Merge tag 'perf-urgent-for-mingo-5.3-20190708-2' of...

Merge tag 'perf-urgent-for-mingo-5.3-20190708-2' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/core

Pull perf/urgent fixes from Arnaldo Carvalho de Melo:

core:

  Arnaldo Carvalho de Melo:

  - Allow references to thread objects after__machine_exit(), fixing a bug with
    'perf sched lat' where that happens, i.e. after perf_session__delete() we
    still have references to threads that were in a linked list whose head was
    freed in perf_session__delete(), causing a segfault, fix it.

  Jiri Olsa:

  - Do not rely on errno values for precise_ip fallback, fixing the default
    use case for 'perf record' on some AMD servers, when no events are specified
    and we try to use "cycles:P", i.e. with the maximum precision level.

BPF:

  Song Liu:

  - Assign proper ff->ph in perf_event__synthesize_features(), fixing a bug
    when using pipe mode, i.e.  'perf record -o -'.

tools headers:

  Arnaldo Carvalho de Melo:

  - Sync kvm headers with the kernel sources

perf tests:

  Seeteena Thoufeek:

  - Fix record+probe_libc_inet_pton.sh for powerpc64, where without the
    debuginfo package for the 'ping' utility we can't resolve its symbols,
    so admit getting "[unknown]" for that backtrace line.

perf python:

  Arnaldo Carvalho de Melo:

  - Remove -fstack-protector-strong if clang doesn't have it, fixing the build
    with clang on fedora:30, oracleline:7, centos:7.

perf jvmti:

  Jiri Olsa:

  - Address gcc string overflow warning for strncpy()

build:

  Arnaldo Carvalho de Melo:

  - Check if gettid() is available before providing helper, as recent
    versions of glibc started to provide gettid().
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

tools/arch/arm64/include/uapi/asm/kvm.h

@@ -260,6 +260,13 @@ struct kvm_vcpu_events {
 	 KVM_REG_SIZE_U256 |						\
 	 ((i) & (KVM_ARM64_SVE_MAX_SLICES - 1)))
 
+/*
+ * Register values for KVM_REG_ARM64_SVE_ZREG(), KVM_REG_ARM64_SVE_PREG() and
+ * KVM_REG_ARM64_SVE_FFR() are represented in memory in an endianness-
+ * invariant layout which differs from the layout used for the FPSIMD
+ * V-registers on big-endian systems: see sigcontext.h for more explanation.
+ */
+
 #define KVM_ARM64_SVE_VQ_MIN __SVE_VQ_MIN
 #define KVM_ARM64_SVE_VQ_MAX __SVE_VQ_MAX
 

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

@@ -239,12 +239,14 @@
 #define X86_FEATURE_BMI1		( 9*32+ 3) /* 1st group bit manipulation extensions */
 #define X86_FEATURE_HLE			( 9*32+ 4) /* Hardware Lock Elision */
 #define X86_FEATURE_AVX2		( 9*32+ 5) /* AVX2 instructions */
+#define X86_FEATURE_FDP_EXCPTN_ONLY	( 9*32+ 6) /* "" FPU data pointer updated only on x87 exceptions */
 #define X86_FEATURE_SMEP		( 9*32+ 7) /* Supervisor Mode Execution Protection */
 #define X86_FEATURE_BMI2		( 9*32+ 8) /* 2nd group bit manipulation extensions */
 #define X86_FEATURE_ERMS		( 9*32+ 9) /* Enhanced REP MOVSB/STOSB instructions */
 #define X86_FEATURE_INVPCID		( 9*32+10) /* Invalidate Processor Context ID */
 #define X86_FEATURE_RTM			( 9*32+11) /* Restricted Transactional Memory */
 #define X86_FEATURE_CQM			( 9*32+12) /* Cache QoS Monitoring */
+#define X86_FEATURE_ZERO_FCS_FDS	( 9*32+13) /* "" Zero out FPU CS and FPU DS */
 #define X86_FEATURE_MPX			( 9*32+14) /* Memory Protection Extension */
 #define X86_FEATURE_RDT_A		( 9*32+15) /* Resource Director Technology Allocation */
 #define X86_FEATURE_AVX512F		( 9*32+16) /* AVX-512 Foundation */
@@ -269,13 +271,19 @@
 #define X86_FEATURE_XGETBV1		(10*32+ 2) /* XGETBV with ECX = 1 instruction */
 #define X86_FEATURE_XSAVES		(10*32+ 3) /* XSAVES/XRSTORS instructions */
 
