The way it is currently done it is possible for read_symbols() to find the
same symbol as parent for ".cold" functions. This leads to a bunch of
complications such as func length being set to 0 and a segfault in
add_switch_table(). Fix by copying the search string instead of modifying
it in place.

Signed-off-by: Artem Savkov <asav...@redhat.com>
---
 tools/objtool/elf.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/tools/objtool/elf.c b/tools/objtool/elf.c
index 6dbb9fae0f9d..781c8afb29b9 100644
--- a/tools/objtool/elf.c
+++ b/tools/objtool/elf.c
@@ -298,6 +298,7 @@ static int read_symbols(struct elf *elf)
        /* Create parent/child links for any cold subfunctions */
        list_for_each_entry(sec, &elf->sections, list) {
                list_for_each_entry(sym, &sec->symbol_list, list) {
+                       char *pname;
                        if (sym->type != STT_FUNC)
                                continue;
                        sym->pfunc = sym->cfunc = sym;
@@ -305,9 +306,9 @@ static int read_symbols(struct elf *elf)
                        if (!coldstr)
                                continue;
 
-                       coldstr[0] = '\0';
-                       pfunc = find_symbol_by_name(elf, sym->name);
-                       coldstr[0] = '.';
+                       pname = strndup(sym->name, coldstr - sym->name);
+                       pfunc = find_symbol_by_name(elf, pname);
+                       free(pname);
 
                        if (!pfunc) {
                                WARN("%s(): can't find parent function",
-- 
2.17.2

Reply via email to