Hi,
and after a little bit of time, here comes the v6 of the HID-BPF series.
Again, for a full explanation of HID-BPF, please refer to the last patch
in this series (23/23).
This version sees some improvements compared to v5 on top of the
usual addressing of the previous comments:
- now I think every eBPF core change has a matching selftest added
- the kfuncs declared in syscall can now actually access the memory of
the context
- the code to retrieve the BTF ID of the various HID hooks is much
simpler (just a plain use of the BTF_ID() API instead of
loading/unloading of a tracing program)
- I also added my HID Surface Dial example that I use locally to provide
a fuller example to users
Cheers,
Benjamin
Benjamin Tissoires (23):
selftests/bpf: fix config for CLS_BPF
bpf/verifier: allow kfunc to read user provided context
bpf/verifier: do not clear meta in check_mem_size
selftests/bpf: add test for accessing ctx from syscall program type
bpf/verifier: allow kfunc to return an allocated mem
selftests/bpf: Add tests for kfunc returning a memory pointer
bpf: prepare for more bpf syscall to be used from kernel and user
space.
libbpf: add map_get_fd_by_id and map_delete_elem in light skeleton
HID: core: store the unique system identifier in hid_device
HID: export hid_report_type to uapi
HID: convert defines of HID class requests into a proper enum
HID: initial BPF implementation
selftests/bpf: add tests for the HID-bpf initial implementation
HID: bpf: allocate data memory for device_event BPF programs
selftests/bpf/hid: add test to change the report size
HID: bpf: introduce hid_hw_request()
selftests/bpf: add tests for bpf_hid_hw_request
HID: bpf: allow to change the report descriptor
selftests/bpf: add report descriptor fixup tests
selftests/bpf: Add a test for BPF_F_INSERT_HEAD
samples/bpf: add new hid_mouse example
HID: bpf: add Surface Dial example
Documentation: add HID-BPF docs
Documentation/hid/hid-bpf.rst | 512 +++++++++
Documentation/hid/index.rst | 1 +
drivers/hid/Kconfig | 2 +
drivers/hid/Makefile | 2 +
drivers/hid/bpf/Kconfig | 19 +
drivers/hid/bpf/Makefile | 11 +
drivers/hid/bpf/entrypoints/Makefile | 88 ++
drivers/hid/bpf/entrypoints/README | 4 +
drivers/hid/bpf/entrypoints/entrypoints.bpf.c | 66 ++
.../hid/bpf/entrypoints/entrypoints.lskel.h | 682 ++++++++++++
drivers/hid/bpf/hid_bpf_dispatch.c | 554 ++++++++++
drivers/hid/bpf/hid_bpf_dispatch.h | 28 +
drivers/hid/bpf/hid_bpf_jmp_table.c | 577 ++++++++++
drivers/hid/hid-core.c | 49 +-
include/linux/bpf.h | 10 +-
include/linux/btf.h | 14 +
include/linux/hid.h | 38 +-
include/linux/hid_bpf.h | 145 +++
include/uapi/linux/hid.h | 26 +-
include/uapi/linux/hid_bpf.h | 25 +
kernel/bpf/btf.c | 67 +-
kernel/bpf/syscall.c | 10 +-
kernel/bpf/verifier.c | 67 +-
net/bpf/test_run.c | 23 +
samples/bpf/.gitignore | 2 +
samples/bpf/Makefile | 27 +
samples/bpf/hid_mouse.bpf.c | 134 +++
samples/bpf/hid_mouse.c | 150 +++
samples/bpf/hid_surface_dial.bpf.c | 161 +++
samples/bpf/hid_surface_dial.c | 216 ++++
tools/include/uapi/linux/hid.h | 62 ++
tools/include/uapi/linux/hid_bpf.h | 25 +
tools/lib/bpf/skel_internal.h | 23 +
tools/testing/selftests/bpf/Makefile | 5 +-
tools/testing/selftests/bpf/config | 5 +-
tools/testing/selftests/bpf/prog_tests/hid.c | 990 ++++++++++++++++++
.../selftests/bpf/prog_tests/kfunc_call.c | 68 ++
tools/testing/selftests/bpf/progs/hid.c | 206 ++++
