RE: include/linux/string.h:246:9: warning: '__builtin_strncpy' output truncated before terminating nul copying 4 bytes from a string of the same length
From: Josh Poimboeuf > Sent: 05 June 2018 16:30 ... > What about just changing it to a memcpy? Seems like that would be > cleaner anyway, since the whole point of strncpy is to add the > terminating NULL, which isn't need here. Not really, the point of strncpy is to copy strings that might not be '\0' terminated and to zero fill the target buffer. Unfortunately strncpy() has often been used with the assumption that it always terminates the target string - which isn't true. Unfortunately you can't always replace strncpy with strlcpy or snprintf because both those require the source string be '\0' terminated - which isn't a requirement for strncpy. This warning on __builtin_strncpy() seems ott to me. The only fix is to audit the code and replace at least some of the strncpy() with really_strncpy(). David
RE: include/linux/string.h:246:9: warning: '__builtin_strncpy' output truncated before terminating nul copying 4 bytes from a string of the same length
From: Josh Poimboeuf > Sent: 05 June 2018 16:30 ... > What about just changing it to a memcpy? Seems like that would be > cleaner anyway, since the whole point of strncpy is to add the > terminating NULL, which isn't need here. Not really, the point of strncpy is to copy strings that might not be '\0' terminated and to zero fill the target buffer. Unfortunately strncpy() has often been used with the assumption that it always terminates the target string - which isn't true. Unfortunately you can't always replace strncpy with strlcpy or snprintf because both those require the source string be '\0' terminated - which isn't a requirement for strncpy. This warning on __builtin_strncpy() seems ott to me. The only fix is to audit the code and replace at least some of the strncpy() with really_strncpy(). David
Re: include/linux/string.h:246:9: warning: '__builtin_strncpy' output truncated before terminating nul copying 4 bytes from a string of the same length
On Tue, Jun 5, 2018 at 6:30 PM, Josh Poimboeuf wrote: > On Tue, Jun 05, 2018 at 06:19:07PM +0300, Andy Shevchenko wrote: >> On Tue, May 29, 2018 at 4:35 AM, kbuild test robot wrote: >> > tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git >> > master >> > head: 786b71f5b754273ccef6d9462e52062b3e1f9877 >> > commit: 854e55ad289efe7991f0ada85d5846f5afb9 objtool, perf: Fix GCC 8 >> > -Wrestrict error >> > date: 2 months ago >> > config: x86_64-randconfig-s4-05290856 (attached as .config) >> > compiler: gcc-8 (Debian 8.1.0-3) 8.1.0 >> > reproduce: >> > git checkout 854e55ad289efe7991f0ada85d5846f5afb9 >> > # save the attached .config to linux build tree >> > make ARCH=x86_64 >> > >> >> I guess it's easy to fix by >> >> --- a/drivers/video/fbdev/uvesafb.c >> +++ b/drivers/video/fbdev/uvesafb.c >> @@ -422,7 +422,7 @@ static int uvesafb_vbe_getinfo(struct uvesafb_ktask >> *task, >>task->t.flags = TF_VBEIB; >>task->t.buf_len = sizeof(struct vbe_ib); >>task->buf = >vbe_ib; >> - strncpy(par->vbe_ib.vbe_signature, "VBE2", 4); >> + snprintf(par->vbe_ib.vbe_signature, >> sizeof(par->vbe_ib.vbe_signature), "VBE2"); >> >> The question is do we want this to just shut up a compiler? It's >> obviously false positive. > > What about just changing it to a memcpy? Seems like that would be > cleaner anyway, since the whole point of strncpy is to add the > terminating NULL, which isn't need here. Agree. Btw, Bartlomiej, it seems driver maintainer's address is bouncing. -- With Best Regards, Andy Shevchenko
