On distros using older glibc versions, the pkey tests encounter build
failures due to redefinition of the pkey syscall numbers.
For compatibility, commit 743f3544ff added a wrapper for the
gettid() syscall and included syscall.h if the version of glibc used
is older than 2.30. This leads to different definitions of SYS_pkey_*
as the ones in the pkey test header set numeric constants where as the
ones from syscall.h reuse __NR_pkey_*. The compiler complains about
redefinitions since they are different.
This replaces SYS_pkey_* definitions with __NR_pkey_* such that the
definitions in both syscall.h and pkeys.h are alike. This way, if
syscall.h has to be included for compatibility reasons, builds will
still succeed.
Fixes: 743f3544ff ("selftests/powerpc: Add wrapper for gettid")
Reported-by: Sachin Sant <sachinp@linux.vnet.ibm.com>
Suggested-by: David Laight <david.laight@aculab.com>
Suggested-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sandipan Das <sandipan@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/a4956d838bf59b0a71a2553c5ca81131ea8b49b9.1596561758.git.sandipan@linux.ibm.com
Some of our tests use VSX or newer VMX instructions, so need to be
skipped on older CPUs to avoid SIGILL'ing.
Similarly TAR was added in v2.07, and the PMU event used in the stcx
fail test only works on Power8 or later.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200803020719.96114-1-mpe@ellerman.id.au
When running under older versions of qemu of under newer versions with
old machine types, some security features will not be reported to the
guest. This will lead the guest OS to consider itself Vulnerable to
spectre_v2.
So, spectre_v2 test fails in such cases when the host is mitigated and
miss predictions cannot be detected as expected by the test.
Make it return the skip code instead, for this particular case. We
don't want to miss the case when the test fails and the system reports
as mitigated or not affected. But it is not a problem to miss failures
when the system reports as Vulnerable.
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200728155039.401445-1-cascardo@canonical.com
We have custom stack expansion checks that it turns out are extremely
badly tested and contain bugs, surprise. So add some tests that
exercise the code and capture the current boundary conditions.
The signal test currently fails on 64-bit kernels because the 2048
byte allowance for the signal frame is too small, we will fix that in
a subsequent patch.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200724092528.1578671-1-mpe@ellerman.id.au
For drivers that don't have the error handling callbacks we implement
recovery by removing the device and re-probing it. This causes the sysfs
directory for the PCI device to be removed which causes the following
spurious error to be printed when checking the PE state:
Breaking 0005:03:00.0...
./eeh-basic.sh: line 13: can't open /sys/bus/pci/devices/0005:03:00.0/eeh_pe_state: no such file
0005:03:00.0, waited 0/60
0005:03:00.0, waited 1/60
0005:03:00.0, waited 2/60
0005:03:00.0, waited 3/60
0005:03:00.0, waited 4/60
0005:03:00.0, waited 5/60
0005:03:00.0, waited 6/60
0005:03:00.0, waited 7/60
0005:03:00.0, Recovered after 8 seconds
We currently try to avoid this by checking if the PE state file exists
before reading from it. This is however inherently racy so re-work the
state checking so that we only read from the file once, and we squash any
errors that occur while reading.
Fixes: 85d86c8aa5 ("selftests/powerpc: Add basic EEH selftest")
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200727010127.23698-1-oohall@gmail.com
Commit 192b6a7805 ("powerpc/book3s64/pkeys: Fix
pkey_access_permitted() for execute disable pkey") fixed a
bug that caused repetitive faults for pkeys with no execute
rights alongside some combination of read and write rights.
This removes the last two cases of the test, which check
the behaviour of pkeys with read, write but no execute
rights and all the rights, in favour of checking all the
possible combinations of read, write and execute rights
to be able to detect bugs like the one mentioned above.
Signed-off-by: Sandipan Das <sandipan@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/db467500f8af47727bba6b35796e8974a78b71e5.1595821792.git.sandipan@linux.ibm.com
Update our memcmp selftest, to test the case where we're comparing up
to the end of a page and the subsequent page is not mapped. We have to
make sure we don't read off the end of the page and cause a fault.
We had a bug there in the past, fixed in commit
d947075739 ("powerpc/64: Fix memcmp reading past the end of src/dest").
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200722055315.962391-1-mpe@ellerman.id.au
ISA v3.1 does not support the SAO storage control attribute required to
implement PROT_SAO. PROT_SAO was used by specialised system software
(Lx86) that has been discontinued for about 7 years, and is not thought
to be used elsewhere, so removal should not cause problems.
