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| author | Sven Schnelle <svens@linux.ibm.com> | 2022-04-06 08:44:49 +0200 |
|---|---|---|
| committer | Heiko Carstens <hca@linux.ibm.com> | 2022-04-25 13:54:14 +0200 |
| commit | 9e37a2e8546f9e48ea76c839116fa5174d14e033 (patch) | |
| tree | 1b7d25616ed5845c82abd8c0180ceeffb17dbd34 /arch | |
| parent | s390/vdso: move vdso mapping to its own function (diff) | |
| download | linux-9e37a2e8546f9e48ea76c839116fa5174d14e033.tar.xz linux-9e37a2e8546f9e48ea76c839116fa5174d14e033.zip | |
s390/vdso: map vdso above stack
In the current code vdso is mapped below the stack. This is
problematic when programs mapped to the top of the address space
are allocating a lot of memory, because the heap will clash with
the vdso. To avoid this map the vdso above the stack and move
STACK_TOP so that it all fits into three level paging.
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/s390/include/asm/processor.h | 7 | ||||
| -rw-r--r-- | arch/s390/kernel/vdso.c | 2 |
2 files changed, 5 insertions, 4 deletions
diff --git a/arch/s390/include/asm/processor.h b/arch/s390/include/asm/processor.h index a3ab8cbcc5e4..add764a2be8c 100644 --- a/arch/s390/include/asm/processor.h +++ b/arch/s390/include/asm/processor.h @@ -95,9 +95,10 @@ unsigned long vdso_size(void); (_REGION3_SIZE >> 1) : (_REGION2_SIZE >> 1)) #define TASK_SIZE_MAX (-PAGE_SIZE) -#define STACK_TOP (test_thread_flag(TIF_31BIT) ? \ - _REGION3_SIZE : _REGION2_SIZE) -#define STACK_TOP_MAX _REGION2_SIZE +#define VDSO_BASE (STACK_TOP + PAGE_SIZE) +#define VDSO_LIMIT (test_thread_flag(TIF_31BIT) ? _REGION3_SIZE : _REGION2_SIZE) +#define STACK_TOP (VDSO_LIMIT - vdso_size() - PAGE_SIZE) +#define STACK_TOP_MAX (_REGION2_SIZE - vdso_size() - PAGE_SIZE) #define HAVE_ARCH_PICK_MMAP_LAYOUT diff --git a/arch/s390/kernel/vdso.c b/arch/s390/kernel/vdso.c index 22cb727d5821..7ba84a88ea2a 100644 --- a/arch/s390/kernel/vdso.c +++ b/arch/s390/kernel/vdso.c @@ -221,7 +221,7 @@ unsigned long vdso_size(void) int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) { - return map_vdso(0, vdso_size()); + return map_vdso(VDSO_BASE, vdso_size()); } static struct page ** __init vdso_setup_pages(void *start, void *end) |