->sample_period) & ARCH_PEBS_RELOAD;
+
+		if (pebs_data_cfg && cap.caps) {
+			if (pebs_data_cfg & PEBS_DATACFG_MEMINFO)
+				ext |= ARCH_PEBS_AUX & cap.caps;
+
+			if (pebs_data_cfg & PEBS_DATACFG_GP)
+				ext |= ARCH_PEBS_GPR & cap.caps;
+
+			if (pebs_data_cfg & PEBS_DATACFG_XMMS)
+				ext |= ARCH_PEBS_VECR_XMM & cap.caps;
+
+			if (pebs_data_cfg & PEBS_DATACFG_LBRS)
+				ext |= ARCH_PEBS_LBR & cap.caps;
+
+			if (pebs_data_cfg &
+			    (PEBS_DATACFG_CNTR_MASK << PEBS_DATACFG_CNTR_SHIFT))
+				ext |= ARCH_PEBS_CNTR_GP & cap.caps;
+
+			if (pebs_data_cfg &
+			    (PEBS_DATACFG_FIX_MASK << PEBS_DATACFG_FIX_SHIFT))
+				ext |= ARCH_PEBS_CNTR_FIXED & cap.caps;
+
+			if (pebs_data_cfg & PEBS_DATACFG_METRICS)
+				ext |= ARCH_PEBS_CNTR_METRICS & cap.caps;
+		}
+
+		if (cpuc->n_pebs == cpuc->n_large_pebs)
+			new.thresh = ARCH_PEBS_THRESH_MULTI;
+		else
+			new.thresh = ARCH_PEBS_THRESH_SINGLE;
+
+		rdmsrq(MSR_IA32_PEBS_INDEX, old.whole);
+		if (new.thresh != old.thresh || !old.en) {
+			if (old.thresh == ARCH_PEBS_THRESH_MULTI && old.wr > 0) {
+				/*
+				 * Large PEBS was enabled.
+				 * Drain PEBS buffer before applying the single PEBS.
+				 */
+				intel_pmu_drain_pebs_buffer();
+			} else {
+				new.wr = 0;
+				new.full = 0;
+				new.en = 1;
+				wrmsrq(MSR_IA32_PEBS_INDEX, new.whole);
+			}
+		}
+	}
+
+	if (is_pebs_counter_event_group(event))
+		ext |= ARCH_PEBS_CNTR_ALLOW;
+
+	if (cpuc->cfg_c_val[hwc->idx] != ext)
+		__intel_pmu_update_event_ext(hwc->idx, ext);
+}
+
+DEFINE_STATIC_CALL_NULL(intel_pmu_enable_event_ext, intel_pmu_enable_event_ext);
+
 static void intel_pmu_enable_event(struct perf_event *event)
 {
 	u64 enable_mask = ARCH_PERFMON_EVENTSEL_ENABLE;
@@ -2955,10 +3069,12 @@ static void intel_pmu_enable_event(struct perf_event *event)
 			enable_mask |= ARCH_PERFMON_EVENTSEL_BR_CNTR;
 		intel_set_masks(event, idx);
 		static_call_cond(intel_pmu_enable_acr_event)(event);
+		static_call_cond(intel_pmu_enable_event_ext)(event);
 		__x86_pmu_enable_event(hwc, enable_mask);
 		break;
 	case INTEL_PMC_IDX_FIXED ... INTEL_PMC_IDX_FIXED_BTS - 1:
 		static_call_cond(intel_pmu_enable_acr_event)(event);
+		static_call_cond(intel_pmu_enable_event_ext)(event);
 		fallthrough;
 	case INTEL_PMC_IDX_METRIC_BASE ... INTEL_PMC_IDX_METRIC_END:
 		intel_pmu_enable_fixed(event);
@@ -3215,6 +3331,19 @@ static int handle_pmi_common(struct pt_regs *regs, u64 status)
 			status &= ~GLOBAL_STATUS_PERF_METRICS_OVF_BIT;
 	}
 
+	/*
+	 * Arch PEBS sets bit 54 in the global status register
+	 */
+	if (__test_and_clear_bit(GLOBAL_STATUS_ARCH_PEBS_THRESHOLD_BIT,
+				 (unsigned long *)&status)) {
+		handled++;
+		static_call(x86_pmu_drain_pebs)(regs, &data);
+
+		if (cpuc->events[INTEL_PMC_IDX_FIXED_SLOTS] &&
+		    is_pebs_counter_event_group(cpuc->events[INTEL_PMC_IDX_FIXED_SLOTS]))
+			status &= ~GLOBAL_STATUS_PERF_METRICS_OVF_BIT;
+	}
+
 	/*
 	 * Intel PT
 	 */
@@ -3269,7 +3398,7 @@ static int handle_pmi_common(struct pt_regs *regs, u64 status)
 		 * The PEBS buffer has to be drained before handling the A-PMI
 		 */
 		if (is_pebs_counter_event_group(event))
-			x86_pmu.drain_pebs(regs, &data);
+			static_call(x86_pmu_drain_pebs)(regs, &data);
 
 		last_period = event->hw.last_period;
 
@@ -4029,7 +4158,9 @@ static unsigned long intel_pmu_large_pebs_flags(struct perf_event *event)
 	if (!event->attr.exclude_kernel)
 		flags &= ~PERF_SAMPLE_REGS_USER;
 	if (event->attr.sample_regs_user & ~PEBS_GP_REGS)
-		flags &= ~(PERF_SAMPLE_REGS_USER | PERF_SAMPLE_REGS_INTR);
+		flags &= ~PERF_SAMPLE_REGS_USER;
+	if (event->attr.sample_regs_intr & ~PEBS_GP_REGS)
+		flags &= ~PERF_SAMPLE_REGS_INTR;
 	return flags;
 }
 
@@ -4204,6 +4335,20 @@ static bool intel_pmu_is_acr_group(struct perf_event *event)
 	return false;
 }
 
+static inline bool intel_pmu_has_pebs_counter_group(struct pmu *pmu)
+{
+	u64 caps;
+
+	if (x86_pmu.intel_cap.pebs_format >= 6 && x86_pmu.intel_cap.pebs_baseline)
+		return true;
+
+	caps = hybrid(pmu, arch_pebs_cap).caps;
+	if (x86_pmu.arch_pebs && (caps & ARCH_PEBS_CNTR_MASK))
+		return true;
+
+	return false;
+}
+
 static inline void intel_pmu_set_acr_cntr_constr(struct perf_event *event,
 						 u64 *cause_mask, int *num)
 {
@@ -4237,6 +4382,8 @@ static int intel_pmu_hw_config(struct perf_event *event)
 	}
 
 	if (event->attr.precise_ip) {
+		struct arch_pebs_cap pebs_cap = hybrid(event->pmu, arch_pebs_cap);
+
 		if ((event->attr.config & INTEL_ARCH_EVENT_MASK) == INTEL_FIXED_VLBR_EVENT)
 			return -EINVAL;
 
@@ -4250,6 +4397,15 @@ static int intel_pmu_hw_config(struct perf_event *event)
 		}
 		if (x86_pmu.pebs_aliases)
 			x86_pmu.pebs_aliases(event);
+
+		if (x86_pmu.arch_pebs) {
+			u64 cntr_mask = hybrid(event->pmu, intel_ctrl) &
+						~GLOBAL_CTRL_EN_PERF_METRICS;
+			u64 pebs_mask = event->attr.precise_ip >= 3 ?
+						pebs_cap.pdists : pebs_cap.counters;
+			if (cntr_mask != pebs_mask)
+				event->hw.dyn_constraint &= pebs_mask;
+		}
 	}
 
 	if (needs_branch_stack(event)) {
@@ -4341,8 +4497,7 @@ static int intel_pmu_hw_config(struct perf_event *event)
 	}
 
 	if ((event->attr.sample_type & PERF_SAMPLE_READ) &&
-	    (x86_pmu.intel_cap.pebs_format >= 6) &&
+	    intel_pmu_has_pebs_counter_group(event->pmu) &&
-	    x86_pmu.intel_cap.pebs_baseline &&
 	    is_sampling_event(event) &&
 	    event->attr.precise_ip)
 		event->group_leader->hw.flags |= PERF_X86_EVENT_PEBS_CNTR;
@@ -5212,7 +5367,13 @@ int intel_cpuc_prepare(struct cpu_hw_events *cpuc, int cpu)
 
 static int intel_pmu_cpu_prepare(int cpu)
 {
-	return intel_cpuc_prepare(&per_cpu(cpu_hw_events, cpu), cpu);
+	int ret;
+
+	ret = intel_cpuc_prepare(&per_cpu(cpu_hw_events, cpu), cpu);
+	if (ret)
+		return ret;
+
+	return alloc_arch_pebs_buf_on_cpu(cpu);
 }
 
 static void flip_smm_bit(void *data)
@@ -5257,6 +5418,163 @@ static void intel_pmu_check_event_constraints(struct event_constraint *event_con
 					      u64 fixed_cntr_mask,
 					      u64 intel_ctrl);
 
+enum dyn_constr_type {
+	DYN_CONSTR_NONE,
+	DYN_CONSTR_BR_CNTR,
+	DYN_CONSTR_ACR_CNTR,
+	DYN_CONSTR_ACR_CAUSE,
+	DYN_CONSTR_PEBS,
+	DYN_CONSTR_PDIST,
+
+	DYN_CONSTR_MAX,
+};
+
+static const char * const dyn_constr_type_name[] = {
+	[DYN_CONSTR_NONE] = "a normal event",
+	[DYN_CONSTR_BR_CNTR] = "a branch counter logging event",
+	[DYN_CONSTR_ACR_CNTR] = "an auto-counter reload event",
+	[DYN_CONSTR_ACR_CAUSE] = "an auto-counter reload cause event",
+	[DYN_CONSTR_PEBS] = "a PEBS event",
+	[DYN_CONSTR_PDIST] = "a PEBS PDIST event",
+};
+
+static void __intel_pmu_check_dyn_constr(struct event_constraint *constr,
+					 enum dyn_constr_type type, u64 mask)
+{
+	struct event_constraint *c1, *c2;
+	int new_weight, check_weight;
+	u64 new_mask, check_mask;
+
+	for_each_event_constraint(c1, constr) {
+		new_mask = c1->idxmsk64 & mask;
+		new_weight = hweight64(new_mask);
+
+		/* ignore topdown perf metrics event */
+		if (c1->idxmsk64 & INTEL_PMC_MSK_TOPDOWN)
+			continue;
+
+		if (!new_weight && fls64(c1->idxmsk64) < INTEL_PMC_IDX_FIXED) {
+			pr_info("The event 0x%llx is not supported as %s.\n",
+				c1->code, dyn_constr_type_name[type]);
+		}
+
+		if (new_weight <= 1)
+			continue;
+
+		for_each_event_constraint(c2, c1 + 1) {
+			bool check_fail = false;
+
+			check_mask = c2->idxmsk64 & mask;
+			check_weight = hweight64(check_mask);
+
+			if (c2->idxmsk64 & INTEL_PMC_MSK_TOPDOWN ||
+			    !check_weight)
+				continue;
+
+			/* The same constraints or no overlap */
+			if (new_mask == check_mask ||
+			    (new_mask ^ check_mask) == (new_mask | check_mask))
+				continue;
+
+			/*
+			 * A scheduler issue may be triggered in the following cases.
+			 * - Two overlap constraints have the same weight.
+			 *   E.g., A constraints: 0x3, B constraints: 0x6
+			 *   event	counter		failure case
+			 *   B		PMC[2:1]	1
+			 *   A		PMC[1:0]	0
+			 *   A		PMC[1:0]	FAIL
+			 * - Two overlap constraints have different weight.
+			 *   The constraint has a low weight, but has high last bit.
+			 *   E.g., A constraints: 0x7, B constraints: 0xC
+			 *   event	counter		failure case
+			 *   B		PMC[3:2]	2
+			 *   A		PMC[2:0]	0
+			 *   A		PMC[2:0]	1
+			 *   A		PMC[2:0]	FAIL
+			 */
+			if (new_weight == check_weight) {
+				check_fail = true;
+			} else if (new_weight < check_weight) {
+				if ((new_mask | check_mask) != check_mask &&
+				    fls64(new_mask) > fls64(check_mask))
+					check_fail = true;
+			} else {
+				if ((new_mask | check_mask) != new_mask &&
+				    fls64(new_mask) < fls64(check_mask))
+					check_fail = true;
+			}
+
+			if (check_fail) {
+				pr_info("The two events 0x%llx and 0x%llx may not be "
+					"fully scheduled under some circumstances as "
+					"%s.\n",
+					c1->code, c2->code, dyn_constr_type_name[type]);
+			}
+		}
+	}
+}
+
+static void intel_pmu_check_dyn_constr(struct pmu *pmu,
+				       struct event_constraint *constr,
+				       u64 cntr_mask)
+{
+	enum dyn_constr_type i;
+	u64 mask;
+
+	for (i = DYN_CONSTR_NONE; i < DYN_CONSTR_MAX; i++) {
+		mask = 0;
+		switch (i) {
+		case DYN_CONSTR_NONE:
+			mask = cntr_mask;
+			break;
+		case DYN_CONSTR_BR_CNTR:
+			if (x86_pmu.flags & PMU_FL_BR_CNTR)
+				mask = x86_pmu.lbr_counters;
+			break;
+		case DYN_CONSTR_ACR_CNTR:
+			mask = hybrid(pmu, acr_cntr_mask64) & GENMASK_ULL(INTEL_PMC_MAX_GENERIC - 1, 0);
+			break;
+		case DYN_CONSTR_ACR_CAUSE:
+			if (hybrid(pmu, acr_cntr_mask64) == hybrid(pmu, acr_cause_mask64))
+				continue;
+			mask = hybrid(pmu, acr_cause_mask64) & GENMASK_ULL(INTEL_PMC_MAX_GENERIC - 1, 0);
+			break;
+		case DYN_CONSTR_PEBS:
+			if (x86_pmu.arch_pebs)
+				mask = hybrid(pmu, arch_pebs_cap).counters;
+			break;
+		case DYN_CONSTR_PDIST:
+			if (x86_pmu.arch_pebs)
+				mask = hybrid(pmu, arch_pebs_cap).pdists;
+			break;
+		default:
+			pr_warn("Unsupported dynamic constraint type %d\n", i);
+		}
+
+		if (mask)
+			__intel_pmu_check_dyn_constr(constr, i, mask);
+	}
+}
+
+static void intel_pmu_check_event_constraints_all(struct pmu *pmu)
+{
+	struct event_constraint *event_constraints = hybrid(pmu, event_constraints);
+	struct event_constraint *pebs_constraints = hybrid(pmu, pebs_constraints);
+	u64 cntr_mask = hybrid(pmu, cntr_mask64);
+	u64 fixed_cntr_mask = hybrid(pmu, fixed_cntr_mask64);
+	u64 intel_ctrl = hybrid(pmu, intel_ctrl);
+
+	intel_pmu_check_event_constraints(event_constraints, cntr_mask,
+					  fixed_cntr_mask, intel_ctrl);
+
+	if (event_constraints)
+		intel_pmu_check_dyn_constr(pmu, event_constraints, cntr_mask);
+
+	if (pebs_constraints)
+		intel_pmu_check_dyn_constr(pmu, pebs_constraints, cntr_mask);
+}
+
 static void intel_pmu_check_extra_regs(struct extra_reg *extra_regs);
 
 static inline bool intel_pmu_broken_perf_cap(void)
@@ -5269,34 +5587,89 @@ static inline bool intel_pmu_broken_perf_cap(void)
 	return false;
 }
 
