| Message ID | 20250307061128.2999222-1-sunliming@linux.dev (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | fs: binfmt_elf_efpic: fix variable set but not used warning | expand |
On Fri 07-03-25 14:11:28, sunliming@linux.dev wrote: > From: sunliming <sunliming@kylinos.cn> > > 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@intel.com> > Signed-off-by: sunliming <sunliming@kylinos.cn> The extra ifdef is not pretty but I guess it's better. Feel free to add: Reviewed-by: Jan Kara <jack@suse.cz> 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 >
On Fri, Mar 07, 2025 at 03:47:28PM +0100, Jan Kara wrote: > On Fri 07-03-25 14:11:28, sunliming@linux.dev wrote: > > From: sunliming <sunliming@kylinos.cn> > > > > 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@intel.com> > > Signed-off-by: sunliming <sunliming@kylinos.cn> > > The extra ifdef is not pretty but I guess it's better. Feel free to add: > > Reviewed-by: Jan Kara <jack@suse.cz> 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; > > 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@suse.com> > SUSE Labs, CR
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@linux.dev wrote: >>> From: sunliming <sunliming@kylinos.cn> >>> >>> 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@intel.com> >>> Signed-off-by: sunliming <sunliming@kylinos.cn> >> The extra ifdef is not pretty but I guess it's better. Feel free to add: >> >> Reviewed-by: Jan Kara <jack@suse.cz> > 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@suse.com> >> SUSE Labs, CR
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;