8 files changed, 196 insertions, 19 deletions

diff --git a/tools/perf/arch/arm/Makefile b/tools/perf/arch/arm/Makefile
index 15130b50dfe3..fe9b61e322a5 100644
--- a/tools/perf/arch/arm/Makefile
+++ b/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
diff --git a/tools/perf/arch/arm/include/perf_regs.h b/tools/perf/arch/arm/include/perf_regs.h
new file mode 100644
index 000000000000..2a1cfde66b69
--- /dev/null
+++ b/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 */
diff --git a/tools/perf/arch/arm/util/unwind.c b/tools/perf/arch/arm/util/unwind.c
new file mode 100644
index 000000000000..da3dc950550c
--- /dev/null
+++ b/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;
+}
diff --git a/tools/perf/config/Makefile b/tools/perf/config/Makefile
index 58b2d37ae23a..f5905f2b197d 100644
--- a/tools/perf/config/Makefile
+++ b/tools/perf/config/Makefile
@@ -31,6 +31,10 @@ ifeq ($(ARCH),x86_64)
   endif
   NO_PERF_REGS := 0
 endif
+ifeq ($(ARCH),arm)
+  NO_PERF_REGS := 0
+  LIBUNWIND_LIBS = -lunwind -lunwind-arm
+endif
 
 ifeq ($(NO_PERF_REGS),0)
   CFLAGS += -DHAVE_PERF_REGS_SUPPORT
@@ -305,8 +309,7 @@ ifndef NO_LIBELF
   endif # NO_DWARF
 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
 
@@ -322,8 +325,13 @@ ifndef NO_LIBUNWIND
   endif
 
   ifneq ($(feature-libunwind), 1)
-    msg := $(warning No libunwind found, disabling post unwind support. Please install libunwind-dev[el] >= 0.99);
+    msg := $(warning No libunwind found, disabling post unwind support. Please install libunwind-dev[el] >= 1.1);
     NO_LIBUNWIND := 1
+  else
+    ifneq ($(feature-libunwind-debug-frame), 1)
+      msg := $(warning No debug_frame support found in libunwind);
+      CFLAGS += -DNO_LIBUNWIND_DEBUG_FRAME
+    endif
   endif
 endif
 
diff --git a/tools/perf/config/feature-checks/Makefile b/tools/perf/config/feature-checks/Makefile
index c803f17fb986..e8e195f49a4e 100644
--- a/tools/perf/config/feature-checks/Makefile
+++ b/tools/perf/config/feature-checks/Makefile
@@ -23,6 +23,7 @@ FILES=					\
         test-libpython-version          \
         test-libslang                   \
         test-libunwind                  \
+        test-libunwind-debug-frame      \
         test-on-exit                    \
         test-stackprotector-all         \
         test-stackprotector             \
diff --git a/tools/perf/config/feature-checks/test-all.c b/tools/perf/config/feature-checks/test-all.c
index 59e7a705e146..799865b60772 100644
--- a/tools/perf/config/feature-checks/test-all.c
+++ b/tools/perf/config/feature-checks/test-all.c
@@ -49,6 +49,10 @@
 # include "test-libunwind.c"
 #undef main
 
+#define main main_test_libunwind_debug_frame
+# include "test-libunwind-debug-frame.c"
+#undef main
+
 #define main main_test_libaudit
 # include "test-libaudit.c"
 #undef main
diff --git a/tools/perf/config/feature-checks/test-libunwind-debug-frame.c b/tools/perf/config/feature-checks/test-libunwind-debug-frame.c
new file mode 100644
index 000000000000..0ef8087a104a
--- /dev/null
+++ b/tools/perf/config/feature-checks/test-libunwind-debug-frame.c
@@ -0,0 +1,16 @@
+#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;
+}
diff --git a/tools/perf/util/unwind.c b/tools/perf/util/unwind.c
index 2f891f7e70bf..5390d0b8862a 100644
--- a/tools/perf/util/unwind.c
+++ b/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,