Re: [2.6 patch] add -Werror-implicit-function-declaration to CFLAGS

Re: [2.6 patch] add -Werror-implicit-function-declaration to CFLAGS

[Sam Ravnborg]

On Thu, Jul 06, 2006 at 06:37:28PM +0200, Adrian Bunk wrote:
> Currently, using an undeclared function gives a compile warning, but it 
> can lead to a nasty to debug runtime stack corruptions if the prototype 
> of the function is different from what gcc guessed.
> 
> With -Werror-implicit-function-declaration we are getting an immediate
> compile error instead.
This patch broke (-rc1):

sparc allnoconfig build
ia64 allnoconfig build
ppc64 allnoconfig build

x86_64 succeded an allnoconfig build

I did not try other architectures. We need to fix the allnoconfig cases
at least for the popular architectures before applying this patch
otherwise it will create too much trouble/noise.

linux-arch copied in the hope that the arch maintaines may try it out
and fix their issues.

	Sam

---

 Makefile                               |    3 ++-
 drivers/input/joystick/iforce/Makefile |    2 --
 2 files changed, 2 insertions(+), 3 deletions(-)

--- linux-2.6.17-mm6-full/Makefile.old	2006-07-06 12:17:02.000000000 +0200
+++ linux-2.6.17-mm6-full/Makefile	2006-07-06 12:18:52.000000000 +0200
@@ -318,7 +318,8 @@
 CPPFLAGS        := -D__KERNEL__ $(LINUXINCLUDE)
 
 CFLAGS          := -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs \
-                   -fno-strict-aliasing -fno-common
+                   -fno-strict-aliasing -fno-common \
+		   -Werror-implicit-function-declaration
 # Force gcc to behave correct even for buggy distributions
 CFLAGS          += $(call cc-option, -fno-stack-protector-all \
                                      -fno-stack-protector)
--- linux-2.6.17-mm6-full/drivers/input/joystick/iforce/Makefile.old	2006-07-06 12:19:08.000000000 +0200
+++ linux-2.6.17-mm6-full/drivers/input/joystick/iforce/Makefile	2006-07-06 12:19:16.000000000 +0200
@@ -16,5 +16,3 @@
 ifeq ($(CONFIG_JOYSTICK_IFORCE_USB),y)
 	iforce-objs += iforce-usb.o
 endif
-
-EXTRA_CFLAGS = -Werror-implicit-function-declaration

Re: [2.6 patch] add -Werror-implicit-function-declaration to CFLAGS

[Valdis.Kletnieks]

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On Fri, 07 Jul 2006 05:36:30 +0200, Sam Ravnborg said:
> On Thu, Jul 06, 2006 at 06:37:28PM +0200, Adrian Bunk wrote:
> > With -Werror-implicit-function-declaration we are getting an immediate
> > compile error instead.
> This patch broke (-rc1):
...
> I did not try other architectures. We need to fix the allnoconfig cases
> at least for the popular architectures before applying this patch
> otherwise it will create too much trouble/noise.

What source files did it break on, and with what error message?  And is
there a reason to focus on 'allnoconfig', or do the other canned config
targets (allyes, allmod, rand, and so on) matter too?


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Re: [2.6 patch] add -Werror-implicit-function-declaration to CFLAGS

[Sam Ravnborg]

On Fri, Jul 07, 2006 at 01:02:18AM -0400, Valdis.Kletnieks@vt.edu wrote:
> On Fri, 07 Jul 2006 05:36:30 +0200, Sam Ravnborg said:
> > On Thu, Jul 06, 2006 at 06:37:28PM +0200, Adrian Bunk wrote:
> > > With -Werror-implicit-function-declaration we are getting an immediate
> > > compile error instead.
> > This patch broke (-rc1):
> ...
> > I did not try other architectures. We need to fix the allnoconfig cases
> > at least for the popular architectures before applying this patch
> > otherwise it will create too much trouble/noise.
> 
> What source files did it break on, and with what error message?  And is
> there a reason to focus on 'allnoconfig', or do the other canned config
> targets (allyes, allmod, rand, and so on) matter too?

The other configs matters too - but it just seemed most logical to start
out with the config that deselected the most.
One could say that passing 'allnoconfig' was the minimal test.

The error messages follows (for ia64, sparc and ppc64).
I have not tried to fix any of them.

