[LPC2025] snooper: bpf_task_work_schedule() and file-based dynptr example#358
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[LPC2025] snooper: bpf_task_work_schedule() and file-based dynptr example#358
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WITH task_work_schedule_signal():
$ sudo ./snooper `pidof app`
Snooping on tasks for PID 5331...
Task: app_thread (PID=5331, TID=5332)
No kernel stack
User stack:
00007fbc700b90c2: random @ 0x42080+0x42
00007fbc700b8e7d: rand @ 0x41e70+0xd
00000000004012df: func_b @ 0x40129a+0x45
0000000000401283: func_a @ 0x4011f2+0x91
0000000000401476: thread_func @ 0x4013f6+0x80
00007fbc7010b39d: <no-symbol>
00007fbc7019049c: <no-symbol>
Task: app (PID=5331, TID=5331)
Kernel stack:
ffffffff813e7e49: hrtimer_nanosleep @ 0xffffffff813e7db0+0x99
ffffffff813f1c73: common_nsleep @ 0xffffffff813f1c30+0x43
ffffffff813f2e0d: __x64_sys_clock_nanosleep @ 0xffffffff813f2d50+0xbd
ffffffff8241a09a: do_syscall_64 @ 0xffffffff8241a030+0x6a
ffffffff810000b0: entry_SYSCALL_64_after_hwframe @ 0xffffffff81000065+0x4b
User stack:
00007fbc70158733: clock_nanosleep @ 0xe16d0+0x63
00007fbc70164827: nanosleep @ 0xed810+0x17
00007fbc70176f41: sleep @ 0xfff00+0x41
0000000000401622: main @ 0x40153c+0xe6
00007fbc7009ce08: <no-symbol>
00007fbc7009cecc: __libc_start_main @ 0x25e40+0x8c
0000000000401105: _start @ 0x4010e0+0x25
WITHOUT task_work_schedule_signal() CANNOT get correct stack trace after
multiple tries:
$ sudo ./snooper `pidof app`
Snooping on tasks for PID 5004...
Task: app_thread (PID=5004, TID=5005)
No kernel stack
User stack (frame pointer unwinding):
00000000004011fd: func_mux @ 0x4011f2+0xb
15c15fd673415a00: <no-symbol>
$ sudo ./snooper `pidof app`
Snooping on tasks for PID 5004...
Task: app_thread (PID=5004, TID=5005)
No kernel stack
User stack (frame pointer unwinding):
00007fcbaf2490a8: random @ 0x42080+0x28
000062cbaf248e7d: <no-symbol>
0000000000401269: func_mux @ 0x4011f2+0x77
00000000004012a6: func_a @ 0x40126e+0x38
000000000040124b: func_mux @ 0x4011f2+0x59
15c15fd673415a00: <no-symbol>
Note that 15c15fd673415a00 is NOT a valid address.
Signed-off-by: Andrii Nakryiko <[email protected]>
Signed-off-by: Andrii Nakryiko <[email protected]>
Signed-off-by: Andrii Nakryiko <[email protected]>
Signed-off-by: Andrii Nakryiko <[email protected]>
Signed-off-by: Andrii Nakryiko <[email protected]>
Signed-off-by: Andrii Nakryiko <[email protected]>
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