* [PATCH] tile: support ASLR fully
@ 2013-08-09 19:45 Tony Lu
2013-08-10 16:55 ` Jiri Kosina
0 siblings, 1 reply; 5+ messages in thread
From: Tony Lu @ 2013-08-09 19:45 UTC (permalink / raw)
To: linux-kernel, Jiri Kosina
With this change, tile Linux now supports address-space layout
randomization for shared objects, stack, heap and vdso.
Signed-off-by: Tony Lu <zlu@tilera.com>
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
---
arch/tile/include/asm/elf.h | 4 ++++
arch/tile/mm/mmap.c | 20 ++++++++++++++++++--
2 files changed, 22 insertions(+), 2 deletions(-)
diff --git a/arch/tile/include/asm/elf.h b/arch/tile/include/asm/elf.h
index 31d854f..e1da88e 100644
--- a/arch/tile/include/asm/elf.h
+++ b/arch/tile/include/asm/elf.h
@@ -137,6 +137,10 @@ do { \
NEW_AUX_ENT(AT_SYSINFO_EHDR, VDSO_BASE); \
} while (0)
+struct mm_struct;
+extern unsigned long arch_randomize_brk(struct mm_struct *mm);
+#define arch_randomize_brk arch_randomize_brk
+
#ifdef CONFIG_COMPAT
#define COMPAT_ELF_PLATFORM "tilegx-m32"
diff --git a/arch/tile/mm/mmap.c b/arch/tile/mm/mmap.c
index d67d91e..b3686ce 100644
--- a/arch/tile/mm/mmap.c
+++ b/arch/tile/mm/mmap.c
@@ -58,16 +58,32 @@ void arch_pick_mmap_layout(struct mm_struct *mm)
#else
int is_32bit = 0;
#endif
+ unsigned long random_factor = 0UL;
+
+ if (current->flags & PF_RANDOMIZE) {
+ random_factor = get_random_int();
+ random_factor = random_factor << PAGE_SHIFT;
+ if (is_32bit)
+ random_factor &= 0xfffffful;
+ else
+ random_factor &= 0xffffffful;
+ }
/*
* Use standard layout if the expected stack growth is unlimited
* or we are running native 64 bits.
*/
- if (!is_32bit || rlimit(RLIMIT_STACK) == RLIM_INFINITY) {
- mm->mmap_base = TASK_UNMAPPED_BASE;
+ if (rlimit(RLIMIT_STACK) == RLIM_INFINITY) {
+ mm->mmap_base = TASK_UNMAPPED_BASE + random_factor;
mm->get_unmapped_area = arch_get_unmapped_area;
} else {
mm->mmap_base = mmap_base(mm);
mm->get_unmapped_area = arch_get_unmapped_area_topdown;
}
}
+
+unsigned long arch_randomize_brk(struct mm_struct *mm)
+{
+ unsigned long range_end = mm->brk + 0x02000000;
+ return randomize_range(mm->brk, range_end, 0) ? : mm->brk;
+}
--
1.8.3.1
^ permalink raw reply related [flat|nested] 5+ messages in thread* Re: [PATCH] tile: support ASLR fully
2013-08-09 19:45 [PATCH] tile: support ASLR fully Tony Lu
@ 2013-08-10 16:55 ` Jiri Kosina
2013-08-10 17:23 ` richard -rw- weinberger
2013-08-13 14:45 ` [PATCH v2] " Tony Lu
0 siblings, 2 replies; 5+ messages in thread
From: Jiri Kosina @ 2013-08-10 16:55 UTC (permalink / raw)
To: Tony Lu; +Cc: linux-kernel
On Fri, 9 Aug 2013, Tony Lu wrote:
> With this change, tile Linux now supports address-space layout
> randomization for shared objects, stack, heap and vdso.
