Hello; I decided to turn kgdb on just for the heck of it, I noticed
this once I rebooted:
[ 1.691997] kgdb: Registered I/O driver kgdbts.
[ 1.692485] kgdbts:RUN plant and detach test
[ 1.709377] kgdbts:RUN sw breakpoint test
[ 1.709377] kgdbts:RUN bad memory access test
[ 1.709377] kgdbts:RUN singlestep test 1000 iterations
[ 1.712049] kgdbts:RUN singlestep [0/1000]
[ 1.721988] kgdbts:RUN singlestep [100/1000]
[ 1.739330] kgdbts:RUN singlestep [200/1000]
[ 1.748869] kgdbts: BP mismatch c010852a expected c02753e0
[ 1.749213] ------------[ cut here ]------------
[ 1.749213] WARNING: at drivers/misc/kgdbts.c:302
check_and_rewind_pc+0x9a/0xb4()
[ 1.749213] Modules linked in:
[ 1.749213] Pid: 0, comm: swapper Not tainted 2.6.26-rc4-00168-gc3b25b3 #1
[ 1.749213] [] warn_on_slowpath+0x41/0x6c
[ 1.749213] [] ? release_console_sem+0x188/0x190
[ 1.749213] [] ? sched_clock_cpu+0x10e/0x11c
[ 1.749213] [] ? kgdbts_break_test+0x0/0x1e
[ 1.749214] [] ? printk+0x15/0x17
[ 1.749214] [] ? kgdbts_break_test+0x0/0x1e
[ 1.749214] [] check_and_rewind_pc+0x9a/0xb4
[ 1.749214] [] ? mwait_idle+0x32/0x40
[ 1.749214] [] ? kgdbts_break_test+0x0/0x1e
[ 1.749214] [] validate_simple_test+0x22/0x69
[ 1.749214] [] run_simple_test+0x1a1/0x20e
[ 1.749214] [] kgdbts_put_char+0x14/0x16
[ 1.749214] [] put_packet+0x6b/0xbb
[ 1.749214] [] kgdb_handle_exception+0xb11/0xbe0
[ 1.749214] [] kgdb_notify+0x134/0x15d
[ 1.749214] [] notifier_call_chain+0x2b/0x4a
[ 1.749214] [] __atomic_notifier_call_chain+0x11/0x13
[ 1.749214] [] atomic_notifier_call_chain+0xc/0xe
[ 1.749214] [] notify_die+0x2d/0x2f
[ 1.749214] [] die_nmi+0x1b/0xb7
[ 1.749214] [] nmi_watchdog_tick+0xb3/0x108
[ 1.749214] [] do_nmi+0x84/0x22d
[ 1.749214] [] ? mwait_idle+0x0/0x40
[ 1.749214] [] nmi_stack_correct+0x26/0x2b
[ 1.749214] [] ? mwait_idle+0x0/0x40
[ 1.749214] [] ? mwait_idle+0x32/0x40
[ 1.749214] [] cpu_idle+0xae/0xce
[ 1.749214] [] start_secondary+0x15d/0x162
[ 1.749214] =======================
[ 1.749214] ---[ end trace 4cb23d4b8b3c3614 ]---
[ 1.749214] kgdbts: ERROR PUT: end of test buffer on
'singlestep_breakpoint_test' line 3 expected kgdbts_break_test got
$000000000000000000000000f88410c0a8ffc6f794ffc6f70 100000080b051c0
[ 1.749214] ------------[ cut here ]------------
[ 1.749214] WARNING: at drivers/misc/kgdbts.c:721
run_simple_test+0x1de/0x20e()
[ 1.749214] Modules linked in:
[ 1.749214] Pid: 0, comm: swapper Tainted: G W
2.6.26-rc4-00168-gc3b25b3 #1
[ 1.749214] [] warn_on_slowpath+0x41/0x6c
[ 1.749214] [] ? release_console_sem+0x188/0x190
[ 1.749214] [] ? sched_clock_cpu+0x10e/0x11c
[ 1.749214] [] ? kgdbts_break_test+0x0/0x1e
[ 1.749214] [] ? printk+0x15/0x17
[ 1.749214] [] ? printk+0x15/0x17
