From: AKASHI Takahiro <takahiro.akashi@linaro.org>
To: Jungseok Lee <jungseoklee85@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>,
catalin.marinas@arm.com, will.deacon@arm.com, olof@lixom.net,
broonie@kernel.org, david.griego@linaro.org,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org
Subject: Re: [RFC 2/3] arm64: refactor save_stack_trace()
Date: Fri, 17 Jul 2015 11:04:48 +0900 [thread overview]
Message-ID: <55A862C0.4040101@linaro.org> (raw)
In-Reply-To: <A601CC3C-4B09-4D8B-8564-558349D45815@gmail.com>
Jungseok,
Thank you for your testing and reviews.
On 07/16/2015 10:29 PM, Jungseok Lee wrote:
> On Jul 16, 2015, at 10:08 AM, AKASHI Takahiro wrote:
>
> Hi, AKASHI
>
>> On 07/16/2015 09:27 AM, AKASHI Takahiro wrote:
>>> On 07/16/2015 01:13 AM, Steven Rostedt wrote:
>>>> On Wed, 15 Jul 2015 10:55:36 -0400
>>>> Steven Rostedt <rostedt@goodmis.org> wrote:
>>>>
>>>>
>>>>> I'll take a look at it and try to clean up the code.
>>>>
>>>> Does the following patch make sense for you?
>>>
>>> Looks nice. The patch greatly simplifies changes on arm64 side.
>>
>> As follows:
>>
>> - Takahiro AKASHI
>>
>> diff --git a/arch/arm64/include/asm/ftrace.h b/arch/arm64/include/asm/ftrace.h
>> index c5534fa..868d6f1 100644
>> --- a/arch/arm64/include/asm/ftrace.h
>> +++ b/arch/arm64/include/asm/ftrace.h
>> @@ -15,6 +15,7 @@
>>
>> #define MCOUNT_ADDR ((unsigned long)_mcount)
>> #define MCOUNT_INSN_SIZE AARCH64_INSN_SIZE
>> +#define FTRACE_STACK_FRAME_OFFSET 4 /* sync it up with stacktrace.c */
Well,
#define FTRACE_STACK_FRAME_OFFSET AARCH64_INSN_SIZE
might be better.
> How about binding it to -4 in unwind_frame function?
Do you mean like this?
In unwind_frame(),
frame->pc = *(unsigned long*)(fp + 8) - AARCH64_INSN_SIZE;
> IMHO, it would help other developers trying to change stack trace code
> be aware of this stack tracer feature.
>
>> #ifndef __ASSEMBLY__
>> #include <linux/compat.h>
>> diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
>> index 1da6029..2c1bf7d 100644
>> --- a/include/linux/ftrace.h
>> +++ b/include/linux/ftrace.h
>> @@ -260,6 +260,13 @@ static inline void ftrace_kill(void) { }
>> #endif /* CONFIG_FUNCTION_TRACER */
>>
>> #ifdef CONFIG_STACK_TRACER
>> +/*
>> + * the offset value to add to return address from save_stack_trace()
>> + */
>> +#ifndef FTRACE_STACK_FRAME_OFFSET
>> +#define FTRACE_STACK_FRAME_OFFSET 0
>> +#endif
>> +
>> extern int stack_tracer_enabled;
>> int
>> stack_trace_sysctl(struct ctl_table *table, int write,
>> diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c
>> index 9384647..c5b9748 100644
>> --- a/kernel/trace/trace_stack.c
>> +++ b/kernel/trace/trace_stack.c
>> @@ -105,7 +105,7 @@ check_stack(unsigned long ip, unsigned long *stack)
>>
>> /* Skip over the overhead of the stack tracer itself */
>> for (i = 0; i < max_stack_trace.nr_entries; i++) {
>> - if (stack_dump_trace[i] == ip)
>> + if ((stack_dump_trace[i] + FTRACE_STACK_FRAME_OFFSET) == ip)
>> break;
>> }
>>
>> @@ -131,7 +131,8 @@ check_stack(unsigned long ip, unsigned long *stack)
>> p = start;
>>
>> for (; p < top && i < max_stack_trace.nr_entries; p++) {
>> - if (*p == stack_dump_trace[i]) {
>> + if (*p == (stack_dump_trace[i]
>> + + FTRACE_STACK_FRAME_OFFSET)) {
>> stack_dump_trace[x] = stack_dump_trace[i++];
>> this_size = stack_dump_index[x++] =
>> (top - p) * sizeof(unsigned long);
>> --
>
> I've prepared a kernel with the following patches and reviewed them.