>
> Signed-off-by: Tony Lu <zlu@tilera.com>
> Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
> ---
> arch/tile/include/asm/elf.h | 4 ++++
> arch/tile/mm/mmap.c | 20 ++++++++++++++++++--
> 2 files changed, 22 insertions(+), 2 deletions(-)
>
> diff --git a/arch/tile/include/asm/elf.h b/arch/tile/include/asm/elf.h
> index 31d854f..e1da88e 100644
> --- a/arch/tile/include/asm/elf.h
> +++ b/arch/tile/include/asm/elf.h
> @@ -137,6 +137,10 @@ do { \
> NEW_AUX_ENT(AT_SYSINFO_EHDR, VDSO_BASE); \
> } while (0)
>
> +struct mm_struct;
> +extern unsigned long arch_randomize_brk(struct mm_struct *mm);
> +#define arch_randomize_brk arch_randomize_brk
> +
> #ifdef CONFIG_COMPAT
>
> #define COMPAT_ELF_PLATFORM "tilegx-m32"
> diff --git a/arch/tile/mm/mmap.c b/arch/tile/mm/mmap.c
> index d67d91e..b3686ce 100644
> --- a/arch/tile/mm/mmap.c
> +++ b/arch/tile/mm/mmap.c
> @@ -58,16 +58,32 @@ void arch_pick_mmap_layout(struct mm_struct *mm)
> #else
> int is_32bit = 0;
> #endif
> + unsigned long random_factor = 0UL;
> +
> + if (current->flags & PF_RANDOMIZE) {
> + random_factor = get_random_int();
> + random_factor = random_factor << PAGE_SHIFT;
> + if (is_32bit)
> + random_factor &= 0xfffffful;
> + else
> + random_factor &= 0xffffffful;
> + }
Hi Tony,
to me, the used math seems not to be immediatley understandable on a first
sight. Instead of using full range of get_random_int() and then clamping
it by anding with 0xffffffUL or fffffffUL, how about just using
appropriate division reminder to the result of get_random_int()? (for
inspiration and for understanding of what I mean, please see what
mmap_rnd() is doing on x86).
>
> /*
> * Use standard layout if the expected stack growth is unlimited
> * or we are running native 64 bits.
> */
> - if (!is_32bit || rlimit(RLIMIT_STACK) == RLIM_INFINITY) {
> - mm->mmap_base = TASK_UNMAPPED_BASE;
> + if (rlimit(RLIMIT_STACK) == RLIM_INFINITY) {
> + mm->mmap_base = TASK_UNMAPPED_BASE + random_factor;
> mm->get_unmapped_area = arch_get_unmapped_area;
> } else {
> mm->mmap_base = mmap_base(mm);
> mm->get_unmapped_area = arch_get_unmapped_area_topdown;
> }
> }
> +
> +unsigned long arch_randomize_brk(struct mm_struct *mm)
> +{
> + unsigned long range_end = mm->brk + 0x02000000;
> + return randomize_range(mm->brk, range_end, 0) ? : mm->brk;
> +}
Otherwise the patch looks good to me, so once you either add some
explanatory comment to the get_random_int() math, or convert it to use
division reminder, I'll be happy to Ack it.
Thanks,
--
Jiri Kosina
SUSE Labs
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH] tile: support ASLR fully
2013-08-10 16:55 ` Jiri Kosina
@ 2013-08-10 17:23 ` richard -rw- weinberger
2013-08-13 14:45 ` [PATCH v2] " Tony Lu
1 sibling, 0 replies; 5+ messages in thread
From: richard -rw- weinberger @ 2013-08-10 17:23 UTC (permalink / raw)
To: Jiri Kosina; +Cc: Tony Lu, LKML
On Sat, Aug 10, 2013 at 6:55 PM, Jiri Kosina <jkosina@suse.cz> wrote:
> On Fri, 9 Aug 2013, Tony Lu wrote:
>
>> With this change, tile Linux now supports address-space layout
>> randomization for shared objects, stack, heap and vdso.
>>
>> Signed-off-by: Tony Lu <zlu@tilera.com>
>> Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
>> ---
>> arch/tile/include/asm/elf.h | 4 ++++
>> arch/tile/mm/mmap.c | 20 ++++++++++++++++++--
>> 2 files changed, 22 insertions(+), 2 deletions(-)
>>
>> diff --git a/arch/tile/include/asm/elf.h b/arch/tile/include/asm/elf.h
>> index 31d854f..e1da88e 100644
>> --- a/arch/tile/include/asm/elf.h
>> +++ b/arch/tile/include/asm/elf.h
>> @@ -137,6 +137,10 @@ do { \
>> NEW_AUX_ENT(AT_SYSINFO_EHDR, VDSO_BASE); \
>> } while (0)
>>
>> +struct mm_struct;
>> +extern unsigned long arch_randomize_brk(struct mm_struct *mm);
>> +#define arch_randomize_brk arch_randomize_brk
>> +
>> #ifdef CONFIG_COMPAT
>>
>> #define COMPAT_ELF_PLATFORM "tilegx-m32"
>> diff --git a/arch/tile/mm/mmap.c b/arch/tile/mm/mmap.c
>> index d67d91e..b3686ce 100644
>> --- a/arch/tile/mm/mmap.c
>> +++ b/arch/tile/mm/mmap.c
>> @@ -58,16 +58,32 @@ void arch_pick_mmap_layout(struct mm_struct *mm)
>> #else
>> int is_32bit = 0;
>> #endif
>> + unsigned long random_factor = 0UL;
>> +
>> + if (current->flags & PF_RANDOMIZE) {
>> + random_factor = get_random_int();
>> + random_factor = random_factor << PAGE_SHIFT;
>> + if (is_32bit)
>> + random_factor &= 0xfffffful;
>> + else
>> + random_factor &= 0xffffffful;
>> + }
>
> Hi Tony,
>
> to me, the used math seems not to be immediatley understandable on a first
> sight. Instead of using full range of get_random_int() and then clamping
> it by anding with 0xffffffUL or fffffffUL, how about just using
> appropriate division reminder to the result of get_random_int()? (for
> inspiration and for understanding of what I mean, please see what
> mmap_rnd() is doing on x86).