+static inline void __intel_update_pmu_caps(struct pmu *pmu)
+{
+	struct pmu *dest_pmu = pmu ? pmu : x86_get_pmu(smp_processor_id());
+
+	if (hybrid(pmu, arch_pebs_cap).caps & ARCH_PEBS_VECR_XMM)
+		dest_pmu->capabilities |= PERF_PMU_CAP_EXTENDED_REGS;
+}
+
+static inline void __intel_update_large_pebs_flags(struct pmu *pmu)
+{
+	u64 caps = hybrid(pmu, arch_pebs_cap).caps;
+
+	x86_pmu.large_pebs_flags |= PERF_SAMPLE_TIME;
+	if (caps & ARCH_PEBS_LBR)
+		x86_pmu.large_pebs_flags |= PERF_SAMPLE_BRANCH_STACK;
+	if (caps & ARCH_PEBS_CNTR_MASK)
+		x86_pmu.large_pebs_flags |= PERF_SAMPLE_READ;
+
+	if (!(caps & ARCH_PEBS_AUX))
+		x86_pmu.large_pebs_flags &= ~PERF_SAMPLE_DATA_SRC;
+	if (!(caps & ARCH_PEBS_GPR)) {
+		x86_pmu.large_pebs_flags &=
+			~(PERF_SAMPLE_REGS_INTR | PERF_SAMPLE_REGS_USER);
+	}
+}
+
+#define counter_mask(_gp, _fixed) ((_gp) | ((u64)(_fixed) << INTEL_PMC_IDX_FIXED))
+
 static void update_pmu_cap(struct pmu *pmu)
 {
-	unsigned int cntr, fixed_cntr, ecx, edx;
+	unsigned int eax, ebx, ecx, edx;
-	union cpuid35_eax eax;
+	union cpuid35_eax eax_0;
-	union cpuid35_ebx ebx;
+	union cpuid35_ebx ebx_0;
+	u64 cntrs_mask = 0;
+	u64 pebs_mask = 0;
+	u64 pdists_mask = 0;
 
-	cpuid(ARCH_PERFMON_EXT_LEAF, &eax.full, &ebx.full, &ecx, &edx);
+	cpuid(ARCH_PERFMON_EXT_LEAF, &eax_0.full, &ebx_0.full, &ecx, &edx);
 
-	if (ebx.split.umask2)
+	if (ebx_0.split.umask2)
 		hybrid(pmu, config_mask) |= ARCH_PERFMON_EVENTSEL_UMASK2;
-	if (ebx.split.eq)
+	if (ebx_0.split.eq)
 		hybrid(pmu, config_mask) |= ARCH_PERFMON_EVENTSEL_EQ;
 
-	if (eax.split.cntr_subleaf) {
+	if (eax_0.split.cntr_subleaf) {
 		cpuid_count(ARCH_PERFMON_EXT_LEAF, ARCH_PERFMON_NUM_COUNTER_LEAF,
-			    &cntr, &fixed_cntr, &ecx, &edx);
+			    &eax, &ebx, &ecx, &edx);
-		hybrid(pmu, cntr_mask64) = cntr;
+		hybrid(pmu, cntr_mask64) = eax;
-		hybrid(pmu, fixed_cntr_mask64) = fixed_cntr;
+		hybrid(pmu, fixed_cntr_mask64) = ebx;
+		cntrs_mask = counter_mask(eax, ebx);
 	}
 
-	if (eax.split.acr_subleaf) {
+	if (eax_0.split.acr_subleaf) {
 		cpuid_count(ARCH_PERFMON_EXT_LEAF, ARCH_PERFMON_ACR_LEAF,
-			    &cntr, &fixed_cntr, &ecx, &edx);
+			    &eax, &ebx, &ecx, &edx);
 		/* The mask of the counters which can be reloaded */
-		hybrid(pmu, acr_cntr_mask64) = cntr | ((u64)fixed_cntr << INTEL_PMC_IDX_FIXED);
+		hybrid(pmu, acr_cntr_mask64) = counter_mask(eax, ebx);
-
 		/* The mask of the counters which can cause a reload of reloadable counters */
-		hybrid(pmu, acr_cause_mask64) = ecx | ((u64)edx << INTEL_PMC_IDX_FIXED);
+		hybrid(pmu, acr_cause_mask64) = counter_mask(ecx, edx);
+	}
+
+	/* Bits[5:4] should be set simultaneously if arch-PEBS is supported */
+	if (eax_0.split.pebs_caps_subleaf && eax_0.split.pebs_cnts_subleaf) {
+		cpuid_count(ARCH_PERFMON_EXT_LEAF, ARCH_PERFMON_PEBS_CAP_LEAF,
+			    &eax, &ebx, &ecx, &edx);
+		hybrid(pmu, arch_pebs_cap).caps = (u64)ebx << 32;
+
+		cpuid_count(ARCH_PERFMON_EXT_LEAF, ARCH_PERFMON_PEBS_COUNTER_LEAF,
+			    &eax, &ebx, &ecx, &edx);
+		pebs_mask   = counter_mask(eax, ecx);
+		pdists_mask = counter_mask(ebx, edx);
+		hybrid(pmu, arch_pebs_cap).counters = pebs_mask;
+		hybrid(pmu, arch_pebs_cap).pdists = pdists_mask;
+
+		if (WARN_ON((pebs_mask | pdists_mask) & ~cntrs_mask)) {
+			x86_pmu.arch_pebs = 0;
+		} else {
+			__intel_update_pmu_caps(pmu);
+			__intel_update_large_pebs_flags(pmu);
+		}
+	} else {
+		WARN_ON(x86_pmu.arch_pebs == 1);
+		x86_pmu.arch_pebs = 0;
 	}
 
 	if (!intel_pmu_broken_perf_cap()) {
@@ -5319,10 +5692,7 @@ static void intel_pmu_check_hybrid_pmus(struct x86_hybrid_pmu *pmu)
 	else
 		pmu->intel_ctrl &= ~GLOBAL_CTRL_EN_PERF_METRICS;
 
-	intel_pmu_check_event_constraints(pmu->event_constraints,
+	intel_pmu_check_event_constraints_all(&pmu->pmu);
-					  pmu->cntr_mask64,
-					  pmu->fixed_cntr_mask64,
-					  pmu->intel_ctrl);
 
 	intel_pmu_check_extra_regs(pmu->extra_regs);
 }
@@ -5418,6 +5788,7 @@ static void intel_pmu_cpu_starting(int cpu)
 		return;
 
 	init_debug_store_on_cpu(cpu);
+	init_arch_pebs_on_cpu(cpu);
 	/*
 	 * Deal with CPUs that don't clear their LBRs on power-up, and that may
 	 * even boot with LBRs enabled.
@@ -5456,6 +5827,8 @@ static void intel_pmu_cpu_starting(int cpu)
 		}
 	}
 
+	__intel_update_pmu_caps(cpuc->pmu);
+
 	if (!cpuc->shared_regs)
 		return;
 
@@ -5515,6 +5888,7 @@ static void free_excl_cntrs(struct cpu_hw_events *cpuc)
 static void intel_pmu_cpu_dying(int cpu)
 {
 	fini_debug_store_on_cpu(cpu);
+	fini_arch_pebs_on_cpu(cpu);
 }
 
 void intel_cpuc_finish(struct cpu_hw_events *cpuc)
@@ -5535,6 +5909,7 @@ static void intel_pmu_cpu_dead(int cpu)
 {
 	struct cpu_hw_events *cpuc = &per_cpu(cpu_hw_events, cpu);
 
+	release_arch_pebs_buf_on_cpu(cpu);
 	intel_cpuc_finish(cpuc);
 
 	if (is_hybrid() && cpuc->pmu)
@@ -6250,7 +6625,7 @@ tsx_is_visible(struct kobject *kobj, struct attribute *attr, int i)
 static umode_t
 pebs_is_visible(struct kobject *kobj, struct attribute *attr, int i)
 {
-	return x86_pmu.ds_pebs ? attr->mode : 0;
+	return intel_pmu_has_pebs() ? attr->mode : 0;
 }
 
 static umode_t
@@ -6940,8 +7315,11 @@ __init int intel_pmu_init(void)
 	 * Many features on and after V6 require dynamic constraint,
 	 * e.g., Arch PEBS, ACR.
 	 */
-	if (version >= 6)
+	if (version >= 6) {
 		x86_pmu.flags |= PMU_FL_DYN_CONSTRAINT;
+		x86_pmu.late_setup = intel_pmu_late_setup;
+	}
+
 	/*
 	 * Install the hw-cache-events table:
 	 */
@@ -7727,6 +8105,14 @@ __init int intel_pmu_init(void)
 	if (!is_hybrid() && boot_cpu_has(X86_FEATURE_ARCH_PERFMON_EXT))
 		update_pmu_cap(NULL);
 
+	if (x86_pmu.arch_pebs) {
+		static_call_update(intel_pmu_disable_event_ext,
+				   intel_pmu_disable_event_ext);
+		static_call_update(intel_pmu_enable_event_ext,
+				   intel_pmu_enable_event_ext);
+		pr_cont("Architectural PEBS, ");
+	}
+
 	intel_pmu_check_counters_mask(&x86_pmu.cntr_mask64,
 				      &x86_pmu.fixed_cntr_mask64,
 				      &x86_pmu.intel_ctrl);
@@ -7735,10 +8121,8 @@ __init int intel_pmu_init(void)
 	if (x86_pmu.intel_cap.anythread_deprecated)
 		x86_pmu.format_attrs = intel_arch_formats_attr;
 
-	intel_pmu_check_event_constraints(x86_pmu.event_constraints,
+	intel_pmu_check_event_constraints_all(NULL);
-					  x86_pmu.cntr_mask64,
+
-					  x86_pmu.fixed_cntr_mask64,
-					  x86_pmu.intel_ctrl);
 	/*
 	 * Access LBR MSR may cause #GP under certain circumstances.
 	 * Check all LBR MSR here.

arch/x86/events/intel/cstate.c

@@ -41,7 +41,7 @@
  *	MSR_CORE_C1_RES: CORE C1 Residency Counter
  *			 perf code: 0x00
  *			 Available model: SLM,AMT,GLM,CNL,ICX,TNT,ADL,RPL
- *					  MTL,SRF,GRR,ARL,LNL
+ *					  MTL,SRF,GRR,ARL,LNL,PTL
  *			 Scope: Core (each processor core has a MSR)
  *	MSR_CORE_C3_RESIDENCY: CORE C3 Residency Counter
  *			       perf code: 0x01
@@ -53,31 +53,32 @@
  *			       Available model: SLM,AMT,NHM,WSM,SNB,IVB,HSW,BDW,
  *						SKL,KNL,GLM,CNL,KBL,CML,ICL,ICX,
  *						TGL,TNT,RKL,ADL,RPL,SPR,MTL,SRF,
- *						GRR,ARL,LNL
+ *						GRR,ARL,LNL,PTL
  *			       Scope: Core
  *	MSR_CORE_C7_RESIDENCY: CORE C7 Residency Counter
  *			       perf code: 0x03
  *			       Available model: SNB,IVB,HSW,BDW,SKL,CNL,KBL,CML,
- *						ICL,TGL,RKL,ADL,RPL,MTL,ARL,LNL
+ *						ICL,TGL,RKL,ADL,RPL,MTL,ARL,LNL,
+ *						PTL
  *			       Scope: Core
  *	MSR_PKG_C2_RESIDENCY:  Package C2 Residency Counter.
  *			       perf code: 0x00
  *			       Available model: SNB,IVB,HSW,BDW,SKL,KNL,GLM,CNL,
  *						KBL,CML,ICL,ICX,TGL,TNT,RKL,ADL,
- *						RPL,SPR,MTL,ARL,LNL,SRF
+ *						RPL,SPR,MTL,ARL,LNL,SRF,PTL
  *			       Scope: Package (physical package)
  *	MSR_PKG_C3_RESIDENCY:  Package C3 Residency Counter.
  *			       perf code: 0x01
  *			       Available model: NHM,WSM,SNB,IVB,HSW,BDW,SKL,KNL,
  *						GLM,CNL,KBL,CML,ICL,TGL,TNT,RKL,
- *						ADL,RPL,MTL,ARL,LNL
+ *						ADL,RPL,MTL,ARL
  *			       Scope: Package (physical package)
  *	MSR_PKG_C6_RESIDENCY:  Package C6 Residency Counter.
  *			       perf code: 0x02
  *			       Available model: SLM,AMT,NHM,WSM,SNB,IVB,HSW,BDW,
  *						SKL,KNL,GLM,CNL,KBL,CML,ICL,ICX,
  *						TGL,TNT,RKL,ADL,RPL,SPR,MTL,SRF,
- *						ARL,LNL
+ *						ARL,LNL,PTL
  *			       Scope: Package (physical package)
  *	MSR_PKG_C7_RESIDENCY:  Package C7 Residency Counter.
  *			       perf code: 0x03
@@ -96,7 +97,7 @@
  *	MSR_PKG_C10_RESIDENCY: Package C10 Residency Counter.
  *			       perf code: 0x06
  *			       Available model: HSW ULT,KBL,GLM,CNL,CML,ICL,TGL,
- *						TNT,RKL,ADL,RPL,MTL,ARL,LNL
+ *						TNT,RKL,ADL,RPL,MTL,ARL,LNL,PTL
  *			       Scope: Package (physical package)
  *	MSR_MODULE_C6_RES_MS:  Module C6 Residency Counter.
  *			       perf code: 0x00
@@ -522,7 +523,6 @@ static const struct cstate_model lnl_cstates __initconst = {
 				  BIT(PERF_CSTATE_CORE_C7_RES),
 
