On 2025/3/8 04:30, Kees Cook wrote:
On Fri, Mar 07, 2025 at 03:47:28PM +0100, Jan Kara wrote:
On Fri 07-03-25 14:11:28, sunliming@xxxxxxxxx wrote:
From: sunliming <sunliming@xxxxxxxxxx>
Fix below kernel warning:
fs/binfmt_elf_fdpic.c:1024:52: warning: variable 'excess1' set but not
used [-Wunused-but-set-variable]
Reported-by: kernel test robot <lkp@xxxxxxxxx>
Signed-off-by: sunliming <sunliming@xxxxxxxxxx>
The extra ifdef is not pretty but I guess it's better. Feel free to add:
Reviewed-by: Jan Kara <jack@xxxxxxx>
Since we allow loop-scope variable definitions now, perhaps this is a
case for defining the variable later within the #ifdef, like this?
diff --git a/fs/binfmt_elf_fdpic.c b/fs/binfmt_elf_fdpic.c
index e3cf2801cd64..b0ef71238328 100644
--- a/fs/binfmt_elf_fdpic.c
+++ b/fs/binfmt_elf_fdpic.c
@@ -1024,7 +1024,7 @@ static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params,
/* deal with each load segment separately */
phdr = params->phdrs;
for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
- unsigned long maddr, disp, excess, excess1;
+ unsigned long maddr, disp, excess;
int prot = 0, flags;
if (phdr->p_type != PT_LOAD)
@@ -1120,9 +1120,10 @@ static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params,
* extant in the file
*/
excess = phdr->p_memsz - phdr->p_filesz;
- excess1 = PAGE_SIZE - ((maddr + phdr->p_filesz) & ~PAGE_MASK);
#ifdef CONFIG_MMU
+ const unsigned long excess1 =
+ PAGE_SIZE - ((maddr + phdr->p_filesz) & ~PAGE_MASK);
if (excess > excess1) {
unsigned long xaddr = maddr + phdr->p_filesz + excess1;
unsigned long xmaddr;
I think this is a good idea. I will resend this patch in this way，thanks.
Honza
---
fs/binfmt_elf_fdpic.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/fs/binfmt_elf_fdpic.c b/fs/binfmt_elf_fdpic.c
index e3cf2801cd64..bed13ee8bfec 100644
--- a/fs/binfmt_elf_fdpic.c
+++ b/fs/binfmt_elf_fdpic.c
@@ -1024,8 +1024,11 @@ static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params,
/* deal with each load segment separately */
phdr = params->phdrs;
for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
- unsigned long maddr, disp, excess, excess1;
+ unsigned long maddr, disp, excess;
int prot = 0, flags;
+#ifdef CONFIG_MMU
+ unsigned long excess1;
+#endif
if (phdr->p_type != PT_LOAD)
continue;
@@ -1120,9 +1123,9 @@ static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params,
* extant in the file
*/
excess = phdr->p_memsz - phdr->p_filesz;
- excess1 = PAGE_SIZE - ((maddr + phdr->p_filesz) & ~PAGE_MASK);
#ifdef CONFIG_MMU
+ excess1 = PAGE_SIZE - ((maddr + phdr->p_filesz) & ~PAGE_MASK);
if (excess > excess1) {
unsigned long xaddr = maddr + phdr->p_filesz + excess1;
unsigned long xmaddr;
--
2.25.1
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR
