@@ -63,20 +63,20 @@ int BPF_PROG(handle__tp_btf, struct pt_regs *regs, long id)
return 0;
}
-SEC("kprobe/hrtimer_nanosleep")
-int BPF_KPROBE(handle__kprobe,
- ktime_t rqtp, enum hrtimer_mode mode, clockid_t clockid)
+SEC("kprobe/hrtimer_start_range_ns")
+int BPF_KPROBE(handle__kprobe, struct hrtimer *timer, ktime_t tim, u64 delta_ns,
+ const enum hrtimer_mode mode)
{
- if (rqtp == MY_TV_NSEC)
+ if (tim == MY_TV_NSEC)
kprobe_called = true;
return 0;
}
-SEC("fentry/hrtimer_nanosleep")
-int BPF_PROG(handle__fentry,
- ktime_t rqtp, enum hrtimer_mode mode, clockid_t clockid)
+SEC("fentry/hrtimer_start_range_ns")
+int BPF_PROG(handle__fentry, struct hrtimer *timer, ktime_t tim, u64 delta_ns,
+ const enum hrtimer_mode mode)
{
- if (rqtp == MY_TV_NSEC)
+ if (tim == MY_TV_NSEC)
fentry_called = true;
return 0;
}
The test_vmlinux test uses hrtimer_nanosleep as hook to test tracing programs. But it seems Clang may have done an aggressive optimization, causing fentry and kprobe to not hook on this function properly on a Clang build kernel. A possible fix is switching to use a more reliable function, e.g. the ones exported to kernel modules such as hrtimer_range_start_ns. After we switch to using hrtimer_range_start_ns, the test passes again even on a clang build kernel. Tested: In a clang build kernel, the test fail even when the flags {fentry, kprobe}_called are set unconditionally in handle__kprobe() and handle__fentry(), which implies the programs do not hook on hrtimer_nanosleep() properly. This could be because clang's code transformation is too aggressive. test_vmlinux:PASS:skel_open 0 nsec test_vmlinux:PASS:skel_attach 0 nsec test_vmlinux:PASS:tp 0 nsec test_vmlinux:PASS:raw_tp 0 nsec test_vmlinux:PASS:tp_btf 0 nsec test_vmlinux:FAIL:kprobe not called test_vmlinux:FAIL:fentry not called After we switch to hrtimer_range_start_ns, the test passes. test_vmlinux:PASS:skel_open 0 nsec test_vmlinux:PASS:skel_attach 0 nsec test_vmlinux:PASS:tp 0 nsec test_vmlinux:PASS:raw_tp 0 nsec test_vmlinux:PASS:tp_btf 0 nsec test_vmlinux:PASS:kprobe 0 nsec test_vmlinux:PASS:fentry 0 nsec Signed-off-by: Hao Luo <haoluo@google.com> --- tools/testing/selftests/bpf/progs/test_vmlinux.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-)