[PATCH] powerpc/32: Remove powerpc specific definition of 'ptrdiff_t'

[PATCH] powerpc/32: Remove powerpc specific definition of 'ptrdiff_t'

[Christophe Leroy]

For unknown reason, old commit d27dfd388715 ("Import pre2.0.8")
changed 'ptrdiff_t' from 'int' to 'long'.

GCC expects it as 'int' really, and this leads to the following
warning when building KFENCE:

  CC      mm/kfence/report.o
In file included from ./include/linux/printk.h:7,
                 from ./include/linux/kernel.h:16,
                 from mm/kfence/report.c:10:
mm/kfence/report.c: In function 'kfence_report_error':
./include/linux/kern_levels.h:5:18: warning: format '%td' expects argument of type 'ptrdiff_t', but argument 6 has type 'long int' [-Wformat=]
    5 | #define KERN_SOH "\001"  /* ASCII Start Of Header */
      |                  ^~~~~~
./include/linux/kern_levels.h:11:18: note: in expansion of macro 'KERN_SOH'
   11 | #define KERN_ERR KERN_SOH "3" /* error conditions */
      |                  ^~~~~~~~
./include/linux/printk.h:343:9: note: in expansion of macro 'KERN_ERR'
  343 |  printk(KERN_ERR pr_fmt(fmt), ##__VA_ARGS__)
      |         ^~~~~~~~
mm/kfence/report.c:213:3: note: in expansion of macro 'pr_err'
  213 |   pr_err("Out-of-bounds %s at 0x%p (%luB %s of kfence-#%td):\n",
      |   ^~~~~~

<asm-generic/uapi/posix-types.h> defines it as 'int', and
defines 'size_t' and 'ssize_t' exactly as powerpc do, so
remove the powerpc specific definitions and fallback on
generic ones.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/include/uapi/asm/posix_types.h | 5 -----
 1 file changed, 5 deletions(-)

diff --git a/arch/powerpc/include/uapi/asm/posix_types.h b/arch/powerpc/include/uapi/asm/posix_types.h
index f698400e4bb0..9c0342312544 100644
--- a/arch/powerpc/include/uapi/asm/posix_types.h
+++ b/arch/powerpc/include/uapi/asm/posix_types.h
@@ -12,11 +12,6 @@
 typedef unsigned long	__kernel_old_dev_t;
 #define __kernel_old_dev_t __kernel_old_dev_t
 #else
-typedef unsigned int	__kernel_size_t;
-typedef int		__kernel_ssize_t;
-typedef long		__kernel_ptrdiff_t;
-#define __kernel_size_t __kernel_size_t
-
 typedef short		__kernel_ipc_pid_t;
 #define __kernel_ipc_pid_t __kernel_ipc_pid_t
 #endif
-- 
2.25.0

Re: [PATCH] powerpc/32: Remove powerpc specific definition of 'ptrdiff_t'

[Segher Boessenkool]

On Mon, Apr 05, 2021 at 09:57:27AM +0000, Christophe Leroy wrote:
> For unknown reason, old commit d27dfd388715 ("Import pre2.0.8")
> changed 'ptrdiff_t' from 'int' to 'long'.
> 
> GCC expects it as 'int' really,

It isn't actually defined in the ABI as far as I can see (neither the
old document or the new one), but GCC has defined it as "int" since
forever (which was in 1995), for anything using the SYSV ABI (which
includes powerpc-linux).

> <asm-generic/uapi/posix-types.h> defines it as 'int', and
> defines 'size_t' and 'ssize_t' exactly as powerpc do, so
> remove the powerpc specific definitions and fallback on
> generic ones.
> 
> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>

Thanks!

Acked-by: Segher Boessenkool <segher@kernel.crashing.org>


Segher

Re: [PATCH] powerpc/32: Remove powerpc specific definition of 'ptrdiff_t'

[Michael Ellerman]

On Mon, 5 Apr 2021 09:57:27 +0000 (UTC), Christophe Leroy wrote:
> For unknown reason, old commit d27dfd388715 ("Import pre2.0.8")
> changed 'ptrdiff_t' from 'int' to 'long'.
> 
> GCC expects it as 'int' really, and this leads to the following
> warning when building KFENCE:
> 
>   CC      mm/kfence/report.o
> In file included from ./include/linux/printk.h:7,
>                  from ./include/linux/kernel.h:16,
>                  from mm/kfence/report.c:10:
> mm/kfence/report.c: In function 'kfence_report_error':
> ./include/linux/kern_levels.h:5:18: warning: format '%td' expects argument of type 'ptrdiff_t', but argument 6 has type 'long int' [-Wformat=]
>     5 | #define KERN_SOH "\001"  /* ASCII Start Of Header */
>       |                  ^~~~~~
> ./include/linux/kern_levels.h:11:18: note: in expansion of macro 'KERN_SOH'
>    11 | #define KERN_ERR KERN_SOH "3" /* error conditions */
>       |                  ^~~~~~~~
> ./include/linux/printk.h:343:9: note: in expansion of macro 'KERN_ERR'
>   343 |  printk(KERN_ERR pr_fmt(fmt), ##__VA_ARGS__)
>       |         ^~~~~~~~
> mm/kfence/report.c:213:3: note: in expansion of macro 'pr_err'
>   213 |   pr_err("Out-of-bounds %s at 0x%p (%luB %s of kfence-#%td):\n",
>       |   ^~~~~~
> 
> [...]

Applied to powerpc/next.

[1/1] powerpc/32: Remove powerpc specific definition of 'ptrdiff_t'
      https://git.kernel.org/powerpc/c/c46bbf5d2defae50d61ddf31502017ee8952af83

cheers