The kernel has recently added support for shadow stacks, currently
x86 only using their CET feature but both arm64 and RISC-V have
equivalent features (GCS and Zicfiss respectively), I am actively
working on GCS[1]. With shadow stacks the hardware maintains an
additional stack containing only the return addresses for branch
instructions which is not generally writeable by userspace and ensures
that any returns are to the recorded addresses. This provides some
protection against ROP attacks and making it easier to collect call
stacks. These shadow stacks are allocated in the address space of the
userspace process.
Our API for shadow stacks does not currently offer userspace any
flexiblity for managing the allocation of shadow stacks for newly
created threads, instead the kernel allocates a new shadow stack with
the same size as the normal stack whenever a thread is created with the
feature enabled. The stacks allocated in this way are freed by the
kernel when the thread exits or shadow stacks are disabled for the
thread. This lack of flexibility and control isn't ideal, in the vast
majority of cases the shadow stack will be over allocated and the
implicit allocation and deallocation is not consistent with other
interfaces. As far as I can tell the interface is done in this manner
mainly because the shadow stack patches were in development since before
clone3() was implemented.
Since clone3() is readily extensible let's add support for specifying a
shadow stack when creating a new thread or process in a similar manner
to how the normal stack is specified, keeping the current implicit
allocation behaviour if one is not specified either with clone3() or
through the use of clone(). The user must provide a shadow stack
address and size, this must point to memory mapped for use as a shadow
stackby map_shadow_stack() with a shadow stack token at the top of the
stack.
Please note that the x86 portions of this code are build tested only, I
don't appear to have a system that can run CET avaible to me, I have
done testing with an integration into my pending work for GCS. There is
some possibility that the arm64 implementation may require the use of
clone3() and explicit userspace allocation of shadow stacks, this is
still under discussion.
Please further note that the token consumption done by clone3() is not
currently implemented in an atomic fashion, Rick indicated that he would
look into fixing this if people are OK with the implementation.
A new architecture feature Kconfig option for shadow stacks is added as
here, this was suggested as part of the review comments for the arm64
GCS series and since we need to detect if shadow stacks are supported it
seemed sensible to roll it in here.
[1] https://lore.kernel.org/r/20231009-arm64-gcs-v6-0-78e55deaa4dd@kernel.org/
Signed-off-by: Mark Brown <broonie(a)kernel.org>
---
Changes in v6:
- Rebase onto v6.10-rc3.
- Ensure we don't try to free the parent shadow stack in error paths of
x86 arch code.
- Spelling fixes in userspace API document.
- Additional cleanups and improvements to the clone3() tests to support
the shadow stack tests.
- Link to v5: https://lore.kernel.org/r/20240203-clone3-shadow-stack-v5-0-322c69598e4b@ke…
Changes in v5:
- Rebase onto v6.8-rc2.
- Rework ABI to have the user allocate the shadow stack memory with
map_shadow_stack() and a token.
- Force inlining of the x86 shadow stack enablement.
- Move shadow stack enablement out into a shared header for reuse by
other tests.
- Link to v4: https://lore.kernel.org/r/20231128-clone3-shadow-stack-v4-0-8b28ffe4f676@ke…
Changes in v4:
- Formatting changes.
- Use a define for minimum shadow stack size and move some basic
validation to fork.c.
- Link to v3: https://lore.kernel.org/r/20231120-clone3-shadow-stack-v3-0-a7b8ed3e2acc@ke…
Changes in v3:
- Rebase onto v6.7-rc2.
- Remove stale shadow_stack in internal kargs.
- If a shadow stack is specified unconditionally use it regardless of
CLONE_ parameters.
- Force enable shadow stacks in the selftest.
- Update changelogs for RISC-V feature rename.
- Link to v2: https://lore.kernel.org/r/20231114-clone3-shadow-stack-v2-0-b613f8681155@ke…
Changes in v2:
- Rebase onto v6.7-rc1.
- Remove ability to provide preallocated shadow stack, just specify the
desired size.