-/* Intel-defined CPU QoS Sub-leaf, CPUID level 0x0000000F:0 (EDX), word 11 */
-#define X86_FEATURE_CQM_LLC		(11*32+ 1) /* LLC QoS if 1 */
+/*
+ * Extended auxiliary flags: Linux defined - for features scattered in various
+ * CPUID levels like 0xf, etc.
+ *
+ * Reuse free bits when adding new feature flags!
+ */
+#define X86_FEATURE_CQM_LLC		(11*32+ 0) /* LLC QoS if 1 */
+#define X86_FEATURE_CQM_OCCUP_LLC	(11*32+ 1) /* LLC occupancy monitoring */
+#define X86_FEATURE_CQM_MBM_TOTAL	(11*32+ 2) /* LLC Total MBM monitoring */
+#define X86_FEATURE_CQM_MBM_LOCAL	(11*32+ 3) /* LLC Local MBM monitoring */
 
-/* Intel-defined CPU QoS Sub-leaf, CPUID level 0x0000000F:1 (EDX), word 12 */
-#define X86_FEATURE_CQM_OCCUP_LLC	(12*32+ 0) /* LLC occupancy monitoring */
-#define X86_FEATURE_CQM_MBM_TOTAL	(12*32+ 1) /* LLC Total MBM monitoring */
-#define X86_FEATURE_CQM_MBM_LOCAL	(12*32+ 2) /* LLC Local MBM monitoring */
+/* Intel-defined CPU features, CPUID level 0x00000007:1 (EAX), word 12 */
+#define X86_FEATURE_AVX512_BF16		(12*32+ 5) /* AVX512 BFLOAT16 instructions */
 
 /* AMD-defined CPU features, CPUID level 0x80000008 (EBX), word 13 */
 #define X86_FEATURE_CLZERO		(13*32+ 0) /* CLZERO instruction */
@@ -322,6 +330,7 @@
 #define X86_FEATURE_UMIP		(16*32+ 2) /* User Mode Instruction Protection */
 #define X86_FEATURE_PKU			(16*32+ 3) /* Protection Keys for Userspace */
 #define X86_FEATURE_OSPKE		(16*32+ 4) /* OS Protection Keys Enable */
+#define X86_FEATURE_WAITPKG		(16*32+ 5) /* UMONITOR/UMWAIT/TPAUSE Instructions */
 #define X86_FEATURE_AVX512_VBMI2	(16*32+ 6) /* Additional AVX512 Vector Bit Manipulation Instructions */
 #define X86_FEATURE_GFNI		(16*32+ 8) /* Galois Field New Instructions */
 #define X86_FEATURE_VAES		(16*32+ 9) /* Vector AES */

tools/arch/x86/include/uapi/asm/kvm.h

@@ -383,6 +383,9 @@ struct kvm_sync_regs {
 #define KVM_X86_QUIRK_LAPIC_MMIO_HOLE	(1 << 2)
 #define KVM_X86_QUIRK_OUT_7E_INC_RIP	(1 << 3)
 
+#define KVM_STATE_NESTED_FORMAT_VMX	0
+#define KVM_STATE_NESTED_FORMAT_SVM	1	/* unused */
+
 #define KVM_STATE_NESTED_GUEST_MODE	0x00000001
 #define KVM_STATE_NESTED_RUN_PENDING	0x00000002
 #define KVM_STATE_NESTED_EVMCS		0x00000004
@@ -390,7 +393,14 @@ struct kvm_sync_regs {
 #define KVM_STATE_NESTED_SMM_GUEST_MODE	0x00000001
 #define KVM_STATE_NESTED_SMM_VMXON	0x00000002
 
-struct kvm_vmx_nested_state {
+#define KVM_STATE_NESTED_VMX_VMCS_SIZE	0x1000
+
+struct kvm_vmx_nested_state_data {
+	__u8 vmcs12[KVM_STATE_NESTED_VMX_VMCS_SIZE];
+	__u8 shadow_vmcs12[KVM_STATE_NESTED_VMX_VMCS_SIZE];
+};
+
+struct kvm_vmx_nested_state_hdr {
 	__u64 vmxon_pa;
 	__u64 vmcs12_pa;
 
@@ -401,24 +411,25 @@ struct kvm_vmx_nested_state {
 
 /* for KVM_CAP_NESTED_STATE */
 struct kvm_nested_state {
-	/* KVM_STATE_* flags */
 	__u16 flags;
-
-	/* 0 for VMX, 1 for SVM.  */
 	__u16 format;
-
-	/* 128 for SVM, 128 + VMCS size for VMX.  */
 	__u32 size;
 
 	union {
-		/* VMXON, VMCS */
-		struct kvm_vmx_nested_state vmx;
+		struct kvm_vmx_nested_state_hdr vmx;
 
 		/* Pad the header to 128 bytes.  */
 		__u8 pad[120];
-	};
+	} hdr;
 
-	__u8 data[0];
+	/*
+	 * Define data region as 0 bytes to preserve backwards-compatability
+	 * to old definition of kvm_nested_state in order to avoid changing
+	 * KVM_{GET,PUT}_NESTED_STATE ioctl values.
+	 */
+	union {
+		struct kvm_vmx_nested_state_data vmx[0];
+	} data;
 };
 
