The patch titled
Subject: arm: use STACK_TOP when computing mmap base address
has been added to the -mm tree. Its filename is
arm-use-stack_top-when-computing-mmap-base-address.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/arm-use-stack_top-when-computing-mmap-base-address.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/arm-use-stack_top-when-computing-mmap-base-address.patch
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------------------------------------------------------
From: Alexandre Ghiti <alex@xxxxxxxx>
Subject: arm: use STACK_TOP when computing mmap base address
mmap base address must be computed wrt stack top address, using TASK_SIZE
is wrong since STACK_TOP and TASK_SIZE are not equivalent.
Link: http://lkml.kernel.org/r/20190730055113.23635-8-alex@xxxxxxxx
Signed-off-by: Alexandre Ghiti <alex@xxxxxxxx>
Acked-by: Kees Cook <keescook@xxxxxxxxxxxx>
Reviewed-by: Luis Chamberlain <mcgrof@xxxxxxxxxx>
Cc: Albert Ou <aou@xxxxxxxxxxxxxxxxx>
Cc: Alexander Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Cc: James Hogan <jhogan@xxxxxxxxxx>
Cc: Palmer Dabbelt <palmer@xxxxxxxxxx>
Cc: Paul Burton <paul.burton@xxxxxxxx>
Cc: Ralf Baechle <ralf@xxxxxxxxxxxxxx>
Cc: Russell King <linux@xxxxxxxxxxxxxxx>
Cc: Will Deacon <will.deacon@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
arch/arm/mm/mmap.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
--- a/arch/arm/mm/mmap.c~arm-use-stack_top-when-computing-mmap-base-address
+++ a/arch/arm/mm/mmap.c
@@ -19,7 +19,7 @@
/* gap between mmap and stack */
#define MIN_GAP (128*1024*1024UL)
-#define MAX_GAP ((TASK_SIZE)/6*5)
+#define MAX_GAP ((STACK_TOP)/6*5)
#define STACK_RND_MASK (0x7ff >> (PAGE_SHIFT - 12))
static int mmap_is_legacy(struct rlimit *rlim_stack)
@@ -51,7 +51,7 @@ static unsigned long mmap_base(unsigned
else if (gap > MAX_GAP)
gap = MAX_GAP;
- return PAGE_ALIGN(TASK_SIZE - gap - rnd);
+ return PAGE_ALIGN(STACK_TOP - gap - rnd);
}
/*
_
Patches currently in -mm which might be from alex@xxxxxxxx are
mm-fs-move-randomize_stack_top-from-fs-to-mm.patch
arm64-make-use-of-is_compat_task-instead-of-hardcoding-this-test.patch
arm64-consider-stack-randomization-for-mmap-base-only-when-necessary.patch
arm64-mm-move-generic-mmap-layout-functions-to-mm.patch
arm64-mm-make-randomization-selected-by-generic-topdown-mmap-layout.patch
arm-properly-account-for-stack-randomization-and-stack-guard-gap.patch
arm-use-stack_top-when-computing-mmap-base-address.patch
arm-use-generic-mmap-top-down-layout-and-brk-randomization.patch
mips-properly-account-for-stack-randomization-and-stack-guard-gap.patch
mips-use-stack_top-when-computing-mmap-base-address.patch
mips-adjust-brk-randomization-offset-to-fit-generic-version.patch
mips-replace-arch-specific-way-to-determine-32bit-task-with-generic-version.patch
mips-use-generic-mmap-top-down-layout-and-brk-randomization.patch
riscv-make-mmap-allocation-top-down-by-default.patch
