From: Alexandre Ghiti <alex@ghiti.fr>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: 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>,
Luis Chamberlain <mcgrof@kernel.org>,
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 v4 03/14] arm64: Consider stack randomization for mmap base only when necessary
Date: Sun, 26 May 2019 09:47:35 -0400 [thread overview]
Message-ID: <20190526134746.9315-4-alex@ghiti.fr> (raw)
In-Reply-To: <20190526134746.9315-1-alex@ghiti.fr>
Do not offset mmap base address because of stack randomization if
current task does not want randomization.
Note that x86 already implements this behaviour.
Signed-off-by: Alexandre Ghiti <alex@ghiti.fr>
Acked-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
---
arch/arm64/mm/mmap.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/arch/arm64/mm/mmap.c b/arch/arm64/mm/mmap.c
index ed4f9915f2b8..ac89686c4af8 100644
--- a/arch/arm64/mm/mmap.c
+++ b/arch/arm64/mm/mmap.c
@@ -65,7 +65,11 @@ unsigned long arch_mmap_rnd(void)
static unsigned long mmap_base(unsigned long rnd, struct rlimit *rlim_stack)
{
unsigned long gap = rlim_stack->rlim_cur;
- unsigned long pad = (STACK_RND_MASK << PAGE_SHIFT) + stack_guard_gap;
+ unsigned long pad = stack_guard_gap;
+
+ /* Account for stack randomization if necessary */
+ if (current->flags & PF_RANDOMIZE)
+ pad += (STACK_RND_MASK << PAGE_SHIFT);
/* Values close to RLIM_INFINITY can overflow. */
if (gap + pad > gap)
--
2.20.1
next prev parent reply other threads:[~2019-05-26 13:51 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-26 13:47 [PATCH v4 00/14] Provide generic top-down mmap layout functions Alexandre Ghiti
2019-05-26 13:47 ` [PATCH v4 01/14] mm, fs: Move randomize_stack_top from fs to mm Alexandre Ghiti
2019-05-26 13:47 ` [PATCH v4 02/14] arm64: Make use of is_compat_task instead of hardcoding this test Alexandre Ghiti
2019-06-03 17:32 ` Catalin Marinas
2019-05-26 13:47 ` Alexandre Ghiti [this message]
2019-06-03 17:37 ` [PATCH v4 03/14] arm64: Consider stack randomization for mmap base only when necessary Catalin Marinas
2019-05-26 13:47 ` [PATCH v4 04/14] arm64, mm: Move generic mmap layout functions to mm Alexandre Ghiti
2019-05-29 20:10 ` Kees Cook
2019-06-03 17:38 ` Catalin Marinas
2019-05-26 13:47 ` [PATCH v4 05/14] arm64, mm: Make randomization selected by generic topdown mmap layout Alexandre Ghiti
2019-05-29 20:10 ` Kees Cook
2019-06-01 9:04 ` Christoph Hellwig
2019-06-03 7:05 ` Alexandre Ghiti
2019-06-03 17:40 ` Catalin Marinas
2019-06-04 6:20 ` Alex Ghiti
2019-05-26 13:47 ` [PATCH v4 06/14] arm: Properly account for stack randomization and stack guard gap Alexandre Ghiti
2019-05-26 13:47 ` [PATCH v4 07/14] arm: Use STACK_TOP when computing mmap base address Alexandre Ghiti
2019-05-26 13:47 ` [PATCH v4 08/14] arm: Use generic mmap top-down layout and brk randomization Alexandre Ghiti
2019-05-29 19:26 ` Kees Cook
2019-05-31 4:49 ` Alex Ghiti
2019-05-26 13:47 ` [PATCH v4 09/14] mips: Properly account for stack randomization and stack guard gap Alexandre Ghiti
2019-05-26 13:47 ` [PATCH v4 10/14] mips: Use STACK_TOP when computing mmap base address Alexandre Ghiti
2019-05-26 13:47 ` [PATCH v4 11/14] mips: Adjust brk randomization offset to fit generic version Alexandre Ghiti
2019-05-29 20:12 ` Kees Cook
2019-05-26 13:47 ` [PATCH v4 12/14] mips: Replace arch specific way to determine 32bit task with " Alexandre Ghiti
2019-05-29 20:12 ` Kees Cook
2019-05-26 13:47 ` [PATCH v4 13/14] mips: Use generic mmap top-down layout and brk randomization Alexandre Ghiti
2019-05-29 20:12 ` Kees Cook
2019-05-26 13:47 ` [PATCH v4 14/14] riscv: Make mmap allocation top-down by default Alexandre Ghiti
2019-05-29 20:16 ` [PATCH v4 00/14] Provide generic top-down mmap layout functions Kees Cook
2019-05-31 5:04 ` Alex Ghiti
2019-06-13 5:29 ` Alex Ghiti
2019-06-30 15:34 ` Alex Ghiti
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