linux-stable.git/tools/testing/selftests/rseq/rseq.h, branch linux-4.18.y

rseq/selftests: cleanup: Update comment above rseq_prepare_unload

2018-07-10T20:18:52+00:00

rseq as it was merged does not have rseq_finish_*() in the user-space
selftests anymore. Update the rseq_prepare_unload() helper comment to
adapt to this reality.

Signed-off-by: Mathieu Desnoyers 
Signed-off-by: Thomas Gleixner 
Cc: linux-api@vger.kernel.org
Cc: Peter Zijlstra 
Cc: "Paul E . McKenney" 
Cc: Boqun Feng 
Cc: Andy Lutomirski 
Cc: Dave Watson 
Cc: Paul Turner 
Cc: Andrew Morton 
Cc: Russell King 
Cc: "H . Peter Anvin" 
Cc: Andi Kleen 
Cc: Chris Lameter 
Cc: Ben Maurer 
Cc: Steven Rostedt 
Cc: Josh Triplett 
Cc: Linus Torvalds 
Cc: Catalin Marinas 
Cc: Will Deacon 
Cc: Michael Kerrisk 
Cc: Joel Fernandes 
Cc: "Paul E. McKenney" 
Cc: "H. Peter Anvin" 
Link: https://lkml.kernel.org/r/20180709195155.7654-7-mathieu.desnoyers@efficios.com

rseq: uapi: Declare rseq_cs field as union, update includes

2018-07-10T20:18:52+00:00

Declaring the rseq_cs field as a union between __u64 and two __u32
allows both 32-bit and 64-bit kernels to read the full __u64, and
therefore validate that a 32-bit user-space cleared the upper 32
bits, thus ensuring a consistent behavior between native 32-bit
kernels and 32-bit compat tasks on 64-bit kernels.

Check that the rseq_cs value read is < TASK_SIZE.

The asm/byteorder.h header needs to be included by rseq.h, now
that it is not using linux/types_32_64.h anymore.

Considering that only __32 and __u64 types are declared in linux/rseq.h,
the linux/types.h header should always be included for both kernel and
user-space code: including stdint.h is just for u64 and u32, which are
not used in this header at all.

Use copy_from_user()/clear_user() to interact with a 64-bit field,
because arm32 does not implement 64-bit __get_user, and ppc32 does not
64-bit get_user. Considering that the rseq_cs pointer does not need to
be loaded/stored with single-copy atomicity from the kernel anymore, we
can simply use copy_from_user()/clear_user().

Signed-off-by: Mathieu Desnoyers 
Signed-off-by: Thomas Gleixner 
Cc: linux-api@vger.kernel.org
Cc: Peter Zijlstra 
Cc: "Paul E . McKenney" 
Cc: Boqun Feng 
Cc: Andy Lutomirski 
Cc: Dave Watson 
Cc: Paul Turner 
Cc: Andrew Morton 
Cc: Russell King 
Cc: "H . Peter Anvin" 
Cc: Andi Kleen 
Cc: Chris Lameter 
Cc: Ben Maurer 
Cc: Steven Rostedt 
Cc: Josh Triplett 
Cc: Linus Torvalds 
Cc: Catalin Marinas 
Cc: Will Deacon 
Cc: Michael Kerrisk 
Cc: Joel Fernandes 
Cc: "Paul E. McKenney" 
Cc: "H. Peter Anvin" 
Link: https://lkml.kernel.org/r/20180709195155.7654-5-mathieu.desnoyers@efficios.com

rseq/selftests: Implement MIPS support

2018-06-20T04:14:19+00:00

Implement support for both MIPS32 & MIPS64 in the rseq selftests, in
order to sanity check the recently enabled rseq syscall.

The tests all pass on a MIPS Boston development board running either a
MIPS32r2 interAptiv CPU & a MIPS64r6 I6500 CPU, both of which were
configured with 2 cores each of which have 2 hardware threads (VP(E)s) -
ie. 4 CPUs.

Signed-off-by: Paul Burton 
Reviewed-by: James Hogan 
Patchwork: https://patchwork.linux-mips.org/patch/19524/
Cc: Ralf Baechle 
Cc: Mathieu Desnoyers 
Cc: Peter Zijlstra 
Cc: Paul E. McKenney 
Cc: Boqun Feng 
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org

rseq/selftests: Provide rseq library

2018-06-06T09:58:34+00:00

This rseq helper library provides a user-space API to the rseq()
system call.

The rseq fast-path exposes the instruction pointer addresses where the
rseq assembly blocks begin and end, as well as the associated abort
instruction pointer, in the __rseq_table section. This section allows
debuggers may know where to place breakpoints when single-stepping
through assembly blocks which may be aborted at any point by the kernel.

Signed-off-by: Mathieu Desnoyers 
Signed-off-by: Thomas Gleixner 
Cc: Joel Fernandes 
Cc: Peter Zijlstra 
Cc: Catalin Marinas 
Cc: Dave Watson 
Cc: Will Deacon 
Cc: Shuah Khan 
Cc: Andi Kleen 
Cc: linux-kselftest@vger.kernel.org
Cc: "H . Peter Anvin" 
Cc: Chris Lameter 
Cc: Russell King 
Cc: Andrew Hunter 
Cc: Michael Kerrisk 
Cc: "Paul E . McKenney" 
Cc: Paul Turner 
Cc: Boqun Feng 
Cc: Josh Triplett 
Cc: Steven Rostedt 
Cc: Ben Maurer 
Cc: linux-api@vger.kernel.org
Cc: Andy Lutomirski 
Cc: Andrew Morton 
Cc: Linus Torvalds 
Link: https://lkml.kernel.org/r/20180602124408.8430-13-mathieu.desnoyers@efficios.com