 	.pkg_events		= BIT(PERF_CSTATE_PKG_C2_RES) |
-				  BIT(PERF_CSTATE_PKG_C3_RES) |
 				  BIT(PERF_CSTATE_PKG_C6_RES) |
 				  BIT(PERF_CSTATE_PKG_C10_RES),
 };
@@ -628,6 +628,7 @@ static const struct x86_cpu_id intel_cstates_match[] __initconst = {
 	X86_MATCH_VFM(INTEL_ATOM_GRACEMONT,	&adl_cstates),
 	X86_MATCH_VFM(INTEL_ATOM_CRESTMONT_X,	&srf_cstates),
 	X86_MATCH_VFM(INTEL_ATOM_CRESTMONT,	&grr_cstates),
+	X86_MATCH_VFM(INTEL_ATOM_DARKMONT_X,	&srf_cstates),
 
 	X86_MATCH_VFM(INTEL_ICELAKE_L,		&icl_cstates),
 	X86_MATCH_VFM(INTEL_ICELAKE,		&icl_cstates),
@@ -652,6 +653,7 @@ static const struct x86_cpu_id intel_cstates_match[] __initconst = {
 	X86_MATCH_VFM(INTEL_ARROWLAKE_H,	&adl_cstates),
 	X86_MATCH_VFM(INTEL_ARROWLAKE_U,	&adl_cstates),
 	X86_MATCH_VFM(INTEL_LUNARLAKE_M,	&lnl_cstates),
+	X86_MATCH_VFM(INTEL_PANTHERLAKE_L,	&lnl_cstates),
 	{ },
 };
 MODULE_DEVICE_TABLE(x86cpu, intel_cstates_match);

arch/x86/events/intel/ds.c

@@ -626,13 +626,18 @@ static int alloc_pebs_buffer(int cpu)
 	int max, node = cpu_to_node(cpu);
 	void *buffer, *insn_buff, *cea;
 
-	if (!x86_pmu.ds_pebs)
+	if (!intel_pmu_has_pebs())
 		return 0;
 
 	buffer = dsalloc_pages(bsiz, GFP_KERNEL, cpu);
 	if (unlikely(!buffer))
 		return -ENOMEM;
 
+	if (x86_pmu.arch_pebs) {
+		hwev->pebs_vaddr = buffer;
+		return 0;
+	}
+
 	/*
 	 * HSW+ already provides us the eventing ip; no need to allocate this
 	 * buffer then.
@@ -645,7 +650,7 @@ static int alloc_pebs_buffer(int cpu)
 		}
 		per_cpu(insn_buffer, cpu) = insn_buff;
 	}
-	hwev->ds_pebs_vaddr = buffer;
+	hwev->pebs_vaddr = buffer;
 	/* Update the cpu entry area mapping */
 	cea = &get_cpu_entry_area(cpu)->cpu_debug_buffers.pebs_buffer;
 	ds->pebs_buffer_base = (unsigned long) cea;
@@ -661,17 +666,20 @@ static void release_pebs_buffer(int cpu)
 	struct cpu_hw_events *hwev = per_cpu_ptr(&cpu_hw_events, cpu);
 	void *cea;
 
-	if (!x86_pmu.ds_pebs)
+	if (!intel_pmu_has_pebs())
 		return;
 
+	if (x86_pmu.ds_pebs) {
 		kfree(per_cpu(insn_buffer, cpu));
 		per_cpu(insn_buffer, cpu) = NULL;
 
 		/* Clear the fixmap */
 		cea = &get_cpu_entry_area(cpu)->cpu_debug_buffers.pebs_buffer;
 		ds_clear_cea(cea, x86_pmu.pebs_buffer_size);
-	dsfree_pages(hwev->ds_pebs_vaddr, x86_pmu.pebs_buffer_size);
+	}
-	hwev->ds_pebs_vaddr = NULL;
+
+	dsfree_pages(hwev->pebs_vaddr, x86_pmu.pebs_buffer_size);
+	hwev->pebs_vaddr = NULL;
 }
 
 static int alloc_bts_buffer(int cpu)
@@ -824,6 +832,56 @@ void reserve_ds_buffers(void)
 	}
 }
 
+inline int alloc_arch_pebs_buf_on_cpu(int cpu)
+{
+	if (!x86_pmu.arch_pebs)
+		return 0;
+
+	return alloc_pebs_buffer(cpu);
+}
+
+inline void release_arch_pebs_buf_on_cpu(int cpu)
+{
+	if (!x86_pmu.arch_pebs)
+		return;
+
+	release_pebs_buffer(cpu);
+}
+
+void init_arch_pebs_on_cpu(int cpu)
+{
+	struct cpu_hw_events *cpuc = per_cpu_ptr(&cpu_hw_events, cpu);
+	u64 arch_pebs_base;
+
+	if (!x86_pmu.arch_pebs)
+		return;
+
+	if (!cpuc->pebs_vaddr) {
+		WARN(1, "Fail to allocate PEBS buffer on CPU %d\n", cpu);
+		x86_pmu.pebs_active = 0;
+		return;
+	}
+
+	/*
+	 * 4KB-aligned pointer of the output buffer
+	 * (__alloc_pages_node() return page aligned address)
+	 * Buffer Size = 4KB * 2^SIZE
+	 * contiguous physical buffer (__alloc_pages_node() with order)
+	 */
+	arch_pebs_base = virt_to_phys(cpuc->pebs_vaddr) | PEBS_BUFFER_SHIFT;
+	wrmsr_on_cpu(cpu, MSR_IA32_PEBS_BASE, (u32)arch_pebs_base,
+		     (u32)(arch_pebs_base >> 32));
+	x86_pmu.pebs_active = 1;
+}
+
+inline void fini_arch_pebs_on_cpu(int cpu)
+{
+	if (!x86_pmu.arch_pebs)
+		return;
+
+	wrmsr_on_cpu(cpu, MSR_IA32_PEBS_BASE, 0, 0);
+}
+
 /*
  * BTS
  */
@@ -1471,6 +1529,25 @@ pebs_update_state(bool needed_cb, struct cpu_hw_events *cpuc,
 	}
 }
 
+u64 intel_get_arch_pebs_data_config(struct perf_event *event)
+{
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
+	u64 pebs_data_cfg = 0;
+	u64 cntr_mask;
+
+	if (WARN_ON(event->hw.idx < 0 || event->hw.idx >= X86_PMC_IDX_MAX))
+		return 0;
+
+	pebs_data_cfg |= pebs_update_adaptive_cfg(event);
+
+	cntr_mask = (PEBS_DATACFG_CNTR_MASK << PEBS_DATACFG_CNTR_SHIFT) |
+		    (PEBS_DATACFG_FIX_MASK << PEBS_DATACFG_FIX_SHIFT) |
+		    PEBS_DATACFG_CNTR | PEBS_DATACFG_METRICS;
+	pebs_data_cfg |= cpuc->pebs_data_cfg & cntr_mask;
+
+	return pebs_data_cfg;
+}
+
 void intel_pmu_pebs_add(struct perf_event *event)
 {
 	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
@@ -1532,6 +1609,15 @@ static inline void intel_pmu_drain_large_pebs(struct cpu_hw_events *cpuc)
 		intel_pmu_drain_pebs_buffer();
 }
 
+static void __intel_pmu_pebs_enable(struct perf_event *event)
+{
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
+	struct hw_perf_event *hwc = &event->hw;
+
+	hwc->config &= ~ARCH_PERFMON_EVENTSEL_INT;
+	cpuc->pebs_enabled |= 1ULL << hwc->idx;
+}
+
 void intel_pmu_pebs_enable(struct perf_event *event)
 {
 	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
@@ -1540,9 +1626,7 @@ void intel_pmu_pebs_enable(struct perf_event *event)
 	struct debug_store *ds = cpuc->ds;
 	unsigned int idx = hwc->idx;
 
-	hwc->config &= ~ARCH_PERFMON_EVENTSEL_INT;
+	__intel_pmu_pebs_enable(event);
-
-	cpuc->pebs_enabled |= 1ULL << hwc->idx;
 
 	if ((event->hw.flags & PERF_X86_EVENT_PEBS_LDLAT) && (x86_pmu.version < 5))
 		cpuc->pebs_enabled |= 1ULL << (hwc->idx + 32);
@@ -1604,14 +1688,22 @@ void intel_pmu_pebs_del(struct perf_event *event)
 	pebs_update_state(needed_cb, cpuc, event, false);
 }
 
-void intel_pmu_pebs_disable(struct perf_event *event)
+static void __intel_pmu_pebs_disable(struct perf_event *event)
 {
 	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	struct hw_perf_event *hwc = &event->hw;
 
 	intel_pmu_drain_large_pebs(cpuc);
-
 	cpuc->pebs_enabled &= ~(1ULL << hwc->idx);
+	hwc->config |= ARCH_PERFMON_EVENTSEL_INT;
+}
+
+void intel_pmu_pebs_disable(struct perf_event *event)
+{
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
+	struct hw_perf_event *hwc = &event->hw;
+
+	__intel_pmu_pebs_disable(event);
 
 	if ((event->hw.flags & PERF_X86_EVENT_PEBS_LDLAT) &&
 	    (x86_pmu.version < 5))
@@ -1623,8 +1715,6 @@ void intel_pmu_pebs_disable(struct perf_event *event)
 
 	if (cpuc->enabled)
 		wrmsrq(MSR_IA32_PEBS_ENABLE, cpuc->pebs_enabled);
-
-	hwc->config |= ARCH_PERFMON_EVENTSEL_INT;
 }
 
 void intel_pmu_pebs_enable_all(void)
@@ -2060,6 +2150,90 @@ static inline void __setup_pebs_counter_group(struct cpu_hw_events *cpuc,
 
 #define PEBS_LATENCY_MASK			0xffff
 
+static inline void __setup_perf_sample_data(struct perf_event *event,
+					    struct pt_regs *iregs,
+					    struct perf_sample_data *data)
+{
+	perf_sample_data_init(data, 0, event->hw.last_period);
+
+	/*
+	 * We must however always use iregs for the unwinder to stay sane; the
+	 * record BP,SP,IP can point into thin air when the record is from a
+	 * previous PMI context or an (I)RET happened between the record and
+	 * PMI.
+	 */
+	perf_sample_save_callchain(data, event, iregs);
+}
+
+static inline void __setup_pebs_basic_group(struct perf_event *event,
+					    struct pt_regs *regs,
+					    struct perf_sample_data *data,
+					    u64 sample_type, u64 ip,
+					    u64 tsc, u16 retire)
+{
+	/* The ip in basic is EventingIP */
+	set_linear_ip(regs, ip);
+	regs->flags = PERF_EFLAGS_EXACT;
+	setup_pebs_time(event, data, tsc);
+
+	if (sample_type & PERF_SAMPLE_WEIGHT_STRUCT)
+		data->weight.var3_w = retire;
+}
+
+static inline void __setup_pebs_gpr_group(struct perf_event *event,
+					  struct pt_regs *regs,
+					  struct pebs_gprs *gprs,
+					  u64 sample_type)
+{
+	if (event->attr.precise_ip < 2) {
+		set_linear_ip(regs, gprs->ip);
+		regs->flags &= ~PERF_EFLAGS_EXACT;
+	}
+
+	if (sample_type & (PERF_SAMPLE_REGS_INTR | PERF_SAMPLE_REGS_USER))
+		adaptive_pebs_save_regs(regs, gprs);
+}
+
+static inline void __setup_pebs_meminfo_group(struct perf_event *event,
+					      struct perf_sample_data *data,
+					      u64 sample_type, u64 latency,
+					      u16 instr_latency, u64 address,
+					      u64 aux, u64 tsx_tuning, u64 ax)
+{
+	if (sample_type & PERF_SAMPLE_WEIGHT_TYPE) {
+		u64 tsx_latency = intel_get_tsx_weight(tsx_tuning);
+
+		data->weight.var2_w = instr_latency;
+
+		/*
+		 * Although meminfo::latency is defined as a u64,
+		 * only the lower 32 bits include the valid data
+		 * in practice on Ice Lake and earlier platforms.
+		 */
+		if (sample_type & PERF_SAMPLE_WEIGHT)
+			data->weight.full = latency ?: tsx_latency;
+		else
+			data->weight.var1_dw = (u32)latency ?: tsx_latency;
+
+		data->sample_flags |= PERF_SAMPLE_WEIGHT_TYPE;
+	}
+
+	if (sample_type & PERF_SAMPLE_DATA_SRC) {
+		data->data_src.val = get_data_src(event, aux);
+		data->sample_flags |= PERF_SAMPLE_DATA_SRC;
+	}
+
+	if (sample_type & PERF_SAMPLE_ADDR_TYPE) {
+		data->addr = address;
+		data->sample_flags |= PERF_SAMPLE_ADDR;
+	}
+
+	if (sample_type & PERF_SAMPLE_TRANSACTION) {
+		data->txn = intel_get_tsx_transaction(tsx_tuning, ax);
+		data->sample_flags |= PERF_SAMPLE_TRANSACTION;
+	}
+}
+
 /*
  * With adaptive PEBS the layout depends on what fields are configured.
  */
@@ -2069,12 +2243,14 @@ static void setup_pebs_adaptive_sample_data(struct perf_event *event,
 					    struct pt_regs *regs)
 {
 	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
+	u64 sample_type = event->attr.sample_type;
 	struct pebs_basic *basic = __pebs;
 	void *next_record = basic + 1;
-	u64 sample_type, format_group;
 	struct pebs_meminfo *meminfo = NULL;
 	struct pebs_gprs *gprs = NULL;
 	struct x86_perf_regs *perf_regs;
+	u64 format_group;
+	u16 retire;
 
 	if (basic == NULL)
 		return;
@@ -2082,31 +2258,17 @@ static void setup_pebs_adaptive_sample_data(struct perf_event *event,
 	perf_regs = container_of(regs, struct x86_perf_regs, regs);
 	perf_regs->xmm_regs = NULL;
 
-	sample_type = event->attr.sample_type;
 	format_group = basic->format_group;
-	perf_sample_data_init(data, 0, event->hw.last_period);
 
-	setup_pebs_time(event, data, basic->tsc);
+	__setup_perf_sample_data(event, iregs, data);
-
-	/*
-	 * We must however always use iregs for the unwinder to stay sane; the
-	 * record BP,SP,IP can point into thin air when the record is from a
-	 * previous PMI context or an (I)RET happened between the record and
-	 * PMI.
-	 */
-	perf_sample_save_callchain(data, event, iregs);
 
 	*regs = *iregs;
-	/* The ip in basic is EventingIP */
-	set_linear_ip(regs, basic->ip);
-	regs->flags = PERF_EFLAGS_EXACT;
 