- Link to v1: https://lore.kernel.org/r/20231023-clone3-shadow-stack-v1-0-d867d0b5d4d0@ke…
---
Mark Brown (9):
Documentation: userspace-api: Add shadow stack API documentation
selftests: Provide helper header for shadow stack testing
mm: Introduce ARCH_HAS_USER_SHADOW_STACK
fork: Add shadow stack support to clone3()
selftests/clone3: Remove redundant flushes of output streams
selftests/clone3: Factor more of main loop into test_clone3()
selftests/clone3: Explicitly handle child exits due to signals
selftests/clone3: Allow tests to flag if -E2BIG is a valid error code
selftests/clone3: Test shadow stack support
Documentation/userspace-api/index.rst | 1 +
Documentation/userspace-api/shadow_stack.rst | 41 ++++
arch/x86/Kconfig | 1 +
arch/x86/include/asm/shstk.h | 11 +-
arch/x86/kernel/process.c | 2 +-
arch/x86/kernel/shstk.c | 104 +++++++---
fs/proc/task_mmu.c | 2 +-
include/linux/mm.h | 2 +-
include/linux/sched/task.h | 13 ++
include/uapi/linux/sched.h | 13 +-
kernel/fork.c | 76 ++++++--
mm/Kconfig | 6 +
tools/testing/selftests/clone3/clone3.c | 225 ++++++++++++++++++----
tools/testing/selftests/clone3/clone3_selftests.h | 40 +++-
tools/testing/selftests/ksft_shstk.h | 63 ++++++
15 files changed, 512 insertions(+), 88 deletions(-)
---
base-commit: 83a7eefedc9b56fe7bfeff13b6c7356688ffa670
change-id: 20231019-clone3-shadow-stack-15d40d2bf536
Best regards,
--
Mark Brown <broonie(a)kernel.org>
v2:
- Fix test_cpuset_prs.sh problems reported by test robot
- Relax restriction imposed between cpuset.cpus.exclusive and
cpuset.cpus of sibling cpusets.
- Make cpuset.cpus.exclusive independent of cpuset.cpus.
- Update test_cpuset_prs.sh accordingly.
[v1] https://lore.kernel.org/lkml/20240605171858.1323464-1-longman@redhat.com/
This patchset attempts to address the following cpuset issues.
1) While reviewing the generate_sched_domains() function, I found a bug
in generating sched domains for remote non-isolating partitions.
2) Test robot had reported a test_cpuset_prs.sh test failure.
3) The current exclusivity test between cpuset.cpus.exclusive and
cpuset.cpus and the restriction that the set effective exclusive
CPUs has to be a subset of cpuset.cpus make it harder to preconfigure
the cgroup hierarchy to enable remote partition.
The test_cpuset_prs.sh script is updated to match changes made in this
patchset and was run to verify that the new code did not cause any
regression.
Waiman Long (5):
cgroup/cpuset: Fix remote root partition creation problem
selftest/cgroup: Fix test_cpuset_prs.sh problems reported by test
robot
cgroup/cpuset: Delay setting of CS_CPU_EXCLUSIVE until valid partition
cgroup/cpuset: Make cpuset.cpus.exclusive independent of cpuset.cpus
selftest/cgroup: Update test_cpuset_prs.sh to match changes
Documentation/admin-guide/cgroup-v2.rst | 12 +-
kernel/cgroup/cpuset.c | 158 +++++++++++++-----
.../selftests/cgroup/test_cpuset_prs.sh | 75 ++++++---
3 files changed, 180 insertions(+), 65 deletions(-)
--
2.39.3
From: Allison Henderson <allison.henderson(a)oracle.com>
Hi All,
This series is a new selftest that Vegard, Chuck and myself have been
working on to provide some test coverage for rds. I've made quite a few
updates since the rfc sent a few weeks ago:
I've added several knobs to the script to tune network turbulance, and
documented their usage in the README.txt. By default these options
are left off.
Added an extra flag to specify log location
I've also added a flag to the config.sh to skip gcov configurations if
the coverage report is not desired. run.sh has been adapted to skip
the report if the required configs are not present, or if the required
packages are not available
A time out has been added to prevent the test from hanging
indefinitely
The previous gcov issues have been resolved with an appropriate gcov
patch, as well as some extra logic to detect incompatible gcov and gcc
versions.
The shellcheck nits reported in the last review have been addressed
In order to return an appropriate exit code, the run.sh script has
been adapted to analyze the test.py strace, and determine if the test
passed, failed or timed out.
RDS specific GCOV configs have been documented under
Documentation/dev-tools/gcov.rst
Questions and comments appreciated. Thanks everyone!
