rseq/selftests: fix parametrized test with -fpie
diff mbox series

Message ID 20180918135328.32034-1-mathieu.desnoyers@efficios.com
State New
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  • rseq/selftests: fix parametrized test with -fpie
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Commit Message

Mathieu Desnoyers Sept. 18, 2018, 1:53 p.m. UTC
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 <mathieu.desnoyers@efficios.com>
Cc: <stable@vger.kernel.org> # v4.18
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Joel Fernandes <joelaf@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dave Watson <davejwatson@fb.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Shuah Khan <shuahkh@osg.samsung.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: linux-kselftest@vger.kernel.org
Cc: "H . Peter Anvin" <hpa@zytor.com>
Cc: Chris Lameter <cl@linux.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: "Paul E . McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Paul Turner <pjt@google.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ben Maurer <bmaurer@fb.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
---
 tools/testing/selftests/rseq/param_test.c | 19 ++++++++++---------
 1 file changed, 10 insertions(+), 9 deletions(-)

Comments

Mathieu Desnoyers Sept. 25, 2018, 5:39 p.m. UTC | #1
----- On Sep 18, 2018, at 9:53 AM, Mathieu Desnoyers mathieu.desnoyers@efficios.com 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 <mathieu.desnoyers@efficios.com>
> Cc: <stable@vger.kernel.org> # v4.18
> Cc: Thomas Gleixner <tglx@linutronix.de>
> Cc: Joel Fernandes <joelaf@google.com>
> Cc: Peter Zijlstra <peterz@infradead.org>
> Cc: Catalin Marinas <catalin.marinas@arm.com>
> Cc: Dave Watson <davejwatson@fb.com>
> Cc: Will Deacon <will.deacon@arm.com>
> Cc: Shuah Khan <shuahkh@osg.samsung.com>
> Cc: Andi Kleen <andi@firstfloor.org>
> Cc: linux-kselftest@vger.kernel.org
> Cc: "H . Peter Anvin" <hpa@zytor.com>
> Cc: Chris Lameter <cl@linux.com>
> Cc: Russell King <linux@arm.linux.org.uk>
> Cc: Michael Kerrisk <mtk.manpages@gmail.com>
> Cc: "Paul E . McKenney" <paulmck@linux.vnet.ibm.com>
> Cc: Paul Turner <pjt@google.com>
> Cc: Boqun Feng <boqun.feng@gmail.com>
> Cc: Josh Triplett <josh@joshtriplett.org>
> Cc: Steven Rostedt <rostedt@goodmis.org>
> Cc: Ben Maurer <bmaurer@fb.com>
> Cc: Andy Lutomirski <luto@amacapital.net>
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Cc: Linus Torvalds <torvalds@linux-foundation.org>
> ---
> 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
Steven Rostedt Sept. 27, 2018, 1:22 p.m. UTC | #2
On Tue, 25 Sep 2018 13:39:36 -0400 (EDT)
Mathieu Desnoyers <mathieu.desnoyers@efficios.com> wrote:

> ----- On Sep 18, 2018, at 9:53 AM, Mathieu Desnoyers mathieu.desnoyers@efficios.com 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
Shuah Khan Sept. 27, 2018, 1:58 p.m. UTC | #3
On 09/27/2018 07:22 AM, Steven Rostedt wrote:
> On Tue, 25 Sep 2018 13:39:36 -0400 (EDT)
> Mathieu Desnoyers <mathieu.desnoyers@efficios.com> wrote:
> 
>> ----- On Sep 18, 2018, at 9:53 AM, Mathieu Desnoyers mathieu.desnoyers@efficios.com 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
Mathieu Desnoyers Sept. 27, 2018, 6:02 p.m. UTC | #4
----- On Sep 27, 2018, at 9:58 AM, Shuah Khan shuah.kh@samsung.com wrote:

> On 09/27/2018 07:22 AM, Steven Rostedt wrote:
>> On Tue, 25 Sep 2018 13:39:36 -0400 (EDT)
>> Mathieu Desnoyers <mathieu.desnoyers@efficios.com> wrote:
>> 
>>> ----- On Sep 18, 2018, at 9:53 AM, Mathieu Desnoyers
>>> mathieu.desnoyers@efficios.com 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)
> shuah.kh@samsung.com
Shuah Khan Sept. 27, 2018, 6:10 p.m. UTC | #5
On 09/27/2018 12:02 PM, Mathieu Desnoyers wrote:
> ----- On Sep 27, 2018, at 9:58 AM, Shuah Khan shuah.kh@samsung.com wrote:
> 
>> On 09/27/2018 07:22 AM, Steven Rostedt wrote:
>>> On Tue, 25 Sep 2018 13:39:36 -0400 (EDT)
>>> Mathieu Desnoyers <mathieu.desnoyers@efficios.com> wrote:
>>>
>>>> ----- On Sep 18, 2018, at 9:53 AM, Mathieu Desnoyers
>>>> mathieu.desnoyers@efficios.com 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)
>> shuah.kh@samsung.com
>
Paul E. McKenney Sept. 27, 2018, 6:18 p.m. UTC | #6
On Thu, Sep 27, 2018 at 02:02:08PM -0400, Mathieu Desnoyers wrote:
> ----- On Sep 27, 2018, at 9:58 AM, Shuah Khan shuah.kh@samsung.com wrote:
> 
> > On 09/27/2018 07:22 AM, Steven Rostedt wrote:
> >> On Tue, 25 Sep 2018 13:39:36 -0400 (EDT)
> >> Mathieu Desnoyers <mathieu.desnoyers@efficios.com> wrote:
> >> 
> >>> ----- On Sep 18, 2018, at 9:53 AM, Mathieu Desnoyers
> >>> mathieu.desnoyers@efficios.com 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 <paulmck@linux.ibm.com>

> Thanks,
> 
> Mathieu
> 
> > 
> > thanks,
> > -- Shuah
> > 
> > --
> > Shuah Khan
> > Sr. Linux Kernel Developer
> > Open Source Innovation Group
> > Samsung Research America(Silicon Valley)
> > shuah.kh@samsung.com
> 
> -- 
> Mathieu Desnoyers
> EfficiOS Inc.
> http://www.efficios.com
>
shuah Sept. 27, 2018, 6:26 p.m. UTC | #7
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 shuah.kh@samsung.com wrote:
>>
>>> On 09/27/2018 07:22 AM, Steven Rostedt wrote:
>>>> On Tue, 25 Sep 2018 13:39:36 -0400 (EDT)
>>>> Mathieu Desnoyers <mathieu.desnoyers@efficios.com> wrote:
>>>>
>>>>> ----- On Sep 18, 2018, at 9:53 AM, Mathieu Desnoyers
>>>>> mathieu.desnoyers@efficios.com 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

Patch
diff mbox series

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 \