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2014-09-19sched: Add helper for task stack page overrun checkingAaron Tomlin
This facility is used in a few places so let's introduce a helper function to improve code readability. Signed-off-by: Aaron Tomlin <atomlin@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: aneesh.kumar@linux.vnet.ibm.com Cc: dzickus@redhat.com Cc: bmr@redhat.com Cc: jcastillo@redhat.com Cc: oleg@redhat.com Cc: riel@redhat.com Cc: prarit@redhat.com Cc: jgh@redhat.com Cc: minchan@kernel.org Cc: mpe@ellerman.id.au Cc: tglx@linutronix.de Cc: hannes@cmpxchg.org Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Paul Mackerras <paulus@samba.org> Cc: Seiji Aguchi <seiji.aguchi@hds.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Cc: linuxppc-dev@lists.ozlabs.org Link: http://lkml.kernel.org/r/1410527779-8133-3-git-send-email-atomlin@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-09-19init/main.c: Give init_task a canaryAaron Tomlin
Tasks get their end of stack set to STACK_END_MAGIC with the aim to catch stack overruns. Currently this feature does not apply to init_task. This patch removes this restriction. Note that a similar patch was posted by Prarit Bhargava some time ago but was never merged: http://marc.info/?l=linux-kernel&m=127144305403241&w=2 Signed-off-by: Aaron Tomlin <atomlin@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Michael Ellerman <mpe@ellerman.id.au> Cc: aneesh.kumar@linux.vnet.ibm.com Cc: dzickus@redhat.com Cc: bmr@redhat.com Cc: jcastillo@redhat.com Cc: jgh@redhat.com Cc: minchan@kernel.org Cc: tglx@linutronix.de Cc: hannes@cmpxchg.org Cc: Alex Thorlton <athorlton@sgi.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Daeseok Youn <daeseok.youn@gmail.com> Cc: David Rientjes <rientjes@google.com> Cc: Fabian Frederick <fabf@skynet.be> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Kees Cook <keescook@chromium.org> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Michael Opdenacker <michael.opdenacker@free-electrons.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Prarit Bhargava <prarit@redhat.com> Cc: Rik van Riel <riel@redhat.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Seiji Aguchi <seiji.aguchi@hds.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Vladimir Davydov <vdavydov@parallels.com> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Cc: linuxppc-dev@lists.ozlabs.org Link: http://lkml.kernel.org/r/1410527779-8133-2-git-send-email-atomlin@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-06-02tracing: Print max callstack on stacktrace bugMinchan Kim
While I played with my own feature(ex, something on the way to reclaim), the kernel would easily oops. I guessed that the reason had to do with stack overflow and wanted to prove it. I discovered the stack tracer which proved to be very useful for me but the kernel would oops before my user program gather the information via "watch cat /sys/kernel/debug/tracing/stack_trace" so I couldn't get any message from that. What I needed was to have the stack tracer emit the kernel stack usage before it does the oops so I could find what was hogging the stack. This patch shows the callstack of max stack usage right before an oops so we can find a culprit. So, the result is as follows. [ 1116.522206] init: lightdm main process (1246) terminated with status 1 [ 1119.922916] init: failsafe-x main process (1272) terminated with status 1 [ 3887.728131] kworker/u24:1 (6637) used greatest stack depth: 256 bytes left [ 6397.629227] cc1 (9554) used greatest stack depth: 128 bytes left [ 7174.467392] Depth Size Location (47 entries) [ 7174.467392] ----- ---- -------- [ 7174.467785] 0) 7248 256 get_page_from_freelist+0xa7/0x920 [ 7174.468506] 1) 6992 352 __alloc_pages_nodemask+0x1cd/0xb20 [ 7174.469224] 2) 6640 8 alloc_pages_current+0x10f/0x1f0 [ 7174.469413] 3) 6632 168 new_slab+0x2c5/0x370 [ 7174.469413] 4) 6464 8 __slab_alloc+0x3a9/0x501 [ 7174.469413] 5) 6456 80 __kmalloc+0x1cb/0x200 [ 7174.469413] 6) 6376 376 vring_add_indirect+0x36/0x200 [ 7174.469413] 7) 6000 144 virtqueue_add_sgs+0x2e2/0x320 [ 7174.469413] 8) 5856 288 __virtblk_add_req+0xda/0x1b0 [ 7174.469413] 9) 5568 96 virtio_queue_rq+0xd3/0x1d0 [ 7174.469413] 10) 5472 128 __blk_mq_run_hw_queue+0x1ef/0x440 [ 7174.469413] 11) 5344 16 blk_mq_run_hw_queue+0x35/0x40 [ 7174.469413] 12) 5328 96 blk_mq_insert_requests+0xdb/0x160 [ 7174.469413] 13) 5232 112 blk_mq_flush_plug_list+0x12b/0x140 [ 7174.469413] 14) 5120 112 blk_flush_plug_list+0xc7/0x220 [ 7174.469413] 15) 5008 64 io_schedule_timeout+0x88/0x100 [ 7174.469413] 16) 4944 128 mempool_alloc+0x145/0x170 [ 7174.469413] 17) 4816 96 bio_alloc_bioset+0x10b/0x1d0 [ 7174.469413] 18) 4720 48 get_swap_bio+0x30/0x90 [ 7174.469413] 19) 4672 160 __swap_writepage+0x150/0x230 [ 7174.469413] 20) 4512 32 swap_writepage+0x42/0x90 [ 7174.469413] 21) 4480 320 shrink_page_list+0x676/0xa80 [ 7174.469413] 22) 4160 208 shrink_inactive_list+0x262/0x4e0 [ 7174.469413] 23) 3952 304 shrink_lruvec+0x3e1/0x6a0 [ 7174.469413] 24) 3648 80 shrink_zone+0x3f/0x110 [ 7174.469413] 25) 3568 128 do_try_to_free_pages+0x156/0x4c0 [ 7174.469413] 26) 3440 208 try_to_free_pages+0xf7/0x1e0 [ 7174.469413] 27) 3232 352 __alloc_pages_nodemask+0x783/0xb20 [ 7174.469413] 28) 2880 8 alloc_pages_current+0x10f/0x1f0 [ 7174.469413] 29) 2872 200 __page_cache_alloc+0x13f/0x160 [ 7174.469413] 30) 2672 80 find_or_create_page+0x4c/0xb0 [ 7174.469413] 31) 2592 80 ext4_mb_load_buddy+0x1e9/0x370 [ 7174.469413] 32) 2512 176 ext4_mb_regular_allocator+0x1b7/0x460 [ 7174.469413] 33) 2336 128 ext4_mb_new_blocks+0x458/0x5f0 [ 7174.469413] 34) 2208 256 ext4_ext_map_blocks+0x70b/0x1010 [ 7174.469413] 35) 1952 160 ext4_map_blocks+0x325/0x530 [ 7174.469413] 36) 1792 384 ext4_writepages+0x6d1/0xce0 [ 7174.469413] 37) 1408 16 do_writepages+0x23/0x40 [ 7174.469413] 38) 1392 96 __writeback_single_inode+0x45/0x2e0 [ 7174.469413] 39) 1296 176 writeback_sb_inodes+0x2ad/0x500 [ 7174.469413] 40) 1120 80 __writeback_inodes_wb+0x9e/0xd0 [ 7174.469413] 41) 1040 160 wb_writeback+0x29b/0x350 [ 7174.469413] 42) 880 208 bdi_writeback_workfn+0x11c/0x480 [ 7174.469413] 43) 672 144 process_one_work+0x1d2/0x570 [ 7174.469413] 44) 528 112 worker_thread+0x116/0x370 [ 7174.469413] 45) 416 240 kthread+0xf3/0x110 [ 7174.469413] 46) 176 176 ret_from_fork+0x7c/0xb0 [ 7174.469413] ------------[ cut here ]------------ [ 7174.469413] kernel BUG at kernel/trace/trace_stack.c:174! [ 7174.469413] invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC [ 7174.469413] Dumping ftrace buffer: [ 7174.469413] (ftrace