On 6/10/19 11:16 PM, Christoph Hellwig wrote:
> We can't expose UAPI symbols differently based on CONFIG_ symbols, as
> userspace won't have them available. Instead always define the flag,
> but only repsect it based on the config option.
^^^^^^^
respect
>
> Signed-off-by: Christoph Hellwig <hch@xxxxxx>
> ---
> arch/xtensa/include/uapi/asm/mman.h | 6 +-----
> include/uapi/asm-generic/mman-common.h | 8 +++-----
> mm/nommu.c | 4 +++-
> 3 files changed, 7 insertions(+), 11 deletions(-)
FWIW:
Reviewed-by: Vladimir Murzin <vladimir.murzin@xxxxxxx>
>
> diff --git a/arch/xtensa/include/uapi/asm/mman.h b/arch/xtensa/include/uapi/asm/mman.h
> index be726062412b..ebbb48842190 100644
> --- a/arch/xtensa/include/uapi/asm/mman.h
> +++ b/arch/xtensa/include/uapi/asm/mman.h
> @@ -56,12 +56,8 @@
> #define MAP_STACK 0x40000 /* give out an address that is best suited for process/thread stacks */
> #define MAP_HUGETLB 0x80000 /* create a huge page mapping */
> #define MAP_FIXED_NOREPLACE 0x100000 /* MAP_FIXED which doesn't unmap underlying mapping */
> -#ifdef CONFIG_MMAP_ALLOW_UNINITIALIZED
> -# define MAP_UNINITIALIZED 0x4000000 /* For anonymous mmap, memory could be
> +#define MAP_UNINITIALIZED 0x4000000 /* For anonymous mmap, memory could be
> * uninitialized */
> -#else
> -# define MAP_UNINITIALIZED 0x0 /* Don't support this flag */
> -#endif
>
> /*
> * Flags for msync
> diff --git a/include/uapi/asm-generic/mman-common.h b/include/uapi/asm-generic/mman-common.h
> index abd238d0f7a4..cb556b430e71 100644
> --- a/include/uapi/asm-generic/mman-common.h
> +++ b/include/uapi/asm-generic/mman-common.h
> @@ -19,15 +19,13 @@
> #define MAP_TYPE 0x0f /* Mask for type of mapping */
> #define MAP_FIXED 0x10 /* Interpret addr exactly */
> #define MAP_ANONYMOUS 0x20 /* don't use a file */
> -#ifdef CONFIG_MMAP_ALLOW_UNINITIALIZED
> -# define MAP_UNINITIALIZED 0x4000000 /* For anonymous mmap, memory could be uninitialized */
> -#else
> -# define MAP_UNINITIALIZED 0x0 /* Don't support this flag */
> -#endif
>
> /* 0x0100 - 0x80000 flags are defined in asm-generic/mman.h */
> #define MAP_FIXED_NOREPLACE 0x100000 /* MAP_FIXED which doesn't unmap underlying mapping */
>
> +#define MAP_UNINITIALIZED 0x4000000 /* For anonymous mmap, memory could be
> + * uninitialized */
> +
> /*
> * Flags for mlock
> */
> diff --git a/mm/nommu.c b/mm/nommu.c
> index d8c02fbe03b5..ec75a0dffd4f 100644
> --- a/mm/nommu.c
> +++ b/mm/nommu.c
> @@ -1349,7 +1349,9 @@ unsigned long do_mmap(struct file *file,
> add_nommu_region(region);
>
> /* clear anonymous mappings that don't ask for uninitialized data */
> - if (!vma->vm_file && !(flags & MAP_UNINITIALIZED))
> + if (!vma->vm_file &&
> + (!IS_ENABLED(CONFIG_MMAP_ALLOW_UNINITIALIZED) ||
> + !(flags & MAP_UNINITIALIZED)))
> memset((void *)region->vm_start, 0,
> region->vm_end - region->vm_start);
>
>