.../selftests/bpf/progs/kfunc_call_test.c | 116 ++
39 files changed, 5150 insertions(+), 60 deletions(-)
create mode 100644 Documentation/hid/hid-bpf.rst
create mode 100644 drivers/hid/bpf/Kconfig
create mode 100644 drivers/hid/bpf/Makefile
create mode 100644 drivers/hid/bpf/entrypoints/Makefile
create mode 100644 drivers/hid/bpf/entrypoints/README
create mode 100644 drivers/hid/bpf/entrypoints/entrypoints.bpf.c
create mode 100644 drivers/hid/bpf/entrypoints/entrypoints.lskel.h
create mode 100644 drivers/hid/bpf/hid_bpf_dispatch.c
create mode 100644 drivers/hid/bpf/hid_bpf_dispatch.h
create mode 100644 drivers/hid/bpf/hid_bpf_jmp_table.c
create mode 100644 include/linux/hid_bpf.h
create mode 100644 include/uapi/linux/hid_bpf.h
create mode 100644 samples/bpf/hid_mouse.bpf.c
create mode 100644 samples/bpf/hid_mouse.c
create mode 100644 samples/bpf/hid_surface_dial.bpf.c
create mode 100644 samples/bpf/hid_surface_dial.c
create mode 100644 tools/include/uapi/linux/hid.h
create mode 100644 tools/include/uapi/linux/hid_bpf.h
create mode 100644 tools/testing/selftests/bpf/prog_tests/hid.c
create mode 100644 tools/testing/selftests/bpf/progs/hid.c
--
2.36.1
In rseq_test, there are two threads, which are vCPU thread and migration
worker separately. Unfortunately, the test has the wrong PID passed to
sched_setaffinity() in the migration worker. It forces migration on the
migration worker because zeroed PID represents the calling thread, which
is the migration worker itself. It means the vCPU thread is never enforced
to migration and it can migrate at any time, which eventually leads to
failure as the following logs show.
host# uname -r
5.19.0-rc6-gavin+
host# # cat /proc/cpuinfo | grep processor | tail -n 1
processor : 223
host# pwd
/home/gavin/sandbox/linux.main/tools/testing/selftests/kvm
host# for i in `seq 1 100`; do \
echo "--------> $i"; ./rseq_test; done
--------> 1
--------> 2
--------> 3
--------> 4
--------> 5
--------> 6
==== Test Assertion Failure ====
rseq_test.c:265: rseq_cpu == cpu
pid=3925 tid=3925 errno=4 - Interrupted system call
1 0x0000000000401963: main at rseq_test.c:265 (discriminator 2)
2 0x0000ffffb044affb: ?? ??:0
3 0x0000ffffb044b0c7: ?? ??:0
4 0x0000000000401a6f: _start at ??:?
rseq CPU = 4, sched CPU = 27
Fix the issue by passing correct parameter, TID of the vCPU thread, to
sched_setaffinity() in the migration worker.
Fixes: 61e52f1630f5 ("KVM: selftests: Add a test for KVM_RUN+rseq to detect task migration bugs")
Suggested-by: Sean Christopherson <seanjc(a)google.com>
Signed-off-by: Gavin Shan <gshan(a)redhat.com>
Reviewed-by: Oliver Upton <oliver.upton(a)linux.dev>
---
v4: Pick the code change as Sean suggested.
---
tools/testing/selftests/kvm/rseq_test.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/tools/testing/selftests/kvm/rseq_test.c b/tools/testing/selftests/kvm/rseq_test.c
index 4158da0da2bb..2237d1aac801 100644
--- a/tools/testing/selftests/kvm/rseq_test.c
+++ b/tools/testing/selftests/kvm/rseq_test.c
@@ -82,8 +82,9 @@ static int next_cpu(int cpu)
return cpu;
}
-static void *migration_worker(void *ign)
+static void *migration_worker(void *__rseq_tid)
{
+ pid_t rseq_tid = (pid_t)(unsigned long)__rseq_tid;
cpu_set_t allowed_mask;
int r, i, cpu;
@@ -106,7 +107,7 @@ static void *migration_worker(void *ign)
* stable, i.e. while changing affinity is in-progress.