[ 1.749214] [] run_simple_test+0x1de/0x20e
[ 1.749214] [] kgdbts_put_char+0x14/0x16
[ 1.749214] [] put_packet+0x6b/0xbb
[ 1.749214] [] kgdb_handle_exception+0xb11/0xbe0
[ 1.749214] [] kgdb_notify+0x134/0x15d
[ 1.749214] [] notifier_call_chain+0x2b/0x4a
[ 1.749214] [] __atomic_notifier_call_chain+0x11/0x13
[ 1.749214] [] atomic_notifier_call_chain+0xc/0xe
[ 1.749214] [] notify_die+0x2d/0x2f
[ 1.749214] [] die_nmi+0x1b/0xb7
[ 1.749214] [] nmi_watchdog_tick+0xb3/0x108
[ 1.749214] [] do_nmi+0x84/0x22d
[ 1.749214] [] ? mwait_idle+0x0/0x40
[ 1.749214] [] nmi_stack_correct+0x26/0x2b
[ 1.749214] [] ? mwait_idle+0x0/0x40
[ 1.749214] [] ? mwait_idle+0x32/0x40
[ 1.749214] [] cpu_idle+0xae/0xce
[ 1.749214] [] start_secondary+0x15d/0x162
[ 1.749214] =======================
[ 1.749214] ---[ end trace 4cb23d4b8b3c3614 ]---
[ 1.985151] kgdbts: ERROR PUT: end of test buffer on
'singlestep_breakpoint_test' line 0 expected S0* got
$T05thread:0000000000000001;#a7
[ 1.987857] ------------[ cut here ]------------
[ 1.987857] WARNING: at drivers/misc/kgdbts.c:721
run_simple_test+0x1de/0x20e()
[ 1.987857] Modules linked in:
[ 1.987857] Pid: 1, comm: swapper Tainted: G W
2.6.26-rc4-00168-gc3b25b3 #1
[ 1.987857] [] warn_on_slowpath+0x41/0x6c
[ 1.987857] [] ? release_console_sem+0x188/0x190
[ 1.987857] [] ? sched_clock_cpu+0x10e/0x11c
[ 1.987857] [] ? printk+0x15/0x17
[ 1.987857] [] run_simple_test+0x1de/0x20e
[ 1.987857] [] kgdbts_put_char+0x14/0x16
[ 1.987857] [] put_packet+0x6b/0xbb
[ 1.987857] [] kgdb_handle_exception+0x2e7/0xbe0
[ 1.987857] [] kgdb_notify+0x134/0x15d
[ 1.987857] [] notifier_call_chain+0x2b/0x4a
[ 1.987857] [] __atomic_notifier_call_chain+0x11/0x13
[ 1.987857] [] atomic_notifier_call_chain+0xc/0xe
[ 1.987857] [] notify_die+0x2d/0x2f
[ 1.987857] [] do_int3+0x29/0x67
[ 1.987857] [] int3+0x27/0x2c
[ 1.987857] [] ? sys_init_module+0x409/0x17ea
[ 1.987857] [] ? kgdb_breakpoint+0x13/0x24
[ 1.987857] [] configure_kgdbts+0x1ba/0x3fa
[ 1.987857] [] init_kgdbts+0x13/0x15
[ 1.987857] [] kernel_init+0x127/0x263
[ 1.987857] [] ? init_kgdbts+0x0/0x15
[ 1.987857] [] ? sched_setaffinity+0xca/0xe3
[ 1.987857] [] ? schedule_tail+0x18/0x46
[ 1.987857] [] ? ret_from_fork+0x6/0x1c
[ 1.987857] [] ? kernel_init+0x0/0x263
[ 1.987857] [] ? kernel_init+0x0/0x263
[ 1.987857] [] kernel_thread_helper+0x7/0x10
[ 1.987857] =======================
[ 1.987857] ---[ end trace 4cb23d4b8b3c3614 ]---
[ 2.125614] kgdbts: BP mismatch c0108536 expected c02753e0
[ 2.129360] ------------[ cut here ]------------
[ 2.133108] WARNING: at drivers/misc/kgdbts.c:302
check_and_rewind_pc+0x9a/0xb4()
[ 2.134178] Modules linked in:
[ 2.134178] Pid: 0, comm: swapper Tainted: G W
