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From: Alexandre Ghiti <alex@ghiti.fr>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Paul Walmsley <paul.walmsley@sifive.com>,
	Luis Chamberlain <mcgrof@kernel.org>,
	Christoph Hellwig <hch@lst.de>,
	Russell King <linux@armlinux.org.uk>,
	Catalin Marinas <catalin.marinas@arm.com>,
	Will Deacon <will.deacon@arm.com>,
	Ralf Baechle <ralf@linux-mips.org>,
	Paul Burton <paul.burton@mips.com>,
	James Hogan <jhogan@kernel.org>,
	Palmer Dabbelt <palmer@sifive.com>,
	Albert Ou <aou@eecs.berkeley.edu>,
	Alexander Viro <viro@zeniv.linux.org.uk>,
	Kees Cook <keescook@chromium.org>,
	linux-kernel@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org, linux-mips@vger.kernel.org,
	linux-riscv@lists.infradead.org, linux-fsdevel@vger.kernel.org,
	linux-mm@kvack.org, Alexandre Ghiti <alex@ghiti.fr>
Subject: [PATCH v6 11/14] mips: Adjust brk randomization offset to fit generic version
Date: Thu,  8 Aug 2019 02:17:53 -0400	[thread overview]
Message-ID: <20190808061756.19712-12-alex@ghiti.fr> (raw)
In-Reply-To: <20190808061756.19712-1-alex@ghiti.fr>

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 <keescook@chromium.org>
Signed-off-by: Alexandre Ghiti <alex@ghiti.fr>
Acked-by: Paul Burton <paul.burton@mips.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
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


  parent reply	other threads:[~2019-08-08  6:30 UTC|newest]

Thread overview: 27+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-08-08  6:17 [PATCH v6 00/14] Provide generic top-down mmap layout functions Alexandre Ghiti
2019-08-08  6:17 ` [PATCH v6 01/14] mm, fs: Move randomize_stack_top from fs to mm Alexandre Ghiti
2019-08-08  6:17 ` [PATCH v6 02/14] arm64: Make use of is_compat_task instead of hardcoding this test Alexandre Ghiti
2019-08-08  6:17 ` [PATCH v6 03/14] arm64: Consider stack randomization for mmap base only when necessary Alexandre Ghiti
2019-08-08  6:17 ` [PATCH v6 04/14] arm64, mm: Move generic mmap layout functions to mm Alexandre Ghiti
2019-08-08  6:17 ` [PATCH v6 05/14] arm64, mm: Make randomization selected by generic topdown mmap layout Alexandre Ghiti
2019-08-08  6:17 ` [PATCH v6 06/14] arm: Properly account for stack randomization and stack guard gap Alexandre Ghiti
2019-08-08  6:17 ` [PATCH v6 07/14] arm: Use STACK_TOP when computing mmap base address Alexandre Ghiti
2019-08-08  6:17 ` [PATCH v6 08/14] arm: Use generic mmap top-down layout and brk randomization Alexandre Ghiti
2019-08-08  6:17 ` [PATCH v6 09/14] mips: Properly account for stack randomization and stack guard gap Alexandre Ghiti
     [not found]   ` <bd67507e-8a5b-34b5-1a33-5500bbb724b2@cogentembedded.com>
2019-08-09  9:44     ` Alexandre Ghiti
2019-08-08  6:17 ` [PATCH v6 10/14] mips: Use STACK_TOP when computing mmap base address Alexandre Ghiti
2019-08-08  6:17 ` Alexandre Ghiti [this message]
2019-08-08  9:19   ` [PATCH v6 11/14] mips: Adjust brk randomization offset to fit generic version Sergei Shtylyov
2019-08-09  9:45     ` Alexandre Ghiti
2019-08-08  6:17 ` [PATCH v6 12/14] mips: Replace arch specific way to determine 32bit task with " Alexandre Ghiti
2019-08-08  6:17 ` [PATCH v6 13/14] mips: Use generic mmap top-down layout and brk randomization Alexandre Ghiti
2019-08-08  6:17 ` [PATCH v6 14/14] riscv: Make mmap allocation top-down by default Alexandre Ghiti
2019-10-05  2:12   ` Atish Patra
2019-10-07  9:11     ` Alex Ghiti
2019-10-08  0:46       ` Atish Patra
2019-10-08 11:58         ` Alex Ghiti
2019-10-09  2:07           ` Atish Patra
2019-10-09 18:39             ` Alex Ghiti
2019-10-15  0:31               ` Atish Patra
2019-10-15  7:48                 ` Andreas Schwab
2019-10-08  9:19       ` Alex Ghiti

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