We rather remove it than keep support for older processors, because
live migrating guest partitions to newer processors may not be possible
if SAO is in use (or worse allowed with silent races).
- PROT_SAO stays in the uapi header so code using it would still build.
- arch_validate_prot() is removed, the generic version rejects PROT_SAO
so applications would get a failure at mmap() time.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Drop KVM change for the time being]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200703011958.1166620-3-npiggin@gmail.com
The per_event_excludes test wants to run on Power8 or later. But
currently it checks that AT_BASE_PLATFORM *equals* power8, which means
it only runs on Power8.
Fix it to check for the ISA 2.07 feature, which will be set on Power8
and later CPUs.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200716122142.3776261-1-mpe@ellerman.id.au
ERR_NX_TRANSLATION(CSB.CC=5) is for internal to VAS for fault handling
and should not used by OS. ERR_NX_AT_FAULT(CSB.CC=250) is the proper
error code should be reported by OS when NX encounters address
translation failure.
This patch uses CC=250 to determine the fault address when the request
is not successful.
Signed-off-by: Haren Myneni <haren@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/0315251705baff94f678c33178491b5008723511.camel@linux.ibm.com
An extra count on ebb_state.stats.pmc_count[PMC_INDEX(pmc)] is being per-
formed when count_pmc() is used to reset PMCs on a few selftests. This
extra pmc_count can occasionally invalidate results, such as the ones from
cycles_test shown hereafter. The ebb_check_count() failed with an above
the upper limit error due to the extra value on ebb_state.stats.pmc_count.
Furthermore, this extra count is also indicated by extra PMC1 trace_log on
the output of the cycle test (as well as on pmc56_overflow_test):
==========
...
[21]: counter = 8
[22]: register SPRN_MMCR0 = 0x0000000080000080
[23]: register SPRN_PMC1 = 0x0000000080000004
[24]: counter = 9
[25]: register SPRN_MMCR0 = 0x0000000080000080
[26]: register SPRN_PMC1 = 0x0000000080000004
[27]: counter = 10
[28]: register SPRN_MMCR0 = 0x0000000080000080
[29]: register SPRN_PMC1 = 0x0000000080000004
>> [30]: register SPRN_PMC1 = 0x000000004000051e
PMC1 count (0x280000546) above upper limit 0x2800003e8 (+0x15e)
[FAIL] Test FAILED on line 52
failure: cycles
==========
Signed-off-by: Desnes A. Nunes do Rosario <desnesn@linux.ibm.com>
Tested-by: Sachin Sant <sachinp@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200626164737.21943-1-desnesn@linux.ibm.com
The Power ISA mandates that all writes to the Authority
Mask Register (AMR) must always be preceded as well as
succeeded by a context synchronizing instruction.
This makes sure that the tests follow this requirement
when attempting to update a pkey's access rights.
Signed-off-by: Sandipan Das <sandipan@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200604125610.649668-2-sandipan@linux.ibm.com
We use OUTPUT directory as TMPOUT for checking no-pie option.
Since commit f2f02ebd8f ("kbuild: improve cc-option to clean up all
temporary files") when building powerpc/ from selftests directory, the
OUTPUT directory points to powerpc/pmu/ebb/ and gets removed when
checking for -no-pie option in try-run routine, subsequently build
fails with the following:
$ make -C powerpc
...
TARGET=ebb; BUILD_TARGET=$OUTPUT/$TARGET; mkdir -p $BUILD_TARGET; make OUTPUT=$BUILD_TARGET -k -C $TARGET all
make[2]: Entering directory '/home/linux-master/tools/testing/selftests/powerpc/pmu/ebb'
make[2]: *** No rule to make target 'Makefile'.
make[2]: Failed to remake makefile 'Makefile'.
make[2]: *** No rule to make target 'ebb.c', needed by '/home/linux-master/tools/testing/selftests/powerpc/pmu/ebb/reg_access_test'.
make[2]: *** No rule to make target 'ebb_handler.S', needed by '/home/linux-master/tools/testing/selftests/powerpc/pmu/ebb/reg_access_test'.
make[2]: *** No rule to make target 'trace.c', needed by '/home/linux-master/tools/testing/selftests/powerpc/pmu/ebb/reg_access_test'.
make[2]: *** No rule to make target 'busy_loop.S', needed by '/home/linux-master/tools/testing/selftests/powerpc/pmu/ebb/reg_access_test'.
make[2]: Target 'all' not remade because of errors.
Fix this by adding a suffix to the OUTPUT directory so that the
failure is avoided.
