[PATCH v2 4/4] modpost: remove unreachable code after fatal()

From: Masahiro Yamada
Date: Sun Dec 03 2023 - 04:50:05 EST


Now compilers can recognize fatal() never returns.

While GCC 4.5 dropped support for -Wunreachable-code, Clang is capable
of detecting the unreachable code.

$ make HOSTCC=clang HOSTCFLAGS=-Wunreachable-code-return
[snip]
HOSTCC scripts/mod/modpost.o
scripts/mod/modpost.c:520:11: warning: 'return' will never be executed [-Wunreachable-code-return]
return 0;
^
scripts/mod/modpost.c:477:10: warning: 'return' will never be executed [-Wunreachable-code-return]
return 0;
^
2 warnings generated.

Signed-off-by: Masahiro Yamada <masahiroy@xxxxxxxxxx>
Reviewed-by: Nathan Chancellor <nathan@xxxxxxxxxx>
---

Changes in v2:
- Change the patch order
- Update the commit description and add warning example.

scripts/mod/modpost.c | 9 +++------
1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
index 3233946fa5f6..e2bc180cecc8 100644
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -476,11 +476,9 @@ static int parse_elf(struct elf_info *info, const char *filename)
fatal("%s: not relocatable object.", filename);

/* Check if file offset is correct */
- if (hdr->e_shoff > info->size) {
+ if (hdr->e_shoff > info->size)
fatal("section header offset=%lu in file '%s' is bigger than filesize=%zu\n",
(unsigned long)hdr->e_shoff, filename, info->size);
- return 0;
- }

if (hdr->e_shnum == SHN_UNDEF) {
/*
@@ -518,12 +516,11 @@ static int parse_elf(struct elf_info *info, const char *filename)
const char *secname;
int nobits = sechdrs[i].sh_type == SHT_NOBITS;

- if (!nobits && sechdrs[i].sh_offset > info->size) {
+ if (!nobits && sechdrs[i].sh_offset > info->size)
fatal("%s is truncated. sechdrs[i].sh_offset=%lu > sizeof(*hrd)=%zu\n",
filename, (unsigned long)sechdrs[i].sh_offset,
sizeof(*hdr));
- return 0;
- }
+
secname = secstrings + sechdrs[i].sh_name;
if (strcmp(secname, ".modinfo") == 0) {
if (nobits)
--
2.40.1