diff options
| author | Suresh Siddha <suresh.b.siddha@intel.com> | 2005-06-22 04:14:32 +0400 |
|---|---|---|
| committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-06-22 05:46:12 +0400 |
| commit | 84929801e14d968caeb84795bfbb88f04283fbd9 (patch) | |
| tree | 248fa9fd6cfb411a6df3b7f7fb42aa4f9ceca2bf /include/asm-x86_64/processor.h | |
| parent | 589777eab7360894b7ca1c4ba9d252e03b51225b (diff) | |
| download | linux-84929801e14d968caeb84795bfbb88f04283fbd9.tar.xz | |
[PATCH] x86_64: TASK_SIZE fixes for compatibility mode processes
Appended patch will setup compatibility mode TASK_SIZE properly. This will
fix atleast three known bugs that can be encountered while running
compatibility mode apps.
a) A malicious 32bit app can have an elf section at 0xffffe000. During
exec of this app, we will have a memory leak as insert_vm_struct() is
not checking for return value in syscall32_setup_pages() and thus not
freeing the vma allocated for the vsyscall page. And instead of exec
failing (as it has addresses > TASK_SIZE), we were allowing it to
succeed previously.
b) With a 32bit app, hugetlb_get_unmapped_area/arch_get_unmapped_area
may return addresses beyond 32bits, ultimately causing corruption
because of wrap-around and resulting in SEGFAULT, instead of returning
ENOMEM.
c) 32bit app doing this below mmap will now fail.
mmap((void *)(0xFFFFE000UL), 0x10000UL, PROT_READ|PROT_WRITE,
MAP_FIXED|MAP_PRIVATE|MAP_ANON, 0, 0);
Signed-off-by: Zou Nan hai <nanhai.zou@intel.com>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'include/asm-x86_64/processor.h')
| -rw-r--r-- | include/asm-x86_64/processor.h | 11 |
1 files changed, 6 insertions, 5 deletions
diff --git a/include/asm-x86_64/processor.h b/include/asm-x86_64/processor.h index d641b19f6da5..8b55f139968f 100644 --- a/include/asm-x86_64/processor.h +++ b/include/asm-x86_64/processor.h @@ -160,16 +160,17 @@ static inline void clear_in_cr4 (unsigned long mask) /* * User space process size. 47bits minus one guard page. */ -#define TASK_SIZE (0x800000000000UL - 4096) +#define TASK_SIZE64 (0x800000000000UL - 4096) /* This decides where the kernel will search for a free chunk of vm * space during mmap's. */ #define IA32_PAGE_OFFSET ((current->personality & ADDR_LIMIT_3GB) ? 0xc0000000 : 0xFFFFe000) -#define TASK_UNMAPPED_32 PAGE_ALIGN(IA32_PAGE_OFFSET/3) -#define TASK_UNMAPPED_64 PAGE_ALIGN(TASK_SIZE/3) -#define TASK_UNMAPPED_BASE \ - (test_thread_flag(TIF_IA32) ? TASK_UNMAPPED_32 : TASK_UNMAPPED_64) + +#define TASK_SIZE (test_thread_flag(TIF_IA32) ? IA32_PAGE_OFFSET : TASK_SIZE64) +#define TASK_SIZE_OF(child) ((test_tsk_thread_flag(child, TIF_IA32)) ? IA32_PAGE_OFFSET : TASK_SIZE64) + +#define TASK_UNMAPPED_BASE PAGE_ALIGN(TASK_SIZE/3) /* * Size of io_bitmap. |