Merge branch 'for-rmk/perf' of git://git.kernel.org/pub/scm/linux/kernel/git/will/linux into devel-stable

arch/arm/Kconfig

@@ -51,6 +51,8 @@ config ARM
 	select HAVE_MOD_ARCH_SPECIFIC if ARM_UNWIND
 	select HAVE_OPROFILE if (HAVE_PERF_EVENTS)
 	select HAVE_PERF_EVENTS
+	select HAVE_PERF_REGS
+	select HAVE_PERF_USER_STACK_DUMP
 	select HAVE_REGS_AND_STACK_ACCESS_API
 	select HAVE_SYSCALL_TRACEPOINTS
 	select HAVE_UID16

arch/arm/include/uapi/asm/Kbuild

@@ -7,6 +7,7 @@ header-y += hwcap.h
 header-y += ioctls.h
 header-y += kvm_para.h
 header-y += mman.h
+header-y += perf_regs.h
 header-y += posix_types.h
 header-y += ptrace.h
 header-y += setup.h

arch/arm/include/uapi/asm/perf_regs.h

@@ -0,0 +1,23 @@
+#ifndef _ASM_ARM_PERF_REGS_H
+#define _ASM_ARM_PERF_REGS_H
+
+enum perf_event_arm_regs {
+	PERF_REG_ARM_R0,
+	PERF_REG_ARM_R1,
+	PERF_REG_ARM_R2,
+	PERF_REG_ARM_R3,
+	PERF_REG_ARM_R4,
+	PERF_REG_ARM_R5,
+	PERF_REG_ARM_R6,
+	PERF_REG_ARM_R7,
+	PERF_REG_ARM_R8,
+	PERF_REG_ARM_R9,
+	PERF_REG_ARM_R10,
+	PERF_REG_ARM_FP,
+	PERF_REG_ARM_IP,
+	PERF_REG_ARM_SP,
+	PERF_REG_ARM_LR,
+	PERF_REG_ARM_PC,
+	PERF_REG_ARM_MAX,
+};
+#endif /* _ASM_ARM_PERF_REGS_H */

arch/arm/kernel/Makefile

@@ -78,6 +78,7 @@ obj-$(CONFIG_CPU_XSC3)		+= xscale-cp0.o
 obj-$(CONFIG_CPU_MOHAWK)	+= xscale-cp0.o
 obj-$(CONFIG_CPU_PJ4)		+= pj4-cp0.o
 obj-$(CONFIG_IWMMXT)		+= iwmmxt.o
+obj-$(CONFIG_PERF_EVENTS)	+= perf_regs.o
 obj-$(CONFIG_HW_PERF_EVENTS)	+= perf_event.o perf_event_cpu.o
 AFLAGS_iwmmxt.o			:= -Wa,-mcpu=iwmmxt
 obj-$(CONFIG_ARM_CPU_TOPOLOGY)  += topology.o

arch/arm/kernel/perf_event.c

@@ -256,12 +256,11 @@ validate_event(struct pmu_hw_events *hw_events,
 	       struct perf_event *event)
 {
 	struct arm_pmu *armpmu = to_arm_pmu(event->pmu);
-	struct pmu *leader_pmu = event->group_leader->pmu;
 
 	if (is_software_event(event))
 		return 1;
 
-	if (event->pmu != leader_pmu || event->state < PERF_EVENT_STATE_OFF)
+	if (event->state < PERF_EVENT_STATE_OFF)
 		return 1;
 
 	if (event->state == PERF_EVENT_STATE_OFF && !event->attr.enable_on_exec)

arch/arm/kernel/perf_regs.c

@@ -0,0 +1,30 @@
+
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/perf_event.h>
+#include <linux/bug.h>
+#include <asm/perf_regs.h>
+#include <asm/ptrace.h>
+
+u64 perf_reg_value(struct pt_regs *regs, int idx)
+{
+	if (WARN_ON_ONCE((u32)idx >= PERF_REG_ARM_MAX))
+		return 0;
+
+	return regs->uregs[idx];
+}
+
+#define REG_RESERVED (~((1ULL << PERF_REG_ARM_MAX) - 1))
+
+int perf_reg_validate(u64 mask)
+{
+	if (!mask || mask & REG_RESERVED)
+		return -EINVAL;
+
+	return 0;
+}
+
+u64 perf_reg_abi(struct task_struct *task)
+{
+	return PERF_SAMPLE_REGS_ABI_32;
+}

