On x86-64, the parametrized selftest code for rseq crashes with a
segmentation fault when compiled with -fpie. This happens when the
param_test binary is loaded at an address beyond 32-bit on x86-64.
The issue is caused by use of a 32-bit register to hold the address
of the loop counter variable.
Fix this by using a 64-bit register to calculate the address of the
loop counter variables as an offset from rip.
Signed-off-by: Mathieu Desnoyers <[email protected]>
Cc: <[email protected]> # v4.18
Cc: Thomas Gleixner <[email protected]>
Cc: Joel Fernandes <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Dave Watson <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: Shuah Khan <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: [email protected]
Cc: "H . Peter Anvin" <[email protected]>
Cc: Chris Lameter <[email protected]>
Cc: Russell King <[email protected]>
Cc: Michael Kerrisk <[email protected]>
Cc: "Paul E . McKenney" <[email protected]>
Cc: Paul Turner <[email protected]>
Cc: Boqun Feng <[email protected]>
Cc: Josh Triplett <[email protected]>
Cc: Steven Rostedt <[email protected]>
Cc: Ben Maurer <[email protected]>
Cc: Andy Lutomirski <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Linus Torvalds <[email protected]>
---
tools/testing/selftests/rseq/param_test.c | 19 ++++++++++---------
1 file changed, 10 insertions(+), 9 deletions(-)
diff --git a/tools/testing/selftests/rseq/param_test.c b/tools/testing/selftests/rseq/param_test.c
index 615252331813..4bc071525bf7 100644
--- a/tools/testing/selftests/rseq/param_test.c
+++ b/tools/testing/selftests/rseq/param_test.c
@@ -56,15 +56,13 @@ unsigned int yield_mod_cnt, nr_abort;
printf(fmt, ## __VA_ARGS__); \
} while (0)
-#if defined(__x86_64__) || defined(__i386__)
+#ifdef __i386__
#define INJECT_ASM_REG "eax"
#define RSEQ_INJECT_CLOBBER \
, INJECT_ASM_REG
-#ifdef __i386__
-
#define RSEQ_INJECT_ASM(n) \
"mov asm_loop_cnt_" #n ", %%" INJECT_ASM_REG "\n\t" \
"test %%" INJECT_ASM_REG ",%%" INJECT_ASM_REG "\n\t" \
@@ -76,9 +74,16 @@ unsigned int yield_mod_cnt, nr_abort;
#elif defined(__x86_64__)
+#define INJECT_ASM_REG_P "rax"
+#define INJECT_ASM_REG "eax"
+
+#define RSEQ_INJECT_CLOBBER \
+ , INJECT_ASM_REG_P \
+ , INJECT_ASM_REG
+
#define RSEQ_INJECT_ASM(n) \
- "lea asm_loop_cnt_" #n "(%%rip), %%" INJECT_ASM_REG "\n\t" \
- "mov (%%" INJECT_ASM_REG "), %%" INJECT_ASM_REG "\n\t" \
+ "lea asm_loop_cnt_" #n "(%%rip), %%" INJECT_ASM_REG_P "\n\t" \
+ "mov (%%" INJECT_ASM_REG_P "), %%" INJECT_ASM_REG "\n\t" \
"test %%" INJECT_ASM_REG ",%%" INJECT_ASM_REG "\n\t" \
"jz 333f\n\t" \
"222:\n\t" \
@@ -86,10 +91,6 @@ unsigned int yield_mod_cnt, nr_abort;
"jnz 222b\n\t" \
"333:\n\t"
-#else
-#error "Unsupported architecture"
-#endif
-
#elif defined(__ARMEL__)
#define RSEQ_INJECT_INPUT \
--
2.11.0
----- On Sep 18, 2018, at 9:53 AM, Mathieu Desnoyers [email protected] wrote:
> On x86-64, the parametrized selftest code for rseq crashes with a
> segmentation fault when compiled with -fpie. This happens when the
> param_test binary is loaded at an address beyond 32-bit on x86-64.
>
> The issue is caused by use of a 32-bit register to hold the address
> of the loop counter variable.
>
> Fix this by using a 64-bit register to calculate the address of the
> loop counter variables as an offset from rip.
Should this fix go through tip or the selftests tree ?