Fixes: 9686813f6e ("selftests/powerpc: Fix try-run when source tree is not writable")
Signed-off-by: Harish <harish@linux.ibm.com>
[mpe: Mention that commit that triggered the breakage]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200625165721.264904-1-harish@linux.ibm.com
Extend the alignment handler selftest to exercise prefixed load store
instructions. Add tests for prefixed VSX, floating point and integer
instructions.
Skip prefix tests if ISA version does not support prefixed instructions.
Signed-off-by: Jordan Niethe <jniethe5@gmail.com>
Tested-by: Alistair Popple <alistair@popple.id.au>
[mpe: Fixup PPC_FEATURE2_ARCH_3_1 naming as noted by Alistair]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200520021103.19798-2-jniethe5@gmail.com
The alignment handler selftest needs cache-inhibited memory and
currently /dev/fb0 is relied on to provided this. This prevents running
the test on systems without /dev/fb0 (e.g., mambo). Read the commandline
arguments for an optional path to be used instead, as well as an
optional offset to be for mmaping this path.
Signed-off-by: Jordan Niethe <jniethe5@gmail.com>
Tested-by: Alistair Popple <alistair@popple.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200520021103.19798-1-jniethe5@gmail.com
This is based on the count_instructions test.
However this one also counts the number of failed stcx's, and in
conjunction with knowing the size of the stcx loop, can calculate the
total number of instructions executed even in the face of
non-deterministic stcx failures.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200426114410.3917383-1-mpe@ellerman.id.au
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.
Also, notice that, dynamic memory allocations won't be affected by
this change:
"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]
sizeof(flexible-array-member) triggers a warning because flexible array
members have incomplete type[1]. There are some instances of code in
which the sizeof operator is being incorrectly/erroneously applied to
zero-length arrays and the result is zero. Such instances may be hiding
some bugs. So, this work (flexible-array member conversions) will also
help to get completely rid of those sorts of issues.
This issue was found with the help of Coccinelle.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200507185755.GA15014@embeddedor
It's not very nice to zero trap for this, because then system calls no
longer have trap_is_syscall(regs) invariant, and we can't distinguish
between sc and scv system calls (in a later patch).
Take one last unused bit from the low bits of the pt_regs.trap word
for this instead. There is not a really good reason why it should be
in trap as opposed to another field, but trap has some concept of
flags and it exists. Ideally I think we would move trap to 2-byte
field and have 2 more bytes available independently.
Add a selftests case for this, which can be seen to fail if
trap_norestart() is changed to return false.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Make them static inlines]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200507121332.2233629-4-mpe@ellerman.id.au
Pull more powerpc updates from Michael Ellerman:
"The bulk of this is the series to make CONFIG_COMPAT user-selectable,
it's been around for a long time but was blocked behind the
syscall-in-C series.
Plus there's also a few fixes and other minor things.
Summary:
- A fix for a crash in machine check handling on pseries (ie. guests)
- A small series to make it possible to disable CONFIG_COMPAT, and
turn it off by default for ppc64le where it's not used.
- A few other miscellaneous fixes and small improvements.
Thanks to: Alexey Kardashevskiy, Anju T Sudhakar, Arnd Bergmann,
Christophe Leroy, Dan Carpenter, Ganesh Goudar, Geert Uytterhoeven,
Geoff Levand, Mahesh Salgaonkar, Markus Elfring, Michal Suchanek,
Nicholas Piggin, Stephen Boyd, Wen Xiong"
* tag 'powerpc-5.7-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
selftests/powerpc: Always build the tm-poison test 64-bit
powerpc: Improve ppc_save_regs()
Revert "powerpc/64: irq_work avoid interrupt when called with hardware irqs enabled"
powerpc/time: Replace <linux/clk-provider.h> by <linux/of_clk.h>
powerpc/pseries/ddw: Extend upper limit for huge DMA window for persistent memory
powerpc/perf: split callchain.c by bitness
powerpc/64: Make COMPAT user-selectable disabled on littleendian by default.
powerpc/64: make buildable without CONFIG_COMPAT
powerpc/perf: consolidate valid_user_sp -> invalid_user_sp
powerpc/perf: consolidate read_user_stack_32
powerpc: move common register copy functions from signal_32.c to signal.c
powerpc: Add back __ARCH_WANT_SYS_LLSEEK macro
powerpc/ps3: Set CONFIG_UEVENT_HELPER=y in ps3_defconfig
powerpc/ps3: Remove an unneeded NULL check
powerpc/ps3: Remove duplicate error message
powerpc/powernv: Re-enable imc trace-mode in kernel
powerpc/perf: Implement a global lock to avoid races between trace, core and thread imc events.
powerpc/pseries: Fix MCE handling on pseries
selftests/eeh: Skip ahci adapters
powerpc/64s: Fix doorbell wakeup msgclr optimisation
Pull powerpc updates from Michael Ellerman:
"Slightly late as I had to rebase mid-week to insert a bug fix:
- A large series from Nick for 64-bit to further rework our exception
vectors, and rewrite portions of the syscall entry/exit and
interrupt return in C. The result is much easier to follow code
that is also faster in general.