tools/perf/arch/arm/Makefile

@@ -2,3 +2,6 @@ ifndef NO_DWARF
 PERF_HAVE_DWARF_REGS := 1
 LIB_OBJS += $(OUTPUT)arch/$(ARCH)/util/dwarf-regs.o
 endif
+ifndef NO_LIBUNWIND
+LIB_OBJS += $(OUTPUT)arch/$(ARCH)/util/unwind.o
+endif

tools/perf/arch/arm/include/perf_regs.h

@@ -0,0 +1,54 @@
+#ifndef ARCH_PERF_REGS_H
+#define ARCH_PERF_REGS_H
+
+#include <stdlib.h>
+#include "../../util/types.h"
+#include <asm/perf_regs.h>
+
+#define PERF_REGS_MASK	((1ULL << PERF_REG_ARM_MAX) - 1)
+#define PERF_REG_IP	PERF_REG_ARM_PC
+#define PERF_REG_SP	PERF_REG_ARM_SP
+
+static inline const char *perf_reg_name(int id)
+{
+	switch (id) {
+	case PERF_REG_ARM_R0:
+		return "r0";
+	case PERF_REG_ARM_R1:
+		return "r1";
+	case PERF_REG_ARM_R2:
+		return "r2";
+	case PERF_REG_ARM_R3:
+		return "r3";
+	case PERF_REG_ARM_R4:
+		return "r4";
+	case PERF_REG_ARM_R5:
+		return "r5";
+	case PERF_REG_ARM_R6:
+		return "r6";
+	case PERF_REG_ARM_R7:
+		return "r7";
+	case PERF_REG_ARM_R8:
+		return "r8";
+	case PERF_REG_ARM_R9:
+		return "r9";
+	case PERF_REG_ARM_R10:
+		return "r10";
+	case PERF_REG_ARM_FP:
+		return "fp";
+	case PERF_REG_ARM_IP:
+		return "ip";
+	case PERF_REG_ARM_SP:
+		return "sp";
+	case PERF_REG_ARM_LR:
+		return "lr";
+	case PERF_REG_ARM_PC:
+		return "pc";
+	default:
+		return NULL;
+	}
+
+	return NULL;
+}
+
+#endif /* ARCH_PERF_REGS_H */

tools/perf/arch/arm/util/unwind.c

@@ -0,0 +1,48 @@
+
+#include <errno.h>
+#include <libunwind.h>
+#include "perf_regs.h"
+#include "../../util/unwind.h"
+
+int unwind__arch_reg_id(int regnum)
+{
+	switch (regnum) {
+	case UNW_ARM_R0:
+		return PERF_REG_ARM_R0;
+	case UNW_ARM_R1:
+		return PERF_REG_ARM_R1;
+	case UNW_ARM_R2:
+		return PERF_REG_ARM_R2;
+	case UNW_ARM_R3:
+		return PERF_REG_ARM_R3;
+	case UNW_ARM_R4:
+		return PERF_REG_ARM_R4;
+	case UNW_ARM_R5:
+		return PERF_REG_ARM_R5;
+	case UNW_ARM_R6:
+		return PERF_REG_ARM_R6;
+	case UNW_ARM_R7:
+		return PERF_REG_ARM_R7;
+	case UNW_ARM_R8:
+		return PERF_REG_ARM_R8;
+	case UNW_ARM_R9:
+		return PERF_REG_ARM_R9;
+	case UNW_ARM_R10:
+		return PERF_REG_ARM_R10;
+	case UNW_ARM_R11:
+		return PERF_REG_ARM_FP;
+	case UNW_ARM_R12:
+		return PERF_REG_ARM_IP;
+	case UNW_ARM_R13:
+		return PERF_REG_ARM_SP;
+	case UNW_ARM_R14:
+		return PERF_REG_ARM_LR;
+	case UNW_ARM_R15:
+		return PERF_REG_ARM_PC;
+	default:
+		pr_err("unwind: invalid reg id %d\n", regnum);
+		return -EINVAL;
+	}
+
+	return -EINVAL;
+}

