[tip: objtool/urgent] objtool: initialize all of struct elf

[tip-bot2 for Michal Kubecek]

The following commit has been merged into the objtool/urgent branch of tip:

Commit-ID:     9f71fbcde2820f2af4658313e808cf1e579190a4
Gitweb:        https://git.kernel.org/tip/9f71fbcde2820f2af4658313e808cf1e579190a4
Author:        Michal Kubecek <mkubecek@xxxxxxx>
AuthorDate:    Thu, 29 Jun 2023 12:05:05 +02:00
Committer:     Peter Zijlstra <peterz@xxxxxxxxxxxxx>
CommitterDate: Mon, 10 Jul 2023 09:52:28 +02:00

objtool: initialize all of struct elf

Function elf_open_read() only zero initializes the initial part of
allocated struct elf; num_relocs member was recently added outside the
zeroed part so that it was left uninitialized, resulting in build failures
on some systems.

The partial initialization is a relic of times when struct elf had large
hash tables embedded. This is no longer the case so remove the trap and
initialize the whole structure instead.

Fixes: eb0481bbc4ce ("objtool: Fix reloc_hash size")
Signed-off-by: Michal Kubecek <mkubecek@xxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Acked-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20230629102051.42E8360467@xxxxxxxxxxxxxx
---
 tools/objtool/elf.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/objtool/elf.c b/tools/objtool/elf.c
index d420b5d..081befa 100644
--- a/tools/objtool/elf.c
+++ b/tools/objtool/elf.c
@@ -1005,7 +1005,7 @@ struct elf *elf_open_read(const char *name, int flags)
 		perror("malloc");
 		return NULL;
 	}
-	memset(elf, 0, offsetof(struct elf, sections));
+	memset(elf, 0, sizeof(*elf));
 
 	INIT_LIST_HEAD(&elf->sections);