Commit Graph

43 Commits

Author SHA1 Message Date
Xingxing Su
6f39cecdb6 rseq/selftests: Fix MEMBARRIER_CMD_PRIVATE_EXPEDITED_RSEQ build error under other arch.
Except arch x86, the function rseq_offset_deref_addv is not defined.
The function test_membarrier_manager_thread call rseq_offset_deref_addv
produces a build error.

The RSEQ_ARCH_HAS_OFFSET_DEREF_ADD should contain all the code
for the MEMBARRIER_CMD_PRIVATE_EXPEDITED_RSEQ.
If the other Arch implements this feature,
defined RSEQ_ARCH_HAS_OFFSET_DEREF_ADD in the header file
to ensure that this feature is available.

Following build errors:

param_test.c: In function ‘test_membarrier_worker_thread’:
param_test.c:1164:10: warning: implicit declaration of function ‘rseq_offset_deref_addv’
    ret = rseq_offset_deref_addv(&args->percpu_list_ptr,
          ^~~~~~~~~~~~~~~~~~~~~~
/tmp/ccMj9yHJ.o: In function `test_membarrier_worker_thread':
param_test.c:1164: undefined reference to `rseq_offset_deref_addv'
param_test.c:1164: undefined reference to `rseq_offset_deref_addv'
collect2: error: ld returned 1 exit status
make: *** [/selftests/rseq/param_test_benchmark] Error 1

Signed-off-by: Xingxing Su <suxingxing@loongson.cn>
Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2020-12-07 14:09:45 -07:00
Peter Oskolkov
f166b111e0 rseq/selftests: Test MEMBARRIER_CMD_PRIVATE_EXPEDITED_RSEQ
Based on Google-internal RSEQ work done by Paul Turner and Andrew
Hunter.

This patch adds a selftest for MEMBARRIER_CMD_PRIVATE_EXPEDITED_RSEQ.
The test quite often fails without the previous patch in this
patchset, but consistently passes with it.

Signed-off-by: Peter Oskolkov <posk@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lkml.kernel.org/r/20200923233618.2572849-3-posk@google.com
2020-09-25 14:23:27 +02:00
Peter Oskolkov
ea366dd79c rseq/selftests,x86_64: Add rseq_offset_deref_addv()
This patch adds rseq_offset_deref_addv() function to
tools/testing/selftests/rseq/rseq-x86.h, to be used in a selftest in
the next patch in the patchset.

Once an architecture adds support for this function they should define
"RSEQ_ARCH_HAS_OFFSET_DEREF_ADDV".

Signed-off-by: Peter Oskolkov <posk@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lkml.kernel.org/r/20200923233618.2572849-2-posk@google.com
2020-09-25 14:23:27 +02:00
Masahiro Yamada
d198b34f38 .gitignore: add SPDX License Identifier
Add SPDX License Identifier to all .gitignore files.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-25 11:50:48 +01:00
Michael Ellerman
ef89d05451 selftests/rseq: Fix out-of-tree compilation
Currently if you build with O=... the rseq tests don't build:

  $ make O=$PWD/output -C tools/testing/selftests/ TARGETS=rseq
  make: Entering directory '/linux/tools/testing/selftests'
  ...
  make[1]: Entering directory '/linux/tools/testing/selftests/rseq'
  gcc -O2 -Wall -g -I./ -I../../../../usr/include/ -L./ -Wl,-rpath=./  -shared -fPIC rseq.c -lpthread -o /linux/output/rseq/librseq.so
  gcc -O2 -Wall -g -I./ -I../../../../usr/include/ -L./ -Wl,-rpath=./  basic_test.c -lpthread -lrseq -o /linux/output/rseq/basic_test
  /usr/bin/ld: cannot find -lrseq
  collect2: error: ld returned 1 exit status

This is because the library search path points to the source
directory, not the output.

We can fix it by changing the library search path to $(OUTPUT).

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2020-02-20 08:57:12 -07:00
Michael Ellerman
b9167c8078 selftests: Install settings files to fix TIMEOUT failures
Commit 852c8cbf34 ("selftests/kselftest/runner.sh: Add 45 second
timeout per test") added a 45 second timeout for tests, and also added
a way for tests to customise the timeout via a settings file.