Thanks,
Mathieu
>
> Signed-off-by: Mathieu Desnoyers <[email protected]>
> Cc: <[email protected]> # v4.18
> Cc: Thomas Gleixner <[email protected]>
> Cc: Joel Fernandes <[email protected]>
> Cc: Peter Zijlstra <[email protected]>
> Cc: Catalin Marinas <[email protected]>
> Cc: Dave Watson <[email protected]>
> Cc: Will Deacon <[email protected]>
> Cc: Shuah Khan <[email protected]>
> Cc: Andi Kleen <[email protected]>
> Cc: [email protected]
> Cc: "H . Peter Anvin" <[email protected]>
> Cc: Chris Lameter <[email protected]>
> Cc: Russell King <[email protected]>
> Cc: Michael Kerrisk <[email protected]>
> Cc: "Paul E . McKenney" <[email protected]>
> Cc: Paul Turner <[email protected]>
> Cc: Boqun Feng <[email protected]>
> Cc: Josh Triplett <[email protected]>
> Cc: Steven Rostedt <[email protected]>
> Cc: Ben Maurer <[email protected]>
> Cc: Andy Lutomirski <[email protected]>
> Cc: Andrew Morton <[email protected]>
> Cc: Linus Torvalds <[email protected]>
> ---
> tools/testing/selftests/rseq/param_test.c | 19 ++++++++++---------
> 1 file changed, 10 insertions(+), 9 deletions(-)
>
> diff --git a/tools/testing/selftests/rseq/param_test.c
> b/tools/testing/selftests/rseq/param_test.c
> index 615252331813..4bc071525bf7 100644
> --- a/tools/testing/selftests/rseq/param_test.c
> +++ b/tools/testing/selftests/rseq/param_test.c
> @@ -56,15 +56,13 @@ unsigned int yield_mod_cnt, nr_abort;
> printf(fmt, ## __VA_ARGS__); \
> } while (0)
>
> -#if defined(__x86_64__) || defined(__i386__)
> +#ifdef __i386__
>
> #define INJECT_ASM_REG "eax"
>
> #define RSEQ_INJECT_CLOBBER \
> , INJECT_ASM_REG
>
> -#ifdef __i386__
> -
> #define RSEQ_INJECT_ASM(n) \
> "mov asm_loop_cnt_" #n ", %%" INJECT_ASM_REG "\n\t" \
> "test %%" INJECT_ASM_REG ",%%" INJECT_ASM_REG "\n\t" \
> @@ -76,9 +74,16 @@ unsigned int yield_mod_cnt, nr_abort;
>
> #elif defined(__x86_64__)
>
> +#define INJECT_ASM_REG_P "rax"
> +#define INJECT_ASM_REG "eax"
> +
> +#define RSEQ_INJECT_CLOBBER \
> + , INJECT_ASM_REG_P \
> + , INJECT_ASM_REG
> +
> #define RSEQ_INJECT_ASM(n) \
> - "lea asm_loop_cnt_" #n "(%%rip), %%" INJECT_ASM_REG "\n\t" \
> - "mov (%%" INJECT_ASM_REG "), %%" INJECT_ASM_REG "\n\t" \
> + "lea asm_loop_cnt_" #n "(%%rip), %%" INJECT_ASM_REG_P "\n\t" \
> + "mov (%%" INJECT_ASM_REG_P "), %%" INJECT_ASM_REG "\n\t" \
> "test %%" INJECT_ASM_REG ",%%" INJECT_ASM_REG "\n\t" \
> "jz 333f\n\t" \
> "222:\n\t" \
> @@ -86,10 +91,6 @@ unsigned int yield_mod_cnt, nr_abort;
> "jnz 222b\n\t" \
> "333:\n\t"
>
> -#else
> -#error "Unsupported architecture"
> -#endif
> -
> #elif defined(__ARMEL__)
>
> #define RSEQ_INJECT_INPUT \
> --
> 2.11.0
--
Mathieu Desnoyers
EfficiOS Inc.
http://www.efficios.com
On Tue, 25 Sep 2018 13:39:36 -0400 (EDT)
Mathieu Desnoyers <[email protected]> wrote:
> ----- On Sep 18, 2018, at 9:53 AM, Mathieu Desnoyers [email protected] wrote:
>
> > On x86-64, the parametrized selftest code for rseq crashes with a
> > segmentation fault when compiled with -fpie. This happens when the
> > param_test binary is loaded at an address beyond 32-bit on x86-64.
> >
> > The issue is caused by use of a 32-bit register to hold the address
> > of the loop counter variable.
> >
> > Fix this by using a 64-bit register to calculate the address of the
> > loop counter variables as an offset from rip.
>
> Should this fix go through tip or the selftests tree ?
>
I usually have changes like this pulled through Shuah's tree with an
ack from the maintainer of the code that it tests.
