This is something that I've been thinking about for a while. We had a
discussion at LPC 2020 about this[1] but the proposals suggested there
never materialised.
In short, it is quite difficult for userspace to detect the feature
capability of syscalls at runtime. This is something a lot of programs
want to do, but they are forced to create elaborate scenarios to try to
figure out if a feature is supported without causing damage to the
system. For the vast majority of cases, each individual feature also
needs to be tested individually (because syscall results are
all-or-nothing), so testing even a single syscall's feature set can
easily inflate the startup time of programs.
This patchset implements the fairly minimal design I proposed in this
talk[2] and in some old LKML threads (though I can't find the exact
references ATM). The general flow looks like:
1. Userspace will indicate to the kernel that a syscall should a be
no-op by setting the top bit of the extensible struct size argument.
We will almost certainly never support exabyte sized structs, so the
top bits are free for us to use as makeshift flag bits. This is
preferable to using the per-syscall flag field inside the structure
because seccomp can easily detect the bit in the flag and allow the
probe or forcefully return -EEXTSYS_NOOP.
2. The kernel will then fill the provided structure with every valid
bit pattern that the current kernel understands.
For flags or other bitflag-like fields, this is the set of valid
flags or bits. For pointer fields or fields that take an arbitrary
value, the field has every bit set (0xFF... to fill the field) to
indicate that any value is valid in the field.
3. The syscall then returns -EEXTSYS_NOOP which is an errno that will
only ever be used for this purpose (so userspace can be sure that
the request succeeded).
On older kernels, the syscall will return a different error (usually
-E2BIG or -EFAULT) and userspace can do their old-fashioned checks.
4. Userspace can then check which flags and fields are supported by
looking at the fields in the returned structure. Flags are checked
by doing an AND with the flags field, and field support can checked
by comparing to 0. In principle you could just AND the entire
structure if you wanted to do this check generically without caring
about the structure contents (this is what libraries might consider
doing).
Userspace can even find out the internal kernel structure size by
passing a PAGE_SIZE buffer and seeing how many bytes are non-zero.
As with copy_struct_from_user(), this is designed to be forward- and
backwards- compatible.
This allows programas to get a one-shot understanding of what features a
syscall supports without having to do any elaborate setups or tricks to
detect support for destructive features. Flags can simply be ANDed to
check if they are in the supported set, and fields can just be checked
to see if they are non-zero.
This patchset is IMHO the simplest way we can add the ability to
introspect the feature set of extensible struct (copy_struct_from_user)
syscalls. It doesn't preclude the chance of a more generic mechanism
being added later.
The intended way of using this interface to get feature information
looks something like the following (imagine that openat2 has gained a
new field and a new flag in the future):
static bool openat2_no_automount_supported;
static bool openat2_cwd_fd_supported;
int check_openat2_support(void)
{
int err;
struct open_how how = {};
err = openat2(AT_FDCWD, ".", &how, CHECK_FIELDS | sizeof(how));
assert(err < 0);
switch (errno) {
case EFAULT: case E2BIG:
/* Old kernel... */
check_support_the_old_way();
break;
case EEXTSYS_NOOP:
openat2_no_automount_supported = (how.flags & RESOLVE_NO_AUTOMOUNT);
openat2_cwd_fd_supported = (how.cwd_fd != 0);
break;
}
}
This series adds CHECK_FIELDS support for the following extensible
struct syscalls, as they are quite likely to grow flags in the near
future:
* openat2
* clone3
* mount_setattr
[1]: https://lwn.net/Articles/830666/
[2]: https://youtu.be/ggD-eb3yPVs
Signed-off-by: Aleksa Sarai <cyphar(a)cyphar.com>
---
Changes in v3:
- Fix copy_struct_to_user() return values in case of clear_user() failure.
- v2: <https://lore.kernel.org/r/20240906-extensible-structs-check_fields-v2-0-0f4…>
Changes in v2:
- Add CHECK_FIELDS support to mount_setattr(2).
- Fix build failure on architectures with custom errno values.
- Rework selftests to use the tools/ uAPI headers rather than custom
defining EEXTSYS_NOOP.
- Make sure we return -EINVAL and -E2BIG for invalid sizes even if
CHECK_FIELDS is set, and add some tests for that.
