Re: [PATCH 2/2] arm64: Clear the stack

On Wed, Jul 18, 2018 at 02:10:13PM -0700, Laura Abbott wrote: > > Implementation of stackleak based heavily on the x86 version > > Signed-off-by: Laura Abbott > --- > Since last time: Minor style cleanups. Re-wrote check_alloca to > correctly handle all stack types. While doing that, I also

Re: [PATCH 2/2] arm64: Clear the stack

On Wed, Jul 18, 2018 at 02:10:13PM -0700, Laura Abbott wrote: > > Implementation of stackleak based heavily on the x86 version > > Signed-off-by: Laura Abbott > --- > Since last time: Minor style cleanups. Re-wrote check_alloca to > correctly handle all stack types. While doing that, I also

Re: [PATCH 2/2] arm64: Clear the stack

Hello Laura, Thanks again for your work. Please see some comments below. On 19.07.2018 00:10, Laura Abbott wrote: > Implementation of stackleak based heavily on the x86 version > > Signed-off-by: Laura Abbott > --- > Since last time: Minor style cleanups. Re-wrote check_alloca to > correctly

Re: [PATCH 2/2] arm64: Clear the stack

Hello Laura, Thanks again for your work. Please see some comments below. On 19.07.2018 00:10, Laura Abbott wrote: > Implementation of stackleak based heavily on the x86 version > > Signed-off-by: Laura Abbott > --- > Since last time: Minor style cleanups. Re-wrote check_alloca to > correctly

Re: [PATCH 2/2] arm64: Clear the stack

On Wed, Jul 18, 2018 at 2:10 PM, Laura Abbott wrote: > > Implementation of stackleak based heavily on the x86 version > > Signed-off-by: Laura Abbott > --- > Since last time: Minor style cleanups. Re-wrote check_alloca to > correctly handle all stack types. While doing that, I also realized >

Re: [PATCH 2/2] arm64: Clear the stack

On Wed, Jul 18, 2018 at 2:10 PM, Laura Abbott wrote: > > Implementation of stackleak based heavily on the x86 version > > Signed-off-by: Laura Abbott > --- > Since last time: Minor style cleanups. Re-wrote check_alloca to > correctly handle all stack types. While doing that, I also realized >

[PATCH 2/2] arm64: Clear the stack

Implementation of stackleak based heavily on the x86 version Signed-off-by: Laura Abbott --- Since last time: Minor style cleanups. Re-wrote check_alloca to correctly handle all stack types. While doing that, I also realized current_top_of_stack was incorrect so I fixed that as well. ---

[PATCH 2/2] arm64: Clear the stack

Implementation of stackleak based heavily on the x86 version Signed-off-by: Laura Abbott --- Since last time: Minor style cleanups. Re-wrote check_alloca to correctly handle all stack types. While doing that, I also realized current_top_of_stack was incorrect so I fixed that as well. ---

Re: [PATCH 2/2] arm64: Clear the stack

On Mon, May 14, 2018 at 04:53:12PM +0300, Alexander Popov wrote: > On 14.05.2018 13:06, Mark Rutland wrote: > > I think it is reasonable to panic() here even with CONFIG_VMAP_STACK > > selected. > > It's too tough for CONFIG_VMAP_STACK on x86 - the system can proceed to live. > Anyway, the

Re: [PATCH 2/2] arm64: Clear the stack

On Mon, May 14, 2018 at 04:53:12PM +0300, Alexander Popov wrote: > On 14.05.2018 13:06, Mark Rutland wrote: > > I think it is reasonable to panic() here even with CONFIG_VMAP_STACK > > selected. > > It's too tough for CONFIG_VMAP_STACK on x86 - the system can proceed to live. > Anyway, the

Re: [PATCH 2/2] arm64: Clear the stack

On 14.05.2018 13:06, Mark Rutland wrote: > On Mon, May 14, 2018 at 12:35:25PM +0300, Alexander Popov wrote: >> On 14.05.2018 08:15, Mark Rutland wrote: >>> On Sun, May 13, 2018 at 11:40:07AM +0300, Alexander Popov wrote: So what would you think if I do the following in check_alloca():