>
> 1) Steve's clean up patch
> 2) This patch
> 3) [RFC 2/3]
>
> AFAIU, [RFC 3/3] is not needed any more thanks to Steve's patch.
We don't need [2/3].
> First of all, let's look at the following data.
>
> 1) stack_trace data
> Depth Size Location (55 entries)
> ----- ---- --------
> 0) 4808 16 notifier_call_chain+0x2c/0x94
> 1) 4792 64 raw_notifier_call_chain+0x34/0x44
> 2) 4728 48 timekeeping_update.constprop.9+0xb8/0x114
> 3) 4680 48 update_wall_time+0x408/0x6dc
> 4) 4632 128 tick_do_update_jiffies64+0xd8/0x154
> 5) 4504 80 tick_sched_do_timer+0x50/0x60
> 6) 4424 32 tick_sched_timer+0x34/0x90
> 7) 4392 48 __run_hrtimer+0x60/0x258
> 8) 4344 64 hrtimer_interrupt+0xe8/0x260
> 9) 4280 128 arch_timer_handler_virt+0x38/0x48
> 10) 4152 32 handle_percpu_devid_irq+0x84/0x188
> 11) 4120 64 generic_handle_irq+0x38/0x54
> 12) 4056 32 __handle_domain_irq+0x68/0xbc
> 13) 4024 64 gic_handle_irq+0x38/0x88
> 14) 3960 336 el1_irq+0x64/0xd8
> 15) 3624 16 netif_rx_internal+0x14/0x198
> 16) 3608 64 netif_rx+0x20/0xa4
> 17) 3544 32 loopback_xmit+0x64/0xf4
> 18) 3512 48 dev_hard_start_xmit+0x25c/0x3f8
> 19) 3464 160 __dev_queue_xmit+0x440/0x4dc
> 20) 3304 96 dev_queue_xmit_sk+0x20/0x30
> 21) 3208 32 ip_finish_output+0x1e0/0xabc
> 22) 3176 96 ip_output+0xf0/0x120
> 23) 3080 64 ip_local_out_sk+0x44/0x54
> 24) 3016 32 ip_send_skb+0x24/0xbc
> 25) 2984 48 ip_push_pending_frames+0x40/0x60
> 26) 2936 64 icmp_push_reply+0x104/0x144
> 27) 2872 96 icmp_send+0x3c0/0x3c8
> 28) 2776 192 __udp4_lib_rcv+0x5b8/0x684
> 29) 2584 96 udp_rcv+0x2c/0x3c
> 30) 2488 32 ip_local_deliver+0xa0/0x224
> 31) 2456 48 ip_rcv+0x360/0x57c
> 32) 2408 64 __netif_receive_skb_core+0x4d0/0x80c
> 33) 2344 128 __netif_receive_skb+0x24/0x84
> 34) 2216 32 process_backlog+0x9c/0x15c
> 35) 2184 80 net_rx_action+0x1ec/0x32c
> 36) 2104 160 __do_softirq+0x114/0x2f0
> 37) 1944 128 do_softirq+0x60/0x68
> 38) 1816 32 __local_bh_enable_ip+0xb0/0xd4
> 39) 1784 32 ip_finish_output+0x1f4/0xabc
> 40) 1752 96 ip_output+0xf0/0x120
> 41) 1656 64 ip_local_out_sk+0x44/0x54
> 42) 1592 32 ip_send_skb+0x24/0xbc
> 43) 1560 48 udp_send_skb+0x1b4/0x2f4
> 44) 1512 80 udp_sendmsg+0x2a8/0x7a0
> 45) 1432 272 inet_sendmsg+0xa0/0xd0
> 46) 1160 48 sock_sendmsg+0x30/0x78
> 47) 1112 32 ___sys_sendmsg+0x15c/0x26c
> 48) 1080 400 __sys_sendmmsg+0x94/0x180
> 49) 680 320 SyS_sendmmsg+0x38/0x54
> 50) 360 360 el0_svc_naked+0x20/0x28
>
> 2) stack_max_size data
> 4888
>
> The data looks odd in two points.
> 1) the number of entry
> There is a mismatch between start token and real data
>
> 2) 80-byte gap
> stack_max_size is not aligned with "Depth" field of the first entry of stack_trace.
>
> IMHO, two items are not considered in this series as digging them out.
>
> 1) skipped entries
> As x variable is introduced in Steve's patch, it is needed to track down
> how many entries are recorded in both stack_dump_trace and stack_dump_index.