	Sam

make -C /home/sam/kernel/kbuild.git O=/home/sam/kernel/oia64
  Using /home/sam/kernel/kbuild.git as source for kernel
  GEN     /home/sam/kernel/oia64/Makefile
  CHK     include/linux/version.h
  CHK     include/linux/utsrelease.h
  CC      arch/ia64/kernel/asm-offsets.s
In file included from /home/sam/kernel/kbuild.git/include/linux/poll.h:11,
                 from /home/sam/kernel/kbuild.git/include/linux/rtc.h:113,
                 from /home/sam/kernel/kbuild.git/include/linux/efi.h:19,
                 from include2/asm/sal.h:40,
                 from /home/sam/kernel/kbuild.git/include/asm-ia64/mca.h:20,
                 from /home/sam/kernel/kbuild.git/arch/ia64/kernel/asm-offsets.c:15:
/home/sam/kernel/kbuild.git/include/linux/mm.h: In function `lowmem_page_address':
/home/sam/kernel/kbuild.git/include/linux/mm.h:530: error: implicit declaration of function `page_to_pfn'
In file included from /home/sam/kernel/kbuild.git/include/linux/poll.h:12,
                 from /home/sam/kernel/kbuild.git/include/linux/rtc.h:113,
                 from /home/sam/kernel/kbuild.git/include/linux/efi.h:19,
                 from include2/asm/sal.h:40,
                 from /home/sam/kernel/kbuild.git/include/asm-ia64/mca.h:20,
                 from /home/sam/kernel/kbuild.git/arch/ia64/kernel/asm-offsets.c:15:
include2/asm/uaccess.h: In function `xlate_dev_mem_ptr':
include2/asm/uaccess.h:374: error: implicit declaration of function `pfn_to_page'
include2/asm/uaccess.h:374: warning: assignment makes pointer from integer without a cast
include2/asm/uaccess.h: In function `xlate_dev_kmem_ptr':
include2/asm/uaccess.h:392: warning: assignment makes pointer from integer without a cast
make[3]: *** [arch/ia64/kernel/asm-offsets.s] Error 1
make[2]: *** [prepare0] Error 2
make[1]: *** [_all] Error 2
make: *** [all] Error 2

make -C /home/sam/kernel/kbuild.git O=/home/sam/kernel/oia64
  Using /home/sam/kernel/kbuild.git as source for kernel
  GEN     /home/sam/kernel/oia64/Makefile
  CHK     include/linux/version.h
  CHK     include/linux/utsrelease.h
  CC      arch/ia64/kernel/asm-offsets.s
In file included from /home/sam/kernel/kbuild.git/include/linux/poll.h:11,
                 from /home/sam/kernel/kbuild.git/include/linux/rtc.h:113,
                 from /home/sam/kernel/kbuild.git/include/linux/efi.h:19,
                 from include2/asm/sal.h:40,
                 from /home/sam/kernel/kbuild.git/include/asm-ia64/mca.h:20,
                 from /home/sam/kernel/kbuild.git/arch/ia64/kernel/asm-offsets.c:15:
/home/sam/kernel/kbuild.git/include/linux/mm.h: In function `lowmem_page_address':
/home/sam/kernel/kbuild.git/include/linux/mm.h:530: error: implicit declaration of function `page_to_pfn'
In file included from /home/sam/kernel/kbuild.git/include/linux/poll.h:12,
                 from /home/sam/kernel/kbuild.git/include/linux/rtc.h:113,
                 from /home/sam/kernel/kbuild.git/include/linux/efi.h:19,
                 from include2/asm/sal.h:40,
                 from /home/sam/kernel/kbuild.git/include/asm-ia64/mca.h:20,
                 from /home/sam/kernel/kbuild.git/arch/ia64/kernel/asm-offsets.c:15:
include2/asm/uaccess.h: In function `xlate_dev_mem_ptr':
include2/asm/uaccess.h:374: error: implicit declaration of function `pfn_to_page'
include2/asm/uaccess.h:374: warning: assignment makes pointer from integer without a cast
include2/asm/uaccess.h: In function `xlate_dev_kmem_ptr':
include2/asm/uaccess.h:392: warning: assignment makes pointer from integer without a cast
make[3]: *** [arch/ia64/kernel/asm-offsets.s] Error 1
make[2]: *** [prepare0] Error 2
make[1]: *** [_all] Error 2
make: *** [all] Error 2
make -C /home/sam/kernel/kbuild.git O=/home/sam/kernel/osparc
  Using /home/sam/kernel/kbuild.git as source for kernel
  GEN     /home/sam/kernel/osparc/Makefile
  CHK     include/linux/version.h
  CHK     include/linux/utsrelease.h
  CHK     include/linux/compile.h
  CC      arch/sparc/mm/init.o
In file included from include2/asm/tlb.h:22,
                 from /home/sam/kernel/kbuild.git/arch/sparc/mm/init.c:32:
/home/sam/kernel/kbuild.git/include/asm-generic/tlb.h: In function `tlb_flush_mmu':
/home/sam/kernel/kbuild.git/include/asm-generic/tlb.h:76: error: implicit declaration of function `release_pages'
/home/sam/kernel/kbuild.git/include/asm-generic/tlb.h: In function `tlb_remove_page':
/home/sam/kernel/kbuild.git/include/asm-generic/tlb.h:105: error: implicit declaration of function `page_cache_release'
make[3]: *** [arch/sparc/mm/init.o] Error 1
make[2]: *** [arch/sparc/mm] Error 2
make[1]: *** [_all] Error 2
make: *** [all] Error 2


