diff options
| author | Radu Caragea <sinaelgl@gmail.com> | 2013-08-21 20:55:59 +0300 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2013-09-10 01:57:37 +0100 |
| commit | ac8905cf6be324c76193debc26042fe7a746f89a (patch) | |
| tree | 2e262d6194441dd1f0049da3fdec71e07cebd1fc | |
| parent | caf51a8a6584804bc97ef2fd860eadc37c4b3f92 (diff) | |
x86 get_unmapped_area: Access mmap_legacy_base through mm_struct member
commit 41aacc1eea645c99edbe8fbcf78a97dc9b862adc upstream.
This is the updated version of df54d6fa5427 ("x86 get_unmapped_area():
use proper mmap base for bottom-up direction") that only randomizes the
mmap base address once.
Signed-off-by: Radu Caragea <sinaelgl@gmail.com>
Reported-and-tested-by: Jeff Shorey <shoreyjeff@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Michel Lespinasse <walken@google.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Adrian Sendroiu <molecula2788@gmail.com>
Cc: Greg KH <greg@kroah.com>
Cc: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
| -rw-r--r-- | arch/x86/kernel/sys_x86_64.c | 2 | ||||
| -rw-r--r-- | arch/x86/mm/mmap.c | 6 | ||||
| -rw-r--r-- | include/linux/mm_types.h | 1 |
3 files changed, 6 insertions, 3 deletions
diff --git a/arch/x86/kernel/sys_x86_64.c b/arch/x86/kernel/sys_x86_64.c index 051489082d5..cdb2fc9235b 100644 --- a/arch/x86/kernel/sys_x86_64.c +++ b/arch/x86/kernel/sys_x86_64.c @@ -115,7 +115,7 @@ static void find_start_end(unsigned long flags, unsigned long *begin, *begin = new_begin; } } else { - *begin = TASK_UNMAPPED_BASE; + *begin = current->mm->mmap_legacy_base; *end = TASK_SIZE; } } diff --git a/arch/x86/mm/mmap.c b/arch/x86/mm/mmap.c index 845df6835f9..5c1ae28825c 100644 --- a/arch/x86/mm/mmap.c +++ b/arch/x86/mm/mmap.c @@ -112,12 +112,14 @@ static unsigned long mmap_legacy_base(void) */ void arch_pick_mmap_layout(struct mm_struct *mm) { + mm->mmap_legacy_base = mmap_legacy_base(); + mm->mmap_base = mmap_base(); + if (mmap_is_legacy()) { - mm->mmap_base = mmap_legacy_base(); + mm->mmap_base = mm->mmap_legacy_base; mm->get_unmapped_area = arch_get_unmapped_area; mm->unmap_area = arch_unmap_area; } else { - mm->mmap_base = mmap_base(); mm->get_unmapped_area = arch_get_unmapped_area_topdown; mm->unmap_area = arch_unmap_area_topdown; } diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h index 5b42f1b34eb..de3a3217fda 100644 --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h @@ -297,6 +297,7 @@ struct mm_struct { void (*unmap_area) (struct mm_struct *mm, unsigned long addr); #endif unsigned long mmap_base; /* base of mmap area */ + unsigned long mmap_legacy_base; /* base of mmap area in bottom-up allocations */ unsigned long task_size; /* size of task vm space */ unsigned long cached_hole_size; /* if non-zero, the largest hole below free_area_cache */ unsigned long free_area_cache; /* first hole of size cached_hole_size or larger */ |