-	if (sample_type & PERF_SAMPLE_WEIGHT_STRUCT) {
+	/* basic group */
-		if (x86_pmu.flags & PMU_FL_RETIRE_LATENCY)
+	retire = x86_pmu.flags & PMU_FL_RETIRE_LATENCY ?
-			data->weight.var3_w = basic->retire_latency;
+			basic->retire_latency : 0;
-		else
+	__setup_pebs_basic_group(event, regs, data, sample_type,
-			data->weight.var3_w = 0;
+				 basic->ip, basic->tsc, retire);
-	}
 
 	/*
 	 * The record for MEMINFO is in front of GP
@@ -2122,54 +2284,20 @@ static void setup_pebs_adaptive_sample_data(struct perf_event *event,
 		gprs = next_record;
 		next_record = gprs + 1;
 
-		if (event->attr.precise_ip < 2) {
+		__setup_pebs_gpr_group(event, regs, gprs, sample_type);
-			set_linear_ip(regs, gprs->ip);
-			regs->flags &= ~PERF_EFLAGS_EXACT;
-		}
-
-		if (sample_type & (PERF_SAMPLE_REGS_INTR | PERF_SAMPLE_REGS_USER))
-			adaptive_pebs_save_regs(regs, gprs);
 	}
 
 	if (format_group & PEBS_DATACFG_MEMINFO) {
-		if (sample_type & PERF_SAMPLE_WEIGHT_TYPE) {
 		u64 latency = x86_pmu.flags & PMU_FL_INSTR_LATENCY ?
 				meminfo->cache_latency : meminfo->mem_latency;
+		u64 instr_latency = x86_pmu.flags & PMU_FL_INSTR_LATENCY ?
+				meminfo->instr_latency : 0;
+		u64 ax = gprs ? gprs->ax : 0;
 
-			if (x86_pmu.flags & PMU_FL_INSTR_LATENCY)
+		__setup_pebs_meminfo_group(event, data, sample_type, latency,
-				data->weight.var2_w = meminfo->instr_latency;
+					   instr_latency, meminfo->address,
-
+					   meminfo->aux, meminfo->tsx_tuning,
-			/*
+					   ax);
-			 * Although meminfo::latency is defined as a u64,
-			 * only the lower 32 bits include the valid data
-			 * in practice on Ice Lake and earlier platforms.
-			 */
-			if (sample_type & PERF_SAMPLE_WEIGHT) {
-				data->weight.full = latency ?:
-					intel_get_tsx_weight(meminfo->tsx_tuning);
-			} else {
-				data->weight.var1_dw = (u32)latency ?:
-					intel_get_tsx_weight(meminfo->tsx_tuning);
-			}
-
-			data->sample_flags |= PERF_SAMPLE_WEIGHT_TYPE;
-		}
-
-		if (sample_type & PERF_SAMPLE_DATA_SRC) {
-			data->data_src.val = get_data_src(event, meminfo->aux);
-			data->sample_flags |= PERF_SAMPLE_DATA_SRC;
-		}
-
-		if (sample_type & PERF_SAMPLE_ADDR_TYPE) {
-			data->addr = meminfo->address;
-			data->sample_flags |= PERF_SAMPLE_ADDR;
-		}
-
-		if (sample_type & PERF_SAMPLE_TRANSACTION) {
-			data->txn = intel_get_tsx_transaction(meminfo->tsx_tuning,
-							  gprs ? gprs->ax : 0);
-			data->sample_flags |= PERF_SAMPLE_TRANSACTION;
-		}
 	}
 
 	if (format_group & PEBS_DATACFG_XMMS) {
@@ -2220,6 +2348,135 @@ static void setup_pebs_adaptive_sample_data(struct perf_event *event,
 			format_group);
 }
 
+static inline bool arch_pebs_record_continued(struct arch_pebs_header *header)
+{
+	/* Continue bit or null PEBS record indicates fragment follows. */
+	return header->cont || !(header->format & GENMASK_ULL(63, 16));
+}
+
+static void setup_arch_pebs_sample_data(struct perf_event *event,
+					struct pt_regs *iregs,
+					void *__pebs,
+					struct perf_sample_data *data,
+					struct pt_regs *regs)
+{
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
+	u64 sample_type = event->attr.sample_type;
+	struct arch_pebs_header *header = NULL;
+	struct arch_pebs_aux *meminfo = NULL;
+	struct arch_pebs_gprs *gprs = NULL;
+	struct x86_perf_regs *perf_regs;
+	void *next_record;
+	void *at = __pebs;
+
+	if (at == NULL)
+		return;
+
+	perf_regs = container_of(regs, struct x86_perf_regs, regs);
+	perf_regs->xmm_regs = NULL;
+
+	__setup_perf_sample_data(event, iregs, data);
+
+	*regs = *iregs;
+
+again:
+	header = at;
+	next_record = at + sizeof(struct arch_pebs_header);
+	if (header->basic) {
+		struct arch_pebs_basic *basic = next_record;
+		u16 retire = 0;
+
+		next_record = basic + 1;
+
+		if (sample_type & PERF_SAMPLE_WEIGHT_STRUCT)
+			retire = basic->valid ? basic->retire : 0;
+		__setup_pebs_basic_group(event, regs, data, sample_type,
+				 basic->ip, basic->tsc, retire);
+	}
+
+	/*
+	 * The record for MEMINFO is in front of GP
+	 * But PERF_SAMPLE_TRANSACTION needs gprs->ax.
+	 * Save the pointer here but process later.
+	 */
+	if (header->aux) {
+		meminfo = next_record;
+		next_record = meminfo + 1;
+	}
+
+	if (header->gpr) {
+		gprs = next_record;
+		next_record = gprs + 1;
+
+		__setup_pebs_gpr_group(event, regs,
+				       (struct pebs_gprs *)gprs,
+				       sample_type);
+	}
+
+	if (header->aux) {
+		u64 ax = gprs ? gprs->ax : 0;
+
+		__setup_pebs_meminfo_group(event, data, sample_type,
+					   meminfo->cache_latency,
+					   meminfo->instr_latency,
+					   meminfo->address, meminfo->aux,
+					   meminfo->tsx_tuning, ax);
+	}
+
+	if (header->xmm) {
+		struct pebs_xmm *xmm;
+
+		next_record += sizeof(struct arch_pebs_xer_header);
+
+		xmm = next_record;
+		perf_regs->xmm_regs = xmm->xmm;
+		next_record = xmm + 1;
+	}
+
+	if (header->lbr) {
+		struct arch_pebs_lbr_header *lbr_header = next_record;
+		struct lbr_entry *lbr;
+		int num_lbr;
+
+		next_record = lbr_header + 1;
+		lbr = next_record;
+
+		num_lbr = header->lbr == ARCH_PEBS_LBR_NUM_VAR ?
+				lbr_header->depth :
+				header->lbr * ARCH_PEBS_BASE_LBR_ENTRIES;
+		next_record += num_lbr * sizeof(struct lbr_entry);
+
+		if (has_branch_stack(event)) {
+			intel_pmu_store_pebs_lbrs(lbr);
+			intel_pmu_lbr_save_brstack(data, cpuc, event);
+		}
+	}
+
+	if (header->cntr) {
+		struct arch_pebs_cntr_header *cntr = next_record;
+		unsigned int nr;
+
+		next_record += sizeof(struct arch_pebs_cntr_header);
+
+		if (is_pebs_counter_event_group(event)) {
+			__setup_pebs_counter_group(cpuc, event,
+				(struct pebs_cntr_header *)cntr, next_record);
+			data->sample_flags |= PERF_SAMPLE_READ;
+		}
+
+		nr = hweight32(cntr->cntr) + hweight32(cntr->fixed);
+		if (cntr->metrics == INTEL_CNTR_METRICS)
+			nr += 2;
+		next_record += nr * sizeof(u64);
+	}
+
+	/* Parse followed fragments if there are. */
+	if (arch_pebs_record_continued(header)) {
+		at = at + header->size;
+		goto again;
+	}
+}
+
 static inline void *
 get_next_pebs_record_by_bit(void *base, void *top, int bit)
 {
@@ -2602,6 +2859,57 @@ static void intel_pmu_drain_pebs_nhm(struct pt_regs *iregs, struct perf_sample_d
 	}
 }
 
+static __always_inline void
+__intel_pmu_handle_pebs_record(struct pt_regs *iregs,
+			       struct pt_regs *regs,
+			       struct perf_sample_data *data,
+			       void *at, u64 pebs_status,
+			       short *counts, void **last,
+			       setup_fn setup_sample)
+{
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
+	struct perf_event *event;
+	int bit;
+
+	for_each_set_bit(bit, (unsigned long *)&pebs_status, X86_PMC_IDX_MAX) {
+		event = cpuc->events[bit];
+
+		if (WARN_ON_ONCE(!event) ||
+		    WARN_ON_ONCE(!event->attr.precise_ip))
+			continue;
+
+		if (counts[bit]++) {
+			__intel_pmu_pebs_event(event, iregs, regs, data,
+					       last[bit], setup_sample);
+		}
+
+		last[bit] = at;
+	}
+}
+
+static __always_inline void
+__intel_pmu_handle_last_pebs_record(struct pt_regs *iregs,
+				    struct pt_regs *regs,
+				    struct perf_sample_data *data,
+				    u64 mask, short *counts, void **last,
+				    setup_fn setup_sample)
+{
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
+	struct perf_event *event;
+	int bit;
+
+	for_each_set_bit(bit, (unsigned long *)&mask, X86_PMC_IDX_MAX) {
+		if (!counts[bit])
+			continue;
+
+		event = cpuc->events[bit];
+
+		__intel_pmu_pebs_last_event(event, iregs, regs, data, last[bit],
+					    counts[bit], setup_sample);
+	}
+
+}
+
 static void intel_pmu_drain_pebs_icl(struct pt_regs *iregs, struct perf_sample_data *data)
 {
 	short counts[INTEL_PMC_IDX_FIXED + MAX_FIXED_PEBS_EVENTS] = {};
@@ -2611,9 +2919,7 @@ static void intel_pmu_drain_pebs_icl(struct pt_regs *iregs, struct perf_sample_d
 	struct x86_perf_regs perf_regs;
 	struct pt_regs *regs = &perf_regs.regs;
 	struct pebs_basic *basic;
-	struct perf_event *event;
 	void *base, *at, *top;
-	int bit;
 	u64 mask;
 
 	if (!x86_pmu.pebs_active)
@@ -2626,6 +2932,7 @@ static void intel_pmu_drain_pebs_icl(struct pt_regs *iregs, struct perf_sample_d
 
 	mask = hybrid(cpuc->pmu, pebs_events_mask) |
 	       (hybrid(cpuc->pmu, fixed_cntr_mask64) << INTEL_PMC_IDX_FIXED);
+	mask &= cpuc->pebs_enabled;
 
 	if (unlikely(base >= top)) {
 		intel_pmu_pebs_event_update_no_drain(cpuc, mask);
@@ -2643,38 +2950,114 @@ static void intel_pmu_drain_pebs_icl(struct pt_regs *iregs, struct perf_sample_d
 		if (basic->format_size != cpuc->pebs_record_size)
 			continue;
 
-		pebs_status = basic->applicable_counters & cpuc->pebs_enabled & mask;
+		pebs_status = mask & basic->applicable_counters;
-		for_each_set_bit(bit, (unsigned long *)&pebs_status, X86_PMC_IDX_MAX) {
+		__intel_pmu_handle_pebs_record(iregs, regs, data, at,
-			event = cpuc->events[bit];
+					       pebs_status, counts, last,
-
-			if (WARN_ON_ONCE(!event) ||
-			    WARN_ON_ONCE(!event->attr.precise_ip))
-				continue;
-
-			if (counts[bit]++) {
-				__intel_pmu_pebs_event(event, iregs, regs, data, last[bit],
 					       setup_pebs_adaptive_sample_data);
 	}
-			last[bit] = at;
+
-		}
+	__intel_pmu_handle_last_pebs_record(iregs, regs, data, mask, counts, last,
+					    setup_pebs_adaptive_sample_data);
+}
+
+static void intel_pmu_drain_arch_pebs(struct pt_regs *iregs,
+				      struct perf_sample_data *data)
+{
+	short counts[INTEL_PMC_IDX_FIXED + MAX_FIXED_PEBS_EVENTS] = {};
+	void *last[INTEL_PMC_IDX_FIXED + MAX_FIXED_PEBS_EVENTS];
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
+	union arch_pebs_index index;
+	struct x86_perf_regs perf_regs;
+	struct pt_regs *regs = &perf_regs.regs;
+	void *base, *at, *top;
+	u64 mask;
+
+	rdmsrq(MSR_IA32_PEBS_INDEX, index.whole);
+
+	if (unlikely(!index.wr)) {
+		intel_pmu_pebs_event_update_no_drain(cpuc, X86_PMC_IDX_MAX);
+		return;
 	}
 
-	for_each_set_bit(bit, (unsigned long *)&mask, X86_PMC_IDX_MAX) {
+	base = cpuc->pebs_vaddr;
-		if (!counts[bit])
+	top = cpuc->pebs_vaddr + (index.wr << ARCH_PEBS_INDEX_WR_SHIFT);
+
+	index.wr = 0;
+	index.full = 0;
+	index.en = 1;
+	if (cpuc->n_pebs == cpuc->n_large_pebs)
+		index.thresh = ARCH_PEBS_THRESH_MULTI;
+	else
+		index.thresh = ARCH_PEBS_THRESH_SINGLE;
+	wrmsrq(MSR_IA32_PEBS_INDEX, index.whole);
+
+	mask = hybrid(cpuc->pmu, arch_pebs_cap).counters & cpuc->pebs_enabled;
+
+	if (!iregs)
+		iregs = &dummy_iregs;
+
+	/* Process all but the last event for each counter. */
+	for (at = base; at < top;) {
+		struct arch_pebs_header *header;
+		struct arch_pebs_basic *basic;
+		u64 pebs_status;
+
+		header = at;
+
+		if (WARN_ON_ONCE(!header->size))
+			break;
+
+		/* 1st fragment or single record must have basic group */
+		if (!header->basic) {
+			at += header->size;
 			continue;
-
-		event = cpuc->events[bit];
-
-		__intel_pmu_pebs_last_event(event, iregs, regs, data, last[bit],
-					    counts[bit], setup_pebs_adaptive_sample_data);
 		}
+
+		basic = at + sizeof(struct arch_pebs_header);
+		pebs_status = mask & basic->applicable_counters;
+		__intel_pmu_handle_pebs_record(iregs, regs, data, at,
+					       pebs_status, counts, last,
+					       setup_arch_pebs_sample_data);
+
+		/* Skip non-last fragments */
+		while (arch_pebs_record_continued(header)) {
+			if (!header->size)
+				break;
+			at += header->size;
+			header = at;
+		}
+
+		/* Skip last fragment or the single record */
+		at += header->size;
+	}
+
+	__intel_pmu_handle_last_pebs_record(iregs, regs, data, mask,
+					    counts, last,
+					    setup_arch_pebs_sample_data);
+}
+
+static void __init intel_arch_pebs_init(void)
+{
+	/*
+	 * Current hybrid platforms always both support arch-PEBS or not
+	 * on all kinds of cores. So directly set x86_pmu.arch_pebs flag
+	 * if boot cpu supports arch-PEBS.
+	 */
+	x86_pmu.arch_pebs = 1;
+	x86_pmu.pebs_buffer_size = PEBS_BUFFER_SIZE;
+	x86_pmu.drain_pebs = intel_pmu_drain_arch_pebs;
+	x86_pmu.pebs_capable = ~0ULL;
+	x86_pmu.flags |= PMU_FL_PEBS_ALL;
+
+	x86_pmu.pebs_enable = __intel_pmu_pebs_enable;
+	x86_pmu.pebs_disable = __intel_pmu_pebs_disable;
 }
 