Re: include/linux/string.h:246:9: warning: '__builtin_strncpy' output truncated before terminating nul copying 4 bytes from a string of the same length
On Tue, Jun 5, 2018 at 6:30 PM, Josh Poimboeuf wrote: > On Tue, Jun 05, 2018 at 06:19:07PM +0300, Andy Shevchenko wrote: >> On Tue, May 29, 2018 at 4:35 AM, kbuild test robot wrote: >> > tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git >> > master >> > head: 786b71f5b754273ccef6d9462e52062b3e1f9877 >> > commit: 854e55ad289efe7991f0ada85d5846f5afb9 objtool, perf: Fix GCC 8 >> > -Wrestrict error >> > date: 2 months ago >> > config: x86_64-randconfig-s4-05290856 (attached as .config) >> > compiler: gcc-8 (Debian 8.1.0-3) 8.1.0 >> > reproduce: >> > git checkout 854e55ad289efe7991f0ada85d5846f5afb9 >> > # save the attached .config to linux build tree >> > make ARCH=x86_64 >> > >> >> I guess it's easy to fix by >> >> --- a/drivers/video/fbdev/uvesafb.c >> +++ b/drivers/video/fbdev/uvesafb.c >> @@ -422,7 +422,7 @@ static int uvesafb_vbe_getinfo(struct uvesafb_ktask >> *task, >>task->t.flags = TF_VBEIB; >>task->t.buf_len = sizeof(struct vbe_ib); >>task->buf = >vbe_ib; >> - strncpy(par->vbe_ib.vbe_signature, "VBE2", 4); >> + snprintf(par->vbe_ib.vbe_signature, >> sizeof(par->vbe_ib.vbe_signature), "VBE2"); >> >> The question is do we want this to just shut up a compiler? It's >> obviously false positive. > > What about just changing it to a memcpy? Seems like that would be > cleaner anyway, since the whole point of strncpy is to add the > terminating NULL, which isn't need here. Agree. Btw, Bartlomiej, it seems driver maintainer's address is bouncing. -- With Best Regards, Andy Shevchenko
Re: include/linux/string.h:246:9: warning: '__builtin_strncpy' output truncated before terminating nul copying 4 bytes from a string of the same length
On Tue, Jun 05, 2018 at 06:19:07PM +0300, Andy Shevchenko wrote:
> On Tue, May 29, 2018 at 4:35 AM, kbuild test robot wrote:
> > tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
> > master
> > head: 786b71f5b754273ccef6d9462e52062b3e1f9877
> > commit: 854e55ad289efe7991f0ada85d5846f5afb9 objtool, perf: Fix GCC 8
> > -Wrestrict error
> > date: 2 months ago
> > config: x86_64-randconfig-s4-05290856 (attached as .config)
> > compiler: gcc-8 (Debian 8.1.0-3) 8.1.0
> > reproduce:
> > git checkout 854e55ad289efe7991f0ada85d5846f5afb9
> > # save the attached .config to linux build tree
> > make ARCH=x86_64
> >
>
> I guess it's easy to fix by
>
> --- a/drivers/video/fbdev/uvesafb.c
> +++ b/drivers/video/fbdev/uvesafb.c
> @@ -422,7 +422,7 @@ static int uvesafb_vbe_getinfo(struct uvesafb_ktask *task,
>task->t.flags = TF_VBEIB;
>task->t.buf_len = sizeof(struct vbe_ib);
>task->buf = >vbe_ib;
> - strncpy(par->vbe_ib.vbe_signature, "VBE2", 4);
> + snprintf(par->vbe_ib.vbe_signature,
> sizeof(par->vbe_ib.vbe_signature), "VBE2");
>
> The question is do we want this to just shut up a compiler? It's
> obviously false positive.
What about just changing it to a memcpy? Seems like that would be
cleaner anyway, since the whole point of strncpy is to add the
terminating NULL, which isn't need here.
