From f822566165dd46ff5de9bf895cfa6c51f53bb0c4 Mon Sep 17 00:00:00 2001 From: "Michael S. Tsirkin" Date: Tue, 14 Feb 2006 13:53:08 -0800 Subject: [PATCH] [PATCH] madvise MADV_DONTFORK/MADV_DOFORK Currently, copy-on-write may change the physical address of a page even if the user requested that the page is pinned in memory (either by mlock or by get_user_pages). This happens if the process forks meanwhile, and the parent writes to that page. As a result, the page is orphaned: in case of get_user_pages, the application will never see any data hardware DMA's into this page after the COW. In case of mlock'd memory, the parent is not getting the realtime/security benefits of mlock. In particular, this affects the Infiniband modules which do DMA from and into user pages all the time. This patch adds madvise options to control whether memory range is inherited across fork. Useful e.g. for when hardware is doing DMA from/into these pages. Could also be useful to an application wanting to speed up its forks by cutting large areas out of consideration. Signed-off-by: Michael S. Tsirkin Acked-by: Hugh Dickins Cc: Michael Kerrisk Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/asm-alpha/mman.h | 2 ++ include/asm-arm/mman.h | 2 ++ include/asm-arm26/mman.h | 2 ++ include/asm-cris/mman.h | 2 ++ include/asm-frv/mman.h | 2 ++ include/asm-h8300/mman.h | 2 ++ include/asm-i386/mman.h | 2 ++ include/asm-ia64/mman.h | 2 ++ include/asm-m32r/mman.h | 2 ++ include/asm-m68k/mman.h | 2 ++ include/asm-mips/mman.h | 2 ++ include/asm-parisc/mman.h | 2 ++ include/asm-powerpc/mman.h | 2 ++ include/asm-s390/mman.h | 2 ++ include/asm-sh/mman.h | 2 ++ include/asm-sparc/mman.h | 2 ++ include/asm-sparc64/mman.h | 2 ++ include/asm-v850/mman.h | 2 ++ include/asm-x86_64/mman.h | 2 ++ include/asm-xtensa/mman.h | 2 ++ mm/madvise.c | 21 +++++++++++++++++---- 21 files changed, 57 insertions(+), 4 deletions(-) diff --git a/include/asm-alpha/mman.h b/include/asm-alpha/mman.h index f6439532a2..a21515c16a 100644 --- a/include/asm-alpha/mman.h +++ b/include/asm-alpha/mman.h @@ -43,6 +43,8 @@ #define MADV_SPACEAVAIL 5 /* ensure resources are available */ #define MADV_DONTNEED 6 /* don't need these pages */ #define MADV_REMOVE 7 /* remove these pages & resources */ +#define MADV_DONTFORK 0x30 /* dont inherit across fork */ +#define MADV_DOFORK 0x31 /* do inherit across fork */ /* compatibility flags */ #define MAP_ANON MAP_ANONYMOUS diff --git a/include/asm-arm/mman.h b/include/asm-arm/mman.h index f0bebca2ac..693ed859e6 100644 --- a/include/asm-arm/mman.h +++ b/include/asm-arm/mman.h @@ -36,6 +36,8 @@ #define MADV_WILLNEED 0x3 /* pre-fault pages */ #define MADV_DONTNEED 0x4 /* discard these pages */ #define MADV_REMOVE 0x5 /* remove these pages & resources */ +#define MADV_DONTFORK 0x30 /* dont inherit across fork */ +#define MADV_DOFORK 0x31 /* do inherit across fork */ /* compatibility flags */ #define MAP_ANON MAP_ANONYMOUS diff --git a/include/asm-arm26/mman.h b/include/asm-arm26/mman.h index 0ed7780541..2096c50df8 100644 --- a/include/asm-arm26/mman.h +++ b/include/asm-arm26/mman.h @@ -36,6 +36,8 @@ #define MADV_WILLNEED 0x3 /* pre-fault pages */ #define MADV_DONTNEED 0x4 /* discard these pages */ #define MADV_REMOVE 0x5 /* remove these pages & resources */ +#define MADV_DONTFORK 0x30 /* dont