2.6.26-rc4-00168-gc3b25b3 #1
[ 2.134178] [] warn_on_slowpath+0x41/0x6c
[ 2.134178] [] ? release_console_sem+0x188/0x190
[ 2.134178] [] ? sched_clock_cpu+0x10e/0x11c
[ 2.134179] [] ? kgdbts_break_test+0x0/0x1e
[ 2.134179] [] ? printk+0x15/0x17
[ 2.134179] [] ? kgdbts_break_test+0x0/0x1e
[ 2.134179] [] check_and_rewind_pc+0x9a/0xb4
[ 2.134179] [] ? mwait_idle+0x3e/0x40
[ 2.134179] [] ? kgdbts_break_test+0x0/0x1e
[ 2.134179] [] validate_simple_test+0x22/0x69
[ 2.134179] [] run_simple_test+0x1a1/0x20e
[ 2.134179] [] kgdbts_put_char+0x14/0x16
[ 2.134179] [] put_packet+0x6b/0xbb
[ 2.134179] [] kgdb_handle_exception+0xb11/0xbe0
[ 2.134179] [] ? rebalance_domains+0x10b/0x361
[ 2.134179] [] kgdb_notify+0x134/0x15d
[ 2.134179] [] notifier_call_chain+0x2b/0x4a
[ 2.134179] [] __atomic_notifier_call_chain+0x11/0x13
[ 2.134179] [] atomic_notifier_call_chain+0xc/0xe
[ 2.134179] [] notify_die+0x2d/0x2f
[ 2.134179] [] do_debug+0x56/0xe4
[ 2.134179] [] ? mwait_idle+0x0/0x40
[ 2.134179] [] debug_stack_correct+0x27/0x2c
[ 2.134179] [] ? mwait_idle+0x0/0x40
[ 2.134179] [] ? mwait_idle+0x3e/0x40
[ 2.134179] [] cpu_idle+0xae/0xce
[ 2.134179] [] start_secondary+0x15d/0x162
[ 2.134179] =======================
[ 2.134179] ---[ end trace 4cb23d4b8b3c3614 ]---
[ 2.134179] kgdbts: ERROR PUT: end of test buffer on
'singlestep_breakpoint_test' line 3 expected kgdbts_break_test got
$000000000000000000000000f88410c0a8ffc6f794ffc6f70 100000080b051c0
[ 2.134179] ------------[ cut here ]------------
[ 2.134179] WARNING: at drivers/misc/kgdbts.c:721
run_simple_test+0x1de/0x20e()
[ 2.134179] Modules linked in:
[ 2.134179] Pid: 0, comm: swapper Tainted: G W
2.6.26-rc4-00168-gc3b25b3 #1
[ 2.134179] [] warn_on_slowpath+0x41/0x6c
[ 2.134179] [] ? release_console_sem+0x188/0x190
[ 2.134179] [] ? sched_clock_cpu+0x10e/0x11c
[ 2.134179] [] ? kgdbts_break_test+0x0/0x1e
[ 2.134179] [] ? printk+0x15/0x17
[ 2.134179] [] ? printk+0x15/0x17
[ 2.134179] [] run_simple_test+0x1de/0x20e
[ 2.134179] [] kgdbts_put_char+0x14/0x16
[ 2.134179] [] put_packet+0x6b/0xbb
[ 2.134179] [] kgdb_handle_exception+0xb11/0xbe0
[ 2.134179] [] ? rebalance_domains+0x10b/0x361
[ 2.134179] [] kgdb_notify+0x134/0x15d
[ 2.134179] [] notifier_call_chain+0x2b/0x4a
[ 2.134179] [] __atomic_notifier_call_chain+0x11/0x13
[ 2.134179] [] atomic_notifier_call_chain+0xc/0xe
[ 2.134179] [] notify_die+0x2d/0x2f
[ 2.134179] [] do_debug+0x56/0xe4
[ 2.134179] [] ? mwait_idle+0x0/0x40
[ 2.134179] [] debug_stack_correct+0x27/0x2c
[ 2.134179] [] ? mwait_idle+0x0/0x40
[ 2.134179] [] ? mwait_idle+0x3e/0x40
[ 2.134179] [] cpu_idle+0xae/0xce
[ 2.134179] [] start_secondary+0x15d/0x162