Looks like copy&paste from some other arch's implementation.
IMHO it's time to consolidate all the different but still mostly identical
arch_pick_mmap_layout() implementations.
>>
>> /*
>> * Use standard layout if the expected stack growth is unlimited
>> * or we are running native 64 bits.
>> */
>> - if (!is_32bit || rlimit(RLIMIT_STACK) == RLIM_INFINITY) {
>> - mm->mmap_base = TASK_UNMAPPED_BASE;
>> + if (rlimit(RLIMIT_STACK) == RLIM_INFINITY) {
>> + mm->mmap_base = TASK_UNMAPPED_BASE + random_factor;
>> mm->get_unmapped_area = arch_get_unmapped_area;
>> } else {
>> mm->mmap_base = mmap_base(mm);
>> mm->get_unmapped_area = arch_get_unmapped_area_topdown;
>> }
>> }
>> +
>> +unsigned long arch_randomize_brk(struct mm_struct *mm)
>> +{
>> + unsigned long range_end = mm->brk + 0x02000000;
>> + return randomize_range(mm->brk, range_end, 0) ? : mm->brk;
>> +}
>
> Otherwise the patch looks good to me, so once you either add some
> explanatory comment to the get_random_int() math, or convert it to use
> division reminder, I'll be happy to Ack it.
>
> Thanks,
>
> --
> Jiri Kosina
> SUSE Labs
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at http://www.tux.org/lkml/
--
Thanks,
//richard
^ permalink raw reply [flat|nested] 5+ messages in thread* [PATCH v2] tile: support ASLR fully
2013-08-10 16:55 ` Jiri Kosina
2013-08-10 17:23 ` richard -rw- weinberger
@ 2013-08-13 14:45 ` Tony Lu
2013-08-19 12:01 ` Jiri Kosina
1 sibling, 1 reply; 5+ messages in thread
From: Tony Lu @ 2013-08-13 14:45 UTC (permalink / raw)
To: linux-kernel, cmetcalf, Jiri Kosina
With this change, tile Linux now supports address-space layout
randomization for shared objects, stack, heap and vdso.
Signed-off-by: Tony Lu <zlu@tilera.com>
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
---
v2: implement Jiri Kosina's suggestion to copy the math in
mmap_rnd() for x86.
arch/tile/include/asm/elf.h | 4 ++++
arch/tile/mm/mmap.c | 24 ++++++++++++++++++++++--
2 files changed, 26 insertions(+), 2 deletions(-)
diff --git a/arch/tile/include/asm/elf.h b/arch/tile/include/asm/elf.h
index 31d854f..e1da88e 100644
--- a/arch/tile/include/asm/elf.h
+++ b/arch/tile/include/asm/elf.h
@@ -137,6 +137,10 @@ do { \
NEW_AUX_ENT(AT_SYSINFO_EHDR, VDSO_BASE); \
} while (0)
+struct mm_struct;
+extern unsigned long arch_randomize_brk(struct mm_struct *mm);
+#define arch_randomize_brk arch_randomize_brk
+
#ifdef CONFIG_COMPAT
#define COMPAT_ELF_PLATFORM "tilegx-m32"
diff --git a/arch/tile/mm/mmap.c b/arch/tile/mm/mmap.c
index d67d91e..4b99344 100644
--- a/arch/tile/mm/mmap.c
+++ b/arch/tile/mm/mmap.c
@@ -58,16 +58,36 @@ void arch_pick_mmap_layout(struct mm_struct *mm)
#else
int is_32bit = 0;
#endif
+ unsigned long random_factor = 0UL;
+
+ /*
+ * 8 bits of randomness in 32bit mmaps, 24 address space bits
+ * 12 bits of randomness in 64bit mmaps, 28 address space bits
+ */
+ if (current->flags & PF_RANDOMIZE) {
+ if (is_32bit)
+ random_factor = get_random_int() % (1<<8);
+ else
+ random_factor = get_random_int() % (1<<12);
+
+ random_factor <<= PAGE_SHIFT;
+ }
/*
* Use standard layout if the expected stack growth is unlimited
* or we are running native 64 bits.
