Re: kernel: tracepoints: add support for relative references

From: Steven Rostedt
Date: Tue Sep 19 2017 - 13:55:54 EST

On Tue, 5 Sep 2017 13:49:52 +0100
Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx> wrote:

> OK, thanks for spotting that.
>
> I will fix and resend after the merge window closes.

I also just applied your patches (to 4.13-rc7) and ran the ftrace self
tests in tools/testing/selftests/ftrace/ftracetest and it triggered
this:


=============================
WARNING: suspicious RCU usage
4.13.0-rc7-test+ #101 Tainted: G W
-----------------------------
/work/git/linux-trace.git/arch/x86/kernel/traps.c:305 entry code didn't wake RCU!

other info that might help us debug this:


RCU used illegally from idle CPU!
rcu_scheduler_active = 2, debug_locks = 1
RCU used illegally from extended quiescent state!
no locks held by swapper/0/0.

stack backtrace:
CPU: 0 PID: 0 Comm: swapper/0 Tainted: G W 4.13.0-rc7-test+ #101
Hardware name: Hewlett-Packard HP Compaq Pro 6300 SFF/339A, BIOS K01 v03.03 07/14/2016
Call Trace:
dump_stack+0x86/0xcf
lockdep_rcu_suspicious+0xc5/0x100
do_error_trap+0x125/0x130
? do_error_trap+0x5/0x130
? trace_hardirqs_off_thunk+0x1a/0x1c
? do_invalid_op+0x5/0x30
do_invalid_op+0x20/0x30
invalid_op+0x1e/0x30
RIP: 0010:module_assert_mutex_or_preempt+0x34/0x40
RSP: 0018:ffffffff81e03bc0 EFLAGS: 00010046
RAX: 0000000000000000 RBX: ffffffffa000a077 RCX: 0000000000000002
RDX: 0000000000000000 RSI: 00000000ffffffff RDI: 0000000000000046
RBP: ffffffff81e03bc0 R08: ffffffff81e03f40 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: ffffffff81e16500 R15: ffffffff81ed5760
? 0xffffffffa000a077
__module_address+0x2c/0xf0
? 0xffffffffa000a077
__module_text_address+0x12/0x60
? 0xffffffffa000a077
is_module_text_address+0x1f/0x50
? 0xffffffffa000a077
__kernel_text_address+0x30/0x90
unwind_get_return_address+0x1f/0x30
__save_stack_trace+0x83/0xd0
? 0xffffffffa000a077
? rcu_dynticks_eqs_exit+0x5/0x40
save_stack_trace+0x1b/0x20
check_stack+0xf8/0x2f0
? rcu_dynticks_eqs_enter+0x30/0x30
stack_trace_call+0x6e/0x80
0xffffffffa000a077
? ftrace_graph_caller+0x78/0xa8
? rcu_dynticks_eqs_exit+0x5/0x40
rcu_dynticks_eqs_exit+0x5/0x40
rcu_idle_exit+0xdf/0xf0
? rcu_dynticks_eqs_exit+0x5/0x40
? rcu_idle_exit+0xdf/0xf0
do_idle+0x128/0x200
cpu_startup_entry+0x1d/0x20
rest_init+0xd6/0xe0
start_kernel+0x40c/0x419
? early_idt_handler_array+0x120/0x120
x86_64_start_reservations+0x2a/0x2c
x86_64_start_kernel+0x13e/0x14d
secondary_startup_64+0x9f/0x9f

=============================
WARNING: suspicious RCU usage
4.13.0-rc7-test+ #101 Not tainted
-----------------------------
/work/git/linux-trace.git/kernel/workqueue.c:712 sched RCU or wq_pool_mutex should be held!

other info that might help us debug this:


RCU used illegally from idle CPU!
rcu_scheduler_active = 2, debug_locks = 1
RCU used illegally from extended quiescent state!
2 locks held by swapper/0/0:
#0: (console_lock){+.+.+.}, at: [<ffffffff81118786>] vprintk_emit+0x246/0x3d0
#1: (printing_lock){......}, at: [<ffffffff81529749>] vt_console_print+0x49/0x3b0

stack backtrace:
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.13.0-rc7-test+ #101
Hardware name: Hewlett-Packard HP Compaq Pro 6300 SFF/339A, BIOS K01 v03.03 07/14/2016
Call Trace:

=============================
WARNING: suspicious RCU usage
4.13.0-rc7-test+ #101 Not tainted
-----------------------------
/work/git/linux-trace.git/include/linux/rcupdate.h:611 rcu_read_lock() used illegally while idle!