inherit across fork */ +#define MADV_DOFORK 0x31 /* do inherit across fork */ /* compatibility flags */ #define MAP_ANON MAP_ANONYMOUS diff --git a/include/asm-cris/mman.h b/include/asm-cris/mman.h index 5a382b8bf3..deddfb239f 100644 --- a/include/asm-cris/mman.h +++ b/include/asm-cris/mman.h @@ -38,6 +38,8 @@ #define MADV_WILLNEED 0x3 /* pre-fault pages */ #define MADV_DONTNEED 0x4 /* discard these pages */ #define MADV_REMOVE 0x5 /* remove these pages & resources */ +#define MADV_DONTFORK 0x30 /* dont inherit across fork */ +#define MADV_DOFORK 0x31 /* do inherit across fork */ /* compatibility flags */ #define MAP_ANON MAP_ANONYMOUS diff --git a/include/asm-frv/mman.h b/include/asm-frv/mman.h index 8af4a41c25..d3bca306da 100644 --- a/include/asm-frv/mman.h +++ b/include/asm-frv/mman.h @@ -36,6 +36,8 @@ #define MADV_WILLNEED 0x3 /* pre-fault pages */ #define MADV_DONTNEED 0x4 /* discard these pages */ #define MADV_REMOVE 0x5 /* remove these pages & resources */ +#define MADV_DONTFORK 0x30 /* dont inherit across fork */ +#define MADV_DOFORK 0x31 /* do inherit across fork */ /* compatibility flags */ #define MAP_ANON MAP_ANONYMOUS diff --git a/include/asm-h8300/mman.h b/include/asm-h8300/mman.h index 744a8fb485..ac0346f7d1 100644 --- a/include/asm-h8300/mman.h +++ b/include/asm-h8300/mman.h @@ -36,6 +36,8 @@ #define MADV_WILLNEED 0x3 /* pre-fault pages */ #define MADV_DONTNEED 0x4 /* discard these pages */ #define MADV_REMOVE 0x5 /* remove these pages & resources */ +#define MADV_DONTFORK 0x30 /* dont inherit across fork */ +#define MADV_DOFORK 0x31 /* do inherit across fork */ /* compatibility flags */ #define MAP_ANON MAP_ANONYMOUS diff --git a/include/asm-i386/mman.h b/include/asm-i386/mman.h index ba4941e6f6..ab2339a1d8 100644 --- a/include/asm-i386/mman.h +++ b/include/asm-i386/mman.h @@ -36,6 +36,8 @@ #define MADV_WILLNEED 0x3 /* pre-fault pages */ #define MADV_DONTNEED 0x4 /* discard these pages */ #define MADV_REMOVE 0x5 /* remove these pages & resources */ +#define MADV_DONTFORK 0x30 /* dont inherit across fork */ +#define MADV_DOFORK 0x31 /* do inherit across fork */ /* compatibility flags */ #define MAP_ANON MAP_ANONYMOUS diff --git a/include/asm-ia64/mman.h b/include/asm-ia64/mman.h index 828beb24a2..357ebb780c 100644 --- a/include/asm-ia64/mman.h +++ b/include/asm-ia64/mman.h @@ -44,6 +44,8 @@ #define MADV_WILLNEED 0x3 /* pre-fault pages */ #define MADV_DONTNEED 0x4 /* discard these pages */ #define MADV_REMOVE 0x5 /* remove these pages & resources */ +#define MADV_DONTFORK 0x30 /* dont inherit across fork */ +#define MADV_DOFORK 0x31 /* do inherit across fork */ /* compatibility flags */ #define MAP_ANON MAP_ANONYMOUS diff --git a/include/asm-m32r/mman.h b/include/asm-m32r/mman.h index 12e29747bc..6b02fe3fcf 100644 --- a/include/asm-m32r/mman.h +++ b/include/asm-m32r/mman.h @@ -38,6 +38,8 @@ #define MADV_WILLNEED 0x3 /* pre-fault pages */ #define MADV_DONTNEED 0x4 /* discard these pages */ #define MADV_REMOVE 0x5 /* remove these pages & resources */ +#define MADV_DONTFORK 0x30 /* dont inherit across fork */ +#define MADV_DOFORK 0x31 /* do inherit across fork */ /* compatibility flags */ #define MAP_ANON MAP_ANONYMOUS diff --git a/include/asm-m68k/mman.h b/include/asm-m68k/mman.h index ea262ab88b..efd12bc4cc 100644 --- a/include/asm-m68k/mman.h +++ b/include/asm-m68k/mman.h @@ -36,6 +36,8 @@ #define MADV_WILLNEED 0x3 /* pre-fault pages */ #define MADV_DONTNEED 0x4 /* discard these pages */ #define MADV_REMOVE 0x5 /* remove these pages & resources */ +#define MADV_DONTFORK 0x30 /* dont inherit across fork */ +#define MADV_DOFORK 0x31 /* do inherit across fork */ /* compatibility flags */ #define MAP_ANON MAP_ANONYMOUS diff --git a/include/asm-mips/mman.h b/include/asm-mips/mman.h index dd17c8bd62..6d01e26830 100644 --- a/include/asm-mips/mman.h +++ b/include/asm-mips/mman.h @@ -66,6 +66,8 @@ #define MADV_WILLNEED 0x3 /* pre-fault pages */ #define MADV_DONTNEED 0x4 /* discard these pages */ #define MADV_REMOVE 0x5 /* remove these pages & resources */ +#define MADV_DONTFORK 0x30 /* dont inherit across fork */ +#define MADV_DOFORK 0x31 /* do inherit across fork */ /* compatibility flags */ #define MAP_ANON MAP_ANONYMOUS diff --git a/include/asm-parisc/mman.h b/include/asm-parisc/mman.h index 736b0abcac..a381cf5c8f 100644 --- a/include/asm-parisc/mman.h +++ b/include/asm-parisc/mman.h @@ -49,6 +49,8 @@ #define MADV_4M_PAGES 22 /* Use 4 Megabyte pages */ #define MADV_16M_PAGES 24 /* Use 16 Megabyte pages */ #define MADV_64M_PAGES 26 /* Use 64 Megabyte pages */ +#define MADV_DONTFORK 0x30 /* dont inherit across fork */ +#define MADV_DOFORK 0x31 /* do inherit across fork */ /* compatibility flags */ #define MAP_ANON MAP_ANONYMOUS diff --git a/include/asm-powerpc/mman.h b/include/asm-powerpc/mman.h index a2e34c21b4..fcff25d13f 100644 --- a/include/asm-powerpc/mman.h +++ b/include/asm-powerpc/mman.h @@ -45,6 +45,8 @@ #define MADV_WILLNEED 0x3 /* pre-fault pages */ #define MADV_DONTNEED 0x4 /* discard these pages */ #define MADV_REMOVE 0x5 /* remove these pages & resources */ +#define MADV_DONTFORK 0x30 /* dont inherit across fork */ +#define MADV_DOFORK 0x31 /* do inherit across fork */ /* compatibility flags */ #define MAP_ANON MAP_ANONYMOUS diff --git a/include/asm-s390/mman.h b/include/asm-s390/mman.h index c8d5409b5d..d41ca14770 100644 --- a/include/asm-s390/mman.h +++ b/include/asm-s390/mman.h @@ -44,6 +44,8 @@ #define MADV_WILLNEED 0x3 /* pre-fault pages */ #define MADV_DONTNEED 0x4 /* discard these pages */ #define MADV_REMOVE 0x5 /* remove these pages & resources */ +#define MADV_DONTFORK 0x30 /* dont inherit across fork */ +#define MADV_DOFORK 0x31 /* do inherit across fork */ /* compatibility flags */ #define MAP_ANON MAP_ANONYMOUS diff --git a/include/asm-sh/mman.h b/include/asm-sh/mman.h index 693bd55a37..0e08d0573a 100644 --- a/include/asm-sh/mman.h +++ b/include/asm-sh/mman.h @@ -36,6 +36,8 @@ #define MADV_WILLNEED 0x3 /* pre-fault pages */ #define MADV_DONTNEED 0x4 /* discard these pages */ #define MADV_REMOVE 0x5 /* remove these pages & resources */ +#define MADV_DONTFORK 0x30 /* dont inherit across fork */ +#define MADV_DOFORK 0x31 /* do inherit across fork */ /* compatibility flags */ #define MAP_ANON MAP_ANONYMOUS diff --git a/include/asm-sparc/mman.h b/include/asm-sparc/mman.h index 98435ad861..4a298b2be8 100644 --- a/include/asm-sparc/mman.h +++ b/include/asm-sparc/mman.h @@ -55,6 +55,8 @@ #define MADV_DONTNEED 0x4 /* discard these pages */ #define MADV_FREE 0x5 /* (Solaris) contents can be freed */ #define MADV_REMOVE 0x6 /* remove these pages & resources */ +#define MADV_DONTFORK 0x30 /* dont inherit across fork */ +#define MADV_DOFORK 0x31 /* do inherit across fork */ /* compatibility flags */ #define MAP_ANON MAP_ANONYMOUS diff --git a/include/asm-sparc64/mman.h b/include/asm-sparc64/mman.h index cb4b615619..d705ec92da 100644 --- a/include/asm-sparc64/mman.h +++ b/include/asm-sparc64/mman.h @@ -55,6 +55,8 @@ #define MADV_DONTNEED 0x4 /* discard these pages */ #define MADV_FREE 0x5 /* (Solaris) contents can be freed */ #define MADV_REMOVE 0x6 /* remove these pages & resources */ +#define MADV_DONTFORK 0x30 /* dont inherit across fork */ +#define MADV_DOFORK 0x31 /* do inherit across fork */ /* compatibility flags */ #define MAP_ANON MAP_ANONYMOUS diff --git a/include/asm-v850/mman.h b/include/asm-v850/mman.h index edc7996519..7b851c310e 100644 --- a/include/asm-v850/mman.h +++ b/include/asm-v850/mman.h @@ -33,6 +33,8 @@ #define MADV_WILLNEED 0x3 /* pre-fault pages */ #define MADV_DONTNEED 0x4 /* discard these pages */ #define MADV_REMOVE 0x5 /* remove these pages & resources */ +#define MADV_DONTFORK 0x30 /* dont inherit across fork */ +#define MADV_DOFORK 0x31 /* do inherit across fork */ /* compatibility flags */ #define MAP_ANON MAP_ANONYMOUS diff --git a/include/asm-x86_64/mman.h b/include/asm-x86_64/mman.h index d0e97b74f7..b699a38c1c 100644 --- a/include/asm-x86_64/mman.h +++ b/include/asm-x86_64/mman.h @@ -37,6 +37,8 @@ #define MADV_WILLNEED 0x3 /* pre-fault pages */ #define MADV_DONTNEED 0x4 /* discard these pages */ #define MADV_REMOVE 0x5 /* remove these pages & resources */ +#define MADV_DONTFORK 0x30 /* dont inherit across fork */ +#define MADV_DOFORK 0x31 /* do inherit across fork */ /* compatibility flags */ #define MAP_ANON MAP_ANONYMOUS diff --git a/include/asm-xtensa/mman.h b/include/asm-xtensa/mman.h index 082a750492..e2d7afb679 100644 --- a/include/asm-xtensa/mman.h +++ b/include/asm-xtensa/mman.h @@ -73,6 +73,8 @@ #define MADV_WILLNEED 0x3 /* pre-fault pages */ #define MADV_DONTNEED 0x4 /* discard these pages */ #define MADV_REMOVE 0x5 /* remove these pages & resources */ +#define MADV_DONTFORK 0x30 /* dont inherit across fork */ +#define MADV_DOFORK 0x31 /* do inherit across fork */ /* compatibility flags */ #define MAP_ANON MAP_ANONYMOUS diff --git a/mm/madvise.c b/mm/madvise.c index ae0ae3ea29..af3d573b01 100644 --- a/mm/madvise.c +++ b/mm/madvise.c @@ -22,16 +22,23 @@ static long madvise_behavior(struct vm_area_struct * vma, struct mm_struct * mm = vma->vm_mm; int error = 0; pgoff_t pgoff; - int new_flags = vma->vm_flags & ~VM_READHINTMASK; + int new_flags = vma->vm_flags; switch (behavior) { + case MADV_NORMAL: + new_flags = new_flags & ~VM_RAND_READ & ~VM_SEQ_READ; + break; case MADV_SEQUENTIAL: - new_flags |= VM_SEQ_READ; + new_flags = (new_flags & ~VM_RAND_READ) | VM_SEQ_READ; break; case MADV_RANDOM: - new_flags |= VM_RAND_READ; + new_flags = (new_flags & ~VM_SEQ_READ) | VM_RAND_READ; break; - default: + case MADV_DONTFORK: + new_flags |= VM_DONTCOPY; + break; + case MADV_DOFORK: + new_flags &= ~VM_DONTCOPY; break; } @@ -177,6 +184,12 @@ madvise_vma(struct vm_area_struct *vma, struct vm_area_struct **prev, long error; switch (behavior) { + case MADV_DOFORK: + if (vma->vm_flags & VM_IO) { + error = -EINVAL; + break; + } + case MADV_DONTFORK: case MADV_NORMAL: case MADV_SEQUENTIAL: case MADV_RANDOM: -- 2.39.5