- Cleanup of our ptrace code to split various parts out that had
become badly intertwined with #ifdefs over the years.
- Changes to our NUMA setup under the PowerVM hypervisor which should
hopefully avoid non-sensical topologies which can lead to warnings
from the workqueue code and other problems.
- MAINTAINERS updates to remove some of our old orphan entries and
update the status of others.
- Quite a few other small changes and fixes all over the map.
Thanks to: Abdul Haleem, afzal mohammed, Alexey Kardashevskiy, Andrew
Donnellan, Aneesh Kumar K.V, Balamuruhan S, Cédric Le Goater, Chen
Zhou, Christophe JAILLET, Christophe Leroy, Christoph Hellwig, Clement
Courbet, Daniel Axtens, David Gibson, Douglas Miller, Fabiano Rosas,
Fangrui Song, Ganesh Goudar, Gautham R. Shenoy, Greg Kroah-Hartman,
Greg Kurz, Gustavo Luiz Duarte, Hari Bathini, Ilie Halip, Jan Kara,
Joe Lawrence, Joe Perches, Kajol Jain, Larry Finger, Laurentiu Tudor,
Leonardo Bras, Libor Pechacek, Madhavan Srinivasan, Mahesh Salgaonkar,
Masahiro Yamada, Masami Hiramatsu, Mauricio Faria de Oliveira, Michael
Neuling, Michal Suchanek, Mike Rapoport, Nageswara R Sastry, Nathan
Chancellor, Nathan Lynch, Naveen N. Rao, Nicholas Piggin, Nick
Desaulniers, Oliver O'Halloran, Po-Hsu Lin, Pratik Rajesh Sampat,
Rasmus Villemoes, Ravi Bangoria, Roman Bolshakov, Sam Bobroff,
Sandipan Das, Santosh S, Sedat Dilek, Segher Boessenkool, Shilpasri G
Bhat, Sourabh Jain, Srikar Dronamraju, Stephen Rothwell, Tyrel
Datwyler, Vaibhav Jain, YueHaibing"
* tag 'powerpc-5.7-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (158 commits)
powerpc: Make setjmp/longjmp signature standard
powerpc/cputable: Remove unnecessary copy of cpu_spec->oprofile_type
powerpc: Suppress .eh_frame generation
powerpc: Drop -fno-dwarf2-cfi-asm
powerpc/32: drop unused ISA_DMA_THRESHOLD
powerpc/powernv: Add documentation for the opal sensor_groups sysfs interfaces
selftests/powerpc: Fix try-run when source tree is not writable
powerpc/vmlinux.lds: Explicitly retain .gnu.hash
powerpc/ptrace: move ptrace_triggered() into hw_breakpoint.c
powerpc/ptrace: create ppc_gethwdinfo()
powerpc/ptrace: create ptrace_get_debugreg()
powerpc/ptrace: split out ADV_DEBUG_REGS related functions.
powerpc/ptrace: move register viewing functions out of ptrace.c
powerpc/ptrace: split out TRANSACTIONAL_MEM related functions.
powerpc/ptrace: split out SPE related functions.
powerpc/ptrace: split out ALTIVEC related functions.
powerpc/ptrace: split out VSX related functions.
powerpc/ptrace: drop PARAMETER_SAVE_AREA_OFFSET
powerpc/ptrace: drop unnecessary #ifdefs CONFIG_PPC64
powerpc/ptrace: remove unused header includes
...
The tm-poison test includes inline asm which is 64-bit only, so the
test must be built 64-bit in order to work.
Otherwise it fails, eg:
# file tm-poison
tm-poison: ELF 32-bit MSB executable, PowerPC or cisco 4500, version 1 (SYSV) ...
# ./tm-poison
test: tm_poison_test
Unknown value 0x1fff71150 leaked into f31!