other info that might help us debug this:


RCU used illegally from idle CPU!
rcu_scheduler_active = 2, debug_locks = 1
RCU used illegally from extended quiescent state!
3 locks held by swapper/0/0:
#0: (console_lock){+.+.+.}, at: [<ffffffff81118786>] vprintk_emit+0x246/0x3d0
#1: (printing_lock){......}, at: [<ffffffff81529749>] vt_console_print+0x49/0x3b0
#2: (rcu_read_lock){......}, at: [<ffffffff8117d025>] __is_insn_slot_addr+0x5/0x140

stack backtrace:
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.13.0-rc7-test+ #101
Hardware name: Hewlett-Packard HP Compaq Pro 6300 SFF/339A, BIOS K01 v03.03 07/14/2016
Call Trace:

=============================
WARNING: suspicious RCU usage
4.13.0-rc7-test+ #101 Not tainted
-----------------------------
/work/git/linux-trace.git/include/linux/rcupdate.h:662 rcu_read_unlock() used illegally while idle!

other info that might help us debug this:


RCU used illegally from idle CPU!
rcu_scheduler_active = 2, debug_locks = 1
RCU used illegally from extended quiescent state!
4 locks held by swapper/0/0:
#0: (console_lock){+.+.+.}, at: [<ffffffff81118786>] vprintk_emit+0x246/0x3d0
#1: (printing_lock){......}, at: [<ffffffff81529749>] vt_console_print+0x49/0x3b0
#2: (rcu_read_lock){......}, at: [<ffffffff8117d025>] __is_insn_slot_addr+0x5/0x140
#3: (rcu_read_lock){......}, at: [<ffffffff8117d025>] __is_insn_slot_addr+0x5/0x140

stack backtrace:
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.13.0-rc7-test+ #101
Hardware name: Hewlett-Packard HP Compaq Pro 6300 SFF/339A, BIOS K01 v03.03 07/14/2016
Call Trace:

=============================
WARNING: suspicious RCU usage
4.13.0-rc7-test+ #101 Not tainted
-----------------------------
/work/git/linux-trace.git/include/linux/rcupdate.h:611 rcu_read_lock() used illegally while idle!

other info that might help us debug this:


RCU used illegally from idle CPU!
rcu_scheduler_active = 2, debug_locks = 1
RCU used illegally from extended quiescent state!
5 locks held by swapper/0/0:
#0: (console_lock){+.+.+.}, at: [<ffffffff81118786>] vprintk_emit+0x246/0x3d0
#1: (printing_lock){......}, at: [<ffffffff81529749>] vt_console_print+0x49/0x3b0
#2: (rcu_read_lock){......}, at: [<ffffffff8117d025>] __is_insn_slot_addr+0x5/0x140
#3: (rcu_read_lock){......}, at: [<ffffffff8117d025>] __is_insn_slot_addr+0x5/0x140
#4: (rcu_read_lock){......}, at: [<ffffffff811ca0a5>] is_bpf_text_address+0x5/0xe0

stack backtrace:
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.13.0-rc7-test+ #101
Hardware name: Hewlett-Packard HP Compaq Pro 6300 SFF/339A, BIOS K01 v03.03 07/14/2016
Call Trace:

=============================
WARNING: suspicious RCU usage
4.13.0-rc7-test+ #101 Not tainted
-----------------------------
/work/git/linux-trace.git/include/linux/rcupdate.h:662 rcu_read_unlock() used illegally while idle!

other info that might help us debug this:


RCU used illegally from idle CPU!
rcu_scheduler_active = 2, debug_locks = 1
RCU used illegally from extended quiescent state!
6 locks held by swapper/0/0:
#0: (console_lock){+.+.+.}, at: [<ffffffff81118786>] vprintk_emit+0x246/0x3d0
#1: (printing_lock){......}, at: [<ffffffff81529749>] vt_console_print+0x49/0x3b0
#2: (rcu_read_lock){......}, at: [<ffffffff8117d025>] __is_insn_slot_addr+0x5/0x140
#3: (rcu_read_lock){......}, at: [<ffffffff8117d025>] __is_insn_slot_addr+0x5/0x140
#4: (rcu_read_lock){......}, at: [<ffffffff811ca0a5>] is_bpf_text_address+0x5/0xe0
#5: (rcu_read_lock){......}, at: [<ffffffff811ca0a5>] is_bpf_text_address+0x5/0xe0