>
> > All warnings (new ones prefixed by >>):
> >
> >In file included from include/linux/bitmap.h:9,
> > from include/linux/cpumask.h:12,
> > from arch/x86/include/asm/cpumask.h:5,
> > from arch/x86/include/asm/msr.h:11,
> > from arch/x86/include/asm/processor.h:21,
> > from arch/x86/include/asm/cpufeature.h:5,
> > from arch/x86/include/asm/thread_info.h:53,
> > from include/linux/thread_info.h:38,
> > from arch/x86/include/asm/preempt.h:7,
> > from include/linux/preempt.h:81,
> > from include/linux/spinlock.h:51,
> > from include/linux/seqlock.h:36,
> > from include/linux/time.h:6,
> > from include/linux/stat.h:19,
> > from include/linux/module.h:10,
> > from drivers/video/fbdev/uvesafb.c:12:
> >In function 'strncpy',
> >inlined from 'uvesafb_vbe_getinfo' at
> > drivers/video/fbdev/uvesafb.c:425:2:
> >>> include/linux/string.h:246:9: warning: '__builtin_strncpy' output
> >>> truncated before terminating nul copying 4 bytes from a string of the
> >>> same length [-Wstringop-truncation]
> > return __builtin_strncpy(p, q, size);
> > ^
> >
> > vim +/__builtin_strncpy +246 include/linux/string.h
> >
> > 6974f0c4 Daniel Micay 2017-07-12 237
> > 6974f0c4 Daniel Micay 2017-07-12 238 #if !defined(__NO_FORTIFY) &&
> > defined(__OPTIMIZE__) && defined(CONFIG_FORTIFY_SOURCE)
> > 6974f0c4 Daniel Micay 2017-07-12 239 __FORTIFY_INLINE char *strncpy(char
> > *p, const char *q, __kernel_size_t size)
> > 6974f0c4 Daniel Micay 2017-07-12 240 {
> > 6974f0c4 Daniel Micay 2017-07-12 241 size_t p_size =
> > __builtin_object_size(p, 0);
> > 6974f0c4 Daniel Micay 2017-07-12 242 if (__builtin_constant_p(size) &&
> > p_size < size)
> > 6974f0c4 Daniel Micay 2017-07-12 243 __write_overflow();
> > 6974f0c4 Daniel Micay 2017-07-12 244 if (p_size < size)
> > 6974f0c4 Daniel Micay 2017-07-12 245 fortify_panic(__func__);
> > 6974f0c4 Daniel Micay 2017-07-12 @246 return __builtin_strncpy(p, q,
> > size);
> > 6974f0c4 Daniel Micay 2017-07-12 247 }
> > 6974f0c4 Daniel Micay 2017-07-12 248
> >
> > :: The code at line 246 was first introduced by commit
> > :: 6974f0c4555e285ab217cee58b6e874f776ff409 include/linux/string.h: add
> > the option of fortified string.h functions
> >
> > :: TO: Daniel Micay
> > :: CC: Linus Torvalds
> >
> > ---
> > 0-DAY kernel test infrastructureOpen Source Technology
> > Center
> > https://lists.01.org/pipermail/kbuild-all Intel
> > Corporation
>
>
>
> --
> With Best Regards,
> Andy Shevchenko
--
Josh
Re: include/linux/string.h:246:9: warning: '__builtin_strncpy' output truncated before terminating nul copying 4 bytes from a string of the same length
On Tue, Jun 05, 2018 at 06:19:07PM +0300, Andy Shevchenko wrote:
> On Tue, May 29, 2018 at 4:35 AM, kbuild test robot wrote:
> > tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
> > master
> > head: 786b71f5b754273ccef6d9462e52062b3e1f9877
> > commit: 854e55ad289efe7991f0ada85d5846f5afb9 objtool, perf: Fix GCC 8
> > -Wrestrict error
> > date: 2 months ago
> > config: x86_64-randconfig-s4-05290856 (attached as .config)
> > compiler: gcc-8 (Debian 8.1.0-3) 8.1.0
> > reproduce:
> > git checkout 854e55ad289efe7991f0ada85d5846f5afb9
> > # save the attached .config to linux build tree
> > make ARCH=x86_64
> >
>
> I guess it's easy to fix by
>
> --- a/drivers/video/fbdev/uvesafb.c
> +++ b/drivers/video/fbdev/uvesafb.c
> @@ -422,7 +422,7 @@ static int uvesafb_vbe_getinfo(struct uvesafb_ktask *task,
>task->t.flags = TF_VBEIB;
>task->t.buf_len = sizeof(struct vbe_ib);
>task->buf = >vbe_ib;
> - strncpy(par->vbe_ib.vbe_signature, "VBE2", 4);
> + snprintf(par->vbe_ib.vbe_signature,
> sizeof(par->vbe_ib.vbe_signature), "VBE2");
>
> The question is do we want this to just shut up a compiler? It's
> obviously false positive.