For example the ftrace tests take multiple minutes to run, so they
were given longer in commit b43e78f65b ("tracing/selftests: Turn off
timeout setting").

This works when the tests are run from the source tree. However if the
tests are installed with "make -C tools/testing/selftests install",
the settings files are not copied into the install directory. When the
tests are then run from the install directory the longer timeouts are
not applied and the tests timeout incorrectly.

So add the settings files to TEST_FILES of the appropriate Makefiles
to cause the settings files to be installed using the existing install
logic.

Fixes: 852c8cbf34 ("selftests/kselftest/runner.sh: Add 45 second timeout per test")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2020-02-20 08:56:42 -07:00
Mathieu Desnoyers
2a1f40adfb rseq/selftests: Clarify rseq_prepare_unload() helper requirements
The rseq.h UAPI now documents that the rseq_cs field must be cleared
before reclaiming memory that contains the targeted struct rseq_cs, but
also that the rseq_cs field must be cleared before reclaiming memory of
the code pointed to by the rseq_cs start_ip and post_commit_offset
fields.

While we can expect that use of dlclose(3) will typically unmap
both struct rseq_cs and its associated code at once, nothing would
theoretically prevent a JIT from reclaiming the code without
reclaiming the struct rseq_cs, which would erroneously allow the
kernel to consider new code which is not a rseq critical section
as a rseq critical section following a code reclaim.

Suggested-by: Florian Weimer <fw@deneb.enyo.de>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Cc: Florian Weimer <fw@deneb.enyo.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: "Paul E. McKenney" <paulmck@linux.ibm.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: "H . Peter Anvin" <hpa@zytor.com>
Cc: Paul Turner <pjt@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2019-12-23 10:52:41 -07:00
Mathieu Desnoyers
8df34c5632 rseq/selftests: Fix: Namespace gettid() for compatibility with glibc 2.30
glibc 2.30 introduces gettid() in public headers, which clashes with
the internal static definition within rseq selftests.

Rename gettid() to rseq_gettid() to eliminate this symbol name clash.

Reported-by: Tommi T. Rantala <tommi.t.rantala@nokia.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Cc: Tommi T. Rantala <tommi.t.rantala@nokia.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: "Paul E. McKenney" <paulmck@linux.ibm.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: "H . Peter Anvin" <hpa@zytor.com>
Cc: Paul Turner <pjt@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: <stable@vger.kernel.org>	# v4.18+
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2019-12-23 10:52:41 -07:00
Mathieu Desnoyers
af9cb29c54 rseq/selftests: Turn off timeout setting
As the rseq selftests can run for a long period of time, disable the
timeout that the general selftests have.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: "Paul E. McKenney" <paulmck@linux.ibm.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: "H . Peter Anvin" <hpa@zytor.com>
Cc: Paul Turner <pjt@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2019-12-23 10:52:41 -07:00
Mathieu Desnoyers
ee8a84c60b rseq/selftests: Fix Thumb mode build failure on arm32
Using ".arm .inst" for the arm signature introduces build issues for
programs compiled in Thumb mode because the assembler stays in the
arm mode for the rest of the inline assembly. Revert to using a ".word"
to express the signature as data instead.

The choice of signature is a valid trap instruction on arm32 little
endian, where both code and data are little endian.

ARMv6+ big endian (BE8) generates mixed endianness code vs data:
little-endian code and big-endian data. The data value of the signature
needs to have its byte order reversed to generate the trap instruction.

Prior to ARMv6, -mbig-endian generates big-endian code and data
(which match), so the endianness of the data representation of the
signature should not be reversed. However, the choice between BE32
and BE8 is done by the linker, so we cannot know whether code and
data endianness will be mixed before the linker is invoked. So rather
than try to play tricks with the linker, the rseq signature is simply
data (not a trap instruction) prior to ARMv6 on big endian. This is
why the signature is expressed as data (.word) rather than as
instruction (.inst) in assembler.