buffer empty) [ 7174.469413] Modules linked in: [ 7174.469413] CPU: 0 PID: 440 Comm: kworker/u24:0 Not tainted 3.14.0+ #212 [ 7174.469413] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 [ 7174.469413] Workqueue: writeback bdi_writeback_workfn (flush-253:0) [ 7174.469413] task: ffff880034170000 ti: ffff880029518000 task.ti: ffff880029518000 [ 7174.469413] RIP: 0010:[<ffffffff8112336e>] [<ffffffff8112336e>] stack_trace_call+0x2de/0x340 [ 7174.469413] RSP: 0000:ffff880029518290 EFLAGS: 00010046 [ 7174.469413] RAX: 0000000000000030 RBX: 000000000000002f RCX: 0000000000000000 [ 7174.469413] RDX: 0000000000000000 RSI: 000000000000002f RDI: ffffffff810b7159 [ 7174.469413] RBP: ffff8800295182f0 R08: ffffffffffffffff R09: 0000000000000000 [ 7174.469413] R10: 0000000000000001 R11: 0000000000000001 R12: ffffffff82768dfc [ 7174.469413] R13: 000000000000f2e8 R14: ffff8800295182b8 R15: 00000000000000f8 [ 7174.469413] FS: 0000000000000000(0000) GS:ffff880037c00000(0000) knlGS:0000000000000000 [ 7174.469413] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b [ 7174.469413] CR2: 00002acd0b994000 CR3: 0000000001c0b000 CR4: 00000000000006f0 [ 7174.469413] Stack: [ 7174.469413] 0000000000000000 ffffffff8114fdb7 0000000000000087 0000000000001c50 [ 7174.469413] 0000000000000000 0000000000000000 0000000000000000 0000000000000000 [ 7174.469413] 0000000000000002 ffff880034170000 ffff880034171028 0000000000000000 [ 7174.469413] Call Trace: [ 7174.469413] [<ffffffff8114fdb7>] ? get_page_from_freelist+0xa7/0x920 [ 7174.469413] [<ffffffff816eee3f>] ftrace_call+0x5/0x2f [ 7174.469413] [<ffffffff81165065>] ? next_zones_zonelist+0x5/0x70 [ 7174.469413] [<ffffffff810a23fa>] ? __bfs+0x11a/0x270 [ 7174.469413] [<ffffffff81165065>] ? next_zones_zonelist+0x5/0x70 [ 7174.469413] [<ffffffff8114fdb7>] ? get_page_from_freelist+0xa7/0x920 [ 7174.469413] [<ffffffff8119092f>] ? alloc_pages_current+0x10f/0x1f0 [ 7174.469413] [<ffffffff811507fd>] __alloc_pages_nodemask+0x1cd/0xb20 [ 7174.469413] [<ffffffff810a4de6>] ? check_irq_usage+0x96/0xe0 [ 7174.469413] [<ffffffff816eee3f>] ? ftrace_call+0x5/0x2f [ 7174.469413] [<ffffffff8119092f>] alloc_pages_current+0x10f/0x1f0 [ 7174.469413] [<ffffffff81199cd5>] ? new_slab+0x2c5/0x370 [ 7174.469413] [<ffffffff81199cd5>] new_slab+0x2c5/0x370 [ 7174.469413] [<ffffffff816eee3f>] ? ftrace_call+0x5/0x2f [ 7174.469413] [<ffffffff816db002>] __slab_alloc+0x3a9/0x501 [ 7174.469413] [<ffffffff8119af8b>] ? __kmalloc+0x1cb/0x200 [ 7174.469413] [<ffffffff8141dc46>] ? vring_add_indirect+0x36/0x200 [ 7174.469413] [<ffffffff8141dc46>] ? vring_add_indirect+0x36/0x200 [ 7174.469413] [<ffffffff8141dc46>] ? vring_add_indirect+0x36/0x200 [ 7174.469413] [<ffffffff8119af8b>] __kmalloc+0x1cb/0x200 [ 7174.469413] [<ffffffff8141de10>] ? vring_add_indirect+0x200/0x200 [ 7174.469413] [<ffffffff8141dc46>] vring_add_indirect+0x36/0x200 [ 7174.469413] [<ffffffff8141e402>] virtqueue_add_sgs+0x2e2/0x320 [ 7174.469413] [<ffffffff8148e35a>] __virtblk_add_req+0xda/0x1b0 [ 7174.469413] [<ffffffff8148e503>] virtio_queue_rq+0xd3/0x1d0 [ 7174.469413] [<ffffffff8134aa0f>] __blk_mq_run_hw_queue+0x1ef/0x440 [ 7174.469413] [<ffffffff8134b0d5>] blk_mq_run_hw_queue+0x35/0x40 [ 7174.469413] [<ffffffff8134b7bb>] blk_mq_insert_requests+0xdb/0x160 [ 7174.469413] [<ffffffff8134be5b>] blk_mq_flush_plug_list+0x12b/0x140 [ 7174.469413] [<ffffffff81342237>] blk_flush_plug_list+0xc7/0x220 [ 7174.469413] [<ffffffff816e60ef>] ? _raw_spin_unlock_irqrestore+0x3f/0x70 [ 7174.469413] [<ffffffff816e16e8>] io_schedule_timeout+0x88/0x100 [ 7174.469413] [<ffffffff816e1665>] ? io_schedule_timeout+0x5/0x100 [ 7174.469413] [<ffffffff81149415>] mempool_alloc+0x145/0x170 [ 7174.469413] [<ffffffff8109baf0>] ? __init_waitqueue_head+0x60/0x60 [ 7174.469413] [<ffffffff811e246b>] bio_alloc_bioset+0x10b/0x1d0 [ 7174.469413] [<ffffffff81184230>] ? end_swap_bio_read+0xc0/0xc0 [ 7174.469413] [<ffffffff81184230>] ? end_swap_bio_read+0xc0/0xc0 [ 7174.469413] [<ffffffff81184110>] get_swap_bio+0x30/0x90 [ 7174.469413] [<ffffffff81184230>] ? end_swap_bio_read+0xc0/0xc0 [ 7174.469413] [<ffffffff81184660>] __swap_writepage+0x150/0x230 [ 7174.469413] [<ffffffff810ab405>] ? do_raw_spin_unlock+0x5/0xa0 [ 7174.469413] [<ffffffff81184230>] ? end_swap_bio_read+0xc0/0xc0 [ 7174.469413] [<ffffffff81184515>] ? __swap_writepage+0x5/0x230 [ 7174.469413] [<ffffffff81184782>] swap_writepage+0x42/0x90 [ 7174.469413] [<ffffffff8115ae96>] shrink_page_list+0x676/0xa80 [ 7174.469413] [<ffffffff816eee3f>] ? ftrace_call+0x5/0x2f [ 7174.469413] [<ffffffff8115b872>] shrink_inactive_list+0x262/0x4e0 [ 7174.469413] [<ffffffff8115c1c1>] shrink_lruvec+0x3e1/0x6a0 [ 7174.469413] [<ffffffff8115c4bf>] shrink_zone+0x3f/0x110 [ 7174.469413] [<ffffffff816eee3f>] ? ftrace_call+0x5/0x2f [ 7174.469413] [<ffffffff8115c9e6>] do_try_to_free_pages+0x156/0x4c0 [ 7174.469413] [<ffffffff8115cf47>] try_to_free_pages+0xf7/0x1e0 [ 7174.469413] [<ffffffff81150db3>] __alloc_pages_nodemask+0x783/0xb20 [ 7174.469413] [<ffffffff8119092f>] alloc_pages_current+0x10f/0x1f0 [ 7174.469413] [<ffffffff81145c0f>] ? __page_cache_alloc+0x13f/0x160 [ 7174.469413] [<ffffffff81145c0f>] __page_cache_alloc+0x13f/0x160 [ 7174.469413] [<ffffffff81146c6c>] find_or_create_page+0x4c/0xb0 [ 7174.469413] [<ffffffff811463e5>] ? find_get_page+0x5/0x130 [ 7174.469413] [<ffffffff812837b9>] ext4_mb_load_buddy+0x1e9/0x370 [ 7174.469413] [<ffffffff81284c07>] ext4_mb_regular_allocator+0x1b7/0x460 [ 7174.469413] [<ffffffff81281070>] ? ext4_mb_use_preallocated+0x40/0x360 [ 7174.469413] [<ffffffff816eee3f>] ? ftrace_call+0x5/0x2f [ 7174.469413] [<ffffffff81287eb8>] ext4_mb_new_blocks+0x458/0x5f0 [ 7174.469413] [<ffffffff8127d83b>] ext4_ext_map_blocks+0x70b/0x1010 [ 7174.469413] [<ffffffff8124e6d5>] ext4_map_blocks+0x325/0x530 [ 7174.469413] [<ffffffff81253871>] ext4_writepages+0x6d1/0xce0 [ 7174.469413] [<ffffffff812531a0>] ? ext4_journalled_write_end+0x330/0x330 [ 7174.469413] [<ffffffff811539b3>] do_writepages+0x23/0x40 [ 7174.469413] [<ffffffff811d2365>] __writeback_single_inode+0x45/0x2e0 [ 7174.469413] [<ffffffff811d36ed>] writeback_sb_inodes+0x2ad/0x500 [ 7174.469413] [<ffffffff811d39de>] __writeback_inodes_wb+0x9e/0xd0 [ 7174.469413] [<ffffffff811d40bb>] wb_writeback+0x29b/0x350 [ 7174.469413] [<ffffffff81057c3d>] ? __local_bh_enable_ip+0x6d/0xd0 [ 7174.469413] [<ffffffff811d6e9c>] bdi_writeback_workfn+0x11c/0x480 [ 7174.469413] [<ffffffff81070610>] ? process_one_work+0x170/0x570 [ 7174.469413] [<ffffffff81070672>] process_one_work+0x1d2/0x570 [ 7174.469413] [<ffffffff81070610>] ? process_one_work+0x170/0x570 [ 7174.469413] [<ffffffff81071bb6>] worker_thread+0x116/0x370 [ 7174.469413] [<ffffffff81071aa0>] ? manage_workers.isra.19+0x2e0/0x2e0 [ 7174.469413] [<ffffffff81078e53>] kthread+0xf3/0x110 [ 7174.469413] [<ffffffff81078d60>] ? flush_kthread_worker+0x150/0x150 [ 7174.469413] [<ffffffff816ef0ec>] ret_from_fork+0x7c/0xb0 [ 7174.469413] [<ffffffff81078d60>] ? flush_kthread_worker+0x150/0x150 [ 7174.469413] Code: c0 49 bc fc 8d 76 82 ff ff ff ff e8 44 5a 5b 00 31 f6 8b 05 95 2b b3 00 48 39 c6 7d 0e 4c 8b 04 f5 20 5f c5 81 49 83 f8 ff 75 11 <0f> 0b 48 63 05 71 5a 64 01 48 29 c3 e9 d0 fd ff ff 48 8d 5e 01 [ 7174.469413] RIP [<ffffffff8112336e>] stack_trace_call+0x2de/0x340 [ 7174.469413] RSP <ffff880029518290> [ 7174.469413] ---[ end trace c97d325b36b718f3 ]--- Link: http://lkml.kernel.org/p/1401683592-1651-1-git-send-email-minchan@kernel.org Signed-off-by: Minchan Kim <minchan@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-04-24tracing/stack_trace: Skip 4 instead of 3 when using ftrace_ops_list_funcJiaxing Wang
When using ftrace_ops_list_func, we should skip 4 instead of 3, to avoid ftrace_call+0x5/0xb appearing in the stack trace: Depth Size Location (110 entries) ----- ---- -------- 0) 2956 0 update_curr+0xe/0x1e0 1) 2956 68 ftrace_call+0x5/0xb 2) 2888 92 enqueue_entity+0x53/0xe80 3) 2796 80 enqueue_task_fair+0x47/0x7e0 4) 2716 28 enqueue_task+0x45/0x70 5) 2688 12 activate_task+0x22/0x30 Add a function using_ftrace_ops_list_func() to test for this while keeping ftrace_ops_list_func to remain static. Link: http://lkml.kernel.org/p/1398006644-5935-2-git-send-email-wangjiaxing@insigma.com.cn Signed-off-by: Jiaxing Wang <wangjiaxing@insigma.com.cn> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-03-24tracing: Add BUG_ON when stack end location is over writtenAaron Tomlin
It is difficult to detect a stack overrun when it actually occurs. We have observed that this type of corruption is often silent and can go unnoticed. Once the corrupted region is examined, the outcome is undefined and often results in sporadic system crashes. When the stack tracing feature is enabled, let's check for this condition and take appropriate action. Note: init_task doesn't get its stack end location set to STACK_END_MAGIC. Link: http://lkml.kernel.org/r/1395669837-30209-1-git-send-email-atomlin@redhat.com Signed-off-by: Aaron Tomlin <atomlin@redhat.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-01-02tracing: Add generic tracing_lseek() functionSteven Rostedt (Red Hat)
Trace event triggers added a lseek that uses the ftrace_filter_lseek() function. Unfortunately, when function tracing is not configured in that function is not defined and the kernel fails to build. This is the second time that function was added to a file ops and it broke the build due to requiring special config dependencies. Make a generic tracing_lseek() that all the tracing utilities may use. Also, modify the old ftrace_filter_lseek() to return 0 instead of 1 on WRONLY. Not sure why it was a 1 as that does not make sense. This also changes the old tracing_seek() to modify the file pos pointer on WRONLY as well. Reported-by: kbuild test robot <fengguang.wu@intel.com> Tested-by: Tom Zanussi <tom.zanussi@linux.intel.com> Acked-by: Tom Zanussi <tom.zanussi@linux.intel.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-04-29Merge tag 'trace-3.10' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing updates from Steven Rostedt: "Along with the usual minor fixes and clean ups there are a few major changes with this pull request. 1) Multiple buffers for the ftrace facility This feature has been requested by many people over the last few years. I even heard that Google was about to implement it themselves. I finally had time and cleaned up the code such that you can now create multiple instances of the ftrace buffer and have different events go to different buffers. This way, a low frequency event will not be lost in the noise of a high frequency event. Note, currently only events can go to different buffers, the tracers (ie function, function_graph and the latency tracers) still can only be written to the main buffer. 2) The function tracer triggers have now been extended. The function tracer had two triggers. One to enable tracing when a function is hit, and one to disable tracing. Now you can record a stack trace on a single (or many) function(s), take a snapshot of the buffer (copy it to the snapshot buffer), and you can enable or disable an event to be traced when a function is hit. 3) A perf clock has been added. A "perf" clock can be chosen to be used when tracing. This will cause ftrace to use the same clock as perf uses, and hopefully this will make it easier to interleave the perf and ftrace data for analysis." * tag 'trace-3.10' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (82 commits) tracepoints: Prevent null probe from being added tracing: Compare to 1 instead of zero for is_signed_type() tracing: Remove obsolete macro guard _TRACE_PROFILE_INIT ftrace: Get rid of ftrace_profile_bits tracing: Check return value of tracing_init_dentry() tracing: Get rid of unneeded key calculation in ftrace_hash_move() tracing: Reset ftrace_graph_filter_enabled if count is zero tracing: Fix off-by-one on allocating stat->pages kernel: tracing: Use strlcpy instead of strncpy tracing: Update debugfs README file tracing: Fix ftrace_dump() tracing: Rename trace_event_mutex to trace_event_sem tracing: Fix comment about prefix in arch_syscall_match_sym_name() tracing: Convert trace_destroy_fields() to static tracing: Move find_event_field() into trace_events.c tracing: Use TRACE_MAX_PRINT instead of constant tracing: Use pr_warn_once instead of open coded implementation ring-buffer: Add ring buffer startup selftest tracing: Bring Documentation/trace/ftrace.txt up to date tracing: Add "perf" trace_clock ... Conflicts: kernel/trace/ftrace.c kernel/trace/trace.c
2013-04-12tracing: Check return value of tracing_init_dentry()Namhyung Kim
Check return value and bail out if it's NULL. Link: http://lkml.kernel.org/r/1365553093-10180-2-git-send-email-namhyung@kernel.org Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Namhyung Kim <namhyung.kim@lge.com> Cc: stable@vger.kernel.org Signed-off-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-04-12tracing: Fix possible NULL pointer dereferencesNamhyung Kim
