linux/kernel/trace/trace_events_hist.c, branch v5.8

tracing: Move synthetic events to a separate file

2020-06-01T12:23:22Z

With the addition of the in-kernel synthetic event API, synthetic events are no longer specifically tied to the histogram triggers. The synthetic event code is also making trace_event_hist.c very bloated, so for those reasons, move it to a separate file, trace_events_synth.c, along with a new trace_synth.h header file. Because synthetic events are now independent from hist triggers, add a new CONFIG_SYNTH_EVENTS config option, and have CONFIG_HIST_TRIGGERS select it, and have CONFIG_SYNTH_EVENT_GEN_TEST depend on it. Link: http://lkml.kernel.org/r/4d1fa1f85ed5982706ac44844ac92451dcb04715.1590693308.git.zanussi@kernel.org Signed-off-by: Tom Zanussi Signed-off-by: Steven Rostedt (VMware)

tracing: Add hist_debug trace event files for histogram debugging

2020-06-01T12:22:30Z

Add a new "hist_debug" file for each trace event, which when read will dump out a bunch of internal details about the hist triggers defined on that event. This is normally off but can be enabled by saying 'y' to the new CONFIG_HIST_TRIGGERS_DEBUG config option. This is in support of the new Documentation file describing histogram internals, Documentation/trace/histogram-design.rst, which was requested by developers trying to understand the internals when extending or making use of the hist triggers for higher-level tools. The histogram-design.rst documentation refers to the hist_debug files and demonstrates their use with output in the test examples. Link: http://lkml.kernel.org/r/77914c22b0ba493d9783c53bbfbc6087d6a7e1b1.1585941485.git.zanussi@kernel.org Signed-off-by: Tom Zanussi Signed-off-by: Steven Rostedt (VMware)

tracing: Check state.disabled in synth event trace functions

2020-06-01T12:21:08Z

Since trace_state.disabled is set in __synth_event_trace_start() at the same time -ENOENT is returned, don't bother returning -ENOENT - just have callers check trace_state.disabled instead, and avoid the extra return val munging. Link: http://lkml.kernel.org/r/87315c3889af870e8370e82b76cf48b426d70130.1585941485.git.zanussi@kernel.org Suggested-by: Masami Hiramatsu Signed-off-by: Tom Zanussi Signed-off-by: Steven Rostedt (VMware)

tracing: Fix memory leaks in trace_events_hist.c

2020-04-23T01:24:00Z

kmemleak report 1: [<9092c50b>] kmem_cache_alloc_trace+0x138/0x270 [<05a2c9ed>] create_field_var+0xcf/0x180 [<528a2d68>] action_create+0xe2/0xc80 [<63f50b61>] event_hist_trigger_func+0x15b5/0x1920 [<28ea5d3d>] trigger_process_regex+0x7b/0xc0 [<3138e86f>] event_trigger_write+0x4d/0xb0 [] __vfs_write+0x30/0x200 [<4f424a0d>] vfs_write+0x96/0x1b0 [] ksys_write+0x53/0xc0 [<3717101a>] __ia32_sys_write+0x15/0x20 [] do_fast_syscall_32+0x70/0x250 [<46e2629c>] entry_SYSENTER_32+0xaf/0x102 This is because save_vars[] of struct hist_trigger_data are not destroyed kmemleak report 2: [<9092c50b>] kmem_cache_alloc_trace+0x138/0x270 [<6e5e97c5>] create_var+0x3c/0x110 [] create_field_var+0xaf/0x180 [<528a2d68>] action_create+0xe2/0xc80 [<63f50b61>] event_hist_trigger_func+0x15b5/0x1920 [<28ea5d3d>] trigger_process_regex+0x7b/0xc0 [<3138e86f>] event_trigger_write+0x4d/0xb0 [] __vfs_write+0x30/0x200 [<4f424a0d>] vfs_write+0x96/0x1b0 [] ksys_write+0x53/0xc0 [<3717101a>] __ia32_sys_write+0x15/0x20 [] do_fast_syscall_32+0x70/0x250 [<46e2629c>] entry_SYSENTER_32+0xaf/0x102 struct hist_field allocated through create_var() do not initialize "ref" field to 1. The code in __destroy_hist_field() does not destroy object if "ref" is initialized to zero, the condition if (--hist_field->ref > 1) always passes since unsigned int wraps. kmemleak report 3: [] __kmalloc_track_caller+0x139/0x2b0 [] kstrdup+0x27/0x50 [<39d70006>] init_var_ref+0x58/0xd0 [<8ca76370>] create_var_ref+0x89/0xe0 [] action_create+0x38f/0xc80 [<7c146821>] event_hist_trigger_func+0x15b5/0x1920 [<07de3f61>] trigger_process_regex+0x7b/0xc0 [] event_trigger_write+0x4d/0xb0 [<19bf1512>] __vfs_write+0x30/0x200 [<64ce4d27>] vfs_write+0x96/0x1b0 [] ksys_write+0x53/0xc0 [<7d4230cd>] __ia32_sys_write+0x15/0x20 [<8eadca00>] do_fast_syscall_32+0x70/0x250 [<235cf985>] entry_SYSENTER_32+0xaf/0x102 hist_fields (system & event_name) are not freed Link: http://lkml.kernel.org/r/20200422061503.GA5151@cosmos Signed-off-by: Vamshi K Sthambamkadi Signed-off-by: Steven Rostedt (VMware)

