Merge tag 'perf-urgent-2020-08-15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull perf fixes from Ingo Molnar:
 "Misc fixes, an expansion of perf syscall access to CAP_PERFMON
  privileged tools, plus a RAPL HW-enablement for Intel SPR platforms"

* tag 'perf-urgent-2020-08-15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/x86/rapl: Add support for Intel SPR platform
  perf/x86/rapl: Support multiple RAPL unit quirks
  perf/x86/rapl: Fix missing psys sysfs attributes
  hw_breakpoint: Remove unused __register_perf_hw_breakpoint() declaration
  kprobes: Remove show_registers() function prototype
  perf/core: Take over CAP_SYS_PTRACE creds to CAP_PERFMON capability

Author: torvalds

arch/x86/events/rapl.c

@@ -130,11 +130,17 @@ struct rapl_pmus {
 	struct rapl_pmu		*pmus[];
 };
 
+enum rapl_unit_quirk {
+	RAPL_UNIT_QUIRK_NONE,
+	RAPL_UNIT_QUIRK_INTEL_HSW,
+	RAPL_UNIT_QUIRK_INTEL_SPR,
+};
+
 struct rapl_model {
 	struct perf_msr *rapl_msrs;
 	unsigned long	events;
 	unsigned int	msr_power_unit;
-	bool		apply_quirk;
+	enum rapl_unit_quirk	unit_quirk;
 };
 
  /* 1/2^hw_unit Joule */
@@ -612,14 +618,28 @@ static int rapl_check_hw_unit(struct rapl_model *rm)
 	for (i = 0; i < NR_RAPL_DOMAINS; i++)
 		rapl_hw_unit[i] = (msr_rapl_power_unit_bits >> 8) & 0x1FULL;
 
+	switch (rm->unit_quirk) {
 	/*
 	 * DRAM domain on HSW server and KNL has fixed energy unit which can be
 	 * different than the unit from power unit MSR. See
 	 * "Intel Xeon Processor E5-1600 and E5-2600 v3 Product Families, V2
 	 * of 2. Datasheet, September 2014, Reference Number: 330784-001 "
 	 */
-	if (rm->apply_quirk)
+	case RAPL_UNIT_QUIRK_INTEL_HSW:
+		rapl_hw_unit[PERF_RAPL_RAM] = 16;
+		break;
+	/*
+	 * SPR shares the same DRAM domain energy unit as HSW, plus it
+	 * also has a fixed energy unit for Psys domain.
+	 */
+	case RAPL_UNIT_QUIRK_INTEL_SPR:
 		rapl_hw_unit[PERF_RAPL_RAM] = 16;
+		rapl_hw_unit[PERF_RAPL_PSYS] = 0;
+		break;
+	default:
+		break;
+	}
+
 
 	/*
 	 * Calculate the timer rate:
@@ -665,7 +685,7 @@ static const struct attribute_group *rapl_attr_update[] = {
 	&rapl_events_pkg_group,
 	&rapl_events_ram_group,
 	&rapl_events_gpu_group,
-	&rapl_events_gpu_group,
+	&rapl_events_psys_group,
 	NULL,
 };
 
@@ -698,7 +718,6 @@ static struct rapl_model model_snb = {
 	.events		= BIT(PERF_RAPL_PP0) |
 			  BIT(PERF_RAPL_PKG) |
 			  BIT(PERF_RAPL_PP1),
-	.apply_quirk	= false,
 	.msr_power_unit = MSR_RAPL_POWER_UNIT,
 	.rapl_msrs      = intel_rapl_msrs,
 };
@@ -707,7 +726,6 @@ static struct rapl_model model_snbep = {
 	.events		= BIT(PERF_RAPL_PP0) |
 			  BIT(PERF_RAPL_PKG) |
 			  BIT(PERF_RAPL_RAM),
-	.apply_quirk	= false,
 	.msr_power_unit = MSR_RAPL_POWER_UNIT,
 	.rapl_msrs      = intel_rapl_msrs,
 };
@@ -717,7 +735,6 @@ static struct rapl_model model_hsw = {
 			  BIT(PERF_RAPL_PKG) |
 			  BIT(PERF_RAPL_RAM) |
 			  BIT(PERF_RAPL_PP1),
-	.apply_quirk	= false,
 	.msr_power_unit = MSR_RAPL_POWER_UNIT,
 	.rapl_msrs      = intel_rapl_msrs,
 };
@@ -726,15 +743,15 @@ static struct rapl_model model_hsx = {
 	.events		= BIT(PERF_RAPL_PP0) |
 			  BIT(PERF_RAPL_PKG) |
 			  BIT(PERF_RAPL_RAM),
-	.apply_quirk	= true,
+	.unit_quirk	= RAPL_UNIT_QUIRK_INTEL_HSW,
 	.msr_power_unit = MSR_RAPL_POWER_UNIT,
 	.rapl_msrs      = intel_rapl_msrs,
 };
 