make -C /home/sam/kernel/kbuild.git O=/home/sam/kernel/oppc64
  Using /home/sam/kernel/kbuild.git as source for kernel
  GEN     /home/sam/kernel/oppc64/Makefile
  CHK     include/linux/version.h
  CHK     include/linux/utsrelease.h
  SYMLINK include/asm -> include/asm-powerpc
  CHK     include/linux/compile.h
  CC      arch/powerpc/mm/tlb_32.o
In file included from include2/asm/tlb.h:52,
                 from /home/sam/kernel/kbuild.git/arch/powerpc/mm/tlb_32.c:31:
/home/sam/kernel/kbuild.git/include/asm-generic/tlb.h: In function `tlb_flush_mmu':
/home/sam/kernel/kbuild.git/include/asm-generic/tlb.h:76: error: implicit declaration of function `release_pages'
/home/sam/kernel/kbuild.git/include/asm-generic/tlb.h: In function `tlb_remove_page':
/home/sam/kernel/kbuild.git/include/asm-generic/tlb.h:105: error: implicit declaration of function `page_cache_release'
make[3]: *** [arch/powerpc/mm/tlb_32.o] Error 1
make[2]: *** [arch/powerpc/mm] Error 2
make[1]: *** [_all] Error 2
make: *** [all] Error 2

Re: [2.6 patch] add -Werror-implicit-function-declaration to CFLAGS

[Adrian Bunk]

On Fri, Jul 07, 2006 at 08:42:18AM +0200, Sam Ravnborg wrote:
>...
> make -C /home/sam/kernel/kbuild.git O=/home/sam/kernel/osparc
>   Using /home/sam/kernel/kbuild.git as source for kernel
>   GEN     /home/sam/kernel/osparc/Makefile
>   CHK     include/linux/version.h
>   CHK     include/linux/utsrelease.h
>   CHK     include/linux/compile.h
>   CC      arch/sparc/mm/init.o
> In file included from include2/asm/tlb.h:22,
>                  from /home/sam/kernel/kbuild.git/arch/sparc/mm/init.c:32:
> /home/sam/kernel/kbuild.git/include/asm-generic/tlb.h: In function `tlb_flush_mmu':
> /home/sam/kernel/kbuild.git/include/asm-generic/tlb.h:76: error: implicit declaration of function `release_pages'
> /home/sam/kernel/kbuild.git/include/asm-generic/tlb.h: In function `tlb_remove_page':
> /home/sam/kernel/kbuild.git/include/asm-generic/tlb.h:105: error: implicit declaration of function `page_cache_release'
> make[3]: *** [arch/sparc/mm/init.o] Error 1
> make[2]: *** [arch/sparc/mm] Error 2
> make[1]: *** [_all] Error 2
> make: *** [all] Error 2
>...

OK, I tried starting with this one.

The problem is that in the CONFIG_SWAP=n case, linux/swap.h uses these 
functions.

These implicit declarations are bugs that should be fixed.

I tried adding an #include <linux/pagemap.h> to linux/swap.h, but this 
broke things faster than I could fix them.