 /*
  * PEBS probe and setup
  */
 
-void __init intel_pebs_init(void)
+static void __init intel_ds_pebs_init(void)
 {
 	/*
 	 * No support for 32bit formats
@@ -2736,10 +3119,8 @@ void __init intel_pebs_init(void)
 			break;
 
 		case 6:
-			if (x86_pmu.intel_cap.pebs_baseline) {
+			if (x86_pmu.intel_cap.pebs_baseline)
 				x86_pmu.large_pebs_flags |= PERF_SAMPLE_READ;
-				x86_pmu.late_setup = intel_pmu_late_setup;
-			}
 			fallthrough;
 		case 5:
 			x86_pmu.pebs_ept = 1;
@@ -2789,6 +3170,14 @@ void __init intel_pebs_init(void)
 	}
 }
 
+void __init intel_pebs_init(void)
+{
+	if (x86_pmu.intel_cap.pebs_format == 0xf)
+		intel_arch_pebs_init();
+	else
+		intel_ds_pebs_init();
+}
+
 void perf_restore_debug_store(void)
 {
 	struct debug_store *ds = __this_cpu_read(cpu_hw_events.ds);

arch/x86/events/perf_event.h

@@ -283,8 +283,9 @@ struct cpu_hw_events {
 	 * Intel DebugStore bits
 	 */
 	struct debug_store	*ds;
-	void			*ds_pebs_vaddr;
 	void			*ds_bts_vaddr;
+	/* DS based PEBS or arch-PEBS buffer address */
+	void			*pebs_vaddr;
 	u64			pebs_enabled;
 	int			n_pebs;
 	int			n_large_pebs;
@@ -303,6 +304,8 @@ struct cpu_hw_events {
 	/* Intel ACR configuration */
 	u64			acr_cfg_b[X86_PMC_IDX_MAX];
 	u64			acr_cfg_c[X86_PMC_IDX_MAX];
+	/* Cached CFG_C values */
+	u64			cfg_c_val[X86_PMC_IDX_MAX];
 
 	/*
 	 * Intel LBR bits
@@ -708,6 +711,12 @@ enum hybrid_pmu_type {
 	hybrid_big_small_tiny	= hybrid_big   | hybrid_small_tiny,
 };
 
+struct arch_pebs_cap {
+	u64 caps;
+	u64 counters;
+	u64 pdists;
+};
+
 struct x86_hybrid_pmu {
 	struct pmu			pmu;
 	const char			*name;
@@ -752,6 +761,8 @@ struct x86_hybrid_pmu {
 					mid_ack		:1,
 					enabled_ack	:1;
 
+	struct arch_pebs_cap		arch_pebs_cap;
+
 	u64				pebs_data_source[PERF_PEBS_DATA_SOURCE_MAX];
 };
 
@@ -906,7 +917,7 @@ struct x86_pmu {
 	union perf_capabilities intel_cap;
 
 	/*
-	 * Intel DebugStore bits
+	 * Intel DebugStore and PEBS bits
 	 */
 	unsigned int	bts			:1,
 			bts_active		:1,
@@ -917,7 +928,8 @@ struct x86_pmu {
 			pebs_no_tlb		:1,
 			pebs_no_isolation	:1,
 			pebs_block		:1,
-			pebs_ept		:1;
+			pebs_ept		:1,
+			arch_pebs		:1;
 	int		pebs_record_size;
 	int		pebs_buffer_size;
 	u64		pebs_events_mask;
@@ -929,6 +941,11 @@ struct x86_pmu {
 	u64		rtm_abort_event;
 	u64		pebs_capable;
 
+	/*
+	 * Intel Architectural PEBS
+	 */
+	struct arch_pebs_cap arch_pebs_cap;
+
 	/*
 	 * Intel LBR
 	 */
@@ -1124,7 +1141,6 @@ static struct perf_pmu_format_hybrid_attr format_attr_hybrid_##_name = {\
 	.pmu_type	= _pmu,						\
 }
 
-int is_x86_event(struct perf_event *event);
 struct pmu *x86_get_pmu(unsigned int cpu);
 extern struct x86_pmu x86_pmu __read_mostly;
 
@@ -1217,7 +1233,7 @@ int x86_reserve_hardware(void);
 
 void x86_release_hardware(void);
 
-int x86_pmu_max_precise(void);
+int x86_pmu_max_precise(struct pmu *pmu);
 
 void hw_perf_lbr_event_destroy(struct perf_event *event);
 
@@ -1604,6 +1620,14 @@ extern void intel_cpuc_finish(struct cpu_hw_events *cpuc);
 
 int intel_pmu_init(void);
 
+int alloc_arch_pebs_buf_on_cpu(int cpu);
+
+void release_arch_pebs_buf_on_cpu(int cpu);
+
+void init_arch_pebs_on_cpu(int cpu);
+
+void fini_arch_pebs_on_cpu(int cpu);
+
 void init_debug_store_on_cpu(int cpu);
 
 void fini_debug_store_on_cpu(int cpu);
@@ -1760,6 +1784,8 @@ void intel_pmu_pebs_data_source_cmt(void);
 
 void intel_pmu_pebs_data_source_lnl(void);
 
+u64 intel_get_arch_pebs_data_config(struct perf_event *event);
+
 int intel_pmu_setup_lbr_filter(struct perf_event *event);
 
 void intel_pt_interrupt(void);
@@ -1792,6 +1818,11 @@ static inline int intel_pmu_max_num_pebs(struct pmu *pmu)
 	return fls((u32)hybrid(pmu, pebs_events_mask));
 }
 
+static inline bool intel_pmu_has_pebs(void)
+{
+	return x86_pmu.ds_pebs || x86_pmu.arch_pebs;
+}
+
 #else /* CONFIG_CPU_SUP_INTEL */
 
 static inline void reserve_ds_buffers(void)

arch/x86/include/asm/insn-eval.h

@@ -44,4 +44,6 @@ enum insn_mmio_type {
 
 enum insn_mmio_type insn_decode_mmio(struct insn *insn, int *bytes);
 
+bool insn_is_nop(struct insn *insn);
+
 #endif /* _ASM_X86_INSN_EVAL_H */

arch/x86/include/asm/insn.h

@@ -312,7 +312,6 @@ static inline int insn_offset_immediate(struct insn *insn)
 /**
  * for_each_insn_prefix() -- Iterate prefixes in the instruction
  * @insn: Pointer to struct insn.
- * @idx:  Index storage.
  * @prefix: Prefix byte.
  *
  * Iterate prefix bytes of given @insn. Each prefix byte is stored in @prefix
@@ -321,8 +320,8 @@ static inline int insn_offset_immediate(struct insn *insn)
  * Since prefixes.nbytes can be bigger than 4 if some prefixes
  * are repeated, it cannot be used for looping over the prefixes.
  */
-#define for_each_insn_prefix(insn, idx, prefix)	\
+#define for_each_insn_prefix(insn, prefix)	\
-	for (idx = 0; idx < ARRAY_SIZE(insn->prefixes.bytes) && (prefix = insn->prefixes.bytes[idx]) != 0; idx++)
+	for (int idx = 0; idx < ARRAY_SIZE(insn->prefixes.bytes) && (prefix = insn->prefixes.bytes[idx]) != 0; idx++)
 
 #define POP_SS_OPCODE 0x1f
 #define MOV_SREG_OPCODE 0x8e

arch/x86/include/asm/intel_ds.h

@@ -4,7 +4,15 @@
 #include <linux/percpu-defs.h>
 
 #define BTS_BUFFER_SIZE		(PAGE_SIZE << 4)
-#define PEBS_BUFFER_SIZE	(PAGE_SIZE << 4)
+#define PEBS_BUFFER_SHIFT	4
+#define PEBS_BUFFER_SIZE	(PAGE_SIZE << PEBS_BUFFER_SHIFT)
+
+/*
+ * The largest PEBS record could consume a page, ensure
+ * a record at least can be written after triggering PMI.
+ */
+#define ARCH_PEBS_THRESH_MULTI	((PEBS_BUFFER_SIZE - PAGE_SIZE) >> PEBS_BUFFER_SHIFT)
+#define ARCH_PEBS_THRESH_SINGLE	1
 
 /* The maximal number of PEBS events: */
 #define MAX_PEBS_EVENTS_FMT4	8

arch/x86/include/asm/msr-index.h

@@ -327,6 +327,26 @@
 					 PERF_CAP_PEBS_FORMAT | PERF_CAP_PEBS_BASELINE | \
 					 PERF_CAP_PEBS_TIMING_INFO)
 
+/* Arch PEBS */
+#define MSR_IA32_PEBS_BASE		0x000003f4
+#define MSR_IA32_PEBS_INDEX		0x000003f5
+#define ARCH_PEBS_OFFSET_MASK		0x7fffff
+#define ARCH_PEBS_INDEX_WR_SHIFT	4
+
+#define ARCH_PEBS_RELOAD		0xffffffff
+#define ARCH_PEBS_CNTR_ALLOW		BIT_ULL(35)
+#define ARCH_PEBS_CNTR_GP		BIT_ULL(36)
+#define ARCH_PEBS_CNTR_FIXED		BIT_ULL(37)
+#define ARCH_PEBS_CNTR_METRICS		BIT_ULL(38)
+#define ARCH_PEBS_LBR_SHIFT		40
+#define ARCH_PEBS_LBR			(0x3ull << ARCH_PEBS_LBR_SHIFT)
+#define ARCH_PEBS_VECR_XMM		BIT_ULL(49)
+#define ARCH_PEBS_GPR			BIT_ULL(61)
+#define ARCH_PEBS_AUX			BIT_ULL(62)
+#define ARCH_PEBS_EN			BIT_ULL(63)
+#define ARCH_PEBS_CNTR_MASK		(ARCH_PEBS_CNTR_GP | ARCH_PEBS_CNTR_FIXED | \
+					 ARCH_PEBS_CNTR_METRICS)
+
 #define MSR_IA32_RTIT_CTL		0x00000570
 #define RTIT_CTL_TRACEEN		BIT(0)
 #define RTIT_CTL_CYCLEACC		BIT(1)

arch/x86/include/asm/perf_event.h

@@ -144,13 +144,13 @@
 #define PEBS_DATACFG_GP		BIT_ULL(1)
 #define PEBS_DATACFG_XMMS	BIT_ULL(2)
 #define PEBS_DATACFG_LBRS	BIT_ULL(3)
-#define PEBS_DATACFG_LBR_SHIFT	24
 #define PEBS_DATACFG_CNTR	BIT_ULL(4)
+#define PEBS_DATACFG_METRICS	BIT_ULL(5)
+#define PEBS_DATACFG_LBR_SHIFT	24
 #define PEBS_DATACFG_CNTR_SHIFT	32
 #define PEBS_DATACFG_CNTR_MASK	GENMASK_ULL(15, 0)
 #define PEBS_DATACFG_FIX_SHIFT	48
 #define PEBS_DATACFG_FIX_MASK	GENMASK_ULL(7, 0)
-#define PEBS_DATACFG_METRICS	BIT_ULL(5)
 
 /* Steal the highest bit of pebs_data_cfg for SW usage */
 #define PEBS_UPDATE_DS_SW	BIT_ULL(63)
@@ -200,6 +200,8 @@ union cpuid10_edx {
 #define ARCH_PERFMON_EXT_LEAF			0x00000023
 #define ARCH_PERFMON_NUM_COUNTER_LEAF		0x1
 #define ARCH_PERFMON_ACR_LEAF			0x2
+#define ARCH_PERFMON_PEBS_CAP_LEAF		0x4
+#define ARCH_PERFMON_PEBS_COUNTER_LEAF		0x5
 
 union cpuid35_eax {
 	struct {
@@ -210,7 +212,10 @@ union cpuid35_eax {
 		unsigned int    acr_subleaf:1;
 		/* Events Sub-Leaf */
 		unsigned int    events_subleaf:1;
-		unsigned int	reserved:28;
+		/* arch-PEBS Sub-Leaves */
+		unsigned int	pebs_caps_subleaf:1;
+		unsigned int	pebs_cnts_subleaf:1;
+		unsigned int	reserved:26;
 	} split;
 	unsigned int            full;
 };
@@ -432,6 +437,8 @@ static inline bool is_topdown_idx(int idx)
 #define GLOBAL_STATUS_LBRS_FROZEN		BIT_ULL(GLOBAL_STATUS_LBRS_FROZEN_BIT)
 #define GLOBAL_STATUS_TRACE_TOPAPMI_BIT		55
 #define GLOBAL_STATUS_TRACE_TOPAPMI		BIT_ULL(GLOBAL_STATUS_TRACE_TOPAPMI_BIT)
+#define GLOBAL_STATUS_ARCH_PEBS_THRESHOLD_BIT	54
+#define GLOBAL_STATUS_ARCH_PEBS_THRESHOLD	BIT_ULL(GLOBAL_STATUS_ARCH_PEBS_THRESHOLD_BIT)
 #define GLOBAL_STATUS_PERF_METRICS_OVF_BIT	48
 
 #define GLOBAL_CTRL_EN_PERF_METRICS		BIT_ULL(48)
@@ -502,6 +509,107 @@ struct pebs_cntr_header {
 