Re: [PATCH 2/2] arm64: Clear the stack

On 14.05.2018 13:06, Mark Rutland wrote: > On Mon, May 14, 2018 at 12:35:25PM +0300, Alexander Popov wrote: >> On 14.05.2018 08:15, Mark Rutland wrote: >>> On Sun, May 13, 2018 at 11:40:07AM +0300, Alexander Popov wrote: So what would you think if I do the following in check_alloca():

Re: [PATCH 2/2] arm64: Clear the stack

On Mon, May 14, 2018 at 12:35:25PM +0300, Alexander Popov wrote: > On 14.05.2018 08:15, Mark Rutland wrote: > > On Sun, May 13, 2018 at 11:40:07AM +0300, Alexander Popov wrote: > >> So what would you think if I do the following in check_alloca(): > >> > >>if (size >= stack_left) { > >> #if

Re: [PATCH 2/2] arm64: Clear the stack

On Mon, May 14, 2018 at 12:35:25PM +0300, Alexander Popov wrote: > On 14.05.2018 08:15, Mark Rutland wrote: > > On Sun, May 13, 2018 at 11:40:07AM +0300, Alexander Popov wrote: > >> So what would you think if I do the following in check_alloca(): > >> > >>if (size >= stack_left) { > >> #if

Re: [PATCH 2/2] arm64: Clear the stack

On 14.05.2018 08:15, Mark Rutland wrote: > On Sun, May 13, 2018 at 11:40:07AM +0300, Alexander Popov wrote: >> It seems that previously I was very "lucky" to accidentally have those >> MIN_STACK_LEFT, >> call trace depth and oops=panic together to experience a hang on stack >> overflow >> during

Re: [PATCH 2/2] arm64: Clear the stack

On 14.05.2018 08:15, Mark Rutland wrote: > On Sun, May 13, 2018 at 11:40:07AM +0300, Alexander Popov wrote: >> It seems that previously I was very "lucky" to accidentally have those >> MIN_STACK_LEFT, >> call trace depth and oops=panic together to experience a hang on stack >> overflow >> during

Re: [PATCH 2/2] arm64: Clear the stack

On Sun, May 13, 2018 at 11:40:07AM +0300, Alexander Popov wrote: > It seems that previously I was very "lucky" to accidentally have those > MIN_STACK_LEFT, > call trace depth and oops=panic together to experience a hang on stack > overflow > during BUG(). > > > When I run my test in a loop

Re: [PATCH 2/2] arm64: Clear the stack

On Sun, May 13, 2018 at 11:40:07AM +0300, Alexander Popov wrote: > It seems that previously I was very "lucky" to accidentally have those > MIN_STACK_LEFT, > call trace depth and oops=panic together to experience a hang on stack > overflow > during BUG(). > > > When I run my test in a loop

[PATCH 2/2] arm64: Clear the stack

Hello Mark, Thanks a lot for your reply! On 11.05.2018 19:13, Mark Rutland wrote: > On Fri, May 11, 2018 at 06:50:09PM +0300, Alexander Popov wrote: >> On 06.05.2018 11:22, Alexander Popov wrote: >>> On 04.05.2018 14:09, Mark Rutland wrote: >>> + stack_left = sp & (THREAD_SIZE - 1);

[PATCH 2/2] arm64: Clear the stack

Hello Mark, Thanks a lot for your reply! On 11.05.2018 19:13, Mark Rutland wrote: > On Fri, May 11, 2018 at 06:50:09PM +0300, Alexander Popov wrote: >> On 06.05.2018 11:22, Alexander Popov wrote: >>> On 04.05.2018 14:09, Mark Rutland wrote: >>> + stack_left = sp & (THREAD_SIZE - 1);

Re: [PATCH 2/2] arm64: Clear the stack

On Fri, May 11, 2018 at 06:50:09PM +0300, Alexander Popov wrote: > Hello everyone, > > On 06.05.2018 11:22, Alexander Popov wrote: > > On 04.05.2018 14:09, Mark Rutland wrote: > > + stack_left = sp & (THREAD_SIZE - 1); > > + BUG_ON(stack_left < 256 || size >= stack_left -

