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: <redacted> # v4.18
Cc: Thomas Gleixner <redacted>
Cc: Joel Fernandes <redacted>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dave Watson <redacted>
Cc: Will Deacon <redacted>
Cc: Shuah Khan <redacted>
Cc: Andi Kleen <redacted>
Cc: linux-kselftest@vger.kernel.org
Cc: "H . Peter Anvin" <hpa@zytor.com>
Cc: Chris Lameter <redacted>
Cc: Russell King <redacted>
Cc: Michael Kerrisk <redacted>
Cc: "Paul E . McKenney" <redacted>
Cc: Paul Turner <redacted>
Cc: Boqun Feng <redacted>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ben Maurer <redacted>
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(-)
----- 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
quoted hunk
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: <redacted> # v4.18
Cc: Thomas Gleixner <redacted>
Cc: Joel Fernandes <redacted>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dave Watson <redacted>
Cc: Will Deacon <redacted>
Cc: Shuah Khan <redacted>
Cc: Andi Kleen <redacted>
Cc: linux-kselftest@vger.kernel.org
Cc: "H . Peter Anvin" <hpa@zytor.com>
Cc: Chris Lameter <redacted>
Cc: Russell King <redacted>
Cc: Michael Kerrisk <redacted>
Cc: "Paul E . McKenney" <redacted>
Cc: Paul Turner <redacted>
Cc: Boqun Feng <redacted>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ben Maurer <redacted>
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(-)
----- On Sep 18, 2018, at 9:53 AM, Mathieu Desnoyers mathieu.desnoyers@efficios.com wrote:
quoted
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 Sep 18, 2018, at 9:53 AM, Mathieu Desnoyers mathieu.desnoyers@efficios.com wrote:
quoted
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)
shuah.kh@samsung.com
----- On Sep 18, 2018, at 9:53 AM, Mathieu Desnoyers
mathieu.desnoyers@efficios.com wrote:
quoted
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
----- On Sep 18, 2018, at 9:53 AM, Mathieu Desnoyers
mathieu.desnoyers@efficios.com wrote:
quoted
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
quoted
--
Shuah Khan
Sr. Linux Kernel Developer
Open Source Innovation Group
Samsung Research America(Silicon Valley)
shuah.kh@samsung.com
--
Shuah Khan
Sr. Linux Kernel Developer
Open Source Innovation Group
Samsung Research America(Silicon Valley)
shuah.kh@samsung.com
----- On Sep 18, 2018, at 9:53 AM, Mathieu Desnoyers
mathieu.desnoyers@efficios.com wrote:
quoted
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 <redacted>
Thanks,
Mathieu
quoted
thanks,
-- Shuah
--
Shuah Khan
Sr. Linux Kernel Developer
Open Source Innovation Group
Samsung Research America(Silicon Valley)
shuah.kh@samsung.com
----- On Sep 18, 2018, at 9:53 AM, Mathieu Desnoyers
mathieu.desnoyers@efficios.com wrote:
quoted
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