[ 2.134179] =======================
[ 2.134179] ---[ end trace 4cb23d4b8b3c3614 ]---
[ 2.368316] kgdbts: ERROR PUT: end of test buffer on
'singlestep_breakpoint_test' line 0 expected S0* got
$T05thread:0000000000000001;#a7
[ 2.376366] ------------[ cut here ]------------
[ 2.378308] WARNING: at drivers/misc/kgdbts.c:721
run_simple_test+0x1de/0x20e()
[ 2.378308] Modules linked in:
[ 2.378308] Pid: 1, comm: swapper Tainted: G W
2.6.26-rc4-00168-gc3b25b3 #1
[ 2.378308] [] warn_on_slowpath+0x41/0x6c
[ 2.378308] [] ? release_console_sem+0x188/0x190
[ 2.378308] [] ? get_timestamp+0x8/0x11
[ 2.378308] [] ? sched_clock_cpu+0x10e/0x11c
[ 2.378308] [] ? printk+0x15/0x17
[ 2.378308] [] run_simple_test+0x1de/0x20e
[ 2.378308] [] kgdbts_put_char+0x14/0x16
[ 2.378308] [] put_packet+0x6b/0xbb
[ 2.378308] [] kgdb_handle_exception+0x2e7/0xbe0
[ 2.378308] [] kgdb_notify+0x134/0x15d
[ 2.378308] [] notifier_call_chain+0x2b/0x4a
[ 2.378308] [] __atomic_notifier_call_chain+0x11/0x13
[ 2.378308] [] atomic_notifier_call_chain+0xc/0xe
[ 2.378308] [] notify_die+0x2d/0x2f
[ 2.378308] [] do_int3+0x29/0x67
[ 2.378308] [] int3+0x27/0x2c
[ 2.378308] [] ? sys_init_module+0x409/0x17ea
[ 2.378308] [] ? kgdb_breakpoint+0x13/0x24
[ 2.378308] [] configure_kgdbts+0x1ba/0x3fa
[ 2.378308] [] init_kgdbts+0x13/0x15
[ 2.378308] [] kernel_init+0x127/0x263
[ 2.378308] [] ? init_kgdbts+0x0/0x15
[ 2.378308] [] ? sched_setaffinity+0xca/0xe3
[ 2.378308] [] ? schedule_tail+0x18/0x46
[ 2.378308] [] ? ret_from_fork+0x6/0x1c
[ 2.378308] [] ? kernel_init+0x0/0x263
[ 2.378308] [] ? kernel_init+0x0/0x263
[ 2.378308] [] kernel_thread_helper+0x7/0x10
[ 2.378308] =======================
[ 2.378308] ---[ end trace 4cb23d4b8b3c3614 ]---
[ 2.512115] kgdbts: BP mismatch c0108537 expected c02753e0
[ 2.515884] ------------[ cut here ]------------
[ 2.519708] WARNING: at drivers/misc/kgdbts.c:302
check_and_rewind_pc+0x9a/0xb4()
[ 2.522103] Modules linked in:
[ 2.522103] Pid: 0, comm: swapper Tainted: G W
2.6.26-rc4-00168-gc3b25b3 #1
[ 2.522103] [] warn_on_slowpath+0x41/0x6c
[ 2.522103] [] ? release_console_sem+0x188/0x190
[ 2.522103] [] ? sched_clock_cpu+0x10e/0x11c
[ 2.522103] [] ? kgdbts_break_test+0x0/0x1e
[ 2.522103] [] ? printk+0x15/0x17
[ 2.522103] [] ? kgdbts_break_test+0x0/0x1e
[ 2.522103] [] check_and_rewind_pc+0x9a/0xb4
[ 2.522103] [] ? mwait_idle+0x3f/0x40
[ 2.522103] [] ? kgdbts_break_test+0x0/0x1e
[ 2.522103] [] validate_simple_test+0x22/0x69
[ 2.522103] [] run_simple_test+0x1a1/0x20e
[ 2.522103] [] kgdbts_put_char+0x14/0x16
[ 2.522103] [] put_packet+0x6b/0xbb
[ 2.522103] [] kgdb_handle_exception+0xb11/0xbe0
[ 2.522103] [] kgdb_notify+0x134/0x15d
[ 2.522103] [] notifier_call_chain+0x2b/0x4a
