Eiichi Tsukata
fc19ad387e
tracing/snapshot: Resize spare buffer if size changed
commit 46cc0b44428d0f0e81f11ea98217fc0edfbeab07 upstream.
Current snapshot implementation swaps two ring_buffers even though their
sizes are different from each other, that can cause an inconsistency
between the contents of buffer_size_kb file and the current buffer size.
For example:
# cat buffer_size_kb
7 (expanded: 1408)
# echo 1 > events/enable
# grep bytes per_cpu/cpu0/stats
bytes: 1441020
# echo 1 > snapshot // current:1408, spare:1408
# echo 123 > buffer_size_kb // current:123, spare:1408
# echo 1 > snapshot // current:1408, spare:123
# grep bytes per_cpu/cpu0/stats
bytes: 1443700
# cat buffer_size_kb
123 // != current:1408
And also, a similar per-cpu case hits the following WARNING:
Reproducer:
# echo 1 > per_cpu/cpu0/snapshot
# echo 123 > buffer_size_kb
# echo 1 > per_cpu/cpu0/snapshot
WARNING:
WARNING: CPU: 0 PID: 1946 at kernel/trace/trace.c:1607 update_max_tr_single.part.0+0x2b8/0x380
Modules linked in:
CPU: 0 PID: 1946 Comm: bash Not tainted 5.2.0-rc6 #20
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-2.fc30 04/01/2014
RIP: 0010:update_max_tr_single.part.0+0x2b8/0x380
Code: ff e8 dc da f9 ff 0f 0b e9 88 fe ff ff e8 d0 da f9 ff 44 89 ee bf f5 ff ff ff e8 33 dc f9 ff 41 83 fd f5 74 96 e8 b8 da f9 ff <0f> 0b eb 8d e8 af da f9 ff 0f 0b e9 bf fd ff ff e8 a3 da f9 ff 48
RSP: 0018:ffff888063e4fca0 EFLAGS: 00010093
RAX: ffff888066214380 RBX: ffffffff99850fe0 RCX: ffffffff964298a8
RDX: 0000000000000000 RSI: 00000000fffffff5 RDI: 0000000000000005
RBP: 1ffff1100c7c9f96 R08: ffff888066214380 R09: ffffed100c7c9f9b
R10: ffffed100c7c9f9a R11: 0000000000000003 R12: 0000000000000000
R13: 00000000ffffffea R14: ffff888066214380 R15: ffffffff99851060
FS: 00007f9f8173c700(0000) GS:ffff88806d000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000714dc0 CR3: 0000000066fa6000 CR4: 00000000000006f0
Call Trace:
? trace_array_printk_buf+0x140/0x140
? __mutex_lock_slowpath+0x10/0x10
tracing_snapshot_write+0x4c8/0x7f0
? trace_printk_init_buffers+0x60/0x60
? selinux_file_permission+0x3b/0x540
? tracer_preempt_off+0x38/0x506
? trace_printk_init_buffers+0x60/0x60
__vfs_write+0x81/0x100
vfs_write+0x1e1/0x560
ksys_write+0x126/0x250
? __ia32_sys_read+0xb0/0xb0
? do_syscall_64+0x1f/0x390
do_syscall_64+0xc1/0x390
entry_SYSCALL_64_after_hwframe+0x49/0xbe
This patch adds resize_buffer_duplicate_size() to check if there is a
difference between current/spare buffer sizes and resize a spare buffer
if necessary.
Link: http://lkml.kernel.org/r/20190625012910.13109-1-devel@etsukata.com
Cc: stable@vger.kernel.org
Fixes: ad909e21bb ("tracing: Add internal tracing_snapshot() functions")
Signed-off-by: Eiichi Tsukata <devel@etsukata.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@toshiba.co.jp>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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2019-08-04 09:33:26 +02:00 |
| .. |
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blktrace.c
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tracing/blktrace: Fix to allow setting same value
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2018-09-09 20:01:22 +02:00 |
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bpf_trace.c
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bpf: fix check of allowed specifiers in bpf_trace_printk
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2018-12-17 09:38:33 +01:00 |
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ftrace.c
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kprobes: Mark ftrace mcount handler functions nokprobe
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2019-04-27 09:34:44 +02:00 |
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Kconfig
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This release cycle is rather small. Just a few fixes to tracing.