>
> 2) max_stack_trace.skip value
> max_stack_trace.skip is 0 as applying Steve's patch. The above gap could be
> observed unless the value is not considered in arch code. In the above example,
> 80-byte gap is save_stack_trace function in arch/arm64/kernel/stacktrace.c.
>
> As applying the following fix, stack_trace and stack_max_size are okay.
> However, I'm not sure which code, arch or generic ftrace, should handle trace->skip.
> The latter one is responsible for it under current implementation, not Steve's change.
>
> Please correct me if I am wrong.
I will address these issues in my later replies.
Thanks,
-Takahiro AKASHI
> Best Regards
> Jungseok Lee
>
> ----8<----
>
> diff --git a/arch/arm64/kernel/stacktrace.c b/arch/arm64/kernel/stacktrace.c
> index 978c923..5f6f4df 100644
> --- a/arch/arm64/kernel/stacktrace.c
> +++ b/arch/arm64/kernel/stacktrace.c
> @@ -137,7 +137,9 @@ void save_stack_trace(struct stack_trace *trace)
>
> frame.fp = (unsigned long)__builtin_frame_address(0);
> frame.sp = current_stack_pointer;
> - frame.pc = (unsigned long)save_stack_trace_tsk;
> + frame.pc = (unsigned long)save_stack_trace;
> +
> + trace->skip += 4;
>
> __save_stack_trace(&frame, trace, 0);
> }
> diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c
> index c5b9748..5635683 100644
> --- a/kernel/trace/trace_stack.c
> +++ b/kernel/trace/trace_stack.c
> @@ -158,6 +158,9 @@ check_stack(unsigned long ip, unsigned long *stack)
> i++;
> }
>
> + /* We do not want to include skipped entries */
> + max_stack_trace.nr_entries -= (i - x);
> +
> for (; x < max_stack_trace.nr_entries; x++)
> stack_dump_trace[x] = ULONG_MAX;
>
> @@ -330,7 +333,7 @@ static int t_show(struct seq_file *m, void *v)
> seq_printf(m, " Depth Size Location"
> " (%d entries)\n"
> " ----- ---- --------\n",
> - max_stack_trace.nr_entries - 1);
> + max_stack_trace.nr_entries);
>
> if (!stack_tracer_enabled && !max_stack_size)
> print_disabled(m);
>
> ----8<----
>
> 1) stack_trace data
> Depth Size Location (47 entries)
> ----- ---- --------
> 0) 4648 16 notifier_call_chain+0x2c/0x94
> 1) 4632 64 raw_notifier_call_chain+0x34/0x44
> 2) 4568 48 timekeeping_update.constprop.9+0xb8/0x114
> 3) 4520 48 update_wall_time+0x408/0x6dc
> 4) 4472 128 tick_do_update_jiffies64+0xd8/0x154
> 5) 4344 80 tick_sched_do_timer+0x50/0x60
> 6) 4264 32 tick_sched_timer+0x34/0x90
> 7) 4232 48 __run_hrtimer+0x60/0x258
> 8) 4184 64 hrtimer_interrupt+0xe8/0x260
> 9) 4120 128 arch_timer_handler_virt+0x38/0x48
> 10) 3992 32 handle_percpu_devid_irq+0x84/0x188
> 11) 3960 64 generic_handle_irq+0x38/0x54
> 12) 3896 32 __handle_domain_irq+0x68/0xbc
> 13) 3864 64 gic_handle_irq+0x38/0x88
> 14) 3800 336 el1_irq+0x64/0xd8
> 15) 3464 48 __kmalloc_track_caller+0x40/0x2f8
> 16) 3416 16 __kmalloc_reserve.isra.46+0x44/0x9c
> 17) 3400 144 __alloc_skb+0x70/0x180
> 18) 3256 96 alloc_skb_with_frags+0x74/0x234