What about just changing it to a memcpy? Seems like that would be
cleaner anyway, since the whole point of strncpy is to add the
terminating NULL, which isn't need here.
>
> > All warnings (new ones prefixed by >>):
> >
> >In file included from include/linux/bitmap.h:9,
> > from include/linux/cpumask.h:12,
> > from arch/x86/include/asm/cpumask.h:5,
> > from arch/x86/include/asm/msr.h:11,
> > from arch/x86/include/asm/processor.h:21,
> > from arch/x86/include/asm/cpufeature.h:5,
> > from arch/x86/include/asm/thread_info.h:53,
> > from include/linux/thread_info.h:38,
> > from arch/x86/include/asm/preempt.h:7,
> > from include/linux/preempt.h:81,
> > from include/linux/spinlock.h:51,
> > from include/linux/seqlock.h:36,
> > from include/linux/time.h:6,
> > from include/linux/stat.h:19,
> > from include/linux/module.h:10,
> > from drivers/video/fbdev/uvesafb.c:12:
> >In function 'strncpy',
> >inlined from 'uvesafb_vbe_getinfo' at
> > drivers/video/fbdev/uvesafb.c:425:2:
> >>> include/linux/string.h:246:9: warning: '__builtin_strncpy' output
> >>> truncated before terminating nul copying 4 bytes from a string of the
> >>> same length [-Wstringop-truncation]
> > return __builtin_strncpy(p, q, size);
> > ^
> >
> > vim +/__builtin_strncpy +246 include/linux/string.h
> >
> > 6974f0c4 Daniel Micay 2017-07-12 237
> > 6974f0c4 Daniel Micay 2017-07-12 238 #if !defined(__NO_FORTIFY) &&
> > defined(__OPTIMIZE__) && defined(CONFIG_FORTIFY_SOURCE)
> > 6974f0c4 Daniel Micay 2017-07-12 239 __FORTIFY_INLINE char *strncpy(char
> > *p, const char *q, __kernel_size_t size)
> > 6974f0c4 Daniel Micay 2017-07-12 240 {
> > 6974f0c4 Daniel Micay 2017-07-12 241 size_t p_size =
> > __builtin_object_size(p, 0);
> > 6974f0c4 Daniel Micay 2017-07-12 242 if (__builtin_constant_p(size) &&
> > p_size < size)
> > 6974f0c4 Daniel Micay 2017-07-12 243 __write_overflow();
> > 6974f0c4 Daniel Micay 2017-07-12 244 if (p_size < size)
> > 6974f0c4 Daniel Micay 2017-07-12 245 fortify_panic(__func__);
> > 6974f0c4 Daniel Micay 2017-07-12 @246 return __builtin_strncpy(p, q,
> > size);
> > 6974f0c4 Daniel Micay 2017-07-12 247 }
> > 6974f0c4 Daniel Micay 2017-07-12 248
> >
> > :: The code at line 246 was first introduced by commit
> > :: 6974f0c4555e285ab217cee58b6e874f776ff409 include/linux/string.h: add
> > the option of fortified string.h functions
> >
> > :: TO: Daniel Micay
> > :: CC: Linus Torvalds
> >
> > ---
> > 0-DAY kernel test infrastructureOpen Source Technology
> > Center
> > https://lists.01.org/pipermail/kbuild-all Intel
> > Corporation
>
>
>
> --
> With Best Regards,
> Andy Shevchenko
--
Josh
Re: include/linux/string.h:246:9: warning: '__builtin_strncpy' output truncated before terminating nul copying 4 bytes from a string of the same length
On Tue, May 29, 2018 at 4:35 AM, kbuild test robot wrote:
> tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
> master
> head: 786b71f5b754273ccef6d9462e52062b3e1f9877
> commit: 854e55ad289efe7991f0ada85d5846f5afb9 objtool, perf: Fix GCC 8
> -Wrestrict error
