[PATCH -fixes] bpf: resolve_btfids: Fix integer overflow when calling elf_update()

[Alexandre Ghiti]

The following error was encoutered in [1]:

FAILED elf_update(WRITE): no error

elf_update() returns the total size of the file which here happens to be
a ~2.5GB vmlinux file: this size overflows the integer used to hold the
return value of elf_update() and is then interpreted as being negative.

So fix this by using the correct type expected by elf_update() which is
off_t.

Fixes: fbbb68de80a4 ("bpf: Add resolve_btfids tool to resolve BTF IDs in ELF object")
Link: https://bugzilla.kernel.org/show_bug.cgi?id=218887 [1]
Signed-off-by: Alexandre Ghiti <alexghiti at rivosinc.com>
---
 tools/bpf/resolve_btfids/main.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/bpf/resolve_btfids/main.c b/tools/bpf/resolve_btfids/main.c
index d9520cb826b3..af393c7dee1f 100644
--- a/tools/bpf/resolve_btfids/main.c
+++ b/tools/bpf/resolve_btfids/main.c
@@ -728,7 +728,7 @@ static int sets_patch(struct object *obj)
 
 static int symbols_patch(struct object *obj)
 {
-	int err;
+	off_t err;
 
 	if (__symbols_patch(obj, &obj->structs)  ||
 	    __symbols_patch(obj, &obj->unions)   ||
-- 
2.39.2