> 19) 3160 112 sock_alloc_send_pskb+0x1d0/0x294
> 20) 3048 160 sock_alloc_send_skb+0x44/0x54
> 21) 2888 64 __ip_append_data.isra.40+0x78c/0xb48
> 22) 2824 224 ip_append_data.part.42+0x98/0xe8
> 23) 2600 112 ip_append_data+0x68/0x7c
> 24) 2488 96 icmp_push_reply+0x7c/0x144
> 25) 2392 96 icmp_send+0x3c0/0x3c8
> 26) 2296 192 __udp4_lib_rcv+0x5b8/0x684
> 27) 2104 96 udp_rcv+0x2c/0x3c
> 28) 2008 32 ip_local_deliver+0xa0/0x224
> 29) 1976 48 ip_rcv+0x360/0x57c
> 30) 1928 64 __netif_receive_skb_core+0x4d0/0x80c
> 31) 1864 128 __netif_receive_skb+0x24/0x84
> 32) 1736 32 process_backlog+0x9c/0x15c
> 33) 1704 80 net_rx_action+0x1ec/0x32c
> 34) 1624 160 __do_softirq+0x114/0x2f0
> 35) 1464 128 do_softirq+0x60/0x68
> 36) 1336 32 __local_bh_enable_ip+0xb0/0xd4
> 37) 1304 32 ip_finish_output+0x1f4/0xabc
> 38) 1272 96 ip_output+0xf0/0x120
> 39) 1176 64 ip_local_out_sk+0x44/0x54
> 40) 1112 32 ip_send_skb+0x24/0xbc
> 41) 1080 48 udp_send_skb+0x1b4/0x2f4
> 42) 1032 80 udp_sendmsg+0x2a8/0x7a0
> 43) 952 272 inet_sendmsg+0xa0/0xd0
> 44) 680 48 sock_sendmsg+0x30/0x78
> 45) 632 32 SyS_sendto+0xc4/0x108
> 46) 600 600 el0_svc_naked+0x20/0x28
>
> 2) stack_max_size data
> 4648
>
WARNING: multiple messages have this Message-ID (diff)
From: takahiro.akashi@linaro.org (AKASHI Takahiro)
To: linux-arm-kernel@lists.infradead.org
Subject: [RFC 2/3] arm64: refactor save_stack_trace()
Date: Fri, 17 Jul 2015 11:04:48 +0900 [thread overview]
Message-ID: <55A862C0.4040101@linaro.org> (raw)
In-Reply-To: <A601CC3C-4B09-4D8B-8564-558349D45815@gmail.com>
Jungseok,
Thank you for your testing and reviews.
On 07/16/2015 10:29 PM, Jungseok Lee wrote:
> On Jul 16, 2015, at 10:08 AM, AKASHI Takahiro wrote:
>
> Hi, AKASHI
>
>> On 07/16/2015 09:27 AM, AKASHI Takahiro wrote:
>>> On 07/16/2015 01:13 AM, Steven Rostedt wrote:
>>>> On Wed, 15 Jul 2015 10:55:36 -0400
>>>> Steven Rostedt <rostedt@goodmis.org> wrote:
>>>>
>>>>
>>>>> I'll take a look at it and try to clean up the code.
>>>>
>>>> Does the following patch make sense for you?
>>>
>>> Looks nice. The patch greatly simplifies changes on arm64 side.
>>
>> As follows:
>>
>> - Takahiro AKASHI
>>
>> diff --git a/arch/arm64/include/asm/ftrace.h b/arch/arm64/include/asm/ftrace.h
>> index c5534fa..868d6f1 100644
>> --- a/arch/arm64/include/asm/ftrace.h
>> +++ b/arch/arm64/include/asm/ftrace.h
>> @@ -15,6 +15,7 @@
>>
>> #define MCOUNT_ADDR ((unsigned long)_mcount)
>> #define MCOUNT_INSN_SIZE AARCH64_INSN_SIZE
>> +#define FTRACE_STACK_FRAME_OFFSET 4 /* sync it up with stacktrace.c */
Well,
#define FTRACE_STACK_FRAME_OFFSET AARCH64_INSN_SIZE
might be better.
> How about binding it to -4 in unwind_frame function?
Do you mean like this?
In unwind_frame(),
frame->pc = *(unsigned long*)(fp + 8) - AARCH64_INSN_SIZE;
> IMHO, it would help other developers trying to change stack trace code
> be aware of this stack tracer feature.