> date: 2 months ago
> config: x86_64-randconfig-s4-05290856 (attached as .config)
> compiler: gcc-8 (Debian 8.1.0-3) 8.1.0
> reproduce:
> git checkout 854e55ad289efe7991f0ada85d5846f5afb9
> # save the attached .config to linux build tree
> make ARCH=x86_64
>
I guess it's easy to fix by
--- a/drivers/video/fbdev/uvesafb.c
+++ b/drivers/video/fbdev/uvesafb.c
@@ -422,7 +422,7 @@ static int uvesafb_vbe_getinfo(struct uvesafb_ktask *task,
task->t.flags = TF_VBEIB;
task->t.buf_len = sizeof(struct vbe_ib);
task->buf = >vbe_ib;
- strncpy(par->vbe_ib.vbe_signature, "VBE2", 4);
+ snprintf(par->vbe_ib.vbe_signature,
sizeof(par->vbe_ib.vbe_signature), "VBE2");
The question is do we want this to just shut up a compiler? It's
obviously false positive.
> All warnings (new ones prefixed by >>):
>
>In file included from include/linux/bitmap.h:9,
> from include/linux/cpumask.h:12,
> from arch/x86/include/asm/cpumask.h:5,
> from arch/x86/include/asm/msr.h:11,
> from arch/x86/include/asm/processor.h:21,
> from arch/x86/include/asm/cpufeature.h:5,
> from arch/x86/include/asm/thread_info.h:53,
> from include/linux/thread_info.h:38,
> from arch/x86/include/asm/preempt.h:7,
> from include/linux/preempt.h:81,
> from include/linux/spinlock.h:51,
> from include/linux/seqlock.h:36,
> from include/linux/time.h:6,
> from include/linux/stat.h:19,
> from include/linux/module.h:10,
> from drivers/video/fbdev/uvesafb.c:12:
> In function 'strncpy',
> inlined from 'uvesafb_vbe_getinfo' at
> drivers/video/fbdev/uvesafb.c:425:2:
>>> include/linux/string.h:246:9: warning: '__builtin_strncpy' output truncated
>>> before terminating nul copying 4 bytes from a string of the same length
>>> [-Wstringop-truncation]
> return __builtin_strncpy(p, q, size);
> ^
>
> vim +/__builtin_strncpy +246 include/linux/string.h
>
> 6974f0c4 Daniel Micay 2017-07-12 237
> 6974f0c4 Daniel Micay 2017-07-12 238 #if !defined(__NO_FORTIFY) &&
> defined(__OPTIMIZE__) && defined(CONFIG_FORTIFY_SOURCE)
> 6974f0c4 Daniel Micay 2017-07-12 239 __FORTIFY_INLINE char *strncpy(char
> *p, const char *q, __kernel_size_t size)
> 6974f0c4 Daniel Micay 2017-07-12 240 {
> 6974f0c4 Daniel Micay 2017-07-12 241 size_t p_size =
> __builtin_object_size(p, 0);
> 6974f0c4 Daniel Micay 2017-07-12 242 if (__builtin_constant_p(size) &&
> p_size < size)
> 6974f0c4 Daniel Micay 2017-07-12 243 __write_overflow();
> 6974f0c4 Daniel Micay 2017-07-12 244 if (p_size < size)
> 6974f0c4 Daniel Micay 2017-07-12 245 fortify_panic(__func__);
> 6974f0c4 Daniel Micay 2017-07-12 @246 return __builtin_strncpy(p, q, size);
> 6974f0c4 Daniel Micay 2017-07-12 247 }
> 6974f0c4 Daniel Micay 2017-07-12 248
>
> :: The code at line 246 was first introduced by commit
> :: 6974f0c4555e285ab217cee58b6e874f776ff409 include/linux/string.h: add
> the option of fortified string.h functions
>
> :: TO: Daniel Micay
> :: CC: Linus Torvalds
>
> ---
> 0-DAY kernel test infrastructureOpen Source Technology Center
> https://lists.01.org/pipermail/kbuild-all Intel Corporation
--