 #define INTEL_CNTR_METRICS		0x3
 
+/*
+ * Arch PEBS
+ */
+union arch_pebs_index {
+	struct {
+		u64 rsvd:4,
+		    wr:23,
+		    rsvd2:4,
+		    full:1,
+		    en:1,
+		    rsvd3:3,
+		    thresh:23,
+		    rsvd4:5;
+	};
+	u64 whole;
+};
+
+struct arch_pebs_header {
+	union {
+		u64 format;
+		struct {
+			u64 size:16,	/* Record size */
+			    rsvd:14,
+			    mode:1,	/* 64BIT_MODE */
+			    cont:1,
+			    rsvd2:3,
+			    cntr:5,
+			    lbr:2,
+			    rsvd3:7,
+			    xmm:1,
+			    ymmh:1,
+			    rsvd4:2,
+			    opmask:1,
+			    zmmh:1,
+			    h16zmm:1,
+			    rsvd5:5,
+			    gpr:1,
+			    aux:1,
+			    basic:1;
+		};
+	};
+	u64 rsvd6;
+};
+
+struct arch_pebs_basic {
+	u64 ip;
+	u64 applicable_counters;
+	u64 tsc;
+	u64 retire	:16,	/* Retire Latency */
+	    valid	:1,
+	    rsvd	:47;
+	u64 rsvd2;
+	u64 rsvd3;
+};
+
+struct arch_pebs_aux {
+	u64 address;
+	u64 rsvd;
+	u64 rsvd2;
+	u64 rsvd3;
+	u64 rsvd4;
+	u64 aux;
+	u64 instr_latency	:16,
+	    pad2		:16,
+	    cache_latency	:16,
+	    pad3		:16;
+	u64 tsx_tuning;
+};
+
+struct arch_pebs_gprs {
+	u64 flags, ip, ax, cx, dx, bx, sp, bp, si, di;
+	u64 r8, r9, r10, r11, r12, r13, r14, r15, ssp;
+	u64 rsvd;
+};
+
+struct arch_pebs_xer_header {
+	u64 xstate;
+	u64 rsvd;
+};
+
+#define ARCH_PEBS_LBR_NAN		0x0
+#define ARCH_PEBS_LBR_NUM_8		0x1
+#define ARCH_PEBS_LBR_NUM_16		0x2
+#define ARCH_PEBS_LBR_NUM_VAR		0x3
+#define ARCH_PEBS_BASE_LBR_ENTRIES	8
+struct arch_pebs_lbr_header {
+	u64 rsvd;
+	u64 ctl;
+	u64 depth;
+	u64 ler_from;
+	u64 ler_to;
+	u64 ler_info;
+};
+
+struct arch_pebs_cntr_header {
+	u32 cntr;
+	u32 fixed;
+	u32 metrics;
+	u32 reserved;
+};
+
 /*
  * AMD Extended Performance Monitoring and Debug cpuid feature detection
  */

arch/x86/include/asm/unwind_user.h

@@ -0,0 +1,41 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_X86_UNWIND_USER_H
+#define _ASM_X86_UNWIND_USER_H
+
+#ifdef CONFIG_HAVE_UNWIND_USER_FP
+
+#include <asm/ptrace.h>
+#include <asm/uprobes.h>
+
+#define ARCH_INIT_USER_FP_FRAME(ws)			\
+	.cfa_off	=  2*(ws),			\
+	.ra_off		= -1*(ws),			\
+	.fp_off		= -2*(ws),			\
+	.use_fp		= true,
+
+#define ARCH_INIT_USER_FP_ENTRY_FRAME(ws)		\
+	.cfa_off	=  1*(ws),			\
+	.ra_off		= -1*(ws),			\
+	.fp_off		= 0,				\
+	.use_fp		= false,
+
+static inline int unwind_user_word_size(struct pt_regs *regs)
+{
+	/* We can't unwind VM86 stacks */
+	if (regs->flags & X86_VM_MASK)
+		return 0;
+#ifdef CONFIG_X86_64
+	if (!user_64bit_mode(regs))
+		return sizeof(int);
+#endif
+	return sizeof(long);
+}
+
+static inline bool unwind_user_at_function_start(struct pt_regs *regs)
+{
+	return is_uprobe_at_func_entry(regs);
+}
+
+#endif /* CONFIG_HAVE_UNWIND_USER_FP */
+
+#endif /* _ASM_X86_UNWIND_USER_H */

arch/x86/include/asm/uprobes.h

@@ -62,4 +62,13 @@ struct arch_uprobe_task {
 	unsigned int			saved_tf;
 };
 
+#ifdef CONFIG_UPROBES
+extern bool is_uprobe_at_func_entry(struct pt_regs *regs);
+#else
+static bool is_uprobe_at_func_entry(struct pt_regs *regs)
+{
+	return false;
+}
+#endif /* CONFIG_UPROBES */
+
 #endif	/* _ASM_UPROBES_H */

arch/x86/kernel/alternative.c

@@ -9,6 +9,7 @@
 
 #include <asm/text-patching.h>
 #include <asm/insn.h>
+#include <asm/insn-eval.h>
 #include <asm/ibt.h>
 #include <asm/set_memory.h>
 #include <asm/nmi.h>
@@ -345,25 +346,6 @@ static void add_nop(u8 *buf, unsigned int len)
 		*buf = INT3_INSN_OPCODE;
 }
 
-/*
- * Matches NOP and NOPL, not any of the other possible NOPs.
- */
-static bool insn_is_nop(struct insn *insn)
-{
-	/* Anything NOP, but no REP NOP */
-	if (insn->opcode.bytes[0] == 0x90 &&
-	    (!insn->prefixes.nbytes || insn->prefixes.bytes[0] != 0xF3))
-		return true;
-
-	/* NOPL */
-	if (insn->opcode.bytes[0] == 0x0F && insn->opcode.bytes[1] == 0x1F)
-		return true;
-
-	/* TODO: more nops */
-
-	return false;
-}
-
 /*
  * Find the offset of the first non-NOP instruction starting at @offset
  * but no further than @len.

arch/x86/kernel/kprobes/core.c

@@ -141,7 +141,6 @@ bool can_boost(struct insn *insn, void *addr)
 {
 	kprobe_opcode_t opcode;
 	insn_byte_t prefix;
-	int i;
 
 	if (search_exception_tables((unsigned long)addr))
 		return false;	/* Page fault may occur on this address. */
@@ -154,7 +153,7 @@ bool can_boost(struct insn *insn, void *addr)
 	if (insn->opcode.nbytes != 1)
 		return false;
 
-	for_each_insn_prefix(insn, i, prefix) {
+	for_each_insn_prefix(insn, prefix) {
 		insn_attr_t attr;
 
 		attr = inat_get_opcode_attribute(prefix);

arch/x86/kernel/uprobes.c

@@ -17,6 +17,7 @@
 #include <linux/kdebug.h>
 #include <asm/processor.h>
 #include <asm/insn.h>
+#include <asm/insn-eval.h>
 #include <asm/mmu_context.h>
 #include <asm/nops.h>
 
@@ -258,9 +259,8 @@ static volatile u32 good_2byte_insns[256 / 32] = {
 static bool is_prefix_bad(struct insn *insn)
 {
 	insn_byte_t p;
-	int i;
 
-	for_each_insn_prefix(insn, i, p) {
+	for_each_insn_prefix(insn, p) {
 		insn_attr_t attr;
 
 		attr = inat_get_opcode_attribute(p);
@@ -1158,35 +1158,12 @@ void arch_uprobe_optimize(struct arch_uprobe *auprobe, unsigned long vaddr)
 	mmap_write_unlock(mm);
 }
 
-static bool insn_is_nop(struct insn *insn)
-{
-	return insn->opcode.nbytes == 1 && insn->opcode.bytes[0] == 0x90;
-}
-
-static bool insn_is_nopl(struct insn *insn)
-{
-	if (insn->opcode.nbytes != 2)
-		return false;
-
-	if (insn->opcode.bytes[0] != 0x0f || insn->opcode.bytes[1] != 0x1f)
-		return false;
-
-	if (!insn->modrm.nbytes)
-		return false;
-
-	if (X86_MODRM_REG(insn->modrm.bytes[0]) != 0)
-		return false;
-
-	/* 0f 1f /0 - NOPL */
-	return true;
-}
-
 static bool can_optimize(struct insn *insn, unsigned long vaddr)
 {
 	if (!insn->x86_64 || insn->length != 5)
 		return false;
 
-	if (!insn_is_nop(insn) && !insn_is_nopl(insn))
+	if (!insn_is_nop(insn))
 		return false;
 
 	/* We can't do cross page atomic writes yet. */
@@ -1426,19 +1403,14 @@ static int branch_setup_xol_ops(struct arch_uprobe *auprobe, struct insn *insn)
 {
 	u8 opc1 = OPCODE1(insn);
 	insn_byte_t p;
-	int i;
 
-	/* x86_nops[insn->length]; same as jmp with .offs = 0 */
+	if (insn_is_nop(insn))
-	if (insn->length <= ASM_NOP_MAX &&
-	    !memcmp(insn->kaddr, x86_nops[insn->length], insn->length))
 		goto setup;
 
 	switch (opc1) {
 	case 0xeb:	/* jmp 8 */
 	case 0xe9:	/* jmp 32 */
 		break;
-	case 0x90:	/* prefix* + nop; same as jmp with .offs = 0 */
-		goto setup;
 
 	case 0xe8:	/* call relative */
 		branch_clear_offset(auprobe, insn);
@@ -1463,7 +1435,7 @@ static int branch_setup_xol_ops(struct arch_uprobe *auprobe, struct insn *insn)
 	 * Intel and AMD behavior differ in 64-bit mode: Intel ignores 66 prefix.
 	 * No one uses these insns, reject any branch insns with such prefix.
 	 */
-	for_each_insn_prefix(insn, i, p) {
+	for_each_insn_prefix(insn, p) {
 		if (p == 0x66)
 			return -ENOTSUPP;
 	}
@@ -1819,3 +1791,35 @@ bool arch_uretprobe_is_alive(struct return_instance *ret, enum rp_check ctx,
 	else
 		return regs->sp <= ret->stack;
 }
+
+/*
+ * Heuristic-based check if uprobe is installed at the function entry.
+ *
+ * Under assumption of user code being compiled with frame pointers,
+ * `push %rbp/%ebp` is a good indicator that we indeed are.
+ *
+ * Similarly, `endbr64` (assuming 64-bit mode) is also a common pattern.
+ * If we get this wrong, captured stack trace might have one extra bogus
+ * entry, but the rest of stack trace will still be meaningful.
+ */
+bool is_uprobe_at_func_entry(struct pt_regs *regs)
+{
+	struct arch_uprobe *auprobe;
+
+	if (!current->utask)
+		return false;
+
+	auprobe = current->utask->auprobe;
+	if (!auprobe)
+		return false;
+
+	/* push %rbp/%ebp */
+	if (auprobe->insn[0] == 0x55)
+		return true;
+
+	/* endbr64 (64-bit only) */
+	if (user_64bit_mode(regs) && is_endbr((u32 *)auprobe->insn))
+		return true;
+
+	return false;
+}

arch/x86/lib/insn-eval.c

@@ -63,11 +63,10 @@ static bool is_string_insn(struct insn *insn)
 bool insn_has_rep_prefix(struct insn *insn)
 {
 	insn_byte_t p;
-	int i;
 
 	insn_get_prefixes(insn);
 
-	for_each_insn_prefix(insn, i, p) {
+	for_each_insn_prefix(insn, p) {
 		if (p == 0xf2 || p == 0xf3)
 			return true;
 	}
@@ -92,13 +91,13 @@ bool insn_has_rep_prefix(struct insn *insn)
 static int get_seg_reg_override_idx(struct insn *insn)
 {
 	int idx = INAT_SEG_REG_DEFAULT;
-	int num_overrides = 0, i;
+	int num_overrides = 0;
 	insn_byte_t p;
 
 	insn_get_prefixes(insn);
 
 	/* Look for any segment override prefixes. */
-	for_each_insn_prefix(insn, i, p) {
+	for_each_insn_prefix(insn, p) {
 		insn_attr_t attr;
 
 		attr = inat_get_opcode_attribute(p);
@@ -1676,3 +1675,147 @@ enum insn_mmio_type insn_decode_mmio(struct insn *insn, int *bytes)
 
 	return type;
 }
+
+/*
+ * Recognise typical NOP patterns for both 32bit and 64bit.
+ *
+ * Notably:
+ *  - NOP, but not: REP NOP aka PAUSE
+ *  - NOPL
+ *  - MOV %reg, %reg
+ *  - LEA 0(%reg),%reg
+ *  - JMP +0
+ *
+ * Must not have false-positives; instructions identified as a NOP might be
+ * emulated as a NOP (uprobe) or Run Length Encoded in a larger NOP
+ * (alternatives).
+ *
+ * False-negatives are fine; need not be exhaustive.
+ */
+bool insn_is_nop(struct insn *insn)
+{
+	u8 b3 = 0, x3 = 0, r3 = 0;
+	u8 b4 = 0, x4 = 0, r4 = 0, m = 0;
+	u8 modrm, modrm_mod, modrm_reg, modrm_rm;
+	u8 sib = 0, sib_scale, sib_index, sib_base;
+	u8 nrex, rex;
+	u8 p, rep = 0;
+
+	if ((nrex = insn->rex_prefix.nbytes)) {
+		rex = insn->rex_prefix.bytes[nrex-1];
+
+		r3 = !!X86_REX_R(rex);
+		x3 = !!X86_REX_X(rex);
+		b3 = !!X86_REX_B(rex);
+		if (nrex > 1) {
+			r4 = !!X86_REX2_R(rex);
+			x4 = !!X86_REX2_X(rex);
+			b4 = !!X86_REX2_B(rex);
+			m  = !!X86_REX2_M(rex);
+		}
+
+	} else if (insn->vex_prefix.nbytes) {
+		/*
+		 * Ignore VEX encoded NOPs
+		 */
+		return false;
+	}
+
+	if (insn->modrm.nbytes) {
+		modrm = insn->modrm.bytes[0];
+		modrm_mod = X86_MODRM_MOD(modrm);
+		modrm_reg = X86_MODRM_REG(modrm) + 8*r3 + 16*r4;
+		modrm_rm  = X86_MODRM_RM(modrm)  + 8*b3 + 16*b4;
+		modrm = 1;
+	}
+
+	if (insn->sib.nbytes) {
+		sib = insn->sib.bytes[0];
+		sib_scale = X86_SIB_SCALE(sib);
+		sib_index = X86_SIB_INDEX(sib) + 8*x3 + 16*x4;
+		sib_base  = X86_SIB_BASE(sib)  + 8*b3 + 16*b4;
+		sib = 1;
+
+		modrm_rm = sib_base;
+	}
+
+	for_each_insn_prefix(insn, p) {
+		if (p == 0xf3) /* REPE */
+			rep = 1;
+	}
+
+	/*
+	 * Opcode map munging:
+	 *
+	 * REX2: 0 - single byte opcode
+	 *       1 - 0f second byte opcode
+	 */
+	switch (m) {
+	case 0: break;
+	case 1: insn->opcode.value <<= 8;
+		insn->opcode.value |= 0x0f;
+		break;
+	default:
+		return false;
+	}
+
+	switch (insn->opcode.bytes[0]) {
+	case 0x0f: /* 2nd byte */
+		break;
+
+	case 0x89: /* MOV */
+		if (modrm_mod != 3) /* register-direct */
+			return false;
+
+		/* native size */
+		if (insn->opnd_bytes != 4 * (1 + insn->x86_64))
+			return false;
+
+		return modrm_reg == modrm_rm; /* MOV %reg, %reg */
+
+	case 0x8d: /* LEA */
+		if (modrm_mod == 0 || modrm_mod == 3) /* register-indirect with disp */
+			return false;
+
+		/* native size */
+		if (insn->opnd_bytes != 4 * (1 + insn->x86_64))
+			return false;
+
+		if (insn->displacement.value != 0)
+			return false;
+
+		if (sib && (sib_scale != 0 || sib_index != 4)) /* (%reg, %eiz, 1) */
+			return false;
+
+		for_each_insn_prefix(insn, p) {
+			if (p != 0x3e) /* DS */
+				return false;
+		}
+
+		return modrm_reg == modrm_rm; /* LEA 0(%reg), %reg */
+
+	case 0x90: /* NOP */
+		if (b3 || b4) /* XCHG %r{8,16,24},%rax */
+			return false;
+
+		if (rep) /* REP NOP := PAUSE */
+			return false;
+
+		return true;
+
+	case 0xe9: /* JMP.d32 */
+	case 0xeb: /* JMP.d8 */
+		return insn->immediate.value == 0; /* JMP +0 */
+
+	default:
+		return false;
+	}
+
+	switch (insn->opcode.bytes[1]) {
+	case 0x1f:
+		return modrm_reg == 0; /* 0f 1f /0 -- NOPL */
+
+	default:
+		return false;
+	}
+}

include/linux/irq-entry-common.h

@@ -253,11 +253,11 @@ static __always_inline void exit_to_user_mode_prepare(struct pt_regs *regs)
 static __always_inline void exit_to_user_mode(void)
 {
 	instrumentation_begin();
+	unwind_reset_info();
 	trace_hardirqs_on_prepare();
 	lockdep_hardirqs_on_prepare();
 	instrumentation_end();
 