>
>> #ifndef __ASSEMBLY__
>> #include <linux/compat.h>
>> diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
>> index 1da6029..2c1bf7d 100644
>> --- a/include/linux/ftrace.h
>> +++ b/include/linux/ftrace.h
>> @@ -260,6 +260,13 @@ static inline void ftrace_kill(void) { }
>> #endif /* CONFIG_FUNCTION_TRACER */
>>
>> #ifdef CONFIG_STACK_TRACER
>> +/*
>> + * the offset value to add to return address from save_stack_trace()
>> + */
>> +#ifndef FTRACE_STACK_FRAME_OFFSET
>> +#define FTRACE_STACK_FRAME_OFFSET 0
>> +#endif
>> +
>> extern int stack_tracer_enabled;
>> int
>> stack_trace_sysctl(struct ctl_table *table, int write,
>> diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c
>> index 9384647..c5b9748 100644
>> --- a/kernel/trace/trace_stack.c
>> +++ b/kernel/trace/trace_stack.c
>> @@ -105,7 +105,7 @@ check_stack(unsigned long ip, unsigned long *stack)
>>
>> /* Skip over the overhead of the stack tracer itself */
>> for (i = 0; i < max_stack_trace.nr_entries; i++) {
>> - if (stack_dump_trace[i] == ip)
>> + if ((stack_dump_trace[i] + FTRACE_STACK_FRAME_OFFSET) == ip)
>> break;
>> }
>>
>> @@ -131,7 +131,8 @@ check_stack(unsigned long ip, unsigned long *stack)
>> p = start;
>>
>> for (; p < top && i < max_stack_trace.nr_entries; p++) {
>> - if (*p == stack_dump_trace[i]) {
>> + if (*p == (stack_dump_trace[i]
>> + + FTRACE_STACK_FRAME_OFFSET)) {
>> stack_dump_trace[x] = stack_dump_trace[i++];
>> this_size = stack_dump_index[x++] =
>> (top - p) * sizeof(unsigned long);
>> --
>
> I've prepared a kernel with the following patches and reviewed them.
>
> 1) Steve's clean up patch
> 2) This patch
> 3) [RFC 2/3]
>
> AFAIU, [RFC 3/3] is not needed any more thanks to Steve's patch.
We don't need [2/3].
> First of all, let's look at the following data.
>
> 1) stack_trace data
> Depth Size Location (55 entries)
> ----- ---- --------
> 0) 4808 16 notifier_call_chain+0x2c/0x94
> 1) 4792 64 raw_notifier_call_chain+0x34/0x44
> 2) 4728 48 timekeeping_update.constprop.9+0xb8/0x114
> 3) 4680 48 update_wall_time+0x408/0x6dc
> 4) 4632 128 tick_do_update_jiffies64+0xd8/0x154
> 5) 4504 80 tick_sched_do_timer+0x50/0x60
> 6) 4424 32 tick_sched_timer+0x34/0x90
> 7) 4392 48 __run_hrtimer+0x60/0x258
> 8) 4344 64 hrtimer_interrupt+0xe8/0x260
> 9) 4280 128 arch_timer_handler_virt+0x38/0x48
> 10) 4152 32 handle_percpu_devid_irq+0x84/0x188
> 11) 4120 64 generic_handle_irq+0x38/0x54
> 12) 4056 32 __handle_domain_irq+0x68/0xbc
> 13) 4024 64 gic_handle_irq+0x38/0x88
> 14) 3960 336 el1_irq+0x64/0xd8
> 15) 3624 16 netif_rx_internal+0x14/0x198
> 16) 3608 64 netif_rx+0x20/0xa4
> 17) 3544 32 loopback_xmit+0x64/0xf4
> 18) 3512 48 dev_hard_start_xmit+0x25c/0x3f8
> 19) 3464 160 __dev_queue_xmit+0x440/0x4dc
> 20) 3304 96 dev_queue_xmit_sk+0x20/0x30
> 21) 3208 32 ip_finish_output+0x1e0/0xabc
> 22) 3176 96 ip_output+0xf0/0x120
> 23) 3080 64 ip_local_out_sk+0x44/0x54
> 24) 3016 32 ip_send_skb+0x24/0xbc
> 25) 2984 48 ip_push_pending_frames+0x40/0x60
> 26) 2936 64 icmp_push_reply+0x104/0x144
> 27) 2872 96 icmp_send+0x3c0/0x3c8
> 28) 2776 192 __udp4_lib_rcv+0x5b8/0x684
> 29) 2584 96 udp_rcv+0x2c/0x3c
> 30) 2488 32 ip_local_deliver+0xa0/0x224
> 31) 2456 48 ip_rcv+0x360/0x57c
> 32) 2408 64 __netif_receive_skb_core+0x4d0/0x80c
> 33) 2344 128 __netif_receive_skb+0x24/0x84
> 34) 2216 32 process_backlog+0x9c/0x15c
> 35) 2184 80 net_rx_action+0x1ec/0x32c
> 36) 2104 160 __do_softirq+0x114/0x2f0
> 37) 1944 128 do_softirq+0x60/0x68
> 38) 1816 32 __local_bh_enable_ip+0xb0/0xd4
> 39) 1784 32 ip_finish_output+0x1f4/0xabc
> 40) 1752 96 ip_output+0xf0/0x120
> 41) 1656 64 ip_local_out_sk+0x44/0x54
> 42) 1592 32 ip_send_skb+0x24/0xbc
> 43) 1560 48 udp_send_skb+0x1b4/0x2f4
> 44) 1512 80 udp_sendmsg+0x2a8/0x7a0
> 45) 1432 272 inet_sendmsg+0xa0/0xd0
> 46) 1160 48 sock_sendmsg+0x30/0x78
> 47) 1112 32 ___sys_sendmsg+0x15c/0x26c
> 48) 1080 400 __sys_sendmmsg+0x94/0x180
> 49) 680 320 SyS_sendmmsg+0x38/0x54
> 50) 360 360 el0_svc_naked+0x20/0x28
>
> 2) stack_max_size data
> 4888
>
> The data looks odd in two points.