Currently set_ftrace_pid and set_graph_function files use seq_lseek for their fops. However seq_open() is called only for FMODE_READ in the fops->open() so that if an user tries to seek one of those file when she open it for writing, it sees NULL seq_file and then panic. It can be easily reproduced with following command: $ cd /sys/kernel/debug/tracing $ echo 1234 | sudo tee -a set_ftrace_pid In this example, GNU coreutils' tee opens the file with fopen(, "a") and then the fopen() internally calls lseek(). Link: http://lkml.kernel.org/r/1365663302-2170-1-git-send-email-namhyung@kernel.org Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Namhyung Kim <namhyung.kim@lge.com> Cc: stable@vger.kernel.org Signed-off-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-03-15tracing: Remove most or all of stack tracer stack size from stack_max_sizeSteven Rostedt (Red Hat)
Currently, the depth reported in the stack tracer stack_trace file does not match the stack_max_size file. This is because the stack_max_size includes the overhead of stack tracer itself while the depth does not. The first time a max is triggered, a calculation is not performed that figures out the overhead of the stack tracer and subtracts it from the stack_max_size variable. The overhead is stored and is subtracted from the reported stack size for comparing for a new max. Now the stack_max_size corresponds to the reported depth: # cat stack_max_size 4640 # cat stack_trace Depth Size Location (48 entries) ----- ---- -------- 0) 4640 32 _raw_spin_lock+0x18/0x24 1) 4608 112 ____cache_alloc+0xb7/0x22d 2) 4496 80 kmem_cache_alloc+0x63/0x12f 3) 4416 16 mempool_alloc_slab+0x15/0x17 [...] While testing against and older gcc on x86 that uses mcount instead of fentry, I found that pasing in ip + MCOUNT_INSN_SIZE let the stack trace show one more function deep which was missing before. Cc: stable@vger.kernel.org Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-03-15tracing: Fix stack tracer with fentry useSteven Rostedt (Red Hat)
When gcc 4.6 on x86 is used, the function tracer will use the new option -mfentry which does a call to "fentry" at every function instead of "mcount". The significance of this is that fentry is called as the first operation of the function instead of the mcount usage of being called after the stack. This causes the stack tracer to show some bogus results for the size of the last function traced, as well as showing "ftrace_call" instead of the function. This is due to the stack frame not being set up by the function that is about to be traced. # cat stack_trace Depth Size Location (48 entries) ----- ---- -------- 0) 4824 216 ftrace_call+0x5/0x2f 1) 4608 112 ____cache_alloc+0xb7/0x22d 2) 4496 80 kmem_cache_alloc+0x63/0x12f The 216 size for ftrace_call includes both the ftrace_call stack (which includes the saving of registers it does), as well as the stack size of the parent. To fix this, if CC_USING_FENTRY is defined, then the stack_tracer will reserve the first item in stack_dump_trace[] array when calling save_stack_trace(), and it will fill it in with the parent ip. Then the code will look for the parent pointer on the stack and give the real size of the parent's stack pointer: # cat stack_trace Depth Size Location (14 entries) ----- ---- -------- 0) 2640 48 update_group_power+0x26/0x187 1) 2592 224 update_sd_lb_stats+0x2a5/0x4ac 2) 2368 160 find_busiest_group+0x31/0x1f1 3) 2208 256 load_balance+0xd9/0x662 I'm Cc'ing stable, although it's not urgent, as it only shows bogus size for item #0, the rest of the trace is legit. It should still be corrected in previous stable releases. Cc: stable@vger.kernel.org Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-03-15tracing: Use stack of calling function for stack tracerSteven Rostedt (Red Hat)
Use the stack of stack_trace_call() instead of check_stack() as the test pointer for max stack size. It makes it a bit cleaner and a little more accurate. Adding stable, as a later fix depends on this patch. Cc: stable@vger.kernel.org Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2012-11-19tracing: Remove unneeded checks from the stack tracerAnton Vorontsov
It seems that 'ftrace_enabled' flag should not be used inside the tracer functions. The ftrace core is using this flag for internal purposes, and the flag wasn't meant to be used in tracers' runtime checks. stack tracer is the only tracer that abusing the flag. So stop it from serving as a bad example. Also, there is a local 'stack_trace_disabled' flag in the stack tracer, which is never updated; so it can be removed as well. Link: http://lkml.kernel.org/r/1342637761-9655-1-git-send-email-anton.vorontsov@linaro.org Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2012-07-31ftrace: Add default recursion protection for function tracingSteven Rostedt
As more users of the function tracer utility are being added, they do not always add the necessary recursion protection. To protect from function recursion due to tracing, if the callback ftrace_ops does not specifically specify that it protects against recursion (by setting the FTRACE_OPS_FL_RECURSION_SAFE flag), the list operation will be called by the mcount trampoline which adds recursion protection. If the flag is set, then the function will be called directly with no extra protection. Note, the list operation is called if more than one function callback is registered, or if the arch does not support all of the function tracer features. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2012-07-19ftrace: Return pt_regs to function trace callbackSteven Rostedt
Return as the 4th paramater to the function tracer callback the pt_regs. Later patches that implement regs passing for the architectures will require having the ftrace_ops set the SAVE_REGS flag, which will tell the arch to take the time to pass a full set of pt_regs to the ftrace_ops callback function. If the arch does not support it then it should pass NULL. If an arch can pass full regs, then it should define: ARCH_SUPPORTS_FTRACE_SAVE_REGS to 1 Link: http://lkml.kernel.org/r/20120702201821.019966811@goodmis.org Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2012-07-19ftrace: Pass ftrace_ops as third parameter to function trace callbackSteven Rostedt
Currently the function trace callback receives only the ip and parent_ip of the function that it traced. It would be more powerful to also return the ops that registered the function as well. This allows the same function to act differently depending on what ftrace_ops registered it. Link: http://lkml.kernel.org/r/20120612225424.267254552@goodmis.org Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-12-21tracing: Have stack tracing set filtered functions at bootSteven Rostedt