With Best Regards,
Andy Shevchenko
Re: include/linux/string.h:246:9: warning: '__builtin_strncpy' output truncated before terminating nul copying 4 bytes from a string of the same length
On Tue, May 29, 2018 at 4:35 AM, kbuild test robot wrote:
> tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
> master
> head: 786b71f5b754273ccef6d9462e52062b3e1f9877
> commit: 854e55ad289efe7991f0ada85d5846f5afb9 objtool, perf: Fix GCC 8
> -Wrestrict error
> date: 2 months ago
> config: x86_64-randconfig-s4-05290856 (attached as .config)
> compiler: gcc-8 (Debian 8.1.0-3) 8.1.0
> reproduce:
> git checkout 854e55ad289efe7991f0ada85d5846f5afb9
> # save the attached .config to linux build tree
> make ARCH=x86_64
>
I guess it's easy to fix by
--- a/drivers/video/fbdev/uvesafb.c
+++ b/drivers/video/fbdev/uvesafb.c
@@ -422,7 +422,7 @@ static int uvesafb_vbe_getinfo(struct uvesafb_ktask *task,
task->t.flags = TF_VBEIB;
task->t.buf_len = sizeof(struct vbe_ib);
task->buf = >vbe_ib;
- strncpy(par->vbe_ib.vbe_signature, "VBE2", 4);
+ snprintf(par->vbe_ib.vbe_signature,
sizeof(par->vbe_ib.vbe_signature), "VBE2");
The question is do we want this to just shut up a compiler? It's
obviously false positive.
> All warnings (new ones prefixed by >>):
>
>In file included from include/linux/bitmap.h:9,
> from include/linux/cpumask.h:12,
> from arch/x86/include/asm/cpumask.h:5,
> from arch/x86/include/asm/msr.h:11,
> from arch/x86/include/asm/processor.h:21,
> from arch/x86/include/asm/cpufeature.h:5,
> from arch/x86/include/asm/thread_info.h:53,
> from include/linux/thread_info.h:38,
> from arch/x86/include/asm/preempt.h:7,
> from include/linux/preempt.h:81,
> from include/linux/spinlock.h:51,
> from include/linux/seqlock.h:36,
> from include/linux/time.h:6,
> from include/linux/stat.h:19,
> from include/linux/module.h:10,
> from drivers/video/fbdev/uvesafb.c:12:
> In function 'strncpy',
> inlined from 'uvesafb_vbe_getinfo' at
> drivers/video/fbdev/uvesafb.c:425:2:
>>> include/linux/string.h:246:9: warning: '__builtin_strncpy' output truncated
>>> before terminating nul copying 4 bytes from a string of the same length
>>> [-Wstringop-truncation]
> return __builtin_strncpy(p, q, size);
> ^
>
> vim +/__builtin_strncpy +246 include/linux/string.h
>
> 6974f0c4 Daniel Micay 2017-07-12 237
> 6974f0c4 Daniel Micay 2017-07-12 238 #if !defined(__NO_FORTIFY) &&
> defined(__OPTIMIZE__) && defined(CONFIG_FORTIFY_SOURCE)
> 6974f0c4 Daniel Micay 2017-07-12 239 __FORTIFY_INLINE char *strncpy(char
> *p, const char *q, __kernel_size_t size)
> 6974f0c4 Daniel Micay 2017-07-12 240 {
> 6974f0c4 Daniel Micay 2017-07-12 241 size_t p_size =
> __builtin_object_size(p, 0);
> 6974f0c4 Daniel Micay 2017-07-12 242 if (__builtin_constant_p(size) &&
> p_size < size)
> 6974f0c4 Daniel Micay 2017-07-12 243 __write_overflow();
> 6974f0c4 Daniel Micay 2017-07-12 244 if (p_size < size)
> 6974f0c4 Daniel Micay 2017-07-12 245 fortify_panic(__func__);
> 6974f0c4 Daniel Micay 2017-07-12 @246 return __builtin_strncpy(p, q, size);
