On 6/30/20 5:10 PM, Hao Luo wrote:
Ok, with the help of my colleague Ian Rogers, I think we solved the
mystery. Clang actually inlined hrtimer_nanosleep() inside
SyS_nanosleep(), so there is no call to that function throughout the
path of the nanosleep syscall. I've been looking at the functio
On Tue, Jun 30, 2020 at 1:47 PM Hao Luo wrote:
>
> 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 possib
On 6/30/20 11:49 AM, Hao Luo wrote:
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.
Could you explain why it do