Allison
Vegard Nossum (3):
.gitignore: add .gcda files
net: rds: add option for GCOV profiling
selftests: rds: add testing infrastructure
.gitignore | 1 +
Documentation/dev-tools/gcov.rst | 11 +
MAINTAINERS | 1 +
net/rds/Kconfig | 9 +
net/rds/Makefile | 5 +
tools/testing/selftests/Makefile | 1 +
tools/testing/selftests/net/rds/Makefile | 13 +
tools/testing/selftests/net/rds/README.txt | 41 ++++
tools/testing/selftests/net/rds/config.sh | 56 +++++
tools/testing/selftests/net/rds/init.sh | 69 ++++++
tools/testing/selftests/net/rds/run.sh | 271 +++++++++++++++++++++
tools/testing/selftests/net/rds/test.py | 251 +++++++++++++++++++
12 files changed, 729 insertions(+)
create mode 100644 tools/testing/selftests/net/rds/Makefile
create mode 100644 tools/testing/selftests/net/rds/README.txt
create mode 100755 tools/testing/selftests/net/rds/config.sh
create mode 100755 tools/testing/selftests/net/rds/init.sh
create mode 100755 tools/testing/selftests/net/rds/run.sh
create mode 100644 tools/testing/selftests/net/rds/test.py
--
2.25.1
To verify IFS (In Field Scan [1]) driver functionality, add the following 6
test cases:
1. Verify that IFS sysfs entries are created after loading the IFS module
2. Check if loading an invalid IFS test image fails and loading a valid
one succeeds
3. Perform IFS scan test on each CPU using all the available image files
4. Perform IFS scan with first test image file on a random CPU for 3
rounds
5. Perform IFS ARRAY BIST(Board Integrated System Test) test on each CPU
6. Perform IFS ARRAY BIST test on a random CPU for 3 rounds
These are not exhaustive, but some minimal test runs to check various
parts of the driver. Some negative tests are also included.
[1] https://docs.kernel.org/arch/x86/ifs.html
Pengfei Xu (4):
selftests: ifs: verify test interfaces are created by the driver
selftests: ifs: verify test image loading functionality
selftests: ifs: verify IFS scan test functionality
selftests: ifs: verify IFS ARRAY BIST functionality
MAINTAINERS | 1 +
tools/testing/selftests/Makefile | 1 +
.../drivers/platform/x86/intel/ifs/Makefile | 6 +
.../platform/x86/intel/ifs/test_ifs.sh | 494 ++++++++++++++++++
4 files changed, 502 insertions(+)
create mode 100644 tools/testing/selftests/drivers/platform/x86/intel/ifs/Makefile
create mode 100755 tools/testing/selftests/drivers/platform/x86/intel/ifs/test_ifs.sh
---
Changes:
v1 to v2:
- Rebase to v6.10 cycle kernel and resolve some code conflicts
- Improved checking of IFS ARRAY_BIST support by leveraging sysfs entry
methods (suggested by Ashok)
--
2.43.0
In this series, 4 tests are being conformed to TAP.
Muhammad Usama Anjum (4):
selftests: x86: check_initial_reg_state: conform test to TAP format
output
selftests: x86: corrupt_xstate_header: conform test to TAP format
output
selftests: fsgsbase_restore: conform test to TAP format output
selftests: entry_from_vm86: conform test to TAP format output
.../selftests/x86/check_initial_reg_state.c | 24 ++--
.../selftests/x86/corrupt_xstate_header.c | 30 +++--
tools/testing/selftests/x86/entry_from_vm86.c | 109 ++++++++--------
.../testing/selftests/x86/fsgsbase_restore.c | 117 +++++++++---------
4 files changed, 139 insertions(+), 141 deletions(-)
--
2.39.2
Don't print that 88 sub-tests are going to be executed. But then skip.
The error is printed that executed test was only 1 while 88 should have
run:
Old output:
TAP version 13
1..88
ok 2 # SKIP all tests require euid == 0
# Planned tests != run tests (88 != 1)
# Totals: pass:0 fail:0 xfail:0 xpass:0 skip:1 error:0
New and correct output:
TAP version 13
1..0 # SKIP all tests require euid == 0
Signed-off-by: Muhammad Usama Anjum <usama.anjum(a)collabora.com>
---
tools/testing/selftests/openat2/resolve_test.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/tools/testing/selftests/openat2/resolve_test.c b/tools/testing/selftests/openat2/resolve_test.c
index bbafad440893c..5472ec478d227 100644
--- a/tools/testing/selftests/openat2/resolve_test.c
+++ b/tools/testing/selftests/openat2/resolve_test.c
@@ -508,12 +508,13 @@ void test_openat2_opath_tests(void)
int main(int argc, char **argv)
{
ksft_print_header();
- ksft_set_plan(NUM_TESTS);
/* NOTE: We should be checking for CAP_SYS_ADMIN here... */
- if (geteuid() != 0)
+ if (geteuid())
ksft_exit_skip("all tests require euid == 0\n");
+ ksft_set_plan(NUM_TESTS);
+
test_openat2_opath_tests();
if (ksft_get_fail_cnt() + ksft_get_error_cnt() > 0)
--
2.39.2