Does anyone know our header mess good enough for being able to help me 
with this issue?

cu
Adrian

-- 

       "Is there not promise of rain?" Ling Tan asked suddenly out
        of the darkness. There had been need of rain for many days.
       "Only a promise," Lao Er said.
                                       Pearl S. Buck - Dragon Seed

Re: [2.6 patch] add -Werror-implicit-function-declaration to CFLAGS

[Adrian Bunk]

On Fri, Jul 07, 2006 at 05:36:30AM +0200, Sam Ravnborg wrote:
> On Thu, Jul 06, 2006 at 06:37:28PM +0200, Adrian Bunk wrote:
> > Currently, using an undeclared function gives a compile warning, but it 
> > can lead to a nasty to debug runtime stack corruptions if the prototype 
> > of the function is different from what gcc guessed.
> > 
> > With -Werror-implicit-function-declaration we are getting an immediate
> > compile error instead.
> This patch broke (-rc1):
> 
> sparc allnoconfig build
> ia64 allnoconfig build
> ppc64 allnoconfig build
>...

I did defconfig builds on 12 architectures, but no allnoconfig builds.

I'll try to fix them.

> 	Sam
>...

cu
Adrian

-- 

       "Is there not promise of rain?" Ling Tan asked suddenly out
        of the darkness. There had been need of rain for many days.
       "Only a promise," Lao Er said.
                                       Pearl S. Buck - Dragon Seed

Re: [2.6 patch] add -Werror-implicit-function-declaration to CFLAGS

[Heiko Carstens]

> > Currently, using an undeclared function gives a compile warning, but it 
> > can lead to a nasty to debug runtime stack corruptions if the prototype 
> > of the function is different from what gcc guessed.
> > 
> > With -Werror-implicit-function-declaration we are getting an immediate
> > compile error instead.
> This patch broke (-rc1):
> 
> sparc allnoconfig build
> ia64 allnoconfig build
> ppc64 allnoconfig build
> 
> x86_64 succeded an allnoconfig build
> 
> I did not try other architectures. We need to fix the allnoconfig cases
> at least for the popular architectures before applying this patch
> otherwise it will create too much trouble/noise.

s390 builds with defconfig and allnoconfig and a few other variants as well.

Re: [2.6 patch] add -Werror-implicit-function-declaration to CFLAGS

[Sam Ravnborg]

On Fri, Jul 07, 2006 at 09:49:18AM +0200, Heiko Carstens wrote:
> > > Currently, using an undeclared function gives a compile warning, but it 
> > > can lead to a nasty to debug runtime stack corruptions if the prototype 
> > > of the function is different from what gcc guessed.
> > > 
> > > With -Werror-implicit-function-declaration we are getting an immediate
> > > compile error instead.
> > This patch broke (-rc1):
> > 
> > sparc allnoconfig build
> > ia64 allnoconfig build
> > ppc64 allnoconfig build
> > 
> > x86_64 succeded an allnoconfig build
> > 
> > I did not try other architectures. We need to fix the allnoconfig cases
> > at least for the popular architectures before applying this patch
> > otherwise it will create too much trouble/noise.
> 
> s390 builds with defconfig and allnoconfig and a few other variants as well.
Thanks for testing.

	Sam

RE: [2.6 patch] add -Werror-implicit-function-declaration to CFLAGS

[Luck, Tony]

> This patch broke (-rc1):
> 
> sparc allnoconfig build
> ia64 allnoconfig build
> ppc64 allnoconfig build

ia64 allnoconfig is (and has been for a while) broken for other reasons.

Almost all of the real configurations still build.  The only error
that adding this turned up was building a generic uniprocessor config.

smp_call_function_single() is used without a prototype by
arch/ia64/sn/kernel/sn2/sn_hwperf.c:sn_hwperf_op_cpu()

This isn't a real error because this function actually does return
an "int", so the complier default is correct (plus the caller doesn't
look at the return value, plus on a UP we'd never be able to get to
this call-site because it is in the "else" !!!).

But I'll fix it anyway.

diff --git a/include/asm-ia64/smp.h b/include/asm-ia64/smp.h
index 719ff30..949e3a2 100644
--- a/include/asm-ia64/smp.h
+++ b/include/asm-ia64/smp.h
@@ -133,6 +133,7 @@ #else
 
 #define cpu_logical_id(i)		0
 #define cpu_physical_id(i)		ia64_get_lid()
+#define smp_call_function_single(cpuid, func, info, retry, wait) 0
 
 #endif /* CONFIG_SMP */
 #endif /* _ASM_IA64_SMP_H */

-Tony