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2016-10-06 11:48:41 -07:00 |
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Makefile
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Disable the __builtin_return_address() warning globally after all
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2016-10-12 10:23:41 -07:00 |
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power-traces.c
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cpufreq: schedutil: New governor based on scheduler utilization data
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2016-04-02 01:09:12 +02:00 |
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ring_buffer.c
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trace: Fix preempt_enable_no_resched() abuse
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2019-05-02 09:32:00 +02:00 |
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ring_buffer_benchmark.c
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rpm-traces.c
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trace.c
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tracing/snapshot: Resize spare buffer if size changed
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2019-08-04 09:33:26 +02:00 |
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trace.h
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tracing: Silence GCC 9 array bounds warning
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2019-07-10 09:55:28 +02:00 |
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trace_benchmark.c
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trace_benchmark.h
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trace_branch.c
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trace_clock.c
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trace_entries.h
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tracing: Add NMI tracing in hwlat detector
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2016-09-02 12:47:55 -04:00 |
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trace_event_perf.c
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Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next
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2016-05-17 16:26:30 -07:00 |
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trace_events.c
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tracing: Fix partial reading of trace event's id file
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2019-05-25 18:26:49 +02:00 |
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trace_events_filter.c
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tracing: Fix regex_match_front() to not over compare the test string
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2018-05-16 10:08:43 +02:00 |
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trace_events_filter_test.h
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trace_events_hist.c
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tracing: Use strncpy instead of memcpy for string keys in hist triggers
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2019-03-23 13:19:45 +01:00 |
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trace_events_trigger.c
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tracing: Fix memory leak in set_trigger_filter()
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2018-12-21 14:11:31 +01:00 |
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trace_export.c
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trace_functions.c
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ftrace: Have set_ftrace_pid use the bitmap like events do
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2016-06-20 09:54:19 -04:00 |
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trace_functions_graph.c
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tracing: Fix missing return symbol in function_graph output
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2018-07-11 16:26:43 +02:00 |
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trace_hwlat.c
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tracing: Fix hwlat kthread migration
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2017-02-09 08:08:28 +01:00 |
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trace_irqsoff.c
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tracing: Remove redundant reset per-CPU buff in irqsoff tracer
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2016-03-18 16:39:11 -04:00 |
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trace_kdb.c
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tracing: Silence GCC 9 array bounds warning
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2019-07-10 09:55:28 +02:00 |
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trace_kprobe.c
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tracing: Quiet gcc warning about maybe unused link variable
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2018-08-03 07:55:12 +02:00 |
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trace_mmiotrace.c
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tracing: Expose CPU physical addresses (resource values) for PCI devices
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2016-06-20 09:54:22 -04:00 |
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trace_nop.c
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tracing: Fix typoes in code comment and printk in trace_nop.c
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2016-03-08 11:23:57 -05:00 |
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trace_output.c
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tracing: Add NMI tracing in hwlat detector
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2016-09-02 12:47:55 -04:00 |
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trace_output.h
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trace_printk.c
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tracing: Handle NULL formats in hold_module_trace_bprintk_format()
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2016-06-20 09:46:12 -04:00 |
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trace_probe.c
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tracing: probeevent: Fix to support minus offset from symbol
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2018-03-28 18:39:23 +02:00 |
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trace_probe.h
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tracing: probeevent: Fix to support minus offset from symbol
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2018-03-28 18:39:23 +02:00 |
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trace_sched_switch.c
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trace_sched_wakeup.c
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trace_selftest.c
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ftrace: Fix selftest goto location on error
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2017-09-27 14:39:23 +02:00 |
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trace_selftest_dynamic.c
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trace_seq.c
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trace_stack.c
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trace_stat.c
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kernel/...: convert pr_warning to pr_warn
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2016-03-22 15:36:02 -07:00 |
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trace_stat.h
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trace_syscalls.c
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tracing/syscalls: fix multiline in error message text
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2016-09-29 10:25:23 +02:00 |
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trace_uprobe.c
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tracing/uprobes: Fix output for multiple string arguments
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2019-02-20 10:18:32 +01:00 |
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tracing_map.c
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tracing: Fix kmemleak in tracing_map_array_free()
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2017-08-30 10:21:49 +02:00 |
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tracing_map.h
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tracing: Update some tracing_map constants and comments
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2016-04-19 12:16:06 -04:00 |