*/
smp_wmb();
- r = sched_setaffinity(0, sizeof(allowed_mask), &allowed_mask);
+ r = sched_setaffinity(rseq_tid, sizeof(allowed_mask), &allowed_mask);
TEST_ASSERT(!r, "sched_setaffinity failed, errno = %d (%s)",
errno, strerror(errno));
smp_wmb();
@@ -231,7 +232,8 @@ int main(int argc, char *argv[])
vm = vm_create_default(VCPU_ID, 0, guest_code);
ucall_init(vm, NULL);
- pthread_create(&migration_thread, NULL, migration_worker, 0);
+ pthread_create(&migration_thread, NULL, migration_worker,
+ (void *)(unsigned long)gettid());
for (i = 0; !done; i++) {
vcpu_run(vm, VCPU_ID);
--
2.23.0
Hello Amit Daniel Kachhap,
The patch e9b60476bea0: "kselftest/arm64: Add utilities and a test to
validate mte memory" from Oct 2, 2020, leads to the following Smatch
static checker warning:
./tools/testing/selftests/arm64/mte/mte_common_util.c:336 mte_default_setup()
warn: bitwise AND condition is false here
./tools/testing/selftests/arm64/mte/mte_common_util.c
316 int mte_default_setup(void)
317 {
318 unsigned long hwcaps2 = getauxval(AT_HWCAP2);
319 unsigned long en = 0;
320 int ret;
321
322 if (!(hwcaps2 & HWCAP2_MTE)) {
323 ksft_print_msg("SKIP: MTE features unavailable\n");
324 return KSFT_SKIP;
325 }
326 /* Get current mte mode */
327 ret = prctl(PR_GET_TAGGED_ADDR_CTRL, en, 0, 0, 0);
328 if (ret < 0) {
329 ksft_print_msg("FAIL:prctl PR_GET_TAGGED_ADDR_CTRL with error =%d\n", ret);
330 return KSFT_FAIL;
331 }
332 if (ret & PR_MTE_TCF_SYNC)
333 mte_cur_mode = MTE_SYNC_ERR;
334 else if (ret & PR_MTE_TCF_ASYNC)
335 mte_cur_mode = MTE_ASYNC_ERR;
--> 336 else if (ret & PR_MTE_TCF_NONE)
It looks like the intent was to make PR_MTE_TCF_NONE into an ifdef
configurable thing but that never happened?
337 mte_cur_mode = MTE_NONE_ERR;
338
339 mte_cur_pstate_tco = mte_get_pstate_tco();
340 /* Disable PSTATE.TCO */
341 mte_disable_pstate_tco();
342 return 0;
343 }
regards,
dan carpenter
0Day/LKP observed that the kselftest blocks forever since one of the
pidfd_wait doesn't terminate in 1 of 30 runs. After digging into
the source, we found that it blocks at:
ASSERT_EQ(sys_waitid(P_PIDFD, pidfd, &info, WCONTINUED, NULL), 0);
wait_states has below testing flow:
CHILD PARENT
---------------+--------------
1 STOP itself
2 WAIT for CHILD STOPPED
3 SIGNAL CHILD to CONT
4 CONT
5 STOP itself
5' WAIT for CHILD CONT
6 WAIT for CHILD STOPPED
The problem is that the kernel cannot ensure the order of 5 and 5', once
5's goes first, the test will fail.
we can reproduce it by:
$ while true; do make run_tests -C pidfd; done
Introduce a blocking read in child process to make sure the parent can
check its WCONTINUED.
CC: Philip Li <philip.li(a)intel.com>
Reported-by: kernel test robot <lkp(a)intel.com>
Signed-off-by: Li Zhijian <lizhijian(a)fujitsu.com>
---
I have almost forgotten this patch since the former version post over 6 months
ago. This time I just do a rebase and update the comments.