Add stacktrace_filter= to the kernel command line that lets the user pick specific functions to check the stack on. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-12-21tracing: Have stack_tracer use a separate list of functionsSteven Rostedt
The stack_tracer is used to look at every function and check if the current stack is bigger than the last recorded max stack size. When a new max is found, then it saves that stack off. Currently the stack tracer is limited by the global_ops of the function tracer. As the stack tracer has nothing to do with the ftrace function tracer, except that it uses it as its internal engine, the stack tracer should have its own list. A new file is added to the tracing debugfs directory called: stack_trace_filter that can be used to select which functions you want to check the stack on. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-06-14tracing: Convert to kstrtoul_from_userPeter Huewe
This patch replaces the code for getting an unsigned long from a userspace buffer by a simple call to kstroul_from_user. This makes it easier to read and less error prone. Signed-off-by: Peter Huewe <peterhuewe@gmx.de> Link: http://lkml.kernel.org/r/1307476707-14762-1-git-send-email-peterhuewe@gmx.de Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-05-18ftrace: Implement separate user function filteringSteven Rostedt
ftrace_ops that are registered to trace functions can now be agnostic to each other in respect to what functions they trace. Each ops has their own hash of the functions they want to trace and a hash to what they do not want to trace. A empty hash for the functions they want to trace denotes all functions should be traced that are not in the notrace hash. Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-10-15llseek: automatically add .llseek fopArnd Bergmann
All file_operations should get a .llseek operation so we can make nonseekable_open the default for future file operations without a .llseek pointer. The three cases that we can automatically detect are no_llseek, seq_lseek and default_llseek. For cases where we can we can automatically prove that the file offset is always ignored, we use noop_llseek, which maintains the current behavior of not returning an error from a seek. New drivers should normally not use noop_llseek but instead use no_llseek and call nonseekable_open at open time. Existing drivers can be converted to do the same when the maintainer knows for certain that no user code relies on calling seek on the device file. The generated code is often incorrectly indented and right now contains comments that clarify for each added line why a specific variant was chosen. In the version that gets submitted upstream, the comments will be gone and I will manually fix the indentation, because there does not seem to be a way to do that using coccinelle. Some amount of new code is currently sitting in linux-next that should get the same modifications, which I will do at the end of the merge window. Many thanks to Julia Lawall for helping me learn to write a semantic patch that does all this. ===== begin semantic patch ===== // This adds an llseek= method to all file operations, // as a preparation for making no_llseek the default. // // The rules are // - use no_llseek explicitly if we do nonseekable_open // - use seq_lseek for sequential files // - use default_llseek if we know we access f_pos // - use noop_llseek if we know we don't access f_pos, // but we still want to allow users to call lseek // @ open1 exists @ identifier nested_open; @@ nested_open(...) { <+... nonseekable_open(...) ...+> } @ open exists@ identifier open_f; identifier i, f; identifier open1.nested_open; @@ int open_f(struct inode *i, struct file *f) { <+... ( nonseekable_open(...) | nested_open(...) ) ...+> } @ read disable optional_qualifier exists @ identifier read_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; expression E; identifier func; @@ ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off) { <+... ( *off = E | *off += E | func(..., off, ...) | E = *off ) ...+> } @ read_no_fpos disable optional_qualifier exists @ identifier read_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; @@ ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off) { ... when != off } @ write @ identifier write_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; expression E; identifier func; @@ ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off) { <+... ( *off = E | *off += E | func(..., off, ...) | E = *off ) ...+> } @ write_no_fpos @ identifier write_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; @@ ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off) { ... when != off } @ fops0 @ identifier fops; @@ struct file_operations fops = { ... }; @ has_llseek depends on fops0 @ identifier fops0.fops; identifier llseek_f; @@ struct file_operations fops = { ... .llseek = llseek_f, ... }; @ has_read depends on fops0 @ identifier fops0.fops; identifier read_f; @@ struct file_operations fops = { ... .read = read_f, ... }; @ has_write depends on fops0 @ identifier fops0.fops; identifier write_f; @@ struct file_operations fops = { ... .write = write_f, ... }; @ has_open depends on fops0 @ identifier fops0.fops; identifier open_f; @@ struct file_operations fops = { ... .open = open_f, ... }; // use no_llseek if we call nonseekable_open //////////////////////////////////////////// @ nonseekable1 depends on !has_llseek && has_open @ identifier fops0.fops; identifier nso ~= "nonseekable_open"; @@ struct file_operations fops = { ... .open = nso, ... +.llseek = no_llseek, /* nonseekable */ }; @ nonseekable2 depends on !has_llseek @ identifier fops0.fops; identifier open.open_f; @@ struct file_operations fops = { ... .open = open_f, ... +.llseek = no_llseek, /* open uses nonseekable */ }; // use seq_lseek for sequential files ///////////////////////////////////// @ seq depends on !has_llseek @ identifier fops0.fops; identifier sr ~= "seq_read"; @@ struct file_operations fops = { ... .read = sr, ... +.llseek = seq_lseek, /* we have seq_read */ }; // use default_llseek if there is a readdir /////////////////////////////////////////// @ fops1 depends on !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier readdir_e; @@ // any other fop is used that changes pos struct file_operations fops = { ... .readdir = readdir_e, ... +.llseek = default_llseek, /* readdir is present */ }; // use default_llseek if at least one of read/write touches f_pos ///////////////////////////////////////////////////////////////// @ fops2 depends on !fops1 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read.read_f; @@ // read fops use offset struct file_operations fops = { ... .read = read_f, ... +.llseek = default_llseek, /* read accesses f_pos */ }; @ fops3 depends on !