*/
- if (!is_32bit || rlimit(RLIMIT_STACK) == RLIM_INFINITY) {
- mm->mmap_base = TASK_UNMAPPED_BASE;
+ if (rlimit(RLIMIT_STACK) == RLIM_INFINITY) {
+ mm->mmap_base = TASK_UNMAPPED_BASE + random_factor;
mm->get_unmapped_area = arch_get_unmapped_area;
} else {
mm->mmap_base = mmap_base(mm);
mm->get_unmapped_area = arch_get_unmapped_area_topdown;
}
}
+
+unsigned long arch_randomize_brk(struct mm_struct *mm)
+{
+ unsigned long range_end = mm->brk + 0x02000000;
+ return randomize_range(mm->brk, range_end, 0) ? : mm->brk;
+}
--
1.8.3.1
^ permalink raw reply related [flat|nested] 5+ messages in thread* Re: [PATCH v2] tile: support ASLR fully
2013-08-13 14:45 ` [PATCH v2] " Tony Lu
@ 2013-08-19 12:01 ` Jiri Kosina
0 siblings, 0 replies; 5+ messages in thread
From: Jiri Kosina @ 2013-08-19 12:01 UTC (permalink / raw)
To: Tony Lu; +Cc: linux-kernel, cmetcalf
On Tue, 13 Aug 2013, Tony Lu wrote:
> With this change, tile Linux now supports address-space layout
> randomization for shared objects, stack, heap and vdso.
>
> Signed-off-by: Tony Lu <zlu@tilera.com>
> Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
> ---
> v2: implement Jiri Kosina's suggestion to copy the math in
> mmap_rnd() for x86.
Feel free to add:
Acked-by: Jiri Kosina <jkosina@suse.cz>
Thanks.
> arch/tile/include/asm/elf.h | 4 ++++
> arch/tile/mm/mmap.c | 24 ++++++++++++++++++++++--
> 2 files changed, 26 insertions(+), 2 deletions(-)
>
> diff --git a/arch/tile/include/asm/elf.h b/arch/tile/include/asm/elf.h
> index 31d854f..e1da88e 100644
> --- a/arch/tile/include/asm/elf.h
> +++ b/arch/tile/include/asm/elf.h
> @@ -137,6 +137,10 @@ do { \
> NEW_AUX_ENT(AT_SYSINFO_EHDR, VDSO_BASE); \
> } while (0)
>
> +struct mm_struct;
> +extern unsigned long arch_randomize_brk(struct mm_struct *mm);
> +#define arch_randomize_brk arch_randomize_brk
> +
> #ifdef CONFIG_COMPAT
>
> #define COMPAT_ELF_PLATFORM "tilegx-m32"
> diff --git a/arch/tile/mm/mmap.c b/arch/tile/mm/mmap.c
> index d67d91e..4b99344 100644
> --- a/arch/tile/mm/mmap.c
> +++ b/arch/tile/mm/mmap.c
> @@ -58,16 +58,36 @@ void arch_pick_mmap_layout(struct mm_struct *mm)
> #else
> int is_32bit = 0;
> #endif
> + unsigned long random_factor = 0UL;
> +
> + /*
> + * 8 bits of randomness in 32bit mmaps, 24 address space bits
> + * 12 bits of randomness in 64bit mmaps, 28 address space bits
> + */
> + if (current->flags & PF_RANDOMIZE) {
> + if (is_32bit)
> + random_factor = get_random_int() % (1<<8);
> + else
> + random_factor = get_random_int() % (1<<12);
> +
> + random_factor <<= PAGE_SHIFT;
> + }
>
> /*
> * Use standard layout if the expected stack growth is unlimited
> * or we are running native 64 bits.
> */
> - if (!is_32bit || rlimit(RLIMIT_STACK) == RLIM_INFINITY) {
> - mm->mmap_base = TASK_UNMAPPED_BASE;
> + if (rlimit(RLIMIT_STACK) == RLIM_INFINITY) {
> + mm->mmap_base = TASK_UNMAPPED_BASE + random_factor;
> mm->get_unmapped_area = arch_get_unmapped_area;
> } else {
> mm->mmap_base = mmap_base(mm);
> mm->get_unmapped_area = arch_get_unmapped_area_topdown;
> }
> }
> +
> +unsigned long arch_randomize_brk(struct mm_struct *mm)
> +{
> + unsigned long range_end = mm->brk + 0x02000000;
> + return randomize_range(mm->brk, range_end, 0) ? : mm->brk;
> +}
> --
> 1.8.3.1
>
--
Jiri Kosina
SUSE Labs
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2013-08-19 12:01 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
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2013-08-09 19:45 [PATCH] tile: support ASLR fully Tony Lu
2013-08-10 16:55 ` Jiri Kosina
2013-08-10 17:23 ` richard -rw- weinberger
2013-08-13 14:45 ` [PATCH v2] " Tony Lu
2013-08-19 12:01 ` Jiri Kosina
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