- v1: <https://lore.kernel.org/r/20240902-extensible-structs-check_fields-v1-0-545…>
---
Aleksa Sarai (10):
uaccess: add copy_struct_to_user helper
sched_getattr: port to copy_struct_to_user
openat2: explicitly return -E2BIG for (usize > PAGE_SIZE)
openat2: add CHECK_FIELDS flag to usize argument
selftests: openat2: add 0xFF poisoned data after misaligned struct
selftests: openat2: add CHECK_FIELDS selftests
clone3: add CHECK_FIELDS flag to usize argument
selftests: clone3: add CHECK_FIELDS selftests
mount_setattr: add CHECK_FIELDS flag to usize argument
selftests: mount_setattr: add CHECK_FIELDS selftest
arch/alpha/include/uapi/asm/errno.h | 3 +
arch/mips/include/uapi/asm/errno.h | 3 +
arch/parisc/include/uapi/asm/errno.h | 3 +
arch/sparc/include/uapi/asm/errno.h | 3 +
fs/namespace.c | 17 ++
fs/open.c | 18 ++
include/linux/uaccess.h | 97 ++++++++
include/uapi/asm-generic/errno.h | 3 +
include/uapi/linux/openat2.h | 2 +
kernel/fork.c | 30 ++-
kernel/sched/syscalls.c | 42 +---
tools/arch/alpha/include/uapi/asm/errno.h | 3 +
tools/arch/mips/include/uapi/asm/errno.h | 3 +
tools/arch/parisc/include/uapi/asm/errno.h | 3 +
tools/arch/sparc/include/uapi/asm/errno.h | 3 +
tools/include/uapi/asm-generic/errno.h | 3 +
tools/include/uapi/asm-generic/posix_types.h | 101 ++++++++
tools/testing/selftests/clone3/.gitignore | 1 +
tools/testing/selftests/clone3/Makefile | 4 +-
.../testing/selftests/clone3/clone3_check_fields.c | 264 +++++++++++++++++++++
tools/testing/selftests/mount_setattr/Makefile | 2 +-
.../selftests/mount_setattr/mount_setattr_test.c | 53 ++++-
tools/testing/selftests/openat2/Makefile | 2 +
tools/testing/selftests/openat2/openat2_test.c | 165 ++++++++++++-
24 files changed, 777 insertions(+), 51 deletions(-)
---
base-commit: 98f7e32f20d28ec452afb208f9cffc08448a2652
change-id: 20240803-extensible-structs-check_fields-a47e94cef691
Best regards,
--
Aleksa Sarai <cyphar(a)cyphar.com>
The new option controls tests run on boot or module load. With the new
debugfs "run" dentry allowing to run tests on demand, an ability to disable
automatic tests run becomes a useful option in case of intrusive tests.
The option is set to true by default to preserve the existent behavior. It
can be overridden by either the corresponding module option or by the
corresponding config build option.
Signed-off-by: Stanislav Kinsburskii <skinsburskii(a)linux.microsoft.com>
---
include/kunit/test.h | 4 +++-
lib/kunit/Kconfig | 12 ++++++++++++
lib/kunit/debugfs.c | 2 +-
lib/kunit/executor.c | 21 +++++++++++++++++++--
lib/kunit/test.c | 6 ++++--
5 files changed, 39 insertions(+), 6 deletions(-)
diff --git a/include/kunit/test.h b/include/kunit/test.h
index 34b71e42fb10..58dbab60f853 100644
--- a/include/kunit/test.h
+++ b/include/kunit/test.h
@@ -312,6 +312,7 @@ static inline void kunit_set_failure(struct kunit *test)
}
bool kunit_enabled(void);
+bool kunit_autorun(void);
const char *kunit_action(void);
const char *kunit_filter_glob(void);
char *kunit_filter(void);
@@ -334,7 +335,8 @@ kunit_filter_suites(const struct kunit_suite_set *suite_set,
int *err);
void kunit_free_suite_set(struct kunit_suite_set suite_set);
-int __kunit_test_suites_init(struct kunit_suite * const * const suites, int num_suites);
+int __kunit_test_suites_init(struct kunit_suite * const * const suites, int num_suites,
+ bool run_tests);
void __kunit_test_suites_exit(struct kunit_suite **suites, int num_suites);
diff --git a/lib/kunit/Kconfig b/lib/kunit/Kconfig
index 34d7242d526d..a97897edd964 100644
--- a/lib/kunit/Kconfig
+++ b/lib/kunit/Kconfig
@@ -81,4 +81,16 @@ config KUNIT_DEFAULT_ENABLED
In most cases this should be left as Y. Only if additional opt-in
behavior is needed should this be set to N.