-	unwind_reset_info();
 	user_enter_irqoff();
 	arch_exit_to_user_mode();
 	lockdep_hardirqs_on(CALLER_ADDR0);

include/linux/perf_event.h

@@ -1720,7 +1720,7 @@ extern void perf_callchain_user(struct perf_callchain_entry_ctx *entry, struct p
 extern void perf_callchain_kernel(struct perf_callchain_entry_ctx *entry, struct pt_regs *regs);
 extern struct perf_callchain_entry *
 get_perf_callchain(struct pt_regs *regs, bool kernel, bool user,
-		   u32 max_stack, bool crosstask, bool add_mark);
+		   u32 max_stack, bool crosstask, bool add_mark, u64 defer_cookie);
 extern int get_callchain_buffers(int max_stack);
 extern void put_callchain_buffers(void);
 extern struct perf_callchain_entry *get_callchain_entry(int *rctx);

include/linux/unwind_deferred.h

@@ -6,16 +6,6 @@
 #include <linux/unwind_user.h>
 #include <linux/unwind_deferred_types.h>
 
-struct unwind_work;
-
-typedef void (*unwind_callback_t)(struct unwind_work *work, struct unwind_stacktrace *trace, u64 cookie);
-
-struct unwind_work {
-	struct list_head		list;
-	unwind_callback_t		func;
-	int				bit;
-};
-
 #ifdef CONFIG_UNWIND_USER
 
 enum {
@@ -44,23 +34,23 @@ void unwind_deferred_task_exit(struct task_struct *task);
 static __always_inline void unwind_reset_info(void)
 {
 	struct unwind_task_info *info = &current->unwind_info;
-	unsigned long bits;
+	unsigned long bits = atomic_long_read(&info->unwind_mask);
 
 	/* Was there any unwinding? */
-	if (unlikely(info->unwind_mask)) {
+	if (likely(!bits))
-		bits = info->unwind_mask;
+		return;
+
 	do {
 		/* Is a task_work going to run again before going back */
 		if (bits & UNWIND_PENDING)
 			return;
-		} while (!try_cmpxchg(&info->unwind_mask, &bits, 0UL));
+	} while (!atomic_long_try_cmpxchg(&info->unwind_mask, &bits, 0UL));
 	current->unwind_info.id.id = 0;
 
 	if (unlikely(info->cache)) {
 		info->cache->nr_entries = 0;
 		info->cache->unwind_completed = 0;
 	}
-	}
 }
 
 #else /* !CONFIG_UNWIND_USER */
@@ -68,9 +58,17 @@ static __always_inline void unwind_reset_info(void)
 static inline void unwind_task_init(struct task_struct *task) {}
 static inline void unwind_task_free(struct task_struct *task) {}
 
-static inline int unwind_user_faultable(struct unwind_stacktrace *trace) { return -ENOSYS; }
+static inline int unwind_user_faultable(struct unwind_stacktrace *trace)
-static inline int unwind_deferred_init(struct unwind_work *work, unwind_callback_t func) { return -ENOSYS; }
+{ return -ENOSYS; }
-static inline int unwind_deferred_request(struct unwind_work *work, u64 *timestamp) { return -ENOSYS; }
+
+static inline int
+unwind_deferred_init(struct unwind_work *work, unwind_callback_t func)
+{ return -ENOSYS; }
+
+static inline int
+unwind_deferred_request(struct unwind_work *work, u64 *timestamp)
+{ return -ENOSYS; }
+
 static inline void unwind_deferred_cancel(struct unwind_work *work) {}
 
 static inline void unwind_deferred_task_exit(struct task_struct *task) {}

include/linux/unwind_deferred_types.h

@@ -2,6 +2,9 @@
 #ifndef _LINUX_UNWIND_USER_DEFERRED_TYPES_H
 #define _LINUX_UNWIND_USER_DEFERRED_TYPES_H
 
+#include <linux/types.h>
+#include <linux/atomic.h>
+
 struct unwind_cache {
 	unsigned long		unwind_completed;
 	unsigned int		nr_entries;
@@ -30,10 +33,23 @@ union unwind_task_id {
 };
 
 struct unwind_task_info {
-	unsigned long		unwind_mask;
+	atomic_long_t		unwind_mask;
 	struct unwind_cache	*cache;
 	struct callback_head	work;
 	union unwind_task_id	id;
 };
 
+struct unwind_work;
+struct unwind_stacktrace;
+
+typedef void (*unwind_callback_t)(struct unwind_work *work,
+				  struct unwind_stacktrace *trace,
+				  u64 cookie);
+
+struct unwind_work {
+	struct list_head		list;
+	unwind_callback_t		func;
+	int				bit;
+};
+
 #endif /* _LINUX_UNWIND_USER_DEFERRED_TYPES_H */

include/linux/unwind_user_types.h

@@ -36,8 +36,10 @@ struct unwind_user_state {
 	unsigned long				ip;
 	unsigned long				sp;
 	unsigned long				fp;
+	unsigned int				ws;
 	enum unwind_user_type			current_type;
 	unsigned int				available_types;
+	bool					topmost;
 	bool					done;
 };
 

include/uapi/linux/perf_event.h

@@ -463,7 +463,9 @@ struct perf_event_attr {
 				inherit_thread :  1, /* children only inherit if cloned with CLONE_THREAD */
 				remove_on_exec :  1, /* event is removed from task on exec */
 				sigtrap        :  1, /* send synchronous SIGTRAP on event */
-				__reserved_1   : 26;
+				defer_callchain:  1, /* request PERF_RECORD_CALLCHAIN_DEFERRED records */
+				defer_output   :  1, /* output PERF_RECORD_CALLCHAIN_DEFERRED records */
+				__reserved_1   : 24;
 
 	union {
 		__u32		wakeup_events;	  /* wake up every n events */
@@ -1239,6 +1241,22 @@ enum perf_event_type {
 	 */
 	PERF_RECORD_AUX_OUTPUT_HW_ID		= 21,
 
+	/*
+	 * This user callchain capture was deferred until shortly before
+	 * returning to user space.  Previous samples would have kernel
+	 * callchains only and they need to be stitched with this to make full
+	 * callchains.
+	 *
+	 * struct {
+	 *	struct perf_event_header	header;
+	 *	u64				cookie;
+	 *	u64				nr;
+	 *	u64				ips[nr];
+	 *	struct sample_id		sample_id;
+	 * };
+	 */
+	PERF_RECORD_CALLCHAIN_DEFERRED		= 22,
+
 	PERF_RECORD_MAX,			/* non-ABI */
 };
 
@@ -1269,6 +1287,7 @@ enum perf_callchain_context {
 	PERF_CONTEXT_HV				= (__u64)-32,
 	PERF_CONTEXT_KERNEL			= (__u64)-128,
 	PERF_CONTEXT_USER			= (__u64)-512,
+	PERF_CONTEXT_USER_DEFERRED		= (__u64)-640,
 
 	PERF_CONTEXT_GUEST			= (__u64)-2048,
 	PERF_CONTEXT_GUEST_KERNEL		= (__u64)-2176,

kernel/bpf/stackmap.c

@@ -315,7 +315,7 @@ BPF_CALL_3(bpf_get_stackid, struct pt_regs *, regs, struct bpf_map *, map,
 		max_depth = sysctl_perf_event_max_stack;
 
 	trace = get_perf_callchain(regs, kernel, user, max_depth,
-				   false, false);
+				   false, false, 0);
 
 	if (unlikely(!trace))
 		/* couldn't fetch the stack trace */
@@ -452,7 +452,7 @@ static long __bpf_get_stack(struct pt_regs *regs, struct task_struct *task,
 		trace = get_callchain_entry_for_task(task, max_depth);
 	else
 		trace = get_perf_callchain(regs, kernel, user, max_depth,
-					   crosstask, false);
+					   crosstask, false, 0);
 
 	if (unlikely(!trace) || trace->nr < skip) {
 		if (may_fault)

kernel/events/callchain.c

@@ -218,7 +218,7 @@ static void fixup_uretprobe_trampoline_entries(struct perf_callchain_entry *entr
 
 struct perf_callchain_entry *
 get_perf_callchain(struct pt_regs *regs, bool kernel, bool user,
-		   u32 max_stack, bool crosstask, bool add_mark)
+		   u32 max_stack, bool crosstask, bool add_mark, u64 defer_cookie)
 {
 	struct perf_callchain_entry *entry;
 	struct perf_callchain_entry_ctx ctx;
@@ -251,6 +251,18 @@ get_perf_callchain(struct pt_regs *regs, bool kernel, bool user,
 			regs = task_pt_regs(current);
 		}
 
+		if (defer_cookie) {
+			/*
+			 * Foretell the coming of PERF_RECORD_CALLCHAIN_DEFERRED
+			 * which can be stitched to this one, and add
+			 * the cookie after it (it will be cut off when the
+			 * user stack is copied to the callchain).
+			 */
+			perf_callchain_store_context(&ctx, PERF_CONTEXT_USER_DEFERRED);
+			perf_callchain_store_context(&ctx, defer_cookie);
+			goto exit_put;
+		}
+
 		if (add_mark)
 			perf_callchain_store_context(&ctx, PERF_CONTEXT_USER);
 

kernel/events/core.c

@@ -56,6 +56,7 @@
 #include <linux/buildid.h>
 #include <linux/task_work.h>
 #include <linux/percpu-rwsem.h>
+#include <linux/unwind_deferred.h>
 
 #include "internal.h"
 
@@ -8200,6 +8201,8 @@ static u64 perf_get_page_size(unsigned long addr)
 
 static struct perf_callchain_entry __empty_callchain = { .nr = 0, };
 
+static struct unwind_work perf_unwind_work;
+
 struct perf_callchain_entry *
 perf_callchain(struct perf_event *event, struct pt_regs *regs)
 {
@@ -8208,8 +8211,11 @@ perf_callchain(struct perf_event *event, struct pt_regs *regs)
 		!(current->flags & (PF_KTHREAD | PF_USER_WORKER));
 	/* Disallow cross-task user callchains. */
 	bool crosstask = event->ctx->task && event->ctx->task != current;
+	bool defer_user = IS_ENABLED(CONFIG_UNWIND_USER) && user &&
+			  event->attr.defer_callchain;
 	const u32 max_stack = event->attr.sample_max_stack;
 	struct perf_callchain_entry *callchain;
+	u64 defer_cookie;
 
 	if (!current->mm)
 		user = false;
@@ -8217,8 +8223,13 @@ perf_callchain(struct perf_event *event, struct pt_regs *regs)
 	if (!kernel && !user)
 		return &__empty_callchain;
 
-	callchain = get_perf_callchain(regs, kernel, user,
+	if (!(user && defer_user && !crosstask &&
-				       max_stack, crosstask, true);
+	      unwind_deferred_request(&perf_unwind_work, &defer_cookie) >= 0))
+		defer_cookie = 0;
+
+	callchain = get_perf_callchain(regs, kernel, user, max_stack,
+				       crosstask, true, defer_cookie);
+
 	return callchain ?: &__empty_callchain;
 }
 
@@ -10003,6 +10014,66 @@ void perf_event_bpf_event(struct bpf_prog *prog,
 	perf_iterate_sb(perf_event_bpf_output, &bpf_event, NULL);
 }
 
+struct perf_callchain_deferred_event {
+	struct unwind_stacktrace *trace;
+	struct {
+		struct perf_event_header	header;
+		u64				cookie;
+		u64				nr;
+		u64				ips[];
+	} event;
+};
+
+static void perf_callchain_deferred_output(struct perf_event *event, void *data)
+{
+	struct perf_callchain_deferred_event *deferred_event = data;
+	struct perf_output_handle handle;
+	struct perf_sample_data sample;
+	int ret, size = deferred_event->event.header.size;
+
+	if (!event->attr.defer_output)
+		return;
+
+	/* XXX do we really need sample_id_all for this ??? */
+	perf_event_header__init_id(&deferred_event->event.header, &sample, event);
+
+	ret = perf_output_begin(&handle, &sample, event,
+				deferred_event->event.header.size);
+	if (ret)
+		goto out;
+
+	perf_output_put(&handle, deferred_event->event);
+	for (int i = 0; i < deferred_event->trace->nr; i++) {
+		u64 entry = deferred_event->trace->entries[i];
+		perf_output_put(&handle, entry);
+	}
+	perf_event__output_id_sample(event, &handle, &sample);
+
+	perf_output_end(&handle);
+out:
+	deferred_event->event.header.size = size;
+}
+
+static void perf_unwind_deferred_callback(struct unwind_work *work,
+					 struct unwind_stacktrace *trace, u64 cookie)
+{
+	struct perf_callchain_deferred_event deferred_event = {
+		.trace = trace,
+		.event = {
+			.header = {
+				.type = PERF_RECORD_CALLCHAIN_DEFERRED,
+				.misc = PERF_RECORD_MISC_USER,
+				.size = sizeof(deferred_event.event) +
+					(trace->nr * sizeof(u64)),
+			},
+			.cookie = cookie,
+			.nr = trace->nr,
+		},
+	};
+
+	perf_iterate_sb(perf_callchain_deferred_output, &deferred_event, NULL);
+}
+
 struct perf_text_poke_event {
 	const void		*old_bytes;
 	const void		*new_bytes;
@@ -14809,6 +14880,9 @@ void __init perf_event_init(void)
 
 	idr_init(&pmu_idr);
 