 #endif /* _ASM_X86_KVM_H */

tools/perf/tests/shell/record+probe_libc_inet_pton.sh

@@ -45,7 +45,7 @@ trace_libc_inet_pton_backtrace() {
 		eventattr='max-stack=4'
 		echo "gaih_inet.*\+0x[[:xdigit:]]+[[:space:]]\($libc\)$" >> $expected
 		echo "getaddrinfo\+0x[[:xdigit:]]+[[:space:]]\($libc\)$" >> $expected
-		echo ".*\+0x[[:xdigit:]]+[[:space:]]\(.*/bin/ping.*\)$" >> $expected
+		echo ".*(\+0x[[:xdigit:]]+|\[unknown\])[[:space:]]\(.*/bin/ping.*\)$" >> $expected
 		;;
 	*)
 		eventattr='max-stack=3'

tools/perf/util/evsel.c

@@ -1800,14 +1800,8 @@ static int perf_event_open(struct perf_evsel *evsel,
 		if (fd >= 0)
 			break;
 
-		/*
-		 * Do quick precise_ip fallback if:
-		 *  - there is precise_ip set in perf_event_attr
-		 *  - maximum precise is requested
-		 *  - sys_perf_event_open failed with ENOTSUP error,
-		 *    which is associated with wrong precise_ip
-		 */
-		if (!precise_ip || !evsel->precise_max || (errno != ENOTSUP))
+		/* Do not try less precise if not requested. */
+		if (!evsel->precise_max)
 			break;
 
 		/*

tools/perf/util/header.c

@@ -3683,6 +3683,7 @@ int perf_event__synthesize_features(struct perf_tool *tool,
 		return -ENOMEM;
 
 	ff.size = sz - sz_hdr;
+	ff.ph = &session->header;
 
 	for_each_set_bit(feat, header->adds_features, HEADER_FEAT_BITS) {
 		if (!feat_ops[feat].synthesize) {

tools/perf/util/machine.c

@@ -210,6 +210,18 @@ void machine__exit(struct machine *machine)
 
 	for (i = 0; i < THREADS__TABLE_SIZE; i++) {
 		struct threads *threads = &machine->threads[i];
+		struct thread *thread, *n;
+		/*
+		 * Forget about the dead, at this point whatever threads were
+		 * left in the dead lists better have a reference count taken
+		 * by who is using them, and then, when they drop those references
+		 * and it finally hits zero, thread__put() will check and see that
+		 * its not in the dead threads list and will not try to remove it
+		 * from there, just calling thread__delete() straight away.
+		 */
+		list_for_each_entry_safe(thread, n, &threads->dead, node)
+			list_del_init(&thread->node);
+
 		exit_rwsem(&threads->lock);
 	}
 }
@@ -1759,9 +1771,11 @@ static void __machine__remove_thread(struct machine *machine, struct thread *th,
 	if (threads->last_match == th)
 		threads__set_last_match(threads, NULL);
 
-	BUG_ON(refcount_read(&th->refcnt) == 0);
 	if (lock)
 		down_write(&threads->lock);
+
+	BUG_ON(refcount_read(&th->refcnt) == 0);
+
 	rb_erase_cached(&th->rb_node, &threads->entries);
 	RB_CLEAR_NODE(&th->rb_node);
 	--threads->nr;
@@ -1771,9 +1785,16 @@ static void __machine__remove_thread(struct machine *machine, struct thread *th,
 	 * will be called and we will remove it from the dead_threads list.
 	 */
 	list_add_tail(&th->node, &threads->dead);
+
+	/*
+	 * We need to do the put here because if this is the last refcount,
+	 * then we will be touching the threads->dead head when removing the
+	 * thread.
+	 */
+	thread__put(th);
+
 	if (lock)
 		up_write(&threads->lock);
-	thread__put(th);
 }
 
 void machine__remove_thread(struct machine *machine, struct thread *th)

tools/perf/util/thread.c

@@ -125,9 +125,26 @@ void thread__put(struct thread *thread)
 {
 	if (thread && refcount_dec_and_test(&thread->refcnt)) {
 		/*
-		 * Remove it from the dead_threads list, as last reference
-		 * is gone.
+		 * Remove it from the dead threads list, as last reference is
+		 * gone, if it is in a dead threads list.
+		 *
+		 * We may not be there anymore if say, the machine where it was
+		 * stored was already deleted, so we already removed it from
+		 * the dead threads and some other piece of code still keeps a
+		 * reference.
+		 *
+		 * This is what 'perf sched' does and finally drops it in
+		 * perf_sched__lat(), where it calls perf_sched__read_events(),
+		 * that processes the events by creating a session and deleting
+		 * it, which ends up destroying the list heads for the dead
+		 * threads, but before it does that it removes all threads from
+		 * it using list_del_init().
+		 *
+		 * So we need to check here if it is in a dead threads list and
+		 * if so, remove it before finally deleting the thread, to avoid
+		 * an use after free situation.
 		 */
+		if (!list_empty(&thread->node))
 			list_del_init(&thread->node);
 		thread__delete(thread);
 	}