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| author | dcashman <dcashman@google.com> | 2015-12-29 14:24:39 -0800 |
|---|---|---|
| committer | Ziyan <jaraidaniel@gmail.com> | 2016-10-29 01:33:53 +0200 |
| commit | 56ec74e215e7eed1634e82cdc2bec5e28422808a (patch) | |
| tree | 7e88d04f15a37216bc7fc7ecc628d31acf29e6fe /kernel | |
| parent | b37549b9638e3d702eb6cd28e83767cccb4d164a (diff) | |
| download | kernel_samsung_tuna-56ec74e215e7eed1634e82cdc2bec5e28422808a.zip kernel_samsung_tuna-56ec74e215e7eed1634e82cdc2bec5e28422808a.tar.gz kernel_samsung_tuna-56ec74e215e7eed1634e82cdc2bec5e28422808a.tar.bz2 | |
FROMLIST: mm: mmap: Add new /proc tunable for mmap_base ASLR.
(cherry picked from commit https://lkml.org/lkml/2015/12/21/337)
ASLR only uses as few as 8 bits to generate the random offset for the
mmap base address on 32 bit architectures. This value was chosen to
prevent a poorly chosen value from dividing the address space in such
a way as to prevent large allocations. This may not be an issue on all
platforms. Allow the specification of a minimum number of bits so that
platforms desiring greater ASLR protection may determine where to place
the trade-off.
Bug: 24047224
Signed-off-by: Daniel Cashman <dcashman@android.com>
Signed-off-by: Daniel Cashman <dcashman@google.com>
Change-Id: Ic74424e07710cd9ccb4a02871a829d14ef0cc4bc
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/sysctl.c | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/kernel/sysctl.c b/kernel/sysctl.c index f5284d2..ebf8811 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -1369,6 +1369,28 @@ static struct ctl_table vm_table[] = { .extra2 = &one, }, #endif +#ifdef CONFIG_HAVE_ARCH_MMAP_RND_BITS + { + .procname = "mmap_rnd_bits", + .data = &mmap_rnd_bits, + .maxlen = sizeof(mmap_rnd_bits), + .mode = 0600, + .proc_handler = proc_dointvec_minmax, + .extra1 = (void *)&mmap_rnd_bits_min, + .extra2 = (void *)&mmap_rnd_bits_max, + }, +#endif +#ifdef CONFIG_HAVE_ARCH_MMAP_RND_COMPAT_BITS + { + .procname = "mmap_rnd_compat_bits", + .data = &mmap_rnd_compat_bits, + .maxlen = sizeof(mmap_rnd_compat_bits), + .mode = 0600, + .proc_handler = proc_dointvec_minmax, + .extra1 = (void *)&mmap_rnd_compat_bits_min, + .extra2 = (void *)&mmap_rnd_compat_bits_max, + }, +#endif { } }; |