Re: [PATCH 2/2] arm64: Clear the stack

On Fri, May 11, 2018 at 06:50:09PM +0300, Alexander Popov wrote: > Hello everyone, > > On 06.05.2018 11:22, Alexander Popov wrote: > > On 04.05.2018 14:09, Mark Rutland wrote: > > + stack_left = sp & (THREAD_SIZE - 1); > > + BUG_ON(stack_left < 256 || size >= stack_left -

Re: [PATCH 2/2] arm64: Clear the stack

Hello everyone, On 06.05.2018 11:22, Alexander Popov wrote: > On 04.05.2018 14:09, Mark Rutland wrote: > + stack_left = sp & (THREAD_SIZE - 1); > + BUG_ON(stack_left < 256 || size >= stack_left - 256); Is this arbitrary, or is there something special about 256? Even if

Re: [PATCH 2/2] arm64: Clear the stack

Hello everyone, On 06.05.2018 11:22, Alexander Popov wrote: > On 04.05.2018 14:09, Mark Rutland wrote: > + stack_left = sp & (THREAD_SIZE - 1); > + BUG_ON(stack_left < 256 || size >= stack_left - 256); Is this arbitrary, or is there something special about 256? Even if

[PATCH 2/2] arm64: Clear the stack

On 04.05.2018 14:09, Mark Rutland wrote: > On Thu, May 03, 2018 at 08:33:38PM +0300, Alexander Popov wrote: >> Hello Mark and Laura, >> >> Let me join the discussion. Mark, thanks for your feedback! >> >> On 03.05.2018 10:19, Mark Rutland wrote: >>> Hi Laura, >>> >>> On Wed, May 02, 2018 at

[PATCH 2/2] arm64: Clear the stack

On 04.05.2018 14:09, Mark Rutland wrote: > On Thu, May 03, 2018 at 08:33:38PM +0300, Alexander Popov wrote: >> Hello Mark and Laura, >> >> Let me join the discussion. Mark, thanks for your feedback! >> >> On 03.05.2018 10:19, Mark Rutland wrote: >>> Hi Laura, >>> >>> On Wed, May 02, 2018 at

Re: [PATCH 2/2] arm64: Clear the stack

On Thu, May 03, 2018 at 12:00:26PM -0700, Laura Abbott wrote: > On 05/03/2018 12:19 AM, Mark Rutland wrote: > > On Wed, May 02, 2018 at 01:33:26PM -0700, Laura Abbott wrote: > > > +asmlinkage void erase_kstack(void) > > > +{ > > > + > > > + /* > > > + * So let's write the poison value to the

Re: [PATCH 2/2] arm64: Clear the stack

On Thu, May 03, 2018 at 12:00:26PM -0700, Laura Abbott wrote: > On 05/03/2018 12:19 AM, Mark Rutland wrote: > > On Wed, May 02, 2018 at 01:33:26PM -0700, Laura Abbott wrote: > > > +asmlinkage void erase_kstack(void) > > > +{ > > > + > > > + /* > > > + * So let's write the poison value to the

Re: [PATCH 2/2] arm64: Clear the stack

On Thu, May 03, 2018 at 08:33:38PM +0300, Alexander Popov wrote: > Hello Mark and Laura, > > Let me join the discussion. Mark, thanks for your feedback! > > On 03.05.2018 10:19, Mark Rutland wrote: > > Hi Laura, > > > > On Wed, May 02, 2018 at 01:33:26PM -0700, Laura Abbott wrote: > >> > >>

Re: [PATCH 2/2] arm64: Clear the stack

On Thu, May 03, 2018 at 08:33:38PM +0300, Alexander Popov wrote: > Hello Mark and Laura, > > Let me join the discussion. Mark, thanks for your feedback! > > On 03.05.2018 10:19, Mark Rutland wrote: > > Hi Laura, > > > > On Wed, May 02, 2018 at 01:33:26PM -0700, Laura Abbott wrote: > >> > >>