Because a ".word" is used to emit the signature, it will be interpreted
as a literal pool by a disassembler, not as an actual instruction.
Considering that the signature is not meant to be executed except in
scenarios where the program execution is completely bogus, this should
not be an issue.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Acked-by: Will Deacon <will.deacon@arm.com>
CC: Peter Zijlstra <peterz@infradead.org>
CC: Thomas Gleixner <tglx@linutronix.de>
CC: Joel Fernandes <joelaf@google.com>
CC: Catalin Marinas <catalin.marinas@arm.com>
CC: Dave Watson <davejwatson@fb.com>
CC: Will Deacon <will.deacon@arm.com>
CC: Shuah Khan <shuah@kernel.org>
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: linux-api@vger.kernel.org
CC: Andy Lutomirski <luto@amacapital.net>
CC: Andrew Morton <akpm@linux-foundation.org>
CC: Linus Torvalds <torvalds@linux-foundation.org>
CC: Carlos O'Donell <carlos@redhat.com>
CC: Florian Weimer <fweimer@redhat.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2019-07-08 13:00:41 -06:00
Linus Torvalds
4c7b63a32d Merge tag 'linux-kselftest-5.2-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest
Pull more kselftest updates from Shuah Khan:

 - kselftest framework bpf build/test workflow regression fix

 - Fix to kselftest install to use default install path

 - Fix to kselftest KBUILD_OUTPUT builds to not clutter main
   KBUILD_OUTPUT directory with selftest objects

 - .gitignore fixes (Kelsey Skunberg)

 - rseq selftests updates (Mathieu Desnoyers and Martin Schwidefsky)

   They change the per-architecture pre-abort signatures to ensure those
   are valid trap instructions.

   The way exit points are presented to debuggers is enhanced, ensuring
   all exit points are present, so debuggers don't have to disassemble
   rseq critical section to properly skip over them.

   Discussions with the glibc community is reaching a consensus of
   exposing a __rseq_handled symbol from glibc to coexist with rseq
   early adopters. Update the rseq selftest code to expose and use this
   symbol.

   Support for compiling asm goto with clang is added with the
   "-no-integrated-as" compiler switch, similarly to the top level
   kernel Makefile.

 - kselftest Makefile test run output refactoring and making test output
   TAP13 compliant from Kees Cook:

   This re-factors the selftest Makefiles to extract the test running
   logic to be reused between "run_tests" and "emit_tests", while also
   fixing up the test output to be TAP version 13 compliant:
	- added "plan" line
	- fixed result line syntax
	- moved all test output to be "# "-prefixed as TAP "diagnostic"
	  lines

   The prefixing code includes a fallback mode for limited execution
   environments.

   Additionally, the plan lines are fixed for all callers of
   kselftest.h.

* tag 'linux-kselftest-5.2-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest: (25 commits)
  selftests: avoid KBUILD_OUTPUT dir cluttering with selftest objects
  selftests: drivers: Create .gitignore to include /dma-buf/udmabuf
  selftests: pidfd: Create .gitignore to include pidfd_test
  selftests: fix bpf build/test workflow regression when KBUILD_OUTPUT is set
  selftests: fix install target to use default install path
  rseq/selftests: add -no-integrated-as for clang
  rseq/selftests: mips: use break instruction for RSEQ_SIG
  rseq/selftests: powerpc code signature: generate valid instructions
  rseq/selftests: aarch64 code signature: handle big-endian environment
  rseq/selftests: arm: use udf instruction for RSEQ_SIG
  rseq/selftests: s390: use trap4 for RSEQ_SIG
  rseq/selftests: x86: use ud1 instruction as RSEQ_SIG opcode
  rseq/selftests: s390: use jg instruction for jumps outside of the asm
  rseq/selftests: Use __rseq_handled symbol to coexist with glibc
  rseq/selftests: Introduce __rseq_cs_ptr_array, rename __rseq_table to __rseq_cs
  rseq/selftests: Add __rseq_exit_point_array section for debuggers
  rseq/selftests: x86: Work-around bogus gcc-8 optimisation
  selftests: Add test plan API to kselftest.h and adjust callers
  selftests: Remove KSFT_TAP_LEVEL
  selftests: Move test output to diagnostic lines
  ...
2019-05-16 18:57:58 -07:00
Mathieu Desnoyers
fdeb89d84e rseq/selftests: add -no-integrated-as for clang
Ongoing work for asm goto support from clang requires the
-no-integrated-as compiler flag.

This compiler flag is present in the toplevel kernel Makefile,
but is not replicated for selftests. Add it specifically for
the rseq selftest which requires asm goto.

