From ea637639591def87a54cea811cbac796980cb30d Mon Sep 17 00:00:00 2001 From: Jie Zhang Date: Mon, 14 Dec 2009 18:00:02 -0800 Subject: nommu: fix malloc performance by adding uninitialized flag The NOMMU code currently clears all anonymous mmapped memory. While this is what we want in the default case, all memory allocation from userspace under NOMMU has to go through this interface, including malloc() which is allowed to return uninitialized memory. This can easily be a significant performance penalty. So for constrained embedded systems were security is irrelevant, allow people to avoid clearing memory unnecessarily. This also alters the ELF-FDPIC binfmt such that it obtains uninitialised memory for the brk and stack region. Signed-off-by: Jie Zhang Signed-off-by: Robin Getz Signed-off-by: Mike Frysinger Signed-off-by: David Howells Acked-by: Paul Mundt Acked-by: Greg Ungerer Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/asm-generic/mman-common.h | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'include/asm-generic/mman-common.h') diff --git a/include/asm-generic/mman-common.h b/include/asm-generic/mman-common.h index 5ee13b2fd223..20111265afd8 100644 --- a/include/asm-generic/mman-common.h +++ b/include/asm-generic/mman-common.h @@ -19,6 +19,11 @@ #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 #define MS_ASYNC 1 /* sync memory asynchronously */ #define MS_INVALIDATE 2 /* invalidate the caches */ -- cgit v1.2.3 From afcf938ee0aac4ef95b1a23bac704c6fbeb26de6 Mon Sep 17 00:00:00 2001 From: Andi Kleen Date: Wed, 16 Dec 2009 12:20:00 +0100 Subject: HWPOISON: Add a madvise() injector for soft page offlining Process based injection is much easier to handle for test programs, who can first bring a page into a specific state and then test. So add a new MADV_SOFT_OFFLINE to soft offline a page, similar to the existing hard offline injector. Signed-off-by: Andi Kleen --- include/asm-generic/mman-common.h | 1 + mm/madvise.c | 15 ++++++++++++--- 2 files changed, 13 insertions(+), 3 deletions(-) (limited to 'include/asm-generic/mman-common.h') diff --git a/include/asm-generic/mman-common.h b/include/asm-generic/mman-common.h index 20111265afd8..3da9e2742fa0 100644 --- a/include/asm-generic/mman-common.h +++ b/include/asm-generic/mman-common.h @@ -40,6 +40,7 @@ #define MADV_DONTFORK 10 /* don't inherit across fork */ #define MADV_DOFORK 11 /* do inherit across fork */ #define MADV_HWPOISON 100 /* poison a page for testing */ +#define MADV_SOFT_OFFLINE 101 /* soft offline page for testing */ #define MADV_MERGEABLE 12 /* KSM may merge identical pages */ #define MADV_UNMERGEABLE 13 /* KSM may not merge identical pages */ diff --git a/mm/madvise.c b/mm/madvise.c index 7964e36ba915..319528b8db74 100644 --- a/mm/madvise.c +++ b/mm/madvise.c @@ -9,6 +9,7 @@ #include #include #include +#include #include #include #include @@ -222,7 +223,7 @@ static long madvise_remove(struct vm_area_struct *vma, /* * Error injection support for memory error handling. */ -static int madvise_hwpoison(unsigned long start, unsigned long end) +static int madvise_hwpoison(int bhv, unsigned long start, unsigned long end) { int ret = 0; @@ -233,6 +234,14 @@ static int madvise_hwpoison(unsigned long start, unsigned long end) int ret = get_user_pages_fast(start, 1, 0, &p); if (ret != 1) return ret; + if (bhv == MADV_SOFT_OFFLINE) { + printk(KERN_INFO "Soft offlining page %lx at %lx\n", + page_to_pfn(p), start); + ret = soft_offline_page(p, MF_COUNT_INCREASED); + if (ret) + break; + continue; + } printk(KERN_INFO "Injecting memory failure for page %lx at %lx\n", page_to_pfn(p), start); /* Ignore return value for now */ @@ -333,8 +342,8 @@ SYSCALL_DEFINE3(madvise, unsigned long, start, size_t, len_in, int, behavior) size_t len; #ifdef CONFIG_MEMORY_FAILURE - if (behavior == MADV_HWPOISON) - return madvise_hwpoison(start, start+len_in); + if (behavior == MADV_HWPOISON || behavior == MADV_SOFT_OFFLINE) + return madvise_hwpoison(behavior, start, start+len_in); #endif if (!madvise_behavior_valid(behavior)) return error; -- cgit v1.2.3