Re: [PATCH 2/2] arm64: Clear the stack

On 03.05.2018 22:09, Laura Abbott wrote: > On 05/03/2018 10:33 AM, Alexander Popov wrote: >> On 03.05.2018 10:19, Mark Rutland wrote: >>> On Wed, May 02, 2018 at 01:33:26PM -0700, Laura Abbott wrote: + /* Reset the lowest_stack value for the next syscall */ +

Re: [PATCH 2/2] arm64: Clear the stack

On 03.05.2018 22:09, Laura Abbott wrote: > On 05/03/2018 10:33 AM, Alexander Popov wrote: >> On 03.05.2018 10:19, Mark Rutland wrote: >>> On Wed, May 02, 2018 at 01:33:26PM -0700, Laura Abbott wrote: + /* Reset the lowest_stack value for the next syscall */ +

Re: [PATCH 2/2] arm64: Clear the stack

On 05/03/2018 10:33 AM, Alexander Popov wrote: Hello Mark and Laura, Let me join the discussion. Mark, thanks for your feedback! On 03.05.2018 10:19, Mark Rutland wrote: Hi Laura, On Wed, May 02, 2018 at 01:33:26PM -0700, Laura Abbott wrote: Implementation of stackleak based heavily on the

Re: [PATCH 2/2] arm64: Clear the stack

On 05/03/2018 10:33 AM, Alexander Popov wrote: Hello Mark and Laura, Let me join the discussion. Mark, thanks for your feedback! On 03.05.2018 10:19, Mark Rutland wrote: Hi Laura, On Wed, May 02, 2018 at 01:33:26PM -0700, Laura Abbott wrote: Implementation of stackleak based heavily on the

Re: [PATCH 2/2] arm64: Clear the stack

On 05/03/2018 12:19 AM, Mark Rutland wrote: Hi Laura, On Wed, May 02, 2018 at 01:33:26PM -0700, Laura Abbott wrote: Implementation of stackleak based heavily on the x86 version Signed-off-by: Laura Abbott --- Now written in C instead of a bunch of assembly. This looks

Re: [PATCH 2/2] arm64: Clear the stack

On 05/03/2018 12:19 AM, Mark Rutland wrote: Hi Laura, On Wed, May 02, 2018 at 01:33:26PM -0700, Laura Abbott wrote: Implementation of stackleak based heavily on the x86 version Signed-off-by: Laura Abbott --- Now written in C instead of a bunch of assembly. This looks neat! I have a few

Re: [PATCH 2/2] arm64: Clear the stack

Hello Mark and Laura, Let me join the discussion. Mark, thanks for your feedback! On 03.05.2018 10:19, Mark Rutland wrote: > Hi Laura, > > On Wed, May 02, 2018 at 01:33:26PM -0700, Laura Abbott wrote: >> >> Implementation of stackleak based heavily on the x86 version >> >> Signed-off-by: Laura

Re: [PATCH 2/2] arm64: Clear the stack

Hello Mark and Laura, Let me join the discussion. Mark, thanks for your feedback! On 03.05.2018 10:19, Mark Rutland wrote: > Hi Laura, > > On Wed, May 02, 2018 at 01:33:26PM -0700, Laura Abbott wrote: >> >> Implementation of stackleak based heavily on the x86 version >> >> Signed-off-by: Laura

Re: [PATCH 2/2] arm64: Clear the stack

On Thu, May 3, 2018 at 9:05 AM, Alexander Popov wrote: > Hello Laura and Kees, > > On 03.05.2018 02:07, Laura Abbott wrote: >> On 05/02/2018 02:31 PM, Kees Cook wrote: >>> On Wed, May 2, 2018 at 1:33 PM, Laura Abbott wrote: Implementation of

Re: [PATCH 2/2] arm64: Clear the stack

On Thu, May 3, 2018 at 9:05 AM, Alexander Popov wrote: > Hello Laura and Kees, > > On 03.05.2018 02:07, Laura Abbott wrote: >> On 05/02/2018 02:31 PM, Kees Cook wrote: >>> On Wed, May 2, 2018 at 1:33 PM, Laura Abbott wrote: Implementation of stackleak based heavily on the x86 version