> 1) the number of entry
> There is a mismatch between start token and real data
>
> 2) 80-byte gap
> stack_max_size is not aligned with "Depth" field of the first entry of stack_trace.
>
> IMHO, two items are not considered in this series as digging them out.
>
> 1) skipped entries
> As x variable is introduced in Steve's patch, it is needed to track down
> how many entries are recorded in both stack_dump_trace and stack_dump_index.
>
> 2) max_stack_trace.skip value
> max_stack_trace.skip is 0 as applying Steve's patch. The above gap could be
> observed unless the value is not considered in arch code. In the above example,
> 80-byte gap is save_stack_trace function in arch/arm64/kernel/stacktrace.c.
>
> As applying the following fix, stack_trace and stack_max_size are okay.
> However, I'm not sure which code, arch or generic ftrace, should handle trace->skip.
> The latter one is responsible for it under current implementation, not Steve's change.
>
> Please correct me if I am wrong.
I will address these issues in my later replies.
Thanks,
-Takahiro AKASHI
> Best Regards
> Jungseok Lee
>
> ----8<----
>
> diff --git a/arch/arm64/kernel/stacktrace.c b/arch/arm64/kernel/stacktrace.c
> index 978c923..5f6f4df 100644
> --- a/arch/arm64/kernel/stacktrace.c
> +++ b/arch/arm64/kernel/stacktrace.c
> @@ -137,7 +137,9 @@ void save_stack_trace(struct stack_trace *trace)
>
> frame.fp = (unsigned long)__builtin_frame_address(0);
> frame.sp = current_stack_pointer;
> - frame.pc = (unsigned long)save_stack_trace_tsk;
> + frame.pc = (unsigned long)save_stack_trace;
> +
> + trace->skip += 4;
>
> __save_stack_trace(&frame, trace, 0);
> }
> diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c
> index c5b9748..5635683 100644
> --- a/kernel/trace/trace_stack.c
> +++ b/kernel/trace/trace_stack.c
> @@ -158,6 +158,9 @@ check_stack(unsigned long ip, unsigned long *stack)
> i++;
> }
>
> + /* We do not want to include skipped entries */
> + max_stack_trace.nr_entries -= (i - x);
> +
> for (; x < max_stack_trace.nr_entries; x++)
> stack_dump_trace[x] = ULONG_MAX;
>
> @@ -330,7 +333,7 @@ static int t_show(struct seq_file *m, void *v)
> seq_printf(m, " Depth Size Location"
> " (%d entries)\n"
> " ----- ---- --------\n",
> - max_stack_trace.nr_entries - 1);
> + max_stack_trace.nr_entries);
>
> if (!stack_tracer_enabled && !max_stack_size)
> print_disabled(m);
>
> ----8<----
>
> 1) stack_trace data
> Depth Size Location (47 entries)
> ----- ---- --------
> 0) 4648 16 notifier_call_chain+0x2c/0x94
> 1) 4632 64 raw_notifier_call_chain+0x34/0x44
> 2) 4568 48 timekeeping_update.constprop.9+0xb8/0x114
> 3) 4520 48 update_wall_time+0x408/0x6dc
> 4) 4472 128 tick_do_update_jiffies64+0xd8/0x154
> 5) 4344 80 tick_sched_do_timer+0x50/0x60
> 6) 4264 32 tick_sched_timer+0x34/0x90
> 7) 4232 48 __run_hrtimer+0x60/0x258
> 8) 4184 64 hrtimer_interrupt+0xe8/0x260
> 9) 4120 128 arch_timer_handler_virt+0x38/0x48
> 10) 3992 32 handle_percpu_devid_irq+0x84/0x188
