[PATCH v6 11/14] mips: Adjust brk randomization offset to fit generic version
From: Alexandre Ghiti <alex@ghiti.fr>
Date: 2019-08-08 06:30:13
Also in:
linux-fsdevel, linux-mips, linux-mm, linux-riscv, lkml
Subsystem:
mips, the rest · Maintainers:
Thomas Bogendoerfer, Linus Torvalds
This commit simply bumps up to 32MB and 1GB the random offset of brk, compared to 8MB and 256MB, for 32bit and 64bit respectively. Suggested-by: Kees Cook <redacted> Signed-off-by: Alexandre Ghiti <alex@ghiti.fr> Acked-by: Paul Burton <redacted> Reviewed-by: Kees Cook <redacted> Reviewed-by: Luis Chamberlain <mcgrof@kernel.org> --- arch/mips/mm/mmap.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/arch/mips/mm/mmap.c b/arch/mips/mm/mmap.c
index a7e84b2e71d7..ff6ab87e9c56 100644
--- a/arch/mips/mm/mmap.c
+++ b/arch/mips/mm/mmap.c@@ -16,6 +16,7 @@ #include <linux/random.h> #include <linux/sched/signal.h> #include <linux/sched/mm.h> +#include <linux/sizes.h> unsigned long shm_align_mask = PAGE_SIZE - 1; /* Sane caches */ EXPORT_SYMBOL(shm_align_mask);
@@ -189,11 +190,11 @@ static inline unsigned long brk_rnd(void) unsigned long rnd = get_random_long(); rnd = rnd << PAGE_SHIFT; - /* 8MB for 32bit, 256MB for 64bit */ + /* 32MB for 32bit, 1GB for 64bit */ if (TASK_IS_32BIT_ADDR) - rnd = rnd & 0x7ffffful; + rnd = rnd & (SZ_32M - 1); else - rnd = rnd & 0xffffffful; + rnd = rnd & (SZ_1G - 1); return rnd; }
--
2.20.1
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