> 6974f0c4 Daniel Micay 2017-07-12 247 }
> 6974f0c4 Daniel Micay 2017-07-12 248
>
> :: The code at line 246 was first introduced by commit
> :: 6974f0c4555e285ab217cee58b6e874f776ff409 include/linux/string.h: add
> the option of fortified string.h functions
>
> :: TO: Daniel Micay
> :: CC: Linus Torvalds
>
> ---
> 0-DAY kernel test infrastructureOpen Source Technology Center
> https://lists.01.org/pipermail/kbuild-all Intel Corporation
--
With Best Regards,
Andy Shevchenko
include/linux/string.h:246:9: warning: '__builtin_strncpy' output truncated before terminating nul copying 4 bytes from a string of the same length
tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
master
head: 786b71f5b754273ccef6d9462e52062b3e1f9877
commit: 854e55ad289efe7991f0ada85d5846f5afb9 objtool, perf: Fix GCC 8
-Wrestrict error
date: 2 months ago
config: x86_64-randconfig-s4-05290856 (attached as .config)
compiler: gcc-8 (Debian 8.1.0-3) 8.1.0
reproduce:
git checkout 854e55ad289efe7991f0ada85d5846f5afb9
# save the attached .config to linux build tree
make ARCH=x86_64
All warnings (new ones prefixed by >>):
In file included from include/linux/bitmap.h:9,
from include/linux/cpumask.h:12,
from arch/x86/include/asm/cpumask.h:5,
from arch/x86/include/asm/msr.h:11,
from arch/x86/include/asm/processor.h:21,
from arch/x86/include/asm/cpufeature.h:5,
from arch/x86/include/asm/thread_info.h:53,
from include/linux/thread_info.h:38,
from arch/x86/include/asm/preempt.h:7,
from include/linux/preempt.h:81,
from include/linux/spinlock.h:51,
from include/linux/seqlock.h:36,
from include/linux/time.h:6,
from include/linux/stat.h:19,
from include/linux/module.h:10,
from drivers/video/fbdev/uvesafb.c:12:
In function 'strncpy',
inlined from 'uvesafb_vbe_getinfo' at
drivers/video/fbdev/uvesafb.c:425:2:
>> include/linux/string.h:246:9: warning: '__builtin_strncpy' output truncated
>> before terminating nul copying 4 bytes from a string of the same length
>> [-Wstringop-truncation]
return __builtin_strncpy(p, q, size);
^
vim +/__builtin_strncpy +246 include/linux/string.h
6974f0c4 Daniel Micay 2017-07-12 237
6974f0c4 Daniel Micay 2017-07-12 238 #if !defined(__NO_FORTIFY) &&
defined(__OPTIMIZE__) && defined(CONFIG_FORTIFY_SOURCE)
6974f0c4 Daniel Micay 2017-07-12 239 __FORTIFY_INLINE char *strncpy(char *p,
const char *q, __kernel_size_t size)
6974f0c4 Daniel Micay 2017-07-12 240 {
6974f0c4 Daniel Micay 2017-07-12 241 size_t p_size =
__builtin_object_size(p, 0);
6974f0c4 Daniel Micay 2017-07-12 242 if (__builtin_constant_p(size) &&
p_size < size)
6974f0c4 Daniel Micay 2017-07-12 243 __write_overflow();
6974f0c4 Daniel Micay 2017-07-12 244 if (p_size < size)
6974f0c4 Daniel Micay 2017-07-12 245 fortify_panic(__func__);
6974f0c4 Daniel Micay 2017-07-12 @246 return __builtin_strncpy(p, q, size);
6974f0c4 Daniel Micay 2017-07-12 247 }
6974f0c4 Daniel Micay 2017-07-12 248
:: The code at line 246 was first introduced by commit
:: 6974f0c4555e285ab217cee58b6e874f776ff409 include/linux/string.h: add the