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier write.write_f; @@ // write fops use offset struct file_operations fops = { ... .write = write_f, ... + .llseek = default_llseek, /* write accesses f_pos */ }; // Use noop_llseek if neither read nor write accesses f_pos /////////////////////////////////////////////////////////// @ fops4 depends on !fops1 && !fops2 && !fops3 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read_no_fpos.read_f; identifier write_no_fpos.write_f; @@ // write fops use offset struct file_operations fops = { ... .write = write_f, .read = read_f, ... +.llseek = noop_llseek, /* read and write both use no f_pos */ }; @ depends on has_write && !has_read && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier write_no_fpos.write_f; @@ struct file_operations fops = { ... .write = write_f, ... +.llseek = noop_llseek, /* write uses no f_pos */ }; @ depends on has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read_no_fpos.read_f; @@ struct file_operations fops = { ... .read = read_f, ... +.llseek = noop_llseek, /* read uses no f_pos */ }; @ depends on !has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; @@ struct file_operations fops = { ... +.llseek = noop_llseek, /* no read or write fn */ }; ===== End semantic patch ===== Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Julia Lawall <julia@diku.dk> Cc: Christoph Hellwig <hch@infradead.org>
2010-08-25tracing/trace_stack: Fix stack trace on ppc64Anton Blanchard
save_stack_trace() stores the instruction pointer, not the function descriptor. On ppc64 the trace stack code currently dereferences the instruction pointer and shows 8 bytes of instructions in our backtraces: # cat /sys/kernel/debug/tracing/stack_trace Depth Size Location (26 entries) ----- ---- -------- 0) 5424 112 0x6000000048000004 1) 5312 160 0x60000000ebad01b0 2) 5152 160 0x2c23000041c20030 3) 4992 240 0x600000007c781b79 4) 4752 160 0xe84100284800000c 5) 4592 192 0x600000002fa30000 6) 4400 256 0x7f1800347b7407e0 7) 4144 208 0xe89f0108f87f0070 8) 3936 272 0xe84100282fa30000 Since we aren't dealing with function descriptors, use %pS instead of %pF to fix it: # cat /sys/kernel/debug/tracing/stack_trace Depth Size Location (26 entries) ----- ---- -------- 0) 5424 112 ftrace_call+0x4/0x8 1) 5312 160 .current_io_context+0x28/0x74 2) 5152 160 .get_io_context+0x48/0xa0 3) 4992 240 .cfq_set_request+0x94/0x4c4 4) 4752 160 .elv_set_request+0x60/0x84 5) 4592 192 .get_request+0x2d4/0x468 6) 4400 256 .get_request_wait+0x7c/0x258 7) 4144 208 .__make_request+0x49c/0x610 8) 3936 272 .generic_make_request+0x390/0x434 Signed-off-by: Anton Blanchard <anton@samba.org> Cc: rostedt@goodmis.org Cc: fweisbec@gmail.com LKML-Reference: <20100825013238.GE28360@kryten> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-06-03tracing: Remove ftrace_preempt_disable/enableSteven Rostedt
The ftrace_preempt_disable/enable functions were to address a recursive race caused by the function tracer. The function tracer traces all functions which makes it easily susceptible to recursion. One area was preempt_enable(). This would call the scheduler and the schedulre would call the function tracer and loop. (So was it thought). The ftrace_preempt_disable/enable was made to protect against recursion inside the scheduler by storing the NEED_RESCHED flag. If it was set before the ftrace_preempt_disable() it would not call schedule on ftrace_preempt_enable(), thinking that if it was set before then it would have already scheduled unless it was already in the scheduler. This worked fine except in the case of SMP, where another task would set the NEED_RESCHED flag for a task on another CPU, and then kick off an IPI to trigger it. This could cause the NEED_RESCHED to be saved at ftrace_preempt_disable() but the IPI to arrive in the the preempt disabled section. The ftrace_preempt_enable() would not call the scheduler because the flag was already set before entring the section. This bug would cause a missed preemption check and cause lower latencies. Investigating further, I found that the recusion caused by the function tracer was not due to schedule(), but due to preempt_schedule(). Now that preempt_schedule is completely annotated with notrace, the recusion no longer is an issue. Reported-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-02-02tracing: Fix circular dead lock in stack traceLai Jiangshan
When we cat <debugfs>/tracing/stack_trace, we may cause circular lock: sys_read() t_start() arch_spin_lock(&max_stack_lock); t_show() seq_printf(), vsnprintf() .... /* they are all trace-able, when they are traced, max_stack_lock may be required again. */ The following script can trigger this circular dead lock very easy: #!/bin/bash echo 1 > /proc/sys/kernel/stack_tracer_enabled mount -t debugfs xxx /mnt > /dev/null 2>&1 ( # make check_stack() zealous to require max_stack_lock for ((; ;)) { echo 1 > /mnt/tracing/stack_max_size } ) & for ((; ;)) { cat /mnt/tracing/stack_trace > /dev/null } To fix this bug, we increase the percpu trace_active before require the lock. Reported-by: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> LKML-Reference: <4B67D4F9.9080905@cn.fujitsu.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-12-14locking: Convert __raw_spin* functions to arch_spin*Thomas Gleixner
Name space cleanup. No functional change. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: David S. Miller <davem@davemloft.net> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: linux-arch@vger.kernel.org
2009-12-14locking: Rename __RAW_SPIN_LOCK_UNLOCKED to __ARCH_SPIN_LOCK_UNLOCKEDThomas Gleixner
Further name space cleanup. No functional change Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: David S. Miller <davem@davemloft.net> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: linux-arch@vger.kernel.org
2009-12-14locking: Convert raw_spinlock to arch_spinlockThomas Gleixner
The raw_spin* namespace was taken by lockdep for the architecture specific implementations. raw_spin_* would be the ideal name space for the spinlocks which are not converted to sleeping locks in preempt-rt. Linus suggested to convert the raw_ to arch_ locks and cleanup the name space instead of using an artifical name like core_spin, atomic_spin or whatever No functional change. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: David S. Miller <davem@davemloft.net> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: linux-arch@vger.kernel.org