V2: rewrite with pipe to avoid usleep
---
tools/testing/selftests/pidfd/pidfd_wait.c | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/tools/testing/selftests/pidfd/pidfd_wait.c b/tools/testing/selftests/pidfd/pidfd_wait.c
index 070c1c876df1..3f7bc6517dea 100644
--- a/tools/testing/selftests/pidfd/pidfd_wait.c
+++ b/tools/testing/selftests/pidfd/pidfd_wait.c
@@ -95,20 +95,27 @@ TEST(wait_states)
.flags = CLONE_PIDFD | CLONE_PARENT_SETTID,
.exit_signal = SIGCHLD,
};
+ int ret, pfd[2];
pid_t pid;
siginfo_t info = {
.si_signo = 0,
};
+ ASSERT_EQ(pipe(pfd), 0);
pid = sys_clone3(&args);
ASSERT_GE(pid, 0);
if (pid == 0) {
+ char buf[2];
+ close(pfd[1]);
kill(getpid(), SIGSTOP);
+ ASSERT_EQ(read(pfd[0], buf, 1), 1);
+ close(pfd[0]);
kill(getpid(), SIGSTOP);
exit(EXIT_SUCCESS);
}
+ close(pfd[0]);
ASSERT_EQ(sys_waitid(P_PIDFD, pidfd, &info, WSTOPPED, NULL), 0);
ASSERT_EQ(info.si_signo, SIGCHLD);
ASSERT_EQ(info.si_code, CLD_STOPPED);
@@ -117,6 +124,8 @@ TEST(wait_states)
ASSERT_EQ(sys_pidfd_send_signal(pidfd, SIGCONT, NULL, 0), 0);
ASSERT_EQ(sys_waitid(P_PIDFD, pidfd, &info, WCONTINUED, NULL), 0);
+ ASSERT_EQ(write(pfd[1], "C", 1), 1);
+ close(pfd[1]);
ASSERT_EQ(info.si_signo, SIGCHLD);
ASSERT_EQ(info.si_code, CLD_CONTINUED);
ASSERT_EQ(info.si_pid, parent_tid);
--
2.36.0
In rseq_test, there are two threads, which are vCPU thread and migration
worker separately. Unfortunately, the test has the wrong PID passed to
sched_setaffinity() in the migration worker. It forces migration on the
migration worker because zeroed PID represents the calling thread, which
is the migration worker itself. It means the vCPU thread is never enforced
to migration and it can migrate at any time, which eventually leads to
failure as the following logs show.
host# uname -r
5.19.0-rc6-gavin+
host# # cat /proc/cpuinfo | grep processor | tail -n 1
processor : 223
host# pwd
/home/gavin/sandbox/linux.main/tools/testing/selftests/kvm
host# for i in `seq 1 100`; do \
echo "--------> $i"; ./rseq_test; done
--------> 1
--------> 2
--------> 3
--------> 4
--------> 5
--------> 6
==== Test Assertion Failure ====
rseq_test.c:265: rseq_cpu == cpu
pid=3925 tid=3925 errno=4 - Interrupted system call
1 0x0000000000401963: main at rseq_test.c:265 (discriminator 2)
2 0x0000ffffb044affb: ?? ??:0
3 0x0000ffffb044b0c7: ?? ??:0
4 0x0000000000401a6f: _start at ??:?
rseq CPU = 4, sched CPU = 27
Fix the issue by passing correct parameter, TID of the vCPU thread, to
sched_setaffinity() in the migration worker.
Fixes: 61e52f1630f5 ("KVM: selftests: Add a test for KVM_RUN+rseq to detect task migration bugs")
Signed-off-by: Gavin Shan <gshan(a)redhat.com>
Reviewed-by: Oliver Upton <oliver.upton(a)linux.dev>
---
v3: Improved changelog (Oliver Upon)
---
tools/testing/selftests/kvm/rseq_test.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/tools/testing/selftests/kvm/rseq_test.c b/tools/testing/selftests/kvm/rseq_test.c
index 4158da0da2bb..c83ac7b467f8 100644
--- a/tools/testing/selftests/kvm/rseq_test.c
+++ b/tools/testing/selftests/kvm/rseq_test.c
@@ -38,6 +38,7 @@ static __thread volatile struct rseq __rseq = {
*/
#define NR_TASK_MIGRATIONS 100000
+static pid_t rseq_tid;
static pthread_t migration_thread;
static cpu_set_t possible_mask;
static int min_cpu, max_cpu;
@@ -106,7 +107,8 @@ static void *migration_worker(void *ign)
* stable, i.e. while changing affinity is in-progress.