option of fortified string.h functions
:: TO: Daniel Micay
:: CC: Linus Torvalds
---
0-DAY kernel test infrastructureOpen Source Technology Center
https://lists.01.org/pipermail/kbuild-all Intel Corporation
.config.gz
Description: application/gzip
include/linux/string.h:246:9: warning: '__builtin_strncpy' output truncated before terminating nul copying 4 bytes from a string of the same length
tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
master
head: 786b71f5b754273ccef6d9462e52062b3e1f9877
commit: 854e55ad289efe7991f0ada85d5846f5afb9 objtool, perf: Fix GCC 8
-Wrestrict error
date: 2 months ago
config: x86_64-randconfig-s4-05290856 (attached as .config)
compiler: gcc-8 (Debian 8.1.0-3) 8.1.0
reproduce:
git checkout 854e55ad289efe7991f0ada85d5846f5afb9
# save the attached .config to linux build tree
make ARCH=x86_64
All warnings (new ones prefixed by >>):
In file included from include/linux/bitmap.h:9,
from include/linux/cpumask.h:12,
from arch/x86/include/asm/cpumask.h:5,
from arch/x86/include/asm/msr.h:11,
from arch/x86/include/asm/processor.h:21,
from arch/x86/include/asm/cpufeature.h:5,
from arch/x86/include/asm/thread_info.h:53,
from include/linux/thread_info.h:38,
from arch/x86/include/asm/preempt.h:7,
from include/linux/preempt.h:81,
from include/linux/spinlock.h:51,
from include/linux/seqlock.h:36,
from include/linux/time.h:6,
from include/linux/stat.h:19,
from include/linux/module.h:10,
from drivers/video/fbdev/uvesafb.c:12:
In function 'strncpy',
inlined from 'uvesafb_vbe_getinfo' at
drivers/video/fbdev/uvesafb.c:425:2:
>> include/linux/string.h:246:9: warning: '__builtin_strncpy' output truncated
>> before terminating nul copying 4 bytes from a string of the same length
>> [-Wstringop-truncation]
return __builtin_strncpy(p, q, size);
^
vim +/__builtin_strncpy +246 include/linux/string.h
6974f0c4 Daniel Micay 2017-07-12 237
6974f0c4 Daniel Micay 2017-07-12 238 #if !defined(__NO_FORTIFY) &&
defined(__OPTIMIZE__) && defined(CONFIG_FORTIFY_SOURCE)
6974f0c4 Daniel Micay 2017-07-12 239 __FORTIFY_INLINE char *strncpy(char *p,
const char *q, __kernel_size_t size)
6974f0c4 Daniel Micay 2017-07-12 240 {
6974f0c4 Daniel Micay 2017-07-12 241 size_t p_size =
__builtin_object_size(p, 0);
6974f0c4 Daniel Micay 2017-07-12 242 if (__builtin_constant_p(size) &&
p_size < size)
6974f0c4 Daniel Micay 2017-07-12 243 __write_overflow();
6974f0c4 Daniel Micay 2017-07-12 244 if (p_size < size)
6974f0c4 Daniel Micay 2017-07-12 245 fortify_panic(__func__);
6974f0c4 Daniel Micay 2017-07-12 @246 return __builtin_strncpy(p, q, size);
6974f0c4 Daniel Micay 2017-07-12 247 }
6974f0c4 Daniel Micay 2017-07-12 248
:: The code at line 246 was first introduced by commit
:: 6974f0c4555e285ab217cee58b6e874f776ff409 include/linux/string.h: add the
option of fortified string.h functions
:: TO: Daniel Micay
:: CC: Linus Torvalds
---
0-DAY kernel test infrastructureOpen Source Technology Center
https://lists.01.org/pipermail/kbuild-all Intel Corporation
.config.gz
Description: application/gzip