Unknown value 0x1fff710c0 leaked into vr31!
failure: tm_poison_test
Fixes: a003365cab ("powerpc/tm: Add tm-poison test")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200403095656.3772005-1-mpe@ellerman.id.au
We added a usage of try-run to pmu/ebb/Makefile to detect if the
toolchain supported the -no-pie option.
This fails if we build out-of-tree and the source tree is not
writable, as try-run tries to write its temporary files to the current
directory. That leads to the -no-pie option being silently dropped,
which leads to broken executables with some toolchains.
If we remove the redirect to /dev/null in try-run, we see the error:
make[3]: Entering directory '/linux/tools/testing/selftests/powerpc/pmu/ebb'
/usr/bin/ld: cannot open output file .54.tmp: Read-only file system
collect2: error: ld returned 1 exit status
make[3]: Nothing to be done for 'all'.
And looking with strace we see it's trying to use a file that's in the
source tree:
lstat("/linux/tools/testing/selftests/powerpc/pmu/ebb/.54.tmp", 0x7ffffc0f83c8)
We can fix it by setting TMPOUT to point to the $(OUTPUT) directory,
and we can verify with strace it's now trying to write to the output
directory:
lstat("/output/kselftest/powerpc/pmu/ebb/.54.tmp", 0x7fffd1bf6bf8)
And also see that the -no-pie option is now correctly detected.
Fixes: 0695f8bca9 ("selftests/powerpc: Handle Makefile for unrecognized option")
Cc: stable@vger.kernel.org # v5.5+
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200327095319.2347641-1-mpe@ellerman.id.au
Some specific tests in powerpc can take longer than the default 45
seconds that added in commit 852c8cbf34 ("selftests/kselftest/runner.sh:
Add 45 second timeout per test") to run, the following test result was
collected across 2 Power8 nodes and 1 Power9 node in our pool:
powerpc/benchmarks/futex_bench - 52s
powerpc/dscr/dscr_sysfs_test - 116s
powerpc/signal/signal_fuzzer - 88s
powerpc/tm/tm_unavailable_test - 168s
powerpc/tm/tm-poison - 240s
Thus they will fail with TIMEOUT error. Disable the timeout setting
for these sub-tests to allow them finish properly.
https://bugs.launchpad.net/bugs/1864642
Fixes: 852c8cbf34 ("selftests/kselftest/runner.sh: Add 45 second timeout per test")
Signed-off-by: Po-Hsu Lin <po-hsu.lin@canonical.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200318060004.10685-1-po-hsu.lin@canonical.com
The test case tm-signal-context-force-tm expects a segfault to happen
on returning from signal handler, and then does a setcontext() to run
the test again. However, the test doesn't always segfault, causing the
test to run a single time.
This patch fixes the test by putting it within a loop and jumping, via
setcontext, just prior to the loop in case it segfaults. This way we
get the desired behavior (run the test COUNT_MAX times) regardless if
it segfaults or not. This also reduces the use of setcontext for
control flow logic, keeping it only in the segfault handler.
Also, since 'count' is changed within the signal handler, it is
declared as volatile to prevent any compiler optimization getting
confused with asynchronous changes.
Signed-off-by: Gustavo Luiz Duarte <gustavold@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200211033831.11165-3-gustavold@linux.ibm.com
This test triggers a TM Bad Thing by raising a signal in transactional state
and forcing a pagefault to happen in kernelspace when the kernel signal
handling code first touches the user signal stack.
This is inspired by the test tm-signal-context-force-tm but uses userfaultfd to
make the test deterministic. While this test always triggers the bug in one
run, I had to execute tm-signal-context-force-tm several times (the test runs
5000 times each execution) to trigger the same bug.
tm-signal-context-force-tm is kept instead of replaced because, while this test
is more reliable and triggers the same bug, tm-signal-context-force-tm has a
better coverage, in the sense that by running the test several times it might
trigger the pagefault and/or be preempted at different places.
v3: skip test if userfaultfd is unavailable.
Signed-off-by: Gustavo Luiz Duarte <gustavold@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200211033831.11165-2-gustavold@linux.ibm.com
There's two different paths through the sigreturn code, depending on
whether the VDSO is mapped or not. We recently discovered a bug in the
unmapped case, because it's not commonly used these days.
So add a test that sends itself a signal, then moves the VDSO, takes
another signal and finally unmaps the VDSO before sending itself
another signal. That tests the standard signal path, the code that
handles the VDSO being moved, and also the signal path in the case
where the VDSO is unmapped.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200304110402.6038-1-mpe@ellerman.id.au