+config KUNIT_AUTORUN_ENABLED
+ bool "Default value of kunit.autorun"
+ default y
+ help
+ Sets the default value of kunit.autorun. If set to N then KUnit
+ tests will not run after initialization unless kunit.autorun=1 is
+ passed to the kernel command line. The test can still be run manually
+ via debugfs interface.
+
+ In most cases this should be left as Y. Only if additional opt-in
+ behavior is needed should this be set to N.
+
endif # KUNIT
diff --git a/lib/kunit/debugfs.c b/lib/kunit/debugfs.c
index d548750a325a..9df064f40d98 100644
--- a/lib/kunit/debugfs.c
+++ b/lib/kunit/debugfs.c
@@ -145,7 +145,7 @@ static ssize_t debugfs_run(struct file *file,
struct inode *f_inode = file->f_inode;
struct kunit_suite *suite = (struct kunit_suite *) f_inode->i_private;
- __kunit_test_suites_init(&suite, 1);
+ __kunit_test_suites_init(&suite, 1, true);
return count;
}
diff --git a/lib/kunit/executor.c b/lib/kunit/executor.c
index 34b7b6833df3..3f39955cb0f1 100644
--- a/lib/kunit/executor.c
+++ b/lib/kunit/executor.c
@@ -29,6 +29,22 @@ const char *kunit_action(void)
return action_param;
}
+/*
+ * Run KUnit tests after initialization
+ */
+#ifdef CONFIG_KUNIT_AUTORUN_ENABLED
+static bool autorun_param = true;
+#else
+static bool autorun_param;
+#endif
+module_param_named(autorun, autorun_param, bool, 0);
+MODULE_PARM_DESC(autorun, "Run KUnit tests after initialization");
+
+bool kunit_autorun(void)
+{
+ return autorun_param;
+}
+
static char *filter_glob_param;
static char *filter_param;
static char *filter_action_param;
@@ -260,13 +276,14 @@ kunit_filter_suites(const struct kunit_suite_set *suite_set,
void kunit_exec_run_tests(struct kunit_suite_set *suite_set, bool builtin)
{
size_t num_suites = suite_set->end - suite_set->start;
+ bool autorun = kunit_autorun();
- if (builtin || num_suites) {
+ if (autorun && (builtin || num_suites)) {
pr_info("KTAP version 1\n");
pr_info("1..%zu\n", num_suites);
}
- __kunit_test_suites_init(suite_set->start, num_suites);
+ __kunit_test_suites_init(suite_set->start, num_suites, autorun);
}
void kunit_exec_list_tests(struct kunit_suite_set *suite_set, bool include_attr)
diff --git a/lib/kunit/test.c b/lib/kunit/test.c
index 089c832e3cdb..146d1b48a096 100644
--- a/lib/kunit/test.c
+++ b/lib/kunit/test.c
@@ -708,7 +708,8 @@ bool kunit_enabled(void)
return enable_param;
}
-int __kunit_test_suites_init(struct kunit_suite * const * const suites, int num_suites)
+int __kunit_test_suites_init(struct kunit_suite * const * const suites, int num_suites,
+ bool run_tests)
{
unsigned int i;
@@ -731,7 +732,8 @@ int __kunit_test_suites_init(struct kunit_suite * const * const suites, int num_
for (i = 0; i < num_suites; i++) {
kunit_init_suite(suites[i]);
- kunit_run_tests(suites[i]);
+ if (run_tests)
+ kunit_run_tests(suites[i]);
}
static_branch_dec(&kunit_running);
This series implements feature detection of hardware virtualization on
Linux and macOS; the latter being my primary use case.
