2020-06-23 17:25:20

by Kristen Carlson Accardi

Subject: [PATCH v3 01/10] objtool: Do not assume order of parent/child functions

If a .cold function is examined prior to it's parent, the link
to the parent/child function can be overwritten when the parent
is examined. Only update pfunc and cfunc if they were previously
nil to prevent this from happening.

Signed-off-by: Kristen Carlson Accardi <[email protected]>
Acked-by: Josh Poimboeuf <[email protected]>
---
tools/objtool/elf.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/tools/objtool/elf.c b/tools/objtool/elf.c
index 84225679f96d..f953d3a15612 100644
--- a/tools/objtool/elf.c
+++ b/tools/objtool/elf.c
@@ -434,7 +434,13 @@ static int read_symbols(struct elf *elf)
size_t pnamelen;
if (sym->type != STT_FUNC)
continue;
- sym->pfunc = sym->cfunc = sym;
+
+ if (sym->pfunc == NULL)
+ sym->pfunc = sym;
+
+ if (sym->cfunc == NULL)
+ sym->cfunc = sym;
+
coldstr = strstr(sym->name, ".cold");
if (!coldstr)
continue;
--
2.20.1

2020-06-24 03:12:25

by Josh Poimboeuf

Subject: Re: [PATCH v3 01/10] objtool: Do not assume order of parent/child functions

On Tue, Jun 23, 2020 at 10:23:18AM -0700, Kristen Carlson Accardi wrote:
> If a .cold function is examined prior to it's parent, the link
> to the parent/child function can be overwritten when the parent
> is examined. Only update pfunc and cfunc if they were previously
> nil to prevent this from happening.
>
> Signed-off-by: Kristen Carlson Accardi <[email protected]>
> Acked-by: Josh Poimboeuf <[email protected]>

FYI, this patch is now in the tip tree.

--
Josh