From: Kees Cook <keescook@chromium.org>
To: akpm@linux-foundation.org
Cc: linux-mips@linux-mips.org, "Arun Chandran" <achandran@mvista.com>,
"Heiko Carstens" <heiko.carstens@de.ibm.com>,
linux-kernel@vger.kernel.org,
"Min-Hua Chen" <orca.chen@gmail.com>,
"Paul Mackerras" <paulus@samba.org>,
"Ismael Ripoll" <iripoll@upv.es>,
"Yann Droneaud" <ydroneaud@opteya.com>,
linux-s390@vger.kernel.org,
"Russell King" <linux@arm.linux.org.uk>,
"Andrey Ryabinin" <a.ryabinin@samsung.com>,
x86@kernel.org, "Hector Marco-Gisbert" <hecmargi@upv.es>,
"Ingo Molnar" <mingo@redhat.com>,
"David A. Long" <dave.long@linaro.org>,
"Catalin Marinas" <catalin.marinas@arm.com>,
"Borislav Petkov" <bp@suse.de>,
"Ben Hutchings" <ben@decadent.org.uk>,
"Kees Cook" <keescook@chromium.org>,
"Will Deacon" <will.deacon@arm.com>,
linux-fsdevel@vger.kernel.org,
"Alexander Viro" <viro@zeniv.linux.org.uk>,
"Michael Holzheu" <holzheu@linux.vnet.ibm.com>,
linux-arm-kernel@lists.infradead.org,
"Jeff Bailey" <jeffbailey@google.com>,
"Paul Burton" <paul.burton@imgtec.com>,
"Oleg Nesterov" <oleg@redhat.com>,
"Ralf Baechle" <ralf@linux-mips.org>,
"Andy Lutomirski" <luto@amacapital.net>,
"Vineeth Vijayan" <vvijayan@mvista.com>,
"Markos Chandras" <markos.chandras@imgtec.com>,
"Jan-Simon Möller" <dl9pf@gmx.de>,
"Martin Schwidefsky" <schwidefsky@de.ibm.com>,
linux390@de.ibm.com, linuxppc-dev@lists.ozlabs.org,
"Alex Smith" <alex@alex-smith.me.uk>
Subject: [PATCH v4 05/10] powerpc: standardize mmap_rnd() usage
Date: Wed, 4 Mar 2015 13:10:49 -0800 [thread overview]
Message-ID: <1425503454-7531-6-git-send-email-keescook@chromium.org> (raw)
In-Reply-To: <1425503454-7531-1-git-send-email-keescook@chromium.org>
In preparation for splitting out ET_DYN ASLR, this refactors the use of
mmap_rnd() to be used similarly to arm and x86.
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
---
Can mmap ASLR be safely enabled in the legacy mmap case here? Other archs
use "mm->mmap_base = TASK_UNMAPPED_BASE + random_factor".
---
arch/powerpc/mm/mmap.c | 26 +++++++++++++++-----------
1 file changed, 15 insertions(+), 11 deletions(-)
diff --git a/arch/powerpc/mm/mmap.c b/arch/powerpc/mm/mmap.c
index cb8bdbe4972f..1ad2299d795d 100644
--- a/arch/powerpc/mm/mmap.c
+++ b/arch/powerpc/mm/mmap.c
@@ -55,19 +55,18 @@ static inline int mmap_is_legacy(void)
static unsigned long mmap_rnd(void)
{
- unsigned long rnd = 0;
+ unsigned long rnd;
+
+ /* 8MB for 32bit, 1GB for 64bit */
+ if (is_32bit_task())
+ rnd = (unsigned long)get_random_int() % (1<<(23-PAGE_SHIFT));
+ else
+ rnd = (unsigned long)get_random_int() % (1<<(30-PAGE_SHIFT));
- if (current->flags & PF_RANDOMIZE) {
- /* 8MB for 32bit, 1GB for 64bit */
- if (is_32bit_task())
- rnd = (long)(get_random_int() % (1<<(23-PAGE_SHIFT)));
- else
- rnd = (long)(get_random_int() % (1<<(30-PAGE_SHIFT)));
- }
return rnd << PAGE_SHIFT;
}
-static inline unsigned long mmap_base(void)
+static inline unsigned long mmap_base(unsigned long rnd)
{
unsigned long gap = rlimit(RLIMIT_STACK);
@@ -76,7 +75,7 @@ static inline unsigned long mmap_base(void)
else if (gap > MAX_GAP)
gap = MAX_GAP;
- return PAGE_ALIGN(TASK_SIZE - gap - mmap_rnd());
+ return PAGE_ALIGN(TASK_SIZE - gap - rnd);
}
/*
@@ -85,6 +84,11 @@ static inline unsigned long mmap_base(void)
*/
void arch_pick_mmap_layout(struct mm_struct *mm)
{
+ unsigned long random_factor = 0UL;
+
+ if (current->flags & PF_RANDOMIZE)
+ random_factor = mmap_rnd();
+
/*
* Fall back to the standard layout if the personality
* bit is set, or if the expected stack growth is unlimited:
@@ -93,7 +97,7 @@ void arch_pick_mmap_layout(struct mm_struct *mm)
mm->mmap_base = TASK_UNMAPPED_BASE;
mm->get_unmapped_area = arch_get_unmapped_area;
} else {
- mm->mmap_base = mmap_base();
+ mm->mmap_base = mmap_base(random_factor);
mm->get_unmapped_area = arch_get_unmapped_area_topdown;
}
}
--
1.9.1
next prev parent reply other threads:[~2015-03-04 21:15 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-03-04 21:10 [PATCH v4 0/10] split ET_DYN ASLR from mmap ASLR Kees Cook
2015-03-04 21:10 ` [PATCH v4 01/10] arm: factor out mmap ASLR into mmap_rnd Kees Cook
2015-03-04 21:10 ` [PATCH v4 02/10] x86: standardize mmap_rnd() usage Kees Cook
2015-03-04 21:10 ` [PATCH v4 03/10] arm64: " Kees Cook
2015-03-17 14:47 ` Will Deacon
2015-03-17 15:19 ` Kees Cook
2015-03-04 21:10 ` [PATCH v4 04/10] mips: extract logic for mmap_rnd() Kees Cook
2015-03-04 21:10 ` Kees Cook [this message]
2015-03-04 21:10 ` [PATCH v4 06/10] s390: standardize mmap_rnd() usage Kees Cook
2015-03-09 17:41 ` Martin Schwidefsky
2015-03-04 21:10 ` [PATCH v4 07/10] mm: expose arch_mmap_rnd when available Kees Cook
2015-03-04 21:10 ` [PATCH v4 08/10] s390: redefine randomize_et_dyn for ELF_ET_DYN_BASE Kees Cook
2015-03-09 17:42 ` Martin Schwidefsky
2015-03-04 21:10 ` [PATCH v4 09/10] mm: split ET_DYN ASLR from mmap ASLR Kees Cook
2015-03-04 21:10 ` [PATCH v4 10/10] mm: fold arch_randomize_brk into ARCH_HAS_ELF_RANDOMIZE Kees Cook
2015-03-04 21:54 ` [PATCH v4 0/10] split ET_DYN ASLR from mmap ASLR Ingo Molnar
2015-03-04 21:58 ` Kees Cook
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