Link: https://reviews.llvm.org/D56571
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
CC: Nick Desaulniers <ndesaulniers@google.com>
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 <shuah@kernel.org>
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: linux-api@vger.kernel.org
CC: Andy Lutomirski <luto@amacapital.net>
CC: Andrew Morton <akpm@linux-foundation.org>
CC: Linus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2019-05-07 15:33:17 -06:00
Mathieu Desnoyers
16b96b6ed8 rseq/selftests: mips: use break instruction for RSEQ_SIG
Use break as guard instruction for the restartable sequence abort
handler.

Previously, the chosen signature was simply data, based on the
assumption that it could always sit in a literal pool. However,
some compilation environments favor disabling literal pool. Therefore,
ensure the signature is a valid uncommon trap instruction.

Suggested-by: Paul Burton <paul.burton@mips.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
CC: Paul Burton <paul.burton@mips.com>
CC: James Hogan <jhogan@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2019-05-07 15:33:09 -06:00
Mathieu Desnoyers
496fd0fc9f rseq/selftests: powerpc code signature: generate valid instructions
Use "twui" as the guard instruction for the restartable sequence abort
handler.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
CC: Benjamin Herrenschmidt <benh@kernel.crashing.org>
CC: Paul Mackerras <paulus@samba.org>
CC: Michael Ellerman <mpe@ellerman.id.au>
CC: Boqun Feng <boqun.feng@gmail.com>
CC: Peter Zijlstra <peterz@infradead.org>
CC: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
CC: Alan Modra <amodra@gmail.com>
CC: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2019-05-07 15:33:00 -06:00
Mathieu Desnoyers
7cd4ce2e46 rseq/selftests: aarch64 code signature: handle big-endian environment
Handle compiling with -mbig-endian on aarch64, which generates binaries
with mixed code vs data endianness (little endian code, big endian
data).

Else mismatch between code endianness for the generated signatures and
data endianness for the RSEQ_SIG parameter passed to the rseq
registration will trigger application segmentation faults when the
kernel try to abort rseq critical sections.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Acked-by: Will Deacon <will.deacon@arm.com>
CC: Peter Zijlstra <peterz@infradead.org>
CC: Thomas Gleixner <tglx@linutronix.de>
CC: Joel Fernandes <joelaf@google.com>
CC: Catalin Marinas <catalin.marinas@arm.com>
CC: Dave Watson <davejwatson@fb.com>
CC: Will Deacon <will.deacon@arm.com>
CC: Shuah Khan <shuah@kernel.org>
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: linux-api@vger.kernel.org
CC: Andy Lutomirski <luto@amacapital.net>
CC: Andrew Morton <akpm@linux-foundation.org>
CC: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2019-05-07 15:32:51 -06:00
Mathieu Desnoyers
2b845d4b4a rseq/selftests: arm: use udf instruction for RSEQ_SIG
Use udf as the guard instruction for the restartable sequence abort
handler.

Previously, the chosen signature was not a valid instruction, based
on the assumption that it could always sit in a literal pool. However,
there are compilation environments in which literal pools are not
available, for instance execute-only code. Therefore, we need to
choose a signature value that is also a valid instruction.

Handle compiling with -mbig-endian on ARMv6+, which generates binaries
with mixed code vs data endianness (little endian code, big endian
data).

Else mismatch between code endianness for the generated signatures and
data endianness for the RSEQ_SIG parameter passed to the rseq
registration will trigger application segmentation faults when the
kernel try to abort rseq critical sections.

Prior to ARMv6, -mbig-endian generates big-endian code and data, so
endianness should not be reversed in that case.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
CC: Peter Zijlstra <peterz@infradead.org>
CC: Thomas Gleixner <tglx@linutronix.de>
CC: Joel Fernandes <joelaf@google.com>
CC: Catalin Marinas <catalin.marinas@arm.com>
CC: Dave Watson <davejwatson@fb.com>
CC: Will Deacon <will.deacon@arm.com>
CC: Shuah Khan <shuah@kernel.org>
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: linux-api@vger.kernel.org
CC: Andy Lutomirski <luto@amacapital.net>
CC: Andrew Morton <akpm@linux-foundation.org>
CC: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2019-05-07 15:32:36 -06:00
Martin Schwidefsky
3d4d1f05bc rseq/selftests: s390: use trap4 for RSEQ_SIG
Use trap4 as the guard instruction for the restartable sequence abort
handler.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2019-05-07 15:32:14 -06:00
Mathieu Desnoyers
24fa5d1efe rseq/selftests: x86: use ud1 instruction as RSEQ_SIG opcode
Use ud1 as the guard instruction for the restartable sequence abort
handler. Its benefit compared to nopl is to trap execution if the
program ends up trying to execute it by mistake, which makes debugging
easier.