2009-09-24sysctl: remove "struct file *" argument of ->proc_handlerAlexey Dobriyan
It's unused. It isn't needed -- read or write flag is already passed and sysctl shouldn't care about the rest. It _was_ used in two places at arch/frv for some reason. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Cc: David Howells <dhowells@redhat.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: "David S. Miller" <davem@davemloft.net> Cc: James Morris <jmorris@namei.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-08-17trace_stack: Simplify seqfile codeLi Zefan
Extract duplicate code in t_start() and t_next(). Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <4A891A91.4030602@cn.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-11Merge branch 'linus' into tracing/coreIngo Molnar
Conflicts: kernel/trace/trace_events_filter.c We use the tracing/core version. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-07-23trace_stack: Fix seqfile memory leakLi Zefan
Every time we cat stack_trace, we leak memory allocated by seq_open(). Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> LKML-Reference: <4A67D8E8.3020500@cn.fujitsu.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-07-17tracing/trace_stack: Cleanup for trace_lookup_stack()Xiao Guangrong
We can directly use %pF input format instead of sprint_symbol() and %s input format. Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Reviewed-by: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2009-06-26tracing: Fix stack tracer sysctl handlingLi Zefan
This made my machine completely frozen: # echo 1 > /proc/sys/kernel/stack_tracer_enabled # echo 2 > /proc/sys/kernel/stack_tracer_enabled The cause is register_ftrace_function() was called twice. Also fix ftrace_enabled sysctl, though seems nothing bad happened as I tested it. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <4A448D17.9010305@cn.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-06-03tracing/trace_stack: fix the number of entries in the headerwalimis
The last entry in the stack_dump_trace is ULONG_MAX, which is not a valid entry, but max_stack_trace.nr_entries has accounted for it. So when printing the header, we should decrease it by one. Before fix, print as following, for example: Depth Size Location (53 entries) <--- should be 52 ----- ---- -------- 0) 3264 108 update_wall_time+0x4d5/0x9a0 ... 51) 80 80 syscall_call+0x7/0xb ^^^ it's correct. Signed-off-by: walimis <walimisdev@gmail.com> LKML-Reference: <1244016090-7814-1-git-send-email-walimisdev@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-04-07tracing/ftrace: factorize the tracing files creationFrederic Weisbecker
Impact: cleanup Most of the tracing files creation follow the same pattern: ret = debugfs_create_file(...) if (!ret) pr_warning("Couldn't create ... entry\n") Unify it! Reported-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <1238109938-11840-1-git-send-email-fweisbec@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-03-13tracing: left align location header in stack_traceSteven Rostedt
Ingo Molnar suggested, instead of: Depth Size Location (27 entries) ----- ---- -------- 0) 2880 48 lock_timer_base+0x2b/0x4f 1) 2832 80 __mod_timer+0x33/0xe0 2) 2752 16 __ide_set_handler+0x63/0x65 To have it be: Depth Size Location (27 entries) ----- ---- -------- 0) 2880 48 lock_timer_base+0x2b/0x4f 1) 2832 80 __mod_timer+0x33/0xe0 2) 2752 16 __ide_set_handler+0x63/0x65 Requested-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Steven Rostedt <srostedt@redhat.com>
2009-03-12tracing: explain why stack tracer is emptySteven Rostedt
If the stack tracing is disabled (by default) the stack_trace file will only contain the header: # cat /debug/tracing/stack_trace Depth Size Location (0 entries) ----- ---- -------- This can be frustrating to a developer that does not realize that the stack tracer is disabled. This patch adds the following text: # cat /debug/tracing/stack_trace Depth Size Location (0 entries) ----- ---- -------- # # Stack tracer disabled # # To enable the stack tracer, either add 'stacktrace' to the # kernel command line # or 'echo 1 > /proc/sys/kernel/stack_tracer_enabled' # Signed-off-by: Steven Rostedt <srostedt@redhat.com>
2009-03-12tracing: fix stack tracer headerSteven Rostedt
The stack tracer use to look like this: # cat /debug/tracing/stack_trace Depth Size Location (57 entries) ----- ---- -------- 0) 5088 16 mempool_alloc_slab+0x16/0x18 1) 5072 144 mempool_alloc+0x4d/0xfe 2) 4928 16 scsi_sg_alloc+0x48/0x4a [scsi_mod] Now it looks like this: # cat /debug/tracing/stack_trace Depth Size Location (57 entries) ----- ---- -------- 0) 5088 16 mempool_alloc_slab+0x16/0x18 1) 5072 144 mempool_alloc+0x4d/0xfe 2) 4928 16 scsi_sg_alloc+0x48/0x4a [scsi_mod] Signed-off-by: Steven Rostedt <srostedt@redhat.com>
2008-12-18trace: better use of stack_trace_enabled for boot up codeSteven Rostedt
Impact: clean up Andrew Morton suggested to use the stack_tracer_enabled variable to decide whether or not to start stack tracing on bootup. This lets us remove the start_stack_trace variable. Reported-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-18trace: add a way to enable or disable the stack tracerSteven Rostedt
Impact: enhancement to stack tracer The stack tracer currently is either on when configured in or off when it is not. It can not be disabled when it is configured on. (besides disabling the function tracer that it uses) This patch adds a way to enable or disable the stack tracer at run time. It defaults off on bootup, but a kernel parameter 'stacktrace' has been added to enable it on bootup. A new sysctl has been added "kernel.stack_tracer_enabled" to let the user enable or disable the stack tracer at run time. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-03trace: fix output of stack traceSteven Rostedt
Impact: fix to output of stack trace If a function is not found in the stack of the stack tracer, the number printed is quite strange. This fixes the algorithm to handle missing functions better. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-03ftrace: replace raw_local_irq_save with local_irq_saveSteven Rostedt
Impact: fix for lockdep and ftrace The raw_local_irq_save/restore confuses lockdep. This patch converts them to the local_irq_save/restore variants. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-23Merge branches 'tracing/profiling', 'tracing/options' and 'tracing/urgent' ↵Ingo Molnar