This yields approximately a 6x improvement using HVF on M3 Pro.
Signed-off-by: Tamir Duberstein <tamird(a)gmail.com>
---
Changes in v2:
- Use QEMU accelerator fallback (Alyssa Ross, Thomas Weißschuh).
- Link to v1: https://lore.kernel.org/r/20241025-kunit-qemu-accel-macos-v1-0-2f30c26192d4…
---
Tamir Duberstein (2):
kunit: add fallback for os.sched_getaffinity
kunit: enable hardware acceleration when available
tools/testing/kunit/kunit.py | 11 ++++++++++-
tools/testing/kunit/kunit_kernel.py | 3 +++
tools/testing/kunit/qemu_configs/arm64.py | 2 +-
3 files changed, 14 insertions(+), 2 deletions(-)
---
base-commit: 81983758430957d9a5cb3333fe324fd70cf63e7e
change-id: 20241025-kunit-qemu-accel-macos-2840e4c2def5
Best regards,
--
Tamir Duberstein <tamird(a)gmail.com>
This patch series extends the sev_init2 and the sev_smoke test to
exercise the SEV-SNP VM launch workflow.
Primarily, it introduces the architectural defines, its support in the SEV
library and extends the tests to interact with the SEV-SNP ioctl()
wrappers.
Patch 1 - Do not advertize SNP on incompatible firmware
Patch 2 - SNP test for KVM_SEV_INIT2
Patch 3 - Add VMGEXIT helper
Patch 4 - Introduce SEV+ VM type check
Patch 5 - SNP iotcl() plumbing for the SEV library
Patch 6 - Force set GUEST_MEMFD for SNP
Patch 7 - Cleanups of smoke test - Decouple policy from type
Patch 8 - SNP smoke test
v4:
1. Remove SNP FW API version check in the test and ensure the KVM
capability advertizes the presence of the feature. Retain the minimum
version definitions to exercise these API versions in the smoke test.
2. Retained only the SNP smoke test and SNP_INIT2 test
3. The SNP architectural defined merged with SNP_INIT2 test patch
4. SNP shutdown merged with SNP smoke test patch
5. Add SEV VM type check to abstract comparisons and reduce clutter
6. Define a SNP default policy which sets bits based on the presence of
SMT
7. Decouple privatization and encryption for it to be SNP agnostic
8. Assert for only positive tests using vm_ioctl()
9. Dropped tested-by tags
In summary - based on comments from Sean, I have primarily reduced the
scope of this patch series to focus on breaking down the SNP smoke test
patch (v3 - patch2) to first introduce SEV-SNP support and use this
interface to extend the sev_init2 and the sev_smoke test.
The rest of the v3 patchset that introduces ioctl, pre fault, fallocate
and negative tests, will be re-worked and re-introduced subsequently in
future patch series post addressing the issues discussed.
v3:
https://lore.kernel.org/kvm/20240905124107.6954-1-pratikrajesh.sampat@amd.c…
1. Remove the assignments for the prefault and fallocate test type
enums.
2. Fix error message for sev launch measure and finish.
3. Collect tested-by tags [Peter, Srikanth]
Any feedback/review is highly appreciated!
Pratik R. Sampat (8):
KVM: SEV: Disable SEV-SNP on FW validation failure
KVM: selftests: SEV-SNP test for KVM_SEV_INIT2
KVM: selftests: Add VMGEXIT helper
KVM: selftests: Introduce SEV VM type check
KVM: selftests: Add library support for interacting with SNP
KVM: selftests: Force GUEST_MEMFD flag for SNP VM type
KVM: selftests: Abstractions for SEV to decouple policy from type
KVM: selftests: Add a basic SEV-SNP smoke test
arch/x86/kvm/svm/sev.c | 4 +-
drivers/crypto/ccp/sev-dev.c | 6 ++
include/linux/psp-sev.h | 3 +
.../selftests/kvm/include/x86_64/processor.h | 1 +
.../selftests/kvm/include/x86_64/sev.h | 55 ++++++++++-
tools/testing/selftests/kvm/lib/kvm_util.c | 7 +-
.../selftests/kvm/lib/x86_64/processor.c | 4 +-
tools/testing/selftests/kvm/lib/x86_64/sev.c | 98 ++++++++++++++++++-
.../selftests/kvm/x86_64/sev_init2_tests.c | 13 +++
.../selftests/kvm/x86_64/sev_smoke_test.c | 96 ++++++++++++++----
10 files changed, 258 insertions(+), 29 deletions(-)
--
2.43.0
The new option controls tests run on boot or module load. With the new
debugfs "run" dentry allowing to run tests on demand, an ability to disable
automatic tests run becomes a useful option in case of intrusive tests.