 static struct rapl_model model_knl = {
 	.events		= BIT(PERF_RAPL_PKG) |
 			  BIT(PERF_RAPL_RAM),
-	.apply_quirk	= true,
+	.unit_quirk	= RAPL_UNIT_QUIRK_INTEL_HSW,
 	.msr_power_unit = MSR_RAPL_POWER_UNIT,
 	.rapl_msrs      = intel_rapl_msrs,
 };
@@ -745,14 +762,22 @@ static struct rapl_model model_skl = {
 			  BIT(PERF_RAPL_RAM) |
 			  BIT(PERF_RAPL_PP1) |
 			  BIT(PERF_RAPL_PSYS),
-	.apply_quirk	= false,
+	.msr_power_unit = MSR_RAPL_POWER_UNIT,
+	.rapl_msrs      = intel_rapl_msrs,
+};
+
+static struct rapl_model model_spr = {
+	.events		= BIT(PERF_RAPL_PP0) |
+			  BIT(PERF_RAPL_PKG) |
+			  BIT(PERF_RAPL_RAM) |
+			  BIT(PERF_RAPL_PSYS),
+	.unit_quirk	= RAPL_UNIT_QUIRK_INTEL_SPR,
 	.msr_power_unit = MSR_RAPL_POWER_UNIT,
 	.rapl_msrs      = intel_rapl_msrs,
 };
 
 static struct rapl_model model_amd_fam17h = {
 	.events		= BIT(PERF_RAPL_PKG),
-	.apply_quirk	= false,
 	.msr_power_unit = MSR_AMD_RAPL_POWER_UNIT,
 	.rapl_msrs      = amd_rapl_msrs,
 };
@@ -787,6 +812,7 @@ static const struct x86_cpu_id rapl_model_match[] __initconst = {
 	X86_MATCH_INTEL_FAM6_MODEL(ICELAKE_X,		&model_hsx),
 	X86_MATCH_INTEL_FAM6_MODEL(COMETLAKE_L,		&model_skl),
 	X86_MATCH_INTEL_FAM6_MODEL(COMETLAKE,		&model_skl),
+	X86_MATCH_INTEL_FAM6_MODEL(SAPPHIRERAPIDS_X,	&model_spr),
 	X86_MATCH_VENDOR_FAM(AMD,	0x17,		&model_amd_fam17h),
 	X86_MATCH_VENDOR_FAM(HYGON,	0x18,		&model_amd_fam17h),
 	{},

include/linux/hw_breakpoint.h

@@ -72,7 +72,6 @@ register_wide_hw_breakpoint(struct perf_event_attr *attr,
 			    void *context);
 
 extern int register_perf_hw_breakpoint(struct perf_event *bp);
-extern int __register_perf_hw_breakpoint(struct perf_event *bp);
 extern void unregister_hw_breakpoint(struct perf_event *bp);
 extern void unregister_wide_hw_breakpoint(struct perf_event * __percpu *cpu_events);
 
@@ -119,8 +118,6 @@ register_wide_hw_breakpoint(struct perf_event_attr *attr,
 			    void *context)		{ return NULL; }
 static inline int
 register_perf_hw_breakpoint(struct perf_event *bp)	{ return -ENOSYS; }
-static inline int
-__register_perf_hw_breakpoint(struct perf_event *bp) 	{ return -ENOSYS; }
 static inline void unregister_hw_breakpoint(struct perf_event *bp)	{ }
 static inline void
 unregister_wide_hw_breakpoint(struct perf_event * __percpu *cpu_events)	{ }

kernel/events/core.c

@@ -11706,15 +11706,15 @@ SYSCALL_DEFINE5(perf_event_open,
 			goto err_task;
 
 		/*
-		 * Reuse ptrace permission checks for now.
+		 * Preserve ptrace permission check for backwards compatibility.
 		 *
 		 * We must hold exec_update_mutex across this and any potential
 		 * perf_install_in_context() call for this new event to
 		 * serialize against exec() altering our credentials (and the
 		 * perf_event_exit_task() that could imply).
 		 */
 		err = -EACCES;
-		if (!ptrace_may_access(task, PTRACE_MODE_READ_REALCREDS))
+		if (!perfmon_capable() && !ptrace_may_access(task, PTRACE_MODE_READ_REALCREDS))
 			goto err_cred;
 	}