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| author | Christoph Hellwig <hch@lst.de> | 2019-07-16 16:26:27 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2019-07-16 19:23:21 -0700 |
| commit | 0bf5f9492389aa8df5c8e38fcb4488802d24504d (patch) | |
| tree | 9c62b75ac595ca7dd1c0e25261c9a1ad08fb69f0 | |
| parent | c633324e311243586675e732249339685e5d6faa (diff) | |
| download | linux-0bf5f9492389aa8df5c8e38fcb4488802d24504d.tar.gz linux-0bf5f9492389aa8df5c8e38fcb4488802d24504d.tar.bz2 linux-0bf5f9492389aa8df5c8e38fcb4488802d24504d.zip | |
mm: fix the MAP_UNINITIALIZED flag
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 respect it based on the config option.
Link: http://lkml.kernel.org/r/20190703122359.18200-2-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Vladimir Murzin <vladimir.murzin@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | arch/xtensa/include/uapi/asm/mman.h | 6 | ||||
| -rw-r--r-- | include/uapi/asm-generic/mman-common.h | 8 | ||||
| -rw-r--r-- | mm/nommu.c | 4 |
3 files changed, 7 insertions, 11 deletions
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 eb3e2e558da1..fed1b6e9c89b 100644 --- a/mm/nommu.c +++ b/mm/nommu.c @@ -1261,7 +1261,9 @@ 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); |