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charset=UTF-8 Content-Transfer-Encoding: 7bit On 2025-05-13 18:50, Steven Rostedt wrote: > To trigger this bug: > > # echo 1 > /sys/kernel/tracing/instances/boot_mapped/events/syscalls/sys_enter_fchownat/enable > # touch /tmp/x > # chown sshd /tmp/x > # reboot > > On boot up, the dmesg will have: > Ring buffer meta [0] is from previous boot! > Ring buffer meta [1] is from previous boot! > Ring buffer meta [2] is from previous boot! > Ring buffer meta [3] is from previous boot! > Ring buffer meta [4] commit page not found > Ring buffer meta [5] is from previous boot! > Ring buffer meta [6] is from previous boot! > Ring buffer meta [7] is from previous boot! > > Where the buffer on CPU 4 had a "commit page not found" error and that > buffer is cleared and reset causing the output to be empty and the data lost. > > When it works correctly, it has: > > # cat /sys/kernel/tracing/instances/boot_mapped/trace_pipe > <...>-1137 [004] ..... 998.205323: sys_enter_fchownat: __syscall_nr=0x104 (260) dfd=0xffffff9c (4294967196) filename=(0xffffc90000a0002c) user=0x3e8 (1000) group=0xffffffff (4294967295) flag=0x0 (0 > Tested-by: Tasos Sahanidis Patch resolves the issue on my end. Cheers!