The option is set to true by default to preserve the existent behavior. It
can be overridden by either the corresponding module option or by the
corresponding config build option.
Signed-off-by: Stanislav Kinsburskii <skinsburskii(a)linux.microsoft.com>
---
include/kunit/test.h | 4 +++-
lib/kunit/Kconfig | 12 ++++++++++++
lib/kunit/debugfs.c | 2 +-
lib/kunit/executor.c | 18 +++++++++++++++++-
lib/kunit/test.c | 6 ++++--
5 files changed, 37 insertions(+), 5 deletions(-)
diff --git a/include/kunit/test.h b/include/kunit/test.h
index 34b71e42fb10..58dbab60f853 100644
--- a/include/kunit/test.h
+++ b/include/kunit/test.h
@@ -312,6 +312,7 @@ static inline void kunit_set_failure(struct kunit *test)
}
bool kunit_enabled(void);
+bool kunit_autorun(void);
const char *kunit_action(void);
const char *kunit_filter_glob(void);
char *kunit_filter(void);
@@ -334,7 +335,8 @@ kunit_filter_suites(const struct kunit_suite_set *suite_set,
int *err);
void kunit_free_suite_set(struct kunit_suite_set suite_set);
-int __kunit_test_suites_init(struct kunit_suite * const * const suites, int num_suites);
+int __kunit_test_suites_init(struct kunit_suite * const * const suites, int num_suites,
+ bool run_tests);
void __kunit_test_suites_exit(struct kunit_suite **suites, int num_suites);
diff --git a/lib/kunit/Kconfig b/lib/kunit/Kconfig
index 34d7242d526d..a97897edd964 100644
--- a/lib/kunit/Kconfig
+++ b/lib/kunit/Kconfig
@@ -81,4 +81,16 @@ config KUNIT_DEFAULT_ENABLED
In most cases this should be left as Y. Only if additional opt-in
behavior is needed should this be set to N.
+config KUNIT_AUTORUN_ENABLED
+ bool "Default value of kunit.autorun"
+ default y
+ help
+ Sets the default value of kunit.autorun. If set to N then KUnit
+ tests will not run after initialization unless kunit.autorun=1 is
+ passed to the kernel command line. The test can still be run manually
+ via debugfs interface.
+
+ In most cases this should be left as Y. Only if additional opt-in
+ behavior is needed should this be set to N.
+
endif # KUNIT
diff --git a/lib/kunit/debugfs.c b/lib/kunit/debugfs.c
index d548750a325a..9df064f40d98 100644
--- a/lib/kunit/debugfs.c
+++ b/lib/kunit/debugfs.c
@@ -145,7 +145,7 @@ static ssize_t debugfs_run(struct file *file,
struct inode *f_inode = file->f_inode;
struct kunit_suite *suite = (struct kunit_suite *) f_inode->i_private;
- __kunit_test_suites_init(&suite, 1);
+ __kunit_test_suites_init(&suite, 1, true);
return count;
}
diff --git a/lib/kunit/executor.c b/lib/kunit/executor.c
index 34b7b6833df3..340723571b0f 100644
--- a/lib/kunit/executor.c
+++ b/lib/kunit/executor.c
@@ -29,6 +29,22 @@ const char *kunit_action(void)
return action_param;
}
+/*
+ * Run KUnit tests after initialization
+ */
+#ifdef CONFIG_KUNIT_AUTORUN_ENABLED
+static bool autorun_param = true;
+#else
+static bool autorun_param;
+#endif
+module_param_named(autorun, autorun_param, bool, 0);
+MODULE_PARM_DESC(autorun, "Run KUnit tests after initialization");
+
+bool kunit_autorun(void)
+{
+ return autorun_param;
+}
+
static char *filter_glob_param;
static char *filter_param;
static char *filter_action_param;
@@ -266,7 +282,7 @@ void kunit_exec_run_tests(struct kunit_suite_set *suite_set, bool builtin)
pr_info("1..%zu\n", num_suites);
}
- __kunit_test_suites_init(suite_set->start, num_suites);