The 4-byte signature per se is unchanged (it is the instruction
operand). Only the opcode is changed from nopl to ud1.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Suggested-by: Peter Zijlstra <peterz@infradead.org>
CC: Peter Zijlstra <peterz@infradead.org>
CC: Thomas Gleixner <tglx@linutronix.de>
CC: Joel Fernandes <joelaf@google.com>
CC: Catalin Marinas <catalin.marinas@arm.com>
CC: Dave Watson <davejwatson@fb.com>
CC: Will Deacon <will.deacon@arm.com>
CC: Shuah Khan <shuah@kernel.org>
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: linux-api@vger.kernel.org
CC: Andy Lutomirski <luto@amacapital.net>
CC: Andrew Morton <akpm@linux-foundation.org>
CC: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2019-05-07 15:32:05 -06:00
Mathieu Desnoyers
97b8be8168 rseq/selftests: s390: use jg instruction for jumps outside of the asm
The branch target range of the "j" instruction is 64K, which is not
enough for the general case.

Suggested-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
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 <shuah@kernel.org>
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: linux-api@vger.kernel.org
CC: Andy Lutomirski <luto@amacapital.net>
CC: Andrew Morton <akpm@linux-foundation.org>
CC: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2019-05-07 15:31:55 -06:00
Mathieu Desnoyers
5b0c308a05 rseq/selftests: Use __rseq_handled symbol to coexist with glibc
In order to integrate rseq into user-space applications, expose a
__rseq_handled symbol so many rseq users can be linked into the same
application (e.g. librseq and glibc).

The __rseq_refcount TLS variable is static to the librseq library. It
ensures that rseq syscall registration/unregistration happens only for
the most early/late caller to rseq_{,un}register_current_thread for each
thread, thus ensuring that rseq is registered across the lifetime of all
rseq users for a given thread.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
CC: Shuah Khan <shuah@kernel.org>
CC: Carlos O'Donell <carlos@redhat.com>
CC: Florian Weimer <fweimer@redhat.com>
CC: Joseph Myers <joseph@codesourcery.com>
CC: Szabolcs Nagy <szabolcs.nagy@arm.com>
CC: Thomas Gleixner <tglx@linutronix.de>
CC: Ben Maurer <bmaurer@fb.com>
CC: Peter Zijlstra <peterz@infradead.org>
CC: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
CC: Boqun Feng <boqun.feng@gmail.com>
CC: Will Deacon <will.deacon@arm.com>
CC: Dave Watson <davejwatson@fb.com>
CC: Paul Turner <pjt@google.com>
CC: linux-api@vger.kernel.org
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2019-05-07 15:31:46 -06:00
Mathieu Desnoyers
a3e3131f94 rseq/selftests: Introduce __rseq_cs_ptr_array, rename __rseq_table to __rseq_cs
The entries within __rseq_table are aligned on 32 bytes due to
linux/rseq.h struct rseq_cs uapi requirements, but the start of the
__rseq_table section is not guaranteed to be 32-byte aligned. It can
cause padding to be added at the start of the section, which makes it
hard to use as an array of items by debuggers.

Considering that __rseq_table does not really consist of a table due to
the presence of padding, rename this section to __rseq_cs.

