The patch titled
Subject: mm: fix the MAP_UNINITIALIZED flag
has been added to the -mm tree. Its filename is
mm-fix-the-map_uninitialized-flag.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/mm-fix-the-map_uninitialized-flag.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/mm-fix-the-map_uninitialized-flag.patch
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Christoph Hellwig <hch@xxxxxx>
Subject: 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@xxxxxx
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Reviewed-by: Vladimir Murzin <vladimir.murzin@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
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(-)
--- a/arch/xtensa/include/uapi/asm/mman.h~mm-fix-the-map_uninitialized-flag
+++ a/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
--- a/include/uapi/asm-generic/mman-common.h~mm-fix-the-map_uninitialized-flag
+++ a/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
*/
--- a/mm/nommu.c~mm-fix-the-map_uninitialized-flag
+++ a/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);
_
Patches currently in -mm which might be from hch@xxxxxx are
mm-remove-the-account_page_dirtied-export.patch
mm-fix-an-overly-long-line-in-read_cache_page.patch
mm-dont-cast-readpage-to-filler_t-for-do_read_cache_page.patch
jffs2-pass-the-correct-prototype-to-read_cache_page.patch
9p-pass-the-correct-prototype-to-read_cache_page.patch
mm-use-untagged_addr-for-get_user_pages_fast-addresses.patch
mm-simplify-gup_fast_permitted.patch
mm-lift-the-x86_32-pae-version-of-gup_get_pte-to-common-code.patch
mips-use-the-generic-get_user_pages_fast-code.patch
mips-use-the-generic-get_user_pages_fast-code-fix.patch
sh-add-the-missing-pud_page-definition.patch
sh-add-the-missing-pud_page-definition-fix.patch
sh-use-the-generic-get_user_pages_fast-code.patch
sparc64-add-the-missing-pgd_page-definition.patch
sparc64-add-the-missing-pgd_page-definition-fix.patch
sparc64-define-untagged_addr.patch
sparc64-use-the-generic-get_user_pages_fast-code.patch
mm-rename-config_have_generic_gup-to-config_have_fast_gup.patch
mm-reorder-code-blocks-in-gupc.patch
mm-consolidate-the-get_user_pages-implementations.patch
mm-validate-get_user_pages_fast-flags.patch
mm-move-the-powerpc-hugepd-code-to-mm-gupc.patch
mm-switch-gup_hugepte-to-use-try_get_compound_head.patch
mm-mark-the-page-referenced-in-gup_hugepte.patch
mm-fix-the-map_uninitialized-flag.patch
mm-provide-a-print_vma_addr-stub-for-config_mmu.patch
mm-stub-out-all-of-swapopsh-for-config_mmu.patch