tools/perf/config/Makefile

@@ -29,6 +29,10 @@ ifeq ($(ARCH),x86_64)
   NO_PERF_REGS := 0
   LIBUNWIND_LIBS = -lunwind -lunwind-x86_64
 endif
+ifeq ($(ARCH),arm)
+  NO_PERF_REGS := 0
+  LIBUNWIND_LIBS = -lunwind -lunwind-arm
+endif
 
 ifeq ($(NO_PERF_REGS),0)
   CFLAGS += -DHAVE_PERF_REGS
@@ -208,8 +212,7 @@ ifeq ($(call try-cc,$(SOURCE_ELF_MMAP),$(FLAGS_LIBELF),-DLIBELF_MMAP),y)
 endif # try-cc
 endif # NO_LIBELF
 
-# There's only x86 (both 32 and 64) support for CFI unwind so far
-ifneq ($(ARCH),x86)
+ifeq ($(LIBUNWIND_LIBS),)
   NO_LIBUNWIND := 1
 endif
 
@@ -223,9 +226,13 @@ endif
 
 FLAGS_UNWIND=$(LIBUNWIND_CFLAGS) $(CFLAGS) $(LIBUNWIND_LDFLAGS) $(LDFLAGS) $(EXTLIBS) $(LIBUNWIND_LIBS)
 ifneq ($(call try-cc,$(SOURCE_LIBUNWIND),$(FLAGS_UNWIND),libunwind),y)
-  msg := $(warning No libunwind found, disabling post unwind support. Please install libunwind-dev[el] >= 0.99);
+  msg := $(warning No libunwind found, disabling post unwind support. Please install libunwind-dev[el] >= 1.1);
   NO_LIBUNWIND := 1
 endif # Libunwind support
+ifneq ($(call try-cc,$(SOURCE_LIBUNWIND_DEBUG_FRAME),$(FLAGS_UNWIND),libunwind debug_frame),y)
+  msg := $(warning No debug_frame support found in libunwind);
+CFLAGS += -DNO_LIBUNWIND_DEBUG_FRAME
+endif # debug_frame support in libunwind
 endif # NO_LIBUNWIND
 
 ifndef NO_LIBUNWIND

tools/perf/config/feature-tests.mak

@@ -185,7 +185,6 @@ extern int UNW_OBJ(dwarf_search_unwind_table) (unw_addr_space_t as,
                                       unw_proc_info_t *pi,
                                       int need_unwind_info, void *arg);
 
-
 #define dwarf_search_unwind_table UNW_OBJ(dwarf_search_unwind_table)
 
 int main(void)
@@ -197,6 +196,26 @@ int main(void)
 	return 0;
 }
 endef
+
+define SOURCE_LIBUNWIND_DEBUG_FRAME
+#include <libunwind.h>
+#include <stdlib.h>
+
+extern int
+UNW_OBJ(dwarf_find_debug_frame) (int found, unw_dyn_info_t *di_debug,
+				 unw_word_t ip, unw_word_t segbase,
+				 const char *obj_name, unw_word_t start,
+				 unw_word_t end);
+
+#define dwarf_find_debug_frame UNW_OBJ(dwarf_find_debug_frame)
+
+int main(void)
+{
+	dwarf_find_debug_frame(0, NULL, 0, 0, NULL, 0, 0);
+	return 0;
+}
+endef
+
 endif
 
 ifndef NO_BACKTRACE

tools/perf/util/unwind.c

@@ -39,6 +39,15 @@ UNW_OBJ(dwarf_search_unwind_table) (unw_addr_space_t as,
 
 #define dwarf_search_unwind_table UNW_OBJ(dwarf_search_unwind_table)
 
+extern int
+UNW_OBJ(dwarf_find_debug_frame) (int found, unw_dyn_info_t *di_debug,
+				 unw_word_t ip,
+				 unw_word_t segbase,
+				 const char *obj_name, unw_word_t start,
+				 unw_word_t end);
+
+#define dwarf_find_debug_frame UNW_OBJ(dwarf_find_debug_frame)
+
 #define DW_EH_PE_FORMAT_MASK	0x0f	/* format of the encoded value */
 #define DW_EH_PE_APPL_MASK	0x70	/* how the value is to be applied */
 