Re: [PATCH 2/2] arm64: Clear the stack

Hello Laura and Kees, On 03.05.2018 02:07, Laura Abbott wrote: > On 05/02/2018 02:31 PM, Kees Cook wrote: >> On Wed, May 2, 2018 at 1:33 PM, Laura Abbott wrote: >>> >>> Implementation of stackleak based heavily on the x86 version >> >> Awesome! Notes below for both you and

Re: [PATCH 2/2] arm64: Clear the stack

Hello Laura and Kees, On 03.05.2018 02:07, Laura Abbott wrote: > On 05/02/2018 02:31 PM, Kees Cook wrote: >> On Wed, May 2, 2018 at 1:33 PM, Laura Abbott wrote: >>> >>> Implementation of stackleak based heavily on the x86 version >> >> Awesome! Notes below for both you and Alexander, since I

Re: [PATCH 2/2] arm64: Clear the stack

On 3 May 2018 at 09:19, Mark Rutland wrote: > Hi Laura, > > On Wed, May 02, 2018 at 01:33:26PM -0700, Laura Abbott wrote: >> >> Implementation of stackleak based heavily on the x86 version >> >> Signed-off-by: Laura Abbott >> --- >> Now written in C

Re: [PATCH 2/2] arm64: Clear the stack

On 3 May 2018 at 09:19, Mark Rutland wrote: > Hi Laura, > > On Wed, May 02, 2018 at 01:33:26PM -0700, Laura Abbott wrote: >> >> Implementation of stackleak based heavily on the x86 version >> >> Signed-off-by: Laura Abbott >> --- >> Now written in C instead of a bunch of assembly. > > This looks

Re: [PATCH 2/2] arm64: Clear the stack

Hi Laura, On Wed, May 02, 2018 at 01:33:26PM -0700, Laura Abbott wrote: > > Implementation of stackleak based heavily on the x86 version > > Signed-off-by: Laura Abbott > --- > Now written in C instead of a bunch of assembly. This looks neat! I have a few minor comments

Re: [PATCH 2/2] arm64: Clear the stack

Hi Laura, On Wed, May 02, 2018 at 01:33:26PM -0700, Laura Abbott wrote: > > Implementation of stackleak based heavily on the x86 version > > Signed-off-by: Laura Abbott > --- > Now written in C instead of a bunch of assembly. This looks neat! I have a few minor comments below. > diff --git

Re: [PATCH 2/2] arm64: Clear the stack

On Wed, May 2, 2018 at 4:07 PM, Laura Abbott wrote: > On 05/02/2018 02:31 PM, Kees Cook wrote: >> struct stackleak { >> #ifdef CONFIG_GCC_PLUGIN_STACKLEAK >> unsigned long lowest; >> #ifdef CONFIG_STACKLEAK_METRICS >> unsigned long

Re: [PATCH 2/2] arm64: Clear the stack

On Wed, May 2, 2018 at 4:07 PM, Laura Abbott wrote: > On 05/02/2018 02:31 PM, Kees Cook wrote: >> struct stackleak { >> #ifdef CONFIG_GCC_PLUGIN_STACKLEAK >> unsigned long lowest; >> #ifdef CONFIG_STACKLEAK_METRICS >> unsigned long prev_lowest; >> #endif >>

Re: [PATCH 2/2] arm64: Clear the stack

On 05/02/2018 02:31 PM, Kees Cook wrote: On Wed, May 2, 2018 at 1:33 PM, Laura Abbott wrote: Implementation of stackleak based heavily on the x86 version Awesome! Notes below for both you and Alexander, since I think we can create a common code base instead of having

Re: [PATCH 2/2] arm64: Clear the stack

On 05/02/2018 02:31 PM, Kees Cook wrote: On Wed, May 2, 2018 at 1:33 PM, Laura Abbott wrote: Implementation of stackleak based heavily on the x86 version Awesome! Notes below for both you and Alexander, since I think we can create a common code base instead of having near-duplicates in the

