Merge commit 3669ef9fa7d3 ("x86, tls: Interpret an all-zero struct user_desc as 'no segment'") into x86/asm

Pick up the latestest asm fixes before advancing it any further.

Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 27 insertions, 1 deletions

diff --git a/tools/perf/util/unwind-libunwind.c b/tools/perf/util/unwind-libunwind.c
index 371219a6daf1..6edf535f65c2 100644
--- a/tools/perf/util/unwind-libunwind.c
+++ b/tools/perf/util/unwind-libunwind.c
@@ -185,6 +185,28 @@ static u64 elf_section_offset(int fd, const char *name)
         return offset;
 }
 
+#ifndef NO_LIBUNWIND_DEBUG_FRAME
+static int elf_is_exec(int fd, const char *name)
+{
+        Elf *elf;
+        GElf_Ehdr ehdr;
+        int retval = 0;
+
+        elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
+        if (elf == NULL)
+                return 0;
+        if (gelf_getehdr(elf, &ehdr) == NULL)
+                goto out;
+
+        retval = (ehdr.e_type == ET_EXEC);
+
+out:
+        elf_end(elf);
+        pr_debug("unwind: elf_is_exec(%s): %d\n", name, retval);
+        return retval;
+}
+#endif
+
 struct table_entry {
         u32 start_ip_offset;
         u32 fde_offset;
@@ -322,8 +344,12 @@ find_proc_info(unw_addr_space_t as, unw_word_t ip, unw_proc_info_t *pi,
 #ifndef NO_LIBUNWIND_DEBUG_FRAME
         /* Check the .debug_frame section for unwinding info */
         if (!read_unwind_spec_debug_frame(map->dso, ui->machine, &segbase)) {
+                int fd = dso__data_fd(map->dso, ui->machine);
+                int is_exec = elf_is_exec(fd, map->dso->name);
+                unw_word_t base = is_exec ? 0 : map->start;
+
                 memset(&di, 0, sizeof(di));
-                if (dwarf_find_debug_frame(0, &di, ip, 0, map->dso->name,
+                if (dwarf_find_debug_frame(0, &di, ip, base, map->dso->name,
                                            map->start, map->end))
                         return dwarf_search_unwind_table(as, ip, &di, pi,
                                                          need_unwind_info, arg);