Create a new __rseq_cs_ptr_array section which contains 64-bit packed
pointers to entries within the __rseq_cs section.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
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 <shuah@kernel.org>
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: linux-api@vger.kernel.org
CC: Andy Lutomirski <luto@amacapital.net>
CC: Andrew Morton <akpm@linux-foundation.org>
CC: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2019-05-07 15:31:36 -06:00
Mathieu Desnoyers
4fe2088e16 rseq/selftests: Add __rseq_exit_point_array section for debuggers
Knowing all exit points is useful to assist debuggers stepping over the
rseq critical sections without requiring them to disassemble the content
of the critical section to figure out the exit points.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
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 <shuah@kernel.org>
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: linux-api@vger.kernel.org
CC: Andy Lutomirski <luto@amacapital.net>
CC: Andrew Morton <akpm@linux-foundation.org>
CC: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2019-05-07 15:31:13 -06:00
Mathieu Desnoyers
fe22983d92 rseq/selftests: x86: Work-around bogus gcc-8 optimisation
gcc-8 version 8.1.0, 8.2.0, and 8.3.0 generate broken assembler with asm
goto that have a thread-local storage "m" input operand on both x86-32
and x86-64. For instance:

__thread int var;

static int fct(void)
{
        asm goto (      "jmp %l[testlabel]\n\t"
                        : : [var] "m" (var) : : testlabel);
        return 0;
testlabel:
        return 1;
}

int main()
{
        return fct();
}

% gcc-8 -O2 -o test-asm-goto test-asm-goto.c
/tmp/ccAdHJbe.o: In function `main':
test-asm-goto.c:(.text.startup+0x1): undefined reference to `.L2'
collect2: error: ld returned 1 exit status

% gcc-8 -m32 -O2 -o test-asm-goto test-asm-goto.c
/tmp/ccREsVXA.o: In function `main':
test-asm-goto.c:(.text.startup+0x1): undefined reference to `.L2'
collect2: error: ld returned 1 exit status

Work-around this compiler bug in the rseq-x86.h header by passing the
address of the __rseq_abi TLS as a register operand rather than using
the "m" input operand.

Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90193
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
CC: Ingo Molnar <mingo@redhat.com>
CC: Peter Zijlstra <peterz@infradead.org>
CC: Thomas Gleixner <tglx@linutronix.de>
CC: Joel Fernandes <joelaf@google.com>
CC: Catalin Marinas <catalin.marinas@arm.com>
CC: Dave Watson <davejwatson@fb.com>
CC: Will Deacon <will.deacon@arm.com>
CC: Shuah Khan <shuah@kernel.org>
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: linux-api@vger.kernel.org
CC: Andy Lutomirski <luto@amacapital.net>
CC: Andrew Morton <akpm@linux-foundation.org>
CC: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2019-05-07 15:30:14 -06:00
Linus Torvalds
71ae5fc87c Merge tag 'linux-kselftest-5.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest
Pull Kselftest updates from Shuah Khan:

 - fixes to seccomp test, and kselftest framework

 - cleanups to remove duplicate header defines

 - fixes to efivarfs "make clean" target

 - cgroup cleanup path

 - Moving the IMA kexec_load selftest to selftests/kexec work from Mimi
   Johar and Petr Vorel

 - A framework to kselftest for writing kernel test modules addition
   from Tobin C. Harding

* tag 'linux-kselftest-5.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest: (29 commits)
  selftests: build and run gpio when output directory is the src dir
  selftests/ipc: Fix msgque compiler warnings
  selftests/efivarfs: clean up test files from test_create*()
  selftests: fix headers_install circular dependency
  selftests/kexec: update get_secureboot_mode
  selftests/kexec: make kexec_load test independent of IMA being enabled
  selftests/kexec: check kexec_load and kexec_file_load are enabled
  selftests/kexec: Add missing '=y' to config options
  selftests/kexec: kexec_file_load syscall test
  selftests/kexec: define "require_root_privileges"
  selftests/kexec: define common logging functions
  selftests/kexec: define a set of common functions
  selftests/kexec: cleanup the kexec selftest
  selftests/kexec: move the IMA kexec_load selftest to selftests/kexec
  selftests/harness: Add 30 second timeout per test
  selftests/seccomp: Handle namespace failures gracefully
  selftests: cgroup: fix cleanup path in test_memcg_subtree_control()
  selftests: efivarfs: remove the test_create_read file if it was exist
  rseq/selftests: Adapt number of threads to the number of detected cpus
  lib: Add test module for strscpy_pad
  ...
2019-05-06 20:29:45 -07:00
Martin Schwidefsky
e24e4712ef s390/rseq: use trap4 for RSEQ_SIG
Use trap4 as the guard instruction for the restartable sequence abort
handler.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-10 17:48:34 +02:00