Huacai Chen c4d262c26e MIPS: VDSO: Reduce VDSO_RANDOMIZE_SIZE to 64MB for 64bit
[ Upstream commit c61c7def1fa0a722610d89790e0255b74f3c07dd ]

Commit ea7e0480a4b6 ("MIPS: VDSO: Always map near top of user memory")
set VDSO_RANDOMIZE_SIZE to 256MB for 64bit kernel. But take a look at
arch/mips/mm/mmap.c we can see that MIN_GAP is 128MB, which means the
mmap_base may be at (user_address_top - 128MB). This make the stack be
surrounded by mmaped areas, then stack expanding fails and causes a
segmentation fault. Therefore, VDSO_RANDOMIZE_SIZE should be less than
MIN_GAP and this patch reduce it to 64MB.

Signed-off-by: Huacai Chen <chenhc@lemote.com>
Signed-off-by: Paul Burton <paul.burton@mips.com>
Fixes: ea7e0480a4b6 ("MIPS: VDSO: Always map near top of user memory")
Patchwork: https://patchwork.linux-mips.org/patch/20910/
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: James Hogan <jhogan@kernel.org>
Cc: linux-mips@linux-mips.org
Cc: Fuxin Zhang <zhangfx@lemote.com>
Cc: Zhangjin Wu <wuzhangjin@gmail.com>
Cc: Huacai Chen <chenhuacai@gmail.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
2019-05-16 19:42:25 +02:00
..
2019-02-20 10:20:53 +01:00
2018-02-28 10:19:44 +01:00
2019-03-23 14:35:21 +01:00
2019-04-17 08:37:54 +02:00