Re: [PATCH 2/2] arm64: Clear the stack

On Wed, May 2, 2018 at 1:33 PM, Laura Abbott wrote: > > Implementation of stackleak based heavily on the x86 version Awesome! Notes below for both you and Alexander, since I think we can create a common code base instead of having near-duplicates in the arch/ trees... > >

Re: [PATCH 2/2] arm64: Clear the stack

On Wed, May 2, 2018 at 1:33 PM, Laura Abbott wrote: > > Implementation of stackleak based heavily on the x86 version Awesome! Notes below for both you and Alexander, since I think we can create a common code base instead of having near-duplicates in the arch/ trees... > > Signed-off-by: Laura

[PATCH 2/2] arm64: Clear the stack

Implementation of stackleak based heavily on the x86 version Signed-off-by: Laura Abbott --- Now written in C instead of a bunch of assembly. --- arch/arm64/Kconfig| 1 + arch/arm64/include/asm/processor.h| 6 arch/arm64/kernel/Makefile

[PATCH 2/2] arm64: Clear the stack

Implementation of stackleak based heavily on the x86 version Signed-off-by: Laura Abbott --- Now written in C instead of a bunch of assembly. --- arch/arm64/Kconfig| 1 + arch/arm64/include/asm/processor.h| 6 arch/arm64/kernel/Makefile| 3 ++

Re: [PATCH 2/2] arm64: Clear the stack

On 02/21/2018 03:53 PM, Laura Abbott wrote: I *think* this should happen in finish_ret_to_user a few lines down, since we can call C code if we branch to work_pending, dirtying the stack. I think you're right but this didn't immediately work when I tried it. I'll have to dig into this some

Re: [PATCH 2/2] arm64: Clear the stack

On 02/21/2018 03:53 PM, Laura Abbott wrote: I *think* this should happen in finish_ret_to_user a few lines down, since we can call C code if we branch to work_pending, dirtying the stack. I think you're right but this didn't immediately work when I tried it. I'll have to dig into this some

Re: [PATCH 2/2] arm64: Clear the stack

On 02/21/2018 07:38 AM, Mark Rutland wrote: Hi Laura, On Tue, Feb 20, 2018 at 05:13:03PM -0800, Laura Abbott wrote: Implementation of stackleak based heavily on the x86 version Neat! diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S index ec2ee720e33e..b909b436293a 100644

Re: [PATCH 2/2] arm64: Clear the stack

On 02/21/2018 07:38 AM, Mark Rutland wrote: Hi Laura, On Tue, Feb 20, 2018 at 05:13:03PM -0800, Laura Abbott wrote: Implementation of stackleak based heavily on the x86 version Neat! diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S index ec2ee720e33e..b909b436293a 100644

Re: [PATCH 2/2] arm64: Clear the stack

Hi Laura, On Tue, Feb 20, 2018 at 05:13:03PM -0800, Laura Abbott wrote: > Implementation of stackleak based heavily on the x86 version Neat! > diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S > index ec2ee720e33e..b909b436293a 100644 > --- a/arch/arm64/kernel/entry.S > +++

Re: [PATCH 2/2] arm64: Clear the stack

Hi Laura, On Tue, Feb 20, 2018 at 05:13:03PM -0800, Laura Abbott wrote: > Implementation of stackleak based heavily on the x86 version Neat! > diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S > index ec2ee720e33e..b909b436293a 100644 > --- a/arch/arm64/kernel/entry.S > +++

[PATCH 2/2] arm64: Clear the stack

Implementation of stackleak based heavily on the x86 version Signed-off-by: Laura Abbott --- arch/arm64/Kconfig| 1 + arch/arm64/include/asm/processor.h| 6 ++ arch/arm64/kernel/asm-offsets.c | 3 + arch/arm64/kernel/entry.S |

[PATCH 2/2] arm64: Clear the stack

Implementation of stackleak based heavily on the x86 version Signed-off-by: Laura Abbott --- arch/arm64/Kconfig| 1 + arch/arm64/include/asm/processor.h| 6 ++ arch/arm64/kernel/asm-offsets.c | 3 + arch/arm64/kernel/entry.S | 108