> 11) 3960 64 generic_handle_irq+0x38/0x54
> 12) 3896 32 __handle_domain_irq+0x68/0xbc
> 13) 3864 64 gic_handle_irq+0x38/0x88
> 14) 3800 336 el1_irq+0x64/0xd8
> 15) 3464 48 __kmalloc_track_caller+0x40/0x2f8
> 16) 3416 16 __kmalloc_reserve.isra.46+0x44/0x9c
> 17) 3400 144 __alloc_skb+0x70/0x180
> 18) 3256 96 alloc_skb_with_frags+0x74/0x234
> 19) 3160 112 sock_alloc_send_pskb+0x1d0/0x294
> 20) 3048 160 sock_alloc_send_skb+0x44/0x54
> 21) 2888 64 __ip_append_data.isra.40+0x78c/0xb48
> 22) 2824 224 ip_append_data.part.42+0x98/0xe8
> 23) 2600 112 ip_append_data+0x68/0x7c
> 24) 2488 96 icmp_push_reply+0x7c/0x144
> 25) 2392 96 icmp_send+0x3c0/0x3c8
> 26) 2296 192 __udp4_lib_rcv+0x5b8/0x684
> 27) 2104 96 udp_rcv+0x2c/0x3c
> 28) 2008 32 ip_local_deliver+0xa0/0x224
> 29) 1976 48 ip_rcv+0x360/0x57c
> 30) 1928 64 __netif_receive_skb_core+0x4d0/0x80c
> 31) 1864 128 __netif_receive_skb+0x24/0x84
> 32) 1736 32 process_backlog+0x9c/0x15c
> 33) 1704 80 net_rx_action+0x1ec/0x32c
> 34) 1624 160 __do_softirq+0x114/0x2f0
> 35) 1464 128 do_softirq+0x60/0x68
> 36) 1336 32 __local_bh_enable_ip+0xb0/0xd4
> 37) 1304 32 ip_finish_output+0x1f4/0xabc
> 38) 1272 96 ip_output+0xf0/0x120
> 39) 1176 64 ip_local_out_sk+0x44/0x54
> 40) 1112 32 ip_send_skb+0x24/0xbc
> 41) 1080 48 udp_send_skb+0x1b4/0x2f4
> 42) 1032 80 udp_sendmsg+0x2a8/0x7a0
> 43) 952 272 inet_sendmsg+0xa0/0xd0
> 44) 680 48 sock_sendmsg+0x30/0x78
> 45) 632 32 SyS_sendto+0xc4/0x108
> 46) 600 600 el0_svc_naked+0x20/0x28
>
> 2) stack_max_size data
> 4648
>
next prev parent reply other threads:[~2015-07-17 2:05 UTC|newest]
Thread overview: 106+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-07-13 5:29 [RFC 0/3] arm64: ftrace: fix incorrect output from stack tracer AKASHI Takahiro
2015-07-13 5:29 ` AKASHI Takahiro
2015-07-13 5:29 ` [RFC 1/3] ftrace: adjust a function's pc to search for in check_stack() for arm64 AKASHI Takahiro
2015-07-13 5:29 ` AKASHI Takahiro
2015-07-13 15:24 ` Steven Rostedt
2015-07-13 15:24 ` Steven Rostedt
2015-07-15 0:22 ` AKASHI Takahiro
2015-07-15 0:22 ` AKASHI Takahiro
2015-07-13 5:29 ` [RFC 2/3] arm64: refactor save_stack_trace() AKASHI Takahiro
2015-07-13 5:29 ` AKASHI Takahiro
2015-07-14 12:47 ` Jungseok Lee
2015-07-14 12:47 ` Jungseok Lee
2015-07-14 13:31 ` Steven Rostedt
2015-07-14 13:31 ` Steven Rostedt
2015-07-15 0:20 ` AKASHI Takahiro
2015-07-15 0:20 ` AKASHI Takahiro
2015-07-15 2:51 ` Steven Rostedt
2015-07-15 2:51 ` Steven Rostedt
2015-07-15 11:41 ` AKASHI Takahiro
2015-07-15 11:41 ` AKASHI Takahiro
2015-07-15 14:55 ` Steven Rostedt
2015-07-15 14:55 ` Steven Rostedt
2015-07-15 16:13 ` Steven Rostedt
2015-07-15 16:13 ` Steven Rostedt
2015-07-16 0:27 ` AKASHI Takahiro
2015-07-16 0:27 ` AKASHI Takahiro
2015-07-16 1:08 ` AKASHI Takahiro
2015-07-16 1:08 ` AKASHI Takahiro
2015-07-16 1:38 ` Steven Rostedt
2015-07-16 1:38 ` Steven Rostedt
2015-07-17 10:46 ` Will Deacon
2015-07-17 10:46 ` Will Deacon
2015-07-16 13:29 ` Jungseok Lee