[ 2.522103] [] __atomic_notifier_call_chain+0x11/0x13
[ 2.522103] [] atomic_notifier_call_chain+0xc/0xe
[ 2.522103] [] notify_die+0x2d/0x2f
[ 2.522103] [] do_debug+0x56/0xe4
[ 2.522103] [] ? mwait_idle+0x0/0x40
[ 2.522103] [] debug_stack_correct+0x27/0x2c
[ 2.522103] [] ? mwait_idle+0x0/0x40
[ 2.522103] [] ? mwait_idle+0x3f/0x40
[ 2.522103] [] ? cpu_idle+0xae/0xce
[ 2.522103] [] start_secondary+0x15d/0x162
[ 2.522103] =======================
[ 2.522103] ---[ end trace 4cb23d4b8b3c3614 ]---
[ 2.522103] kgdbts: ERROR PUT: end of test buffer on
'singlestep_breakpoint_test' line 3 expected kgdbts_break_test got
$000000000000000000000000f88410c0072510c0a8ffc6f70 100000080b051c0
[ 2.522103] ------------[ cut here ]------------
[ 2.522103] WARNING: at drivers/misc/kgdbts.c:721
run_simple_test+0x1de/0x20e()
[ 2.522103] Modules linked in:
[ 2.522103] Pid: 0, comm: swapper Tainted: G W
2.6.26-rc4-00168-gc3b25b3 #1
[ 2.522103] [] warn_on_slowpath+0x41/0x6c
[ 2.522103] [] ? release_console_sem+0x188/0x190
[ 2.522103] [] ? sched_clock_cpu+0x10e/0x11c
[ 2.522103] [] ? kgdbts_break_test+0x0/0x1e
[ 2.522103] [] ? printk+0x15/0x17
[ 2.522103] [] ? printk+0x15/0x17
[ 2.522103] [] run_simple_test+0x1de/0x20e
[ 2.522103] [] kgdbts_put_char+0x14/0x16
[ 2.522103] [] put_packet+0x6b/0xbb
[ 2.522103] [] kgdb_handle_exception+0xb11/0xbe0
[ 2.522103] [] kgdb_notify+0x134/0x15d
[ 2.522103] [] notifier_call_chain+0x2b/0x4a
[ 2.522103] [] __atomic_notifier_call_chain+0x11/0x13
[ 2.522103] [] atomic_notifier_call_chain+0xc/0xe
[ 2.522103] [] notify_die+0x2d/0x2f
[ 2.522103] [] do_debug+0x56/0xe4
[ 2.522103] [] ? mwait_idle+0x0/0x40
[ 2.522103] [] debug_stack_correct+0x27/0x2c
[ 2.522103] [] ? mwait_idle+0x0/0x40
[ 2.522103] [] ? mwait_idle+0x3f/0x40
[ 2.522103] [] ? cpu_idle+0xae/0xce
[ 2.522103] [] start_secondary+0x15d/0x162
[ 2.522103] =======================
[ 2.522103] ---[ end trace 4cb23d4b8b3c3614 ]---
[ 2.755799] kgdbts:RUN singlestep [300/1000]
[ 2.765281] kgdbts:RUN singlestep [400/1000]
[ 2.775112] kgdbts:RUN singlestep [500/1000]
[ 2.793702] kgdbts:RUN singlestep [600/1000]
[ 2.811507] kgdbts:RUN singlestep [700/1000]
[ 2.828554] kgdbts:RUN singlestep [800/1000]
[ 2.845613] kgdbts:RUN singlestep [900/1000]
[ 2.863079] kgdbts:RUN hw breakpoint test
[ 2.863079] kgdbts:RUN hw write breakpoint test
[ 2.868373] kgdbts:RUN access write breakpoint test
[ 2.878335] kgdbts:RUN do_fork for 100 breakpoints

I'm going to reboot and see if this appears, if so I will turn this
fuction off, due to not needing it.
As for the above I hope this is useful info.
regards;
--
Justin P. Mattock
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