@@ -245,8 +254,9 @@ static int unwind_spec_ehframe(struct dso *dso, struct machine *machine,
 	return 0;
 }
 
-static int read_unwind_spec(struct dso *dso, struct machine *machine,
-			    u64 *table_data, u64 *segbase, u64 *fde_count)
+static int read_unwind_spec_eh_frame(struct dso *dso, struct machine *machine,
+				     u64 *table_data, u64 *segbase,
+				     u64 *fde_count)
 {
 	int ret = -EINVAL, fd;
 	u64 offset;
@@ -255,6 +265,7 @@ static int read_unwind_spec(struct dso *dso, struct machine *machine,
 	if (fd < 0)
 		return -EINVAL;
 
+	/* Check the .eh_frame section for unwinding info */
 	offset = elf_section_offset(fd, ".eh_frame_hdr");
 	close(fd);
 
@@ -263,10 +274,29 @@ static int read_unwind_spec(struct dso *dso, struct machine *machine,
 					  table_data, segbase,
 					  fde_count);
 
-	/* TODO .debug_frame check if eh_frame_hdr fails */
 	return ret;
 }
 
+#ifndef NO_LIBUNWIND_DEBUG_FRAME
+static int read_unwind_spec_debug_frame(struct dso *dso,
+					struct machine *machine, u64 *offset)
+{
+	int fd = dso__data_fd(dso, machine);
+
+	if (fd < 0)
+		return -EINVAL;
+
+	/* Check the .debug_frame section for unwinding info */
+	*offset = elf_section_offset(fd, ".debug_frame");
+	close(fd);
+
+	if (*offset)
+		return 0;
+
+	return -EINVAL;
+}
+#endif
+
 static struct map *find_map(unw_word_t ip, struct unwind_info *ui)
 {
 	struct addr_location al;
@@ -291,20 +321,33 @@ find_proc_info(unw_addr_space_t as, unw_word_t ip, unw_proc_info_t *pi,
 
 	pr_debug("unwind: find_proc_info dso %s\n", map->dso->name);
 
-	if (read_unwind_spec(map->dso, ui->machine,
-			     &table_data, &segbase, &fde_count))
-		return -EINVAL;
+	/* Check the .eh_frame section for unwinding info */
+	if (!read_unwind_spec_eh_frame(map->dso, ui->machine,
+				       &table_data, &segbase, &fde_count)) {
+		memset(&di, 0, sizeof(di));
+		di.format   = UNW_INFO_FORMAT_REMOTE_TABLE;
+		di.start_ip = map->start;
+		di.end_ip   = map->end;
+		di.u.rti.segbase    = map->start + segbase;
+		di.u.rti.table_data = map->start + table_data;
+		di.u.rti.table_len  = fde_count * sizeof(struct table_entry)
+				      / sizeof(unw_word_t);
+		return dwarf_search_unwind_table(as, ip, &di, pi,
+						 need_unwind_info, arg);
+	}
+
+#ifndef NO_LIBUNWIND_DEBUG_FRAME
+	/* Check the .debug_frame section for unwinding info */
+	if (!read_unwind_spec_debug_frame(map->dso, ui->machine, &segbase)) {
+		memset(&di, 0, sizeof(di));
+		dwarf_find_debug_frame(0, &di, ip, 0, map->dso->name,
+				       map->start, map->end);
+		return dwarf_search_unwind_table(as, ip, &di, pi,
+						 need_unwind_info, arg);
+	}
+#endif
 
-	memset(&di, 0, sizeof(di));
-	di.format   = UNW_INFO_FORMAT_REMOTE_TABLE;
-	di.start_ip = map->start;
-	di.end_ip   = map->end;
-	di.u.rti.segbase    = map->start + segbase;
-	di.u.rti.table_data = map->start + table_data;
-	di.u.rti.table_len  = fde_count * sizeof(struct table_entry)
-			      / sizeof(unw_word_t);
-	return dwarf_search_unwind_table(as, ip, &di, pi,
-					 need_unwind_info, arg);
+	return -EINVAL;
 }
 
 static int access_fpreg(unw_addr_space_t __maybe_unused as,