into tracing/core
2008-11-21function tracing: fix wrong position computing of stack_traceLiming Wang
Impact: make output of stack_trace complete if buffer overruns When read buffer overruns, the output of stack_trace isn't complete. When printing records with seq_printf in t_show, if the read buffer has overruned by the current record, then this record won't be printed to user space through read buffer, it will just be dropped in this printing. When next printing, t_start should return the "*pos"th record, which is the one dropped by previous printing, but it just returns (m->private + *pos)th record. Here we use a more sane method to implement seq_operations which can be found in kernel code. Thus we needn't initialize m->private. About testing, it's not easy to overrun read buffer, but we can use seq_printf to print more padding bytes in t_show, then it's easy to check whether or not records are lost. This commit has been tested on both condition of overrun and non overrun. Signed-off-by: Liming Wang <liming.wang@windriver.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-04ftrace: insert in the ftrace_preempt_disable()/enable() functionsSteven Rostedt
Impact: use new, consolidated APIs in ftrace plugins This patch replaces the schedule safe preempt disable code with the ftrace_preempt_disable() and ftrace_preempt_enable() safe functions. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-20ftrace: stack tracer only record when on stackSteven Rostedt
The stack trace API does not record if the stack is not on the current task's stack. That is, if the stack is the interrupt stack or NMI stack, the output does not show. Also, the size of those stacks are not consistent with the size of the thread stack, this makes the calculation of the stack size usually bogus. This all confuses the stack tracer. I unfortunately do not have time to fix all these problems, but this patch does record the worst stack when the stack pointer is on the tasks stack (instead of bogus numbers). The patch simply returns if the stack pointer is not on the task's stack. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-14ftrace: stack trace add indexesSteven Rostedt
This patch adds indexes into the stack that the functions in the stack dump were found at. As an added bonus, I also added a diff to show which function is the most notorious consumer of the stack. The output now looks like this: # cat /debug/tracing/stack_trace Depth Size Location (48 entries) ----- ---- -------- 0) 2476 212 blk_recount_segments+0x39/0x59 1) 2264 12 bio_phys_segments+0x16/0x1d 2) 2252 20 blk_rq_bio_prep+0x23/0xaf 3) 2232 12 init_request_from_bio+0x74/0x77 4) 2220 56 __make_request+0x294/0x331 5) 2164 136 generic_make_request+0x34f/0x37d 6) 2028 56 submit_bio+0xe7/0xef 7) 1972 28 submit_bh+0xd1/0xf0 8) 1944 112 block_read_full_page+0x299/0x2a9 9) 1832 8 blkdev_readpage+0x14/0x16 10) 1824 28 read_cache_page_async+0x7e/0x109 11) 1796 16 read_cache_page+0x11/0x49 12) 1780 32 read_dev_sector+0x3c/0x72 13) 1748 48 read_lba+0x4d/0xaa 14) 1700 168 efi_partition+0x85/0x61b 15) 1532 72 rescan_partitions+0x10e/0x266 16) 1460 40 do_open+0x1c7/0x24e 17) 1420 292 __blkdev_get+0x79/0x84 18) 1128 12 blkdev_get+0x12/0x14 19) 1116 20 register_disk+0xd1/0x11e 20) 1096 28 add_disk+0x34/0x90 21) 1068 52 sd_probe+0x2b1/0x366 22) 1016 20 driver_probe_device+0xa5/0x120 23) 996 8 __device_attach+0xd/0xf 24) 988 32 bus_for_each_drv+0x3e/0x68 25) 956 24 device_attach+0x56/0x6c 26) 932 16 bus_attach_device+0x26/0x4d 27) 916 64 device_add+0x380/0x4b4 28) 852 28 scsi_sysfs_add_sdev+0xa1/0x1c9 29) 824 160 scsi_probe_and_add_lun+0x919/0xa2a 30) 664 36 __scsi_add_device+0x88/0xae 31) 628 44 ata_scsi_scan_host+0x9e/0x21c 32) 584 28 ata_host_register+0x1cb/0x1db 33) 556 24 ata_host_activate+0x98/0xb5 34) 532 192 ahci_init_one+0x9bd/0x9e9 35) 340 20 pci_device_probe+0x3e/0x5e 36) 320 20 driver_probe_device+0xa5/0x120 37) 300 20 __driver_attach+0x3f/0x5e 38) 280 36 bus_for_each_dev+0x40/0x62 39) 244 12 driver_attach+0x19/0x1b 40) 232 28 bus_add_driver+0x9c/0x1af 41) 204 28 driver_register+0x76/0xd2 42) 176 20 __pci_register_driver+0x44/0x71 43) 156 8 ahci_init+0x14/0x16 44) 148 100 _stext+0x42/0x122 45) 48 20 kernel_init+0x175/0x1dc 46) 28 28 kernel_thread_helper+0x7/0x10 The first column is simply an index starting from the inner most function and counting down to the outer most. The next column is the location that the function was found on the stack. The next column is the size of the stack for that function. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-14ftrace: add stack tracerSteven Rostedt
This is another tracer using the ftrace infrastructure, that examines at each function call the size of the stack. If the stack use is greater than the previous max it is recorded. You can always see (and set) the max stack size seen. By setting it to zero will start the recording again. The backtrace is also available. For example: # cat /debug/tracing/stack_max_size 1856 # cat /debug/tracing/stack_trace [<c027764d>] stack_trace_call+0x8f/0x101 [<c021b966>] ftrace_call+0x5/0x8 [<c02553cc>] clocksource_get_next+0x12/0x48 [<c02542a5>] update_wall_time+0x538/0x6d1 [<c0245913>] do_timer+0x23/0xb0 [<c0257657>] tick_do_update_jiffies64+0xd9/0xf1 [<c02576b9>] tick_sched_timer+0x4a/0xad [<c0250fe6>] __run_hrtimer+0x3e/0x75 [<c02518ed>] hrtimer_interrupt+0xf1/0x154 [<c022c870>] smp_apic_timer_interrupt+0x71/0x84 [<c021b7e9>] apic_timer_interrupt+0x2d/0x34 [<c0238597>] finish_task_switch+0x29/0xa0 [<c05abd13>] schedule+0x765/0x7be [<c05abfca>] schedule_timeout+0x1b/0x90 [<c05ab4d4>] wait_for_common+0xab/0x101 [<c05ab5ac>] wait_for_completion+0x12/0x14 [<c033cfc3>] blk_execute_rq+0x84/0x99 [<c0402470>] scsi_execute+0xc2/0x105 [<c040250a>] scsi_execute_req+0x57/0x7f [<c043afe0>] sr_test_unit_ready+0x3e/0x97 [<c043bbd6>] sr_media_change+0x43/0x205 [<c046b59f>] media_changed+0x48/0x77 [<c046b5ff>] cdrom_media_changed+0x31/0x37 [<c043b091>] sr_block_media_changed+0x16/0x18 [<c02b9e69>] check_disk_change+0x1b/0x63 [<c046f4c3>] cdrom_open+0x7a1/0x806 [<c043b148>] sr_block_open+0x78/0x8d [<c02ba4c0>] do_open+0x90/0x257 [<c02ba869>] blkdev_open+0x2d/0x56 [<c0296a1f>] __dentry_open+0x14d/0x23c [<c0296b32>] nameidata_to_filp+0x24/0x38 [<c02a1c68>] do_filp_open+0x347/0x626 [<c02967ef>] do_sys_open+0x47/0xbc [<c02968b0>] sys_open+0x23/0x2b [<c021aadd>] sysenter_do_call+0x12/0x26 I've tested this on both x86_64 and i386. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
generated by cgit v1.2.3 (git 2.25.1) at 2024-12-15 11:40:09 +0000