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From:   Alexandre Ghiti <alex@ghiti.fr>
To:     "James E . J . Bottomley" <James.Bottomley@HansenPartnership.com>,
        Helge Deller <deller@gmx.de>,
        Andrew Morton <akpm@linux-foundation.org>,
        Alexandre Ghiti <alex@ghiti.fr>,
        Kees Cook <keescook@chromium.org>,
        linux-parisc@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH] parisc: Consider stack randomization for mmap base only when necessary
Date:   Thu,  4 Apr 2019 02:26:22 -0400
Message-Id: <20190404062622.26009-1-alex@ghiti.fr>
MIME-Version: 1.0
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Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

Do not offset mmap base address because of stack randomization if
current task does not want randomization.

Signed-off-by: Alexandre Ghiti <alex@ghiti.fr>
---
 arch/parisc/kernel/sys_parisc.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/parisc/kernel/sys_parisc.c b/arch/parisc/kernel/sys_parisc.c
index 376ea0d1b275..4407ac4c1d84 100644
--- a/arch/parisc/kernel/sys_parisc.c
+++ b/arch/parisc/kernel/sys_parisc.c
@@ -86,7 +86,8 @@ static unsigned long mmap_upper_limit(struct rlimit *rlim_stack)
 		stack_base = STACK_SIZE_MAX;
 
 	/* Add space for stack randomization. */
-	stack_base += (STACK_RND_MASK << PAGE_SHIFT);
+	if (current->flags & PF_RANDOMIZE)
+		stack_base += (STACK_RND_MASK << PAGE_SHIFT);
 
 	return PAGE_ALIGN(STACK_TOP - stack_base);
 }
-- 
2.20.1