*/
smp_wmb();
- r = sched_setaffinity(0, sizeof(allowed_mask), &allowed_mask);
+ r = sched_setaffinity(rseq_tid, sizeof(allowed_mask),
+ &allowed_mask);
TEST_ASSERT(!r, "sched_setaffinity failed, errno = %d (%s)",
errno, strerror(errno));
smp_wmb();
@@ -231,6 +233,7 @@ int main(int argc, char *argv[])
vm = vm_create_default(VCPU_ID, 0, guest_code);
ucall_init(vm, NULL);
+ rseq_tid = gettid();
pthread_create(&migration_thread, NULL, migration_worker, 0);
for (i = 0; !done; i++) {
--
2.23.0
In rseq_test, there are two threads, which are thread group leader
and migration worker. The migration worker relies on sched_setaffinity()
to force migration on the thread group leader. Unfortunately, we
have wrong parameter (0) passed to sched_getaffinity(). It's actually
forcing migration on the migration worker instead of the thread group
leader. It also means migration can happen on the thread group leader
at any time, which eventually leads to failure as the following logs
show.
host# uname -r
5.19.0-rc6-gavin+
host# # cat /proc/cpuinfo | grep processor | tail -n 1
processor : 223
host# pwd
/home/gavin/sandbox/linux.main/tools/testing/selftests/kvm
host# for i in `seq 1 100`; \
do echo "--------> $i"; ./rseq_test; done
--------> 1
--------> 2
--------> 3
--------> 4
--------> 5
--------> 6
==== Test Assertion Failure ====
rseq_test.c:265: rseq_cpu == cpu
pid=3925 tid=3925 errno=4 - Interrupted system call
1 0x0000000000401963: main at rseq_test.c:265 (discriminator 2)
2 0x0000ffffb044affb: ?? ??:0
3 0x0000ffffb044b0c7: ?? ??:0
4 0x0000000000401a6f: _start at ??:?
rseq CPU = 4, sched CPU = 27
This fixes the issue by passing correct parameter, tid of the group
thread leader, to sched_setaffinity().
Fixes: 61e52f1630f5 ("KVM: selftests: Add a test for KVM_RUN+rseq to detect task migration bugs")
Signed-off-by: Gavin Shan <gshan(a)redhat.com>
---
tools/testing/selftests/kvm/rseq_test.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/tools/testing/selftests/kvm/rseq_test.c b/tools/testing/selftests/kvm/rseq_test.c
index 4158da0da2bb..c83ac7b467f8 100644
--- a/tools/testing/selftests/kvm/rseq_test.c
+++ b/tools/testing/selftests/kvm/rseq_test.c
@@ -38,6 +38,7 @@ static __thread volatile struct rseq __rseq = {
*/
#define NR_TASK_MIGRATIONS 100000
+static pid_t rseq_tid;
static pthread_t migration_thread;
static cpu_set_t possible_mask;
static int min_cpu, max_cpu;
@@ -106,7 +107,8 @@ static void *migration_worker(void *ign)
* stable, i.e. while changing affinity is in-progress.
*/
smp_wmb();
- r = sched_setaffinity(0, sizeof(allowed_mask), &allowed_mask);
+ r = sched_setaffinity(rseq_tid, sizeof(allowed_mask),
+ &allowed_mask);
TEST_ASSERT(!r, "sched_setaffinity failed, errno = %d (%s)",
errno, strerror(errno));
smp_wmb();
@@ -231,6 +233,7 @@ int main(int argc, char *argv[])
vm = vm_create_default(VCPU_ID, 0, guest_code);
ucall_init(vm, NULL);
+ rseq_tid = gettid();
pthread_create(&migration_thread, NULL, migration_worker, 0);
for (i = 0; !done; i++) {
--
2.23.0