Re: [PATCH v3 16/27] PPC: use helpers for rlimits

[Benjamin Herrenschmidt <benh@kernel.crashing.org>]

On Sat, 2009-11-28 at 00:05 +0100, Jiri Slaby wrote:
> Make sure compiler won't do weird things with limits. E.g. fetching
> them twice may return 2 different values after writable limits are
> implemented.
> 
> I.e. either use newly added rlimit helpers or ACCESS_ONCE if not
> applicable.

Thanks. I have that already queued up.

Cheers,
Ben.

> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
> Cc: James Morris <jmorris@namei.org>
> Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Cc: Ingo Molnar <mingo@elte.hu>
> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> Cc: Paul Mackerras <paulus@samba.org>
> Cc: linuxppc-dev@ozlabs.org
> ---
>  arch/powerpc/mm/mmap_64.c                    |    4 ++--
>  arch/powerpc/platforms/cell/spufs/coredump.c |    2 +-
>  2 files changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/arch/powerpc/mm/mmap_64.c b/arch/powerpc/mm/mmap_64.c
> index 0d957a4..8df1299 100644
> --- a/arch/powerpc/mm/mmap_64.c
> +++ b/arch/powerpc/mm/mmap_64.c
> @@ -47,7 +47,7 @@ static inline int mmap_is_legacy(void)
>  	if (current->personality & ADDR_COMPAT_LAYOUT)
>  		return 1;
>  
> -	if (current->signal->rlim[RLIMIT_STACK].rlim_cur == RLIM_INFINITY)
> +	if (rlim_get_cur(RLIMIT_STACK) == RLIM_INFINITY)
>  		return 1;
>  
>  	return sysctl_legacy_va_layout;
> @@ -77,7 +77,7 @@ static unsigned long mmap_rnd(void)
>  
>  static inline unsigned long mmap_base(void)
>  {
> -	unsigned long gap = current->signal->rlim[RLIMIT_STACK].rlim_cur;
> +	unsigned long gap = rlim_get_cur(RLIMIT_STACK);
>  
>  	if (gap < MIN_GAP)
>  		gap = MIN_GAP;
> diff --git a/arch/powerpc/platforms/cell/spufs/coredump.c b/arch/powerpc/platforms/cell/spufs/coredump.c
> index c4d4a19..4ef1c92 100644
> --- a/arch/powerpc/platforms/cell/spufs/coredump.c
> +++ b/arch/powerpc/platforms/cell/spufs/coredump.c
> @@ -54,7 +54,7 @@ static ssize_t do_coredump_read(int num, struct spu_context *ctx, void *buffer,
>   */
>  static int spufs_dump_write(struct file *file, const void *addr, int nr, loff_t *foffset)
>  {
> -	unsigned long limit = current->signal->rlim[RLIMIT_CORE].rlim_cur;
> +	unsigned long limit = rlim_get_cur(RLIMIT_CORE);
>  	ssize_t written;
>  
>  	if (*foffset + nr > limit)