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authorSven Schnelle <svens@linux.ibm.com>2022-04-06 08:44:49 +0200
committerHeiko Carstens <hca@linux.ibm.com>2022-04-25 13:54:14 +0200
commit9e37a2e8546f9e48ea76c839116fa5174d14e033 (patch)
tree1b7d25616ed5845c82abd8c0180ceeffb17dbd34 /arch/s390/include/asm/processor.h
parents390/vdso: move vdso mapping to its own function (diff)
downloadlinux-dev-9e37a2e8546f9e48ea76c839116fa5174d14e033.tar.xz
linux-dev-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/s390/include/asm/processor.h')
-rw-r--r--arch/s390/include/asm/processor.h7
1 files changed, 4 insertions, 3 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