+	unwind_deferred_init(&perf_unwind_work,
+			     perf_unwind_deferred_callback);
+
 	perf_event_init_all_cpus();
 	init_srcu_struct(&pmus_srcu);
 	perf_pmu_register(&perf_swevent, "software", PERF_TYPE_SOFTWARE);

kernel/exit.c

@@ -940,7 +940,6 @@ void __noreturn do_exit(long code)
 
 	tsk->exit_code = code;
 	taskstats_exit(tsk, group_dead);
-	unwind_deferred_task_exit(tsk);
 	trace_sched_process_exit(tsk, group_dead);
 
 	/*
@@ -951,6 +950,12 @@ void __noreturn do_exit(long code)
 	 * gets woken up by child-exit notifications.
 	 */
 	perf_event_exit_task(tsk);
+	/*
+	 * PF_EXITING (above) ensures unwind_deferred_request() will no
+	 * longer add new unwinds. While exit_mm() (below) will destroy the
+	 * abaility to do unwinds. So flush any pending unwinds here.
+	 */
+	unwind_deferred_task_exit(tsk);
 
 	exit_mm();
 

kernel/task_work.c

@@ -9,7 +9,12 @@ static struct callback_head work_exited; /* all we need is ->next == NULL */
 #ifdef CONFIG_IRQ_WORK
 static void task_work_set_notify_irq(struct irq_work *entry)
 {
-	test_and_set_tsk_thread_flag(current, TIF_NOTIFY_RESUME);
+	/*
+	 * no-op IPI
+	 *
+	 * TWA_NMI_CURRENT will already have set the TIF flag, all
+	 * this interrupt does it tickle the return-to-user path.
+	 */
 }
 static DEFINE_PER_CPU(struct irq_work, irq_work_NMI_resume) =
 	IRQ_WORK_INIT_HARD(task_work_set_notify_irq);
@@ -86,6 +91,7 @@ int task_work_add(struct task_struct *task, struct callback_head *work,
 		break;
 #ifdef CONFIG_IRQ_WORK
 	case TWA_NMI_CURRENT:
+		set_tsk_thread_flag(current, TIF_NOTIFY_RESUME);
 		irq_work_queue(this_cpu_ptr(&irq_work_NMI_resume));
 		break;
 #endif

kernel/unwind/deferred.c

@@ -53,7 +53,7 @@ DEFINE_STATIC_SRCU(unwind_srcu);
 
 static inline bool unwind_pending(struct unwind_task_info *info)
 {
-	return test_bit(UNWIND_PENDING_BIT, &info->unwind_mask);
+	return atomic_long_read(&info->unwind_mask) & UNWIND_PENDING;
 }
 
 /*
@@ -79,6 +79,8 @@ static u64 get_cookie(struct unwind_task_info *info)
 {
 	u32 cnt = 1;
 
+	lockdep_assert_irqs_disabled();
+
 	if (info->id.cpu)
 		return info->id.id;
 
@@ -126,23 +128,20 @@ int unwind_user_faultable(struct unwind_stacktrace *trace)
 
 	cache = info->cache;
 	trace->entries = cache->entries;
-
+	trace->nr = cache->nr_entries;
-	if (cache->nr_entries) {
 	/*
 	 * The user stack has already been previously unwound in this
 	 * entry context.  Skip the unwind and use the cache.
 	 */
-		trace->nr = cache->nr_entries;
+	if (trace->nr)
 		return 0;
-	}
 
-	trace->nr = 0;
 	unwind_user(trace, UNWIND_MAX_ENTRIES);
 
 	cache->nr_entries = trace->nr;
 
 	/* Clear nr_entries on way back to user space */
-	set_bit(UNWIND_USED_BIT, &info->unwind_mask);
+	atomic_long_or(UNWIND_USED, &info->unwind_mask);
 
 	return 0;
 }
@@ -160,7 +159,7 @@ static void process_unwind_deferred(struct task_struct *task)
 
 	/* Clear pending bit but make sure to have the current bits */
 	bits = atomic_long_fetch_andnot(UNWIND_PENDING,
-				  (atomic_long_t *)&info->unwind_mask);
+					&info->unwind_mask);
 	/*
 	 * From here on out, the callback must always be called, even if it's
 	 * just an empty trace.
@@ -231,6 +230,7 @@ void unwind_deferred_task_exit(struct task_struct *task)
 int unwind_deferred_request(struct unwind_work *work, u64 *cookie)
 {
 	struct unwind_task_info *info = &current->unwind_info;
+	int twa_mode = TWA_RESUME;
 	unsigned long old, bits;
 	unsigned long bit;
 	int ret;
@@ -246,8 +246,11 @@ int unwind_deferred_request(struct unwind_work *work, u64 *cookie)
 	 * Trigger a warning to make it obvious that an architecture
 	 * is using this in NMI when it should not be.
 	 */
-	if (WARN_ON_ONCE(!CAN_USE_IN_NMI && in_nmi()))
+	if (in_nmi()) {
+		if (WARN_ON_ONCE(!CAN_USE_IN_NMI))
 			return -EINVAL;
+		twa_mode = TWA_NMI_CURRENT;
+	}
 
 	/* Do not allow cancelled works to request again */
 	bit = READ_ONCE(work->bit);
@@ -261,7 +264,7 @@ int unwind_deferred_request(struct unwind_work *work, u64 *cookie)
 
 	*cookie = get_cookie(info);
 
-	old = READ_ONCE(info->unwind_mask);
+	old = atomic_long_read(&info->unwind_mask);
 
 	/* Is this already queued or executed */
 	if (old & bit)
@@ -274,7 +277,7 @@ int unwind_deferred_request(struct unwind_work *work, u64 *cookie)
 	 * to have a callback.
 	 */
 	bits = UNWIND_PENDING | bit;
-	old = atomic_long_fetch_or(bits, (atomic_long_t *)&info->unwind_mask);
+	old = atomic_long_fetch_or(bits, &info->unwind_mask);
 	if (old & bits) {
 		/*
 		 * If the work's bit was set, whatever set it had better
@@ -285,10 +288,10 @@ int unwind_deferred_request(struct unwind_work *work, u64 *cookie)
 	}
 
 	/* The work has been claimed, now schedule it. */
-	ret = task_work_add(current, &info->work, TWA_RESUME);
+	ret = task_work_add(current, &info->work, twa_mode);
 
 	if (WARN_ON_ONCE(ret))
-		WRITE_ONCE(info->unwind_mask, 0);
+		atomic_long_set(&info->unwind_mask, 0);
 
 	return ret;
 }
@@ -320,7 +323,8 @@ void unwind_deferred_cancel(struct unwind_work *work)
 	guard(rcu)();
 	/* Clear this bit from all threads */
 	for_each_process_thread(g, t) {
-		clear_bit(bit, &t->unwind_info.unwind_mask);
+		atomic_long_andnot(BIT(bit),
+				   &t->unwind_info.unwind_mask);
 		if (t->unwind_info.cache)
 			clear_bit(bit, &t->unwind_info.cache->unwind_completed);
 	}
@@ -350,7 +354,7 @@ void unwind_task_init(struct task_struct *task)
 
 	memset(info, 0, sizeof(*info));
 	init_task_work(&info->work, unwind_deferred_task_work);
-	info->unwind_mask = 0;
+	atomic_long_set(&info->unwind_mask, 0);
 }
 
 void unwind_task_free(struct task_struct *task)

kernel/unwind/user.c

@@ -8,18 +8,28 @@
 #include <linux/unwind_user.h>
 #include <linux/uaccess.h>
 
-static const struct unwind_user_frame fp_frame = {
-	ARCH_INIT_USER_FP_FRAME
-};
-
 #define for_each_user_frame(state) \
 	for (unwind_user_start(state); !(state)->done; unwind_user_next(state))
 
-static int unwind_user_next_fp(struct unwind_user_state *state)
+static inline int
+get_user_word(unsigned long *word, unsigned long base, int off, unsigned int ws)
+{
+	unsigned long __user *addr = (void __user *)base + off;
+#ifdef CONFIG_COMPAT
+	if (ws == sizeof(int)) {
+		unsigned int data;
+		int ret = get_user(data, (unsigned int __user *)addr);
+		*word = data;
+		return ret;
+	}
+#endif
+	return get_user(*word, addr);
+}
+
+static int unwind_user_next_common(struct unwind_user_state *state,
+				   const struct unwind_user_frame *frame)
 {
-	const struct unwind_user_frame *frame = &fp_frame;
 	unsigned long cfa, fp, ra;
-	unsigned int shift;
 
 	if (frame->use_fp) {
 		if (state->fp < state->sp)
@@ -37,24 +47,45 @@ static int unwind_user_next_fp(struct unwind_user_state *state)
 		return -EINVAL;
 
 	/* Make sure that the address is word aligned */
-	shift = sizeof(long) == 4 ? 2 : 3;
+	if (cfa & (state->ws - 1))
-	if (cfa & ((1 << shift) - 1))
 		return -EINVAL;
 
 	/* Find the Return Address (RA) */
-	if (get_user(ra, (unsigned long *)(cfa + frame->ra_off)))
+	if (get_user_word(&ra, cfa, frame->ra_off, state->ws))
 		return -EINVAL;
 
-	if (frame->fp_off && get_user(fp, (unsigned long __user *)(cfa + frame->fp_off)))
+	if (frame->fp_off && get_user_word(&fp, cfa, frame->fp_off, state->ws))
 		return -EINVAL;
 
 	state->ip = ra;
 	state->sp = cfa;
 	if (frame->fp_off)
 		state->fp = fp;
+	state->topmost = false;
 	return 0;
 }
 
+static int unwind_user_next_fp(struct unwind_user_state *state)
+{
+#ifdef CONFIG_HAVE_UNWIND_USER_FP
+	struct pt_regs *regs = task_pt_regs(current);
+
+	if (state->topmost && unwind_user_at_function_start(regs)) {
+		const struct unwind_user_frame fp_entry_frame = {
+			ARCH_INIT_USER_FP_ENTRY_FRAME(state->ws)
+		};
+		return unwind_user_next_common(state, &fp_entry_frame);
+	}
+
+	const struct unwind_user_frame fp_frame = {
+		ARCH_INIT_USER_FP_FRAME(state->ws)
+	};
+	return unwind_user_next_common(state, &fp_frame);
+#else
+	return -EINVAL;
+#endif
+}
+
 static int unwind_user_next(struct unwind_user_state *state)
 {
 	unsigned long iter_mask = state->available_types;
@@ -102,6 +133,12 @@ static int unwind_user_start(struct unwind_user_state *state)
 	state->ip = instruction_pointer(regs);
 	state->sp = user_stack_pointer(regs);
 	state->fp = frame_pointer(regs);
+	state->ws = unwind_user_word_size(regs);
+	if (!state->ws) {
+		state->done = true;
+		return -EINVAL;
+	}
+	state->topmost = true;
 
 	return 0;
 }

tools/arch/x86/include/asm/insn.h

@@ -312,7 +312,6 @@ static inline int insn_offset_immediate(struct insn *insn)
 /**
  * for_each_insn_prefix() -- Iterate prefixes in the instruction
  * @insn: Pointer to struct insn.
- * @idx:  Index storage.
  * @prefix: Prefix byte.
  *
  * Iterate prefix bytes of given @insn. Each prefix byte is stored in @prefix
@@ -321,8 +320,8 @@ static inline int insn_offset_immediate(struct insn *insn)
  * Since prefixes.nbytes can be bigger than 4 if some prefixes
  * are repeated, it cannot be used for looping over the prefixes.
  */
-#define for_each_insn_prefix(insn, idx, prefix)	\
+#define for_each_insn_prefix(insn, prefix)	\
-	for (idx = 0; idx < ARRAY_SIZE(insn->prefixes.bytes) && (prefix = insn->prefixes.bytes[idx]) != 0; idx++)
+	for (int idx = 0; idx < ARRAY_SIZE(insn->prefixes.bytes) && (prefix = insn->prefixes.bytes[idx]) != 0; idx++)
 
 #define POP_SS_OPCODE 0x1f
 #define MOV_SREG_OPCODE 0x8e

tools/include/uapi/linux/perf_event.h

@@ -463,7 +463,9 @@ struct perf_event_attr {
 				inherit_thread :  1, /* children only inherit if cloned with CLONE_THREAD */
 				remove_on_exec :  1, /* event is removed from task on exec */
 				sigtrap        :  1, /* send synchronous SIGTRAP on event */
-				__reserved_1   : 26;
+				defer_callchain:  1, /* request PERF_RECORD_CALLCHAIN_DEFERRED records */
+				defer_output   :  1, /* output PERF_RECORD_CALLCHAIN_DEFERRED records */
+				__reserved_1   : 24;
 
 	union {
 		__u32		wakeup_events;	  /* wake up every n events */
@@ -1239,6 +1241,22 @@ enum perf_event_type {
 	 */
 	PERF_RECORD_AUX_OUTPUT_HW_ID		= 21,
 
+	/*
+	 * This user callchain capture was deferred until shortly before
+	 * returning to user space.  Previous samples would have kernel
+	 * callchains only and they need to be stitched with this to make full
+	 * callchains.
+	 *
+	 * struct {
+	 *	struct perf_event_header	header;
+	 *	u64				cookie;
+	 *	u64				nr;
+	 *	u64				ips[nr];
+	 *	struct sample_id		sample_id;
+	 * };
+	 */
+	PERF_RECORD_CALLCHAIN_DEFERRED		= 22,
+
 	PERF_RECORD_MAX,			/* non-ABI */
 };
 
@@ -1269,6 +1287,7 @@ enum perf_callchain_context {
 	PERF_CONTEXT_HV				= (__u64)-32,
 	PERF_CONTEXT_KERNEL			= (__u64)-128,
 	PERF_CONTEXT_USER			= (__u64)-512,
+	PERF_CONTEXT_USER_DEFERRED		= (__u64)-640,
 
 	PERF_CONTEXT_GUEST			= (__u64)-2048,
 	PERF_CONTEXT_GUEST_KERNEL		= (__u64)-2176,