-- Steve
On 09/27/2018 07:22 AM, Steven Rostedt wrote:
> On Tue, 25 Sep 2018 13:39:36 -0400 (EDT)
> Mathieu Desnoyers <[email protected]> wrote:
>
>> ----- On Sep 18, 2018, at 9:53 AM, Mathieu Desnoyers [email protected] wrote:
>>
>>> On x86-64, the parametrized selftest code for rseq crashes with a
>>> segmentation fault when compiled with -fpie. This happens when the
>>> param_test binary is loaded at an address beyond 32-bit on x86-64.
>>>
>>> The issue is caused by use of a 32-bit register to hold the address
>>> of the loop counter variable.
>>>
>>> Fix this by using a 64-bit register to calculate the address of the
>>> loop counter variables as an offset from rip.
>>
>> Should this fix go through tip or the selftests tree ?
>>
>
> I usually have changes like this pulled through Shuah's tree with an
> ack from the maintainer of the code that it tests.
>
> -- Steve
>
Right that is what I prefer. I usually wait for an Ack. I can pull this
in.
thanks,
-- Shuah
--
Shuah Khan
Sr. Linux Kernel Developer
Open Source Innovation Group
Samsung Research America(Silicon Valley)
[email protected]
----- On Sep 27, 2018, at 9:58 AM, Shuah Khan [email protected] wrote:
> On 09/27/2018 07:22 AM, Steven Rostedt wrote:
>> On Tue, 25 Sep 2018 13:39:36 -0400 (EDT)
>> Mathieu Desnoyers <[email protected]> wrote:
>>
>>> ----- On Sep 18, 2018, at 9:53 AM, Mathieu Desnoyers
>>> [email protected] wrote:
>>>
>>>> On x86-64, the parametrized selftest code for rseq crashes with a
>>>> segmentation fault when compiled with -fpie. This happens when the
>>>> param_test binary is loaded at an address beyond 32-bit on x86-64.
>>>>
>>>> The issue is caused by use of a 32-bit register to hold the address
>>>> of the loop counter variable.
>>>>
>>>> Fix this by using a 64-bit register to calculate the address of the
>>>> loop counter variables as an offset from rip.
>>>
>>> Should this fix go through tip or the selftests tree ?
>>>
>>
>> I usually have changes like this pulled through Shuah's tree with an
>> ack from the maintainer of the code that it tests.
>>
>> -- Steve
>>
>
> Right that is what I prefer. I usually wait for an Ack. I can pull this
> in.
I am maintainer of the code that it tests as well, so being both author
of the selftest patch and giving an ack to it seems a bit silly. :) Other
rseq co-maintainers could weight in though: Peter, Paul, and Boqun.
Thanks,
Mathieu
>
> thanks,
> -- Shuah
>
> --
> Shuah Khan
> Sr. Linux Kernel Developer
> Open Source Innovation Group
> Samsung Research America(Silicon Valley)
> [email protected]
--
Mathieu Desnoyers
EfficiOS Inc.
http://www.efficios.com
On 09/27/2018 12:02 PM, Mathieu Desnoyers wrote:
> ----- On Sep 27, 2018, at 9:58 AM, Shuah Khan [email protected] wrote:
>
>> On 09/27/2018 07:22 AM, Steven Rostedt wrote:
>>> On Tue, 25 Sep 2018 13:39:36 -0400 (EDT)
>>> Mathieu Desnoyers <[email protected]> wrote:
>>>
>>>> ----- On Sep 18, 2018, at 9:53 AM, Mathieu Desnoyers
>>>> [email protected] wrote:
>>>>
>>>>> On x86-64, the parametrized selftest code for rseq crashes with a
>>>>> segmentation fault when compiled with -fpie. This happens when the
>>>>> param_test binary is loaded at an address beyond 32-bit on x86-64.
>>>>>
>>>>> The issue is caused by use of a 32-bit register to hold the address
>>>>> of the loop counter variable.
>>>>>
>>>>> Fix this by using a 64-bit register to calculate the address of the
>>>>> loop counter variables as an offset from rip.
>>>>
>>>> Should this fix go through tip or the selftests tree ?
>>>>
>>>
>>> I usually have changes like this pulled through Shuah's tree with an
>>> ack from the maintainer of the code that it tests.
>>>
>>> -- Steve
>>>
>>
>> Right that is what I prefer. I usually wait for an Ack. I can pull this
>> in.
>
> I am maintainer of the code that it tests as well, so being both author
> of the selftest patch and giving an ack to it seems a bit silly. :) Other
> rseq co-maintainers could weight in though: Peter, Paul, and Boqun.
>
I was commenting in general, not specific to this patch. No worries. I will
apply this right away.