stack backtrace:
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.13.0-rc7-test+ #101
Hardware name: Hewlett-Packard HP Compaq Pro 6300 SFF/339A, BIOS K01 v03.03 07/14/2016
Call Trace:
dump_stack+0x86/0xcf
lockdep_rcu_suspicious+0xc5/0x100
is_bpf_text_address+0xdc/0xe0
__kernel_text_address+0x74/0x90
show_trace_log_lvl+0x160/0x380
? dump_stack+0x86/0xcf
show_stack+0x44/0x60
dump_stack+0x86/0xcf
lockdep_rcu_suspicious+0xc5/0x100
is_bpf_text_address+0xb2/0xe0
__kernel_text_address+0x74/0x90
show_trace_log_lvl+0x160/0x380
? dump_stack+0x86/0xcf
show_stack+0x44/0x60
dump_stack+0x86/0xcf
lockdep_rcu_suspicious+0xc5/0x100
__is_insn_slot_addr+0x114/0x140
__kernel_text_address+0x68/0x90
show_trace_log_lvl+0x160/0x380
? dump_stack+0x86/0xcf
show_stack+0x44/0x60
dump_stack+0x86/0xcf
lockdep_rcu_suspicious+0xc5/0x100
__is_insn_slot_addr+0xe0/0x140
__kernel_text_address+0x68/0x90
show_trace_log_lvl+0x160/0x380
? dump_stack+0x86/0xcf
show_stack+0x44/0x60
dump_stack+0x86/0xcf
lockdep_rcu_suspicious+0xc5/0x100
get_work_pool+0x87/0x90
__queue_work+0x9c/0x5e0
queue_work_on+0x8a/0xa0

=============================
WARNING: suspicious RCU usage
4.13.0-rc7-test+ #101 Not tainted
-----------------------------
/work/git/linux-trace.git/kernel/notifier.c:548 notify_die called but RCU thinks we're quiescent!

other info that might help us debug this:


RCU used illegally from idle CPU!
rcu_scheduler_active = 2, debug_locks = 1
RCU used illegally from extended quiescent state!
6 locks held by swapper/0/0:
#0: (console_lock){+.+.+.}, at: [<ffffffff81118786>] vprintk_emit+0x246/0x3d0
#1: (printing_lock){......}, at: [<ffffffff81529749>] vt_console_print+0x49/0x3b0
#2: (rcu_read_lock){......}, at: [<ffffffff8117d025>] __is_insn_slot_addr+0x5/0x140
#3: (rcu_read_lock){......}, at: [<ffffffff8117d025>] __is_insn_slot_addr+0x5/0x140
#4: (rcu_read_lock){......}, at: [<ffffffff811ca0a5>] is_bpf_text_address+0x5/0xe0
#5: (rcu_read_lock){......}, at: [<ffffffff811ca0a5>] is_bpf_text_address+0x5/0xe0

stack backtrace:
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.13.0-rc7-test+ #101
Hardware name: Hewlett-Packard HP Compaq Pro 6300 SFF/339A, BIOS K01 v03.03 07/14/2016
Call Trace:
dump_stack+0x86/0xcf
lockdep_rcu_suspicious+0xc5/0x100
notify_die+0x72/0x80
do_error_trap+0x54/0x130
? do_error_trap+0x5/0x130
? trace_hardirqs_off_thunk+0x1a/0x1c
? do_invalid_op+0x5/0x30

=============================
WARNING: suspicious RCU usage
4.13.0-rc7-test+ #101 Not tainted
-----------------------------
/work/git/linux-trace.git/include/linux/rcupdate.h:611 rcu_read_lock() used illegally while idle!

other info that might help us debug this:


RCU used illegally from idle CPU!
rcu_scheduler_active = 2, debug_locks = 1
RCU used illegally from extended quiescent state!
7 locks held by swapper/0/0:
#0: (console_lock){+.+.+.}, at: [<ffffffff81118786>] vprintk_emit+0x246/0x3d0
#1: (printing_lock){......}, at: [<ffffffff81529749>] vt_console_print+0x49/0x3b0
#2: (rcu_read_lock){......}, at: [<ffffffff8117d025>] __is_insn_slot_addr+0x5/0x140
#3: (rcu_read_lock){......}, at: [<ffffffff8117d025>] __is_insn_slot_add
Lost 1926 message(s)!


Config attached.

-- Steve

Attachment: config.gz
Description: application/gzip