+ __kunit_test_suites_init(suite_set->start, num_suites, kunit_autorun());
}
void kunit_exec_list_tests(struct kunit_suite_set *suite_set, bool include_attr)
diff --git a/lib/kunit/test.c b/lib/kunit/test.c
index 089c832e3cdb..146d1b48a096 100644
--- a/lib/kunit/test.c
+++ b/lib/kunit/test.c
@@ -708,7 +708,8 @@ bool kunit_enabled(void)
return enable_param;
}
-int __kunit_test_suites_init(struct kunit_suite * const * const suites, int num_suites)
+int __kunit_test_suites_init(struct kunit_suite * const * const suites, int num_suites,
+ bool run_tests)
{
unsigned int i;
@@ -731,7 +732,8 @@ int __kunit_test_suites_init(struct kunit_suite * const * const suites, int num_
for (i = 0; i < num_suites; i++) {
kunit_init_suite(suites[i]);
- kunit_run_tests(suites[i]);
+ if (run_tests)
+ kunit_run_tests(suites[i]);
}
static_branch_dec(&kunit_running);
After reviewing the code, it was found that these macros are never
referenced in the code. Just remove them.
Signed-off-by: Ba Jing <bajing(a)cmss.chinamobile.com>
---
tools/testing/selftests/landlock/ptrace_test.c | 2 --
1 file changed, 2 deletions(-)
diff --git a/tools/testing/selftests/landlock/ptrace_test.c b/tools/testing/selftests/landlock/ptrace_test.c
index a19db4d0b3bd..8f31b673ff2d 100644
--- a/tools/testing/selftests/landlock/ptrace_test.c
+++ b/tools/testing/selftests/landlock/ptrace_test.c
@@ -22,8 +22,6 @@
/* Copied from security/yama/yama_lsm.c */
#define YAMA_SCOPE_DISABLED 0
#define YAMA_SCOPE_RELATIONAL 1
-#define YAMA_SCOPE_CAPABILITY 2
-#define YAMA_SCOPE_NO_ATTACH 3
static void create_domain(struct __test_metadata *const _metadata)
{
--
2.33.0
If you wish to utilise a pidfd interface to refer to the current process or
thread it is rather cumbersome, requiring something like:
int pidfd = pidfd_open(getpid(), 0 or PIDFD_THREAD);
...
close(pidfd);
Or the equivalent call opening /proc/self. It is more convenient to use a
sentinel value to indicate to an interface that accepts a pidfd that we
simply wish to refer to the current process thread.
This series introduces sentinels for this purposes which can be passed as
the pidfd in this instance rather than having to establish a dummy fd for
this purpose.
It is useful to refer to both the current thread from the userland's
perspective for which we use PIDFD_SELF, and the current process from the
userland's perspective, for which we use PIDFD_SELF_PROCESS.
There is unfortunately some confusion between the kernel and userland as to
what constitutes a process - a thread from the userland perspective is a
process in userland, and a userland process is a thread group (more
specifically the thread group leader from the kernel perspective). We
therefore alias things thusly:
* PIDFD_SELF_THREAD aliased by PIDFD_SELF - use PIDTYPE_PID.
* PIDFD_SELF_THREAD_GROUP alised by PIDFD_SELF_PROCESS - use PIDTYPE_TGID.
In all of the kernel code we refer to PIDFD_SELF_THREAD and
PIDFD_SELF_THREAD_GROUP. However we expect users to use PIDFD_SELF and
PIDFD_SELF_PROCESS.
This matters for cases where, for instance, a user unshare()'s FDs or does
thread-specific signal handling and where the user would be hugely confused
if the FDs referenced or signal processed referred to the thread group
leader rather than the individual thread.