I have been traveling the last couple of weeks and in the catch up mode still.
thanks,
-- Shuah
>>
>> --
>> Shuah Khan
>> Sr. Linux Kernel Developer
>> Open Source Innovation Group
>> Samsung Research America(Silicon Valley)
>> [email protected]
>
--
Shuah Khan
Sr. Linux Kernel Developer
Open Source Innovation Group
Samsung Research America(Silicon Valley)
[email protected]
On Thu, Sep 27, 2018 at 02:02:08PM -0400, Mathieu Desnoyers wrote:
> ----- On Sep 27, 2018, at 9:58 AM, Shuah Khan [email protected] wrote:
>
> > On 09/27/2018 07:22 AM, Steven Rostedt wrote:
> >> On Tue, 25 Sep 2018 13:39:36 -0400 (EDT)
> >> Mathieu Desnoyers <[email protected]> wrote:
> >>
> >>> ----- On Sep 18, 2018, at 9:53 AM, Mathieu Desnoyers
> >>> [email protected] wrote:
> >>>
> >>>> On x86-64, the parametrized selftest code for rseq crashes with a
> >>>> segmentation fault when compiled with -fpie. This happens when the
> >>>> param_test binary is loaded at an address beyond 32-bit on x86-64.
> >>>>
> >>>> The issue is caused by use of a 32-bit register to hold the address
> >>>> of the loop counter variable.
> >>>>
> >>>> Fix this by using a 64-bit register to calculate the address of the
> >>>> loop counter variables as an offset from rip.
> >>>
> >>> Should this fix go through tip or the selftests tree ?
> >>>
> >>
> >> I usually have changes like this pulled through Shuah's tree with an
> >> ack from the maintainer of the code that it tests.
> >>
> >> -- Steve
> >>
> >
> > Right that is what I prefer. I usually wait for an Ack. I can pull this
> > in.
>
> I am maintainer of the code that it tests as well, so being both author
> of the selftest patch and giving an ack to it seems a bit silly. :) Other
> rseq co-maintainers could weight in though: Peter, Paul, and Boqun.
Here you go! ;-)
Acked-by: Paul E. McKenney <[email protected]>
> Thanks,
>
> Mathieu
>
> >
> > thanks,
> > -- Shuah
> >
> > --
> > Shuah Khan
> > Sr. Linux Kernel Developer
> > Open Source Innovation Group
> > Samsung Research America(Silicon Valley)
> > [email protected]
>
> --
> Mathieu Desnoyers
> EfficiOS Inc.
> http://www.efficios.com
>
On 09/27/2018 12:10 PM, Shuah Khan wrote:
> On 09/27/2018 12:02 PM, Mathieu Desnoyers wrote:
>> ----- On Sep 27, 2018, at 9:58 AM, Shuah Khan [email protected] wrote:
>>
>>> On 09/27/2018 07:22 AM, Steven Rostedt wrote:
>>>> On Tue, 25 Sep 2018 13:39:36 -0400 (EDT)
>>>> Mathieu Desnoyers <[email protected]> wrote:
>>>>
>>>>> ----- On Sep 18, 2018, at 9:53 AM, Mathieu Desnoyers
>>>>> [email protected] wrote:
>>>>>
>>>>>> On x86-64, the parametrized selftest code for rseq crashes with a
>>>>>> segmentation fault when compiled with -fpie. This happens when the
>>>>>> param_test binary is loaded at an address beyond 32-bit on x86-64.
>>>>>>
>>>>>> The issue is caused by use of a 32-bit register to hold the address
>>>>>> of the loop counter variable.
>>>>>>
>>>>>> Fix this by using a 64-bit register to calculate the address of the
>>>>>> loop counter variables as an offset from rip.
>>>>>
>>>>> Should this fix go through tip or the selftests tree ?
>>>>>
>>>>
>>>> I usually have changes like this pulled through Shuah's tree with an
>>>> ack from the maintainer of the code that it tests.
>>>>
>>>> -- Steve
>>>>
>>>
>>> Right that is what I prefer. I usually wait for an Ack. I can pull this
>>> in.
>>
>> I am maintainer of the code that it tests as well, so being both author
>> of the selftest patch and giving an ack to it seems a bit silly. :) Other
>> rseq co-maintainers could weight in though: Peter, Paul, and Boqun.
>>
>
> I was commenting in general, not specific to this patch. No worries. I will
> apply this right away.
>
> I have been traveling the last couple of weeks and in the catch up mode still.
>
Hmm. this patch doesn't apply to linux-kselftest fixes branch which is at 4.19-rc4.
Also you don't have my current email from getmaintainers.
Could you please rebase and send it to me.
thanks,
-- Shuah