2015-07-16 13:29 ` Jungseok Lee
2015-07-16 13:54 ` Jungseok Lee
2015-07-16 13:54 ` Jungseok Lee
2015-07-16 14:24 ` Steven Rostedt
2015-07-16 14:24 ` Steven Rostedt
2015-07-16 15:01 ` Jungseok Lee
2015-07-16 15:01 ` Jungseok Lee
2015-07-16 15:31 ` Steven Rostedt
2015-07-16 15:31 ` Steven Rostedt
2015-07-16 15:52 ` Jungseok Lee
2015-07-16 15:52 ` Jungseok Lee
2015-07-16 20:22 ` Steven Rostedt
2015-07-16 20:22 ` Steven Rostedt
2015-07-17 2:49 ` AKASHI Takahiro
2015-07-17 2:49 ` AKASHI Takahiro
2015-07-17 3:21 ` Steven Rostedt
2015-07-17 3:21 ` Steven Rostedt
2015-07-16 16:16 ` Steven Rostedt
2015-07-16 16:16 ` Steven Rostedt
2015-07-17 12:40 ` Mark Rutland
2015-07-17 12:40 ` Mark Rutland
2015-07-17 12:51 ` Steven Rostedt
2015-07-17 12:51 ` Steven Rostedt
2015-07-17 13:00 ` Steven Rostedt
2015-07-17 13:00 ` Steven Rostedt
2015-07-17 14:28 ` Jungseok Lee
2015-07-17 14:28 ` Jungseok Lee
2015-07-17 14:41 ` Steven Rostedt
2015-07-17 14:41 ` Steven Rostedt
2015-07-17 14:59 ` Jungseok Lee
2015-07-17 14:59 ` Jungseok Lee
2015-07-17 15:34 ` Jungseok Lee
2015-07-17 15:34 ` Jungseok Lee
2015-07-17 16:01 ` Steven Rostedt
2015-07-17 16:01 ` Steven Rostedt
2015-07-20 16:20 ` Will Deacon
2015-07-20 16:20 ` Will Deacon
2015-07-20 23:53 ` AKASHI Takahiro
2015-07-20 23:53 ` AKASHI Takahiro
2015-07-21 10:26 ` AKASHI Takahiro
2015-07-21 10:26 ` AKASHI Takahiro
2015-07-21 14:34 ` Jungseok Lee
2015-07-21 14:34 ` Jungseok Lee
2015-08-03 9:09 ` Will Deacon
2015-08-03 9:09 ` Will Deacon
2015-08-03 14:01 ` Steven Rostedt
2015-08-03 14:01 ` Steven Rostedt
2015-08-03 14:04 ` Will Deacon
2015-08-03 14:04 ` Will Deacon
2015-08-03 16:30 ` Jungseok Lee
2015-08-03 16:30 ` Jungseok Lee
2015-08-03 16:57 ` Steven Rostedt
2015-08-03 16:57 ` Steven Rostedt
2015-08-03 17:22 ` Jungseok Lee
2015-08-03 17:22 ` Jungseok Lee
2015-08-03 17:32 ` Steven Rostedt
2015-08-03 17:32 ` Steven Rostedt
2015-08-04 7:41 ` AKASHI Takahiro
2015-08-04 7:41 ` AKASHI Takahiro
2015-07-17 2:04 ` AKASHI Takahiro [this message]
2015-07-17 2:04 ` AKASHI Takahiro
2015-07-17 14:38 ` Jungseok Lee
2015-07-17 14:38 ` Jungseok Lee
2015-07-16 14:28 ` Mark Rutland
2015-07-16 14:28 ` Mark Rutland
2015-07-16 14:34 ` Steven Rostedt
2015-07-16 14:34 ` Steven Rostedt
2015-07-17 2:09 ` AKASHI Takahiro
2015-07-17 2:09 ` AKASHI Takahiro
2015-07-13 5:29 ` [RFC 3/3] arm64: ftrace: mcount() should not create a stack frame AKASHI Takahiro
2015-07-13 5:29 ` AKASHI Takahiro
2015-07-13 15:01 ` [RFC 0/3] arm64: ftrace: fix incorrect output from stack tracer Jungseok Lee
2015-07-13 15:01 ` Jungseok Lee
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=55A862C0.4040101@linaro.org \
--to=takahiro.akashi@linaro.org \
--cc=broonie@kernel.org \
--cc=catalin.marinas@arm.com \
--cc=david.griego@linaro.org \
--cc=jungseoklee85@gmail.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=olof@lixom.net \
--cc=rostedt@goodmis.org \
--cc=will.deacon@arm.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.