We ensure that pidfd_send_signal() and pidfd_getfd() work correctly, and
assert as much in selftests. All other interfaces except setns() will work
implicitly with this new interface, however it doesn't make sense to test
waitid(P_PIDFD, ...) as waiting on ourselves is a blocking operation.
In the case of setns() we explicitly disallow use of PIDFD_SELF* as it
doesn't make sense to obtain the namespaces of our own process, and it
would require work to implement this functionality there that would be of
no use.
We also do not provide the ability to utilise PIDFD_SELF* in ordinary fd
operations such as open() or poll(), as this would require extensive work
and be of no real use.
v6:
* Avoid static inline in UAPI header as suggested by Pedro.
* Place PIDFD_SELF values out of range of errors and any other sentinel as
suggested by Pedro.
v5:
* Fixup self test dependencies on pidfd/pidfd.h.
https://lore.kernel.org/linux-mm/cover.1729848252.git.lorenzo.stoakes@oracl…
v4:
* Avoid returning an fd in the __pidfd_get_pid() function as pointed out by
Christian, instead simply always pin the pid and maintain fd scope in the
helper alone.
* Add wrapper header file in tools/include/linux to allow for import of
UAPI pidfd.h header without encountering the collision between system
fcntl.h and linux/fcntl.h as discussed with Shuah and John.
* Fixup tests to import the UAPI pidfd.h header working around conflicts
between system fcntl.h and linux/fcntl.h which the UAPI pidfd.h imports,
as reported by Shuah.
* Use an int for pidfd_is_self_sentinel() to avoid any dependency on
stdbool.h in userland.
https://lore.kernel.org/linux-mm/cover.1729198898.git.lorenzo.stoakes@oracl…
v3:
* Do not fput() an invalid fd as reported by kernel test bot.
* Fix unintended churn from moving variable declaration.
https://lore.kernel.org/linux-mm/cover.1729073310.git.lorenzo.stoakes@oracl…
v2:
* Fix tests as reported by Shuah.
* Correct RFC version lore link.
https://lore.kernel.org/linux-mm/cover.1728643714.git.lorenzo.stoakes@oracl…
Non-RFC v1:
* Removed RFC tag - there seems to be general consensus that this change is
a good idea, but perhaps some debate to be had on implementation. It
seems sensible then to move forward with the RFC flag removed.
* Introduced PIDFD_SELF_THREAD, PIDFD_SELF_THREAD_GROUP and their aliases
PIDFD_SELF and PIDFD_SELF_PROCESS respectively.
* Updated testing accordingly.
https://lore.kernel.org/linux-mm/cover.1728578231.git.lorenzo.stoakes@oracl…
RFC version:
https://lore.kernel.org/linux-mm/cover.1727644404.git.lorenzo.stoakes@oracl…
Lorenzo Stoakes (5):
pidfd: extend pidfd_get_pid() and de-duplicate pid lookup
pidfd: add PIDFD_SELF_* sentinels to refer to own thread/process
tools: testing: separate out wait_for_pid() into helper header
selftests: pidfd: add pidfd.h UAPI wrapper
selftests: pidfd: add tests for PIDFD_SELF_*
include/linux/pid.h | 34 ++++-
include/uapi/linux/pidfd.h | 10 ++
kernel/exit.c | 4 +-
kernel/nsproxy.c | 1 +
kernel/pid.c | 65 +++++---
kernel/signal.c | 29 +---
tools/include/linux/pidfd.h | 14 ++
tools/testing/selftests/cgroup/test_kill.c | 2 +-
.../pid_namespace/regression_enomem.c | 2 +-
tools/testing/selftests/pidfd/Makefile | 3 +-
tools/testing/selftests/pidfd/pidfd.h | 28 +---
.../selftests/pidfd/pidfd_getfd_test.c | 141 ++++++++++++++++++
tools/testing/selftests/pidfd/pidfd_helpers.h | 39 +++++
.../selftests/pidfd/pidfd_setns_test.c | 11 ++
tools/testing/selftests/pidfd/pidfd_test.c | 76 ++++++++--
15 files changed, 371 insertions(+), 88 deletions(-)
create mode 100644 tools/include/linux/pidfd.h
create mode 100644 tools/testing/selftests/pidfd/pidfd_helpers.h
--
2.47.0