The patch titled
Subject: arm64-mm-support-arch_mmap_rnd_bits-v6
has been added to the -mm tree. Its filename is
arm64-mm-support-arch_mmap_rnd_bits-v6.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/arm64-mm-support-arch_mmap_rnd_bits-v6.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/arm64-mm-support-arch_mmap_rnd_bits-v6.patch
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/SubmitChecklist when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Daniel Cashman <dcashman@xxxxxxxxxx>
Subject: arm64-mm-support-arch_mmap_rnd_bits-v6
arm64: arch_mmap_rnd() uses STACK_RND_MASK to generate the
random offset for the mmap base address. This value represents a
compromise between increased ASLR effectiveness and avoiding
address-space fragmentation. Replace it with a Kconfig option, which
is sensibly bounded, so that platform developers may choose where to
place this compromise. Keep default values as new minimums.
Signed-off-by: Daniel Cashman <dcashman@xxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
arch/arm64/Kconfig | 14 ++++++++------
1 file changed, 8 insertions(+), 6 deletions(-)
diff -puN arch/arm64/Kconfig~arm64-mm-support-arch_mmap_rnd_bits-v6 arch/arm64/Kconfig
--- a/arch/arm64/Kconfig~arm64-mm-support-arch_mmap_rnd_bits-v6
+++ a/arch/arm64/Kconfig
@@ -51,8 +51,8 @@ config ARM64
select HAVE_ARCH_JUMP_LABEL
select HAVE_ARCH_KASAN if SPARSEMEM_VMEMMAP && !(ARM64_16K_PAGES && ARM64_VA_BITS_48)
select HAVE_ARCH_KGDB
- select HAVE_ARCH_MMAP_RND_BITS if MMU
- select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT
+ select HAVE_ARCH_MMAP_RND_BITS
+ select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT
select HAVE_ARCH_SECCOMP_FILTER
select HAVE_ARCH_TRACEHOOK
select HAVE_BPF_JIT
@@ -107,10 +107,12 @@ config MMU
def_bool y
config ARCH_MMAP_RND_BITS_MIN
- default 15 if ARM64_64K_PAGES
- default 17 if ARM64_16K_PAGES
- default 19
+ default 14 if ARM64_64K_PAGES
+ default 16 if ARM64_16K_PAGES
+ default 18
+# max bits determined by the following formula:
+# VA_BITS - PAGE_SHIFT - 3
config ARCH_MMAP_RND_BITS_MAX
default 19 if ARM64_VA_BITS=36
default 20 if ARM64_64K_PAGES && ARM64_VA_BITS=39
@@ -125,7 +127,7 @@ config ARCH_MMAP_RND_BITS_MAX
default 33 if ARM64_VA_BITS=48
default 15 if ARM64_64K_PAGES
default 17 if ARM64_16K_PAGES
- default 19
+ default 18
config ARCH_MMAP_RND_COMPAT_BITS_MIN
default 7 if ARM64_64K_PAGES
_
Patches currently in -mm which might be from dcashman@xxxxxxxxxx are
mm-mmap-add-new-proc-tunable-for-mmap_base-aslr.patch
arm-mm-support-arch_mmap_rnd_bits.patch
arm64-mm-support-arch_mmap_rnd_bits.patch
arm64-mm-support-arch_mmap_rnd_bits-v6.patch
x86-mm-support-arch_mmap_rnd_bits.patch
--
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
