queue mips-vdso-reduce-vdso_randomize_size-to-64mb-for-64b.patch for 4.19

Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/queue-4.19/mips-vdso-reduce-vdso_randomize_size-to-64mb-for-64b.patch b/queue-4.19/mips-vdso-reduce-vdso_randomize_size-to-64mb-for-64b.patch
new file mode 100644 (file)
index 0000000..c3435e9
--- /dev/null
+++ b/queue-4.19/mips-vdso-reduce-vdso_randomize_size-to-64mb-for-64b.patch
@@ -0,0 +1,47 @@
+From 8d0d28a6ca5c6263e67aa633c138436b61c78cba Mon Sep 17 00:00:00 2001
+From: Huacai Chen <chenhc@lemote.com>
+Date: Mon, 5 Nov 2018 22:58:30 +0000
+Subject: 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>
+Cc: stable@vger.kernel.org # 4.19
+Signed-off-by: Sasha Levin <sashal@kernel.org>
+---
+ arch/mips/include/asm/processor.h | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/arch/mips/include/asm/processor.h b/arch/mips/include/asm/processor.h
+index 49d6046ca1d0..c373eb605040 100644
+--- a/arch/mips/include/asm/processor.h
++++ b/arch/mips/include/asm/processor.h
+@@ -81,7 +81,7 @@ extern unsigned int vced_count, vcei_count;
+ 
+ #endif
+ 
+-#define VDSO_RANDOMIZE_SIZE   (TASK_IS_32BIT_ADDR ? SZ_1M : SZ_256M)
++#define VDSO_RANDOMIZE_SIZE   (TASK_IS_32BIT_ADDR ? SZ_1M : SZ_64M)
+ 
+ extern unsigned long mips_stack_top(void);
+ #define STACK_TOP             mips_stack_top()
+-- 
+2.17.1
+

diff --git a/queue-4.19/series b/queue-4.19/series
index d0c3675a0536389a23827c56352698a961fd02f8..71d208ab114d421d4ae9376d0e1089125ebb0ce4 100644 (file)
--- a/queue-4.19/series
+++ b/queue-4.19/series
@@ -1 +1,2 @@
 bpf-fix-partial-copy-of-map_ptr-when-dst-is-scalar.patch
+mips-vdso-reduce-vdso_randomize_size-to-64mb-for-64b.patch