Merge tag 'trace-v5.6-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

2020-02-26T18:34:42Z

Pull tracing and bootconfig updates: "Fixes and changes to bootconfig before it goes live in a release. Change in API of bootconfig (before it comes live in a release): - Have a magic value "BOOTCONFIG" in initrd to know a bootconfig exists - Set CONFIG_BOOT_CONFIG to 'n' by default - Show error if "bootconfig" on cmdline but not compiled in - Prevent redefining the same value - Have a way to append values - Added a SELECT BLK_DEV_INITRD to fix a build failure Synthetic event fixes: - Switch to raw_smp_processor_id() for recording CPU value in preempt section. (No care for what the value actually is) - Fix samples always recording u64 values - Fix endianess - Check number of values matches number of fields - Fix a printing bug Fix of trace_printk() breaking postponed start up tests Make a function static that is only used in a single file" * tag 'trace-v5.6-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: bootconfig: Fix CONFIG_BOOTTIME_TRACING dependency issue bootconfig: Add append value operator support bootconfig: Prohibit re-defining value on same key bootconfig: Print array as multiple commands for legacy command line bootconfig: Reject subkey and value on same parent key tools/bootconfig: Remove unneeded error message silencer bootconfig: Add bootconfig magic word for indicating bootconfig explicitly bootconfig: Set CONFIG_BOOT_CONFIG=n by default tracing: Clear trace_state when starting trace bootconfig: Mark boot_config_checksum() static tracing: Disable trace_printk() on post poned tests tracing: Have synthetic event test use raw_smp_processor_id() tracing: Fix number printing bug in print_synth_event() tracing: Check that number of vals matches number of synth event fields tracing: Make synth_event trace functions endian-correct tracing: Make sure synth_event_trace() example always uses u64

tracing: Clear trace_state when starting trace

2020-02-20T22:48:59Z

Clear trace_state data structure when starting trace in __synth_event_trace_start() internal function. Currently trace_state is initialized only in the synth_event_trace_start() API, but the trace_state in synth_event_trace() and synth_event_trace_array() are on the stack without initialization. This means those APIs will see wrong parameters and wil skip closing process in __synth_event_trace_end() because trace_state->disabled may be !0. Link: http://lkml.kernel.org/r/158193315899.8868.1781259176894639952.stgit@devnote2 Reviewed-by: Tom Zanussi Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware)

tracing: Fix number printing bug in print_synth_event()

2020-02-20T21:24:17Z

Fix a varargs-related bug in print_synth_event() which resulted in strange output and oopses on 32-bit x86 systems. The problem is that trace_seq_printf() expects the varargs to match the format string, but print_synth_event() was always passing u64 values regardless. This results in unspecified behavior when unpacking with va_arg() in trace_seq_printf(). Add a function that takes the size into account when calling trace_seq_printf(). Before: modprobe-1731 [003] .... 919.039758: gen_synth_test: next_pid_field=777(null)next_comm_field=hula hoops ts_ns=1000000 ts_ms=1000 cpu=3(null)my_string_field=thneed my_int_field=598(null) After: insmod-1136 [001] .... 36.634590: gen_synth_test: next_pid_field=777 next_comm_field=hula hoops ts_ns=1000000 ts_ms=1000 cpu=1 my_string_field=thneed my_int_field=598 Link: http://lkml.kernel.org/r/a9b59eb515dbbd7d4abe53b347dccf7a8e285657.1581720155.git.zanussi@kernel.org Reported-by: Steven Rostedt (VMware) Signed-off-by: Tom Zanussi Signed-off-by: Steven Rostedt (VMware)

tracing: Check that number of vals matches number of synth event fields

2020-02-20T21:24:17Z

Commit 7276531d4036('tracing: Consolidate trace() functions') inadvertently dropped the synth_event_trace() and synth_event_trace_array() checks that verify the number of values passed in matches the number of fields in the synthetic event being traced, so add them back. Link: http://lkml.kernel.org/r/32819cac708714693669e0dfe10fe9d935e94a16.1581720155.git.zanussi@kernel.org Signed-off-by: Tom Zanussi Signed-off-by: Steven Rostedt (VMware)

tracing: Make synth_event trace functions endian-correct

2020-02-20T21:24:17Z

synth_event_trace(), synth_event_trace_array() and __synth_event_add_val() write directly into the trace buffer and need to take endianness into account, like trace_event_raw_event_synth() does. Link: http://lkml.kernel.org/r/2011354355e405af9c9d28abba430d1f5ff7771a.1581720155.git.zanussi@kernel.org Signed-off-by: Tom Zanussi Signed-off-by: Steven Rostedt (VMware)

Merge tag 'trace-v5.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

2020-02-12T00:39:18Z

Pull tracing fixes from Steven Rostedt: "Various fixes: - Fix an uninitialized variable - Fix compile bug to bootconfig userspace tool (in tools directory) - Suppress some error messages of bootconfig userspace tool - Remove unneded CONFIG_LIBXBC from bootconfig - Allocate bootconfig xbc_nodes dynamically. To ease complaints about taking up static memory at boot up - Use of parse_args() to parse bootconfig instead of strstr() usage Prevents issues of double quotes containing the interested string - Fix missing ring_buffer_nest_end() on synthetic event error path - Return zero not -EINVAL on soft disabled synthetic event (soft disabling must be the same as hard disabling, which returns zero) - Consolidate synthetic event code (remove duplicate code)" * tag 'trace-v5.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: tracing: Consolidate trace() functions tracing: Don't return -EINVAL when tracing soft disabled synth events tracing: Add missing nest end to synth_event_trace_start() error case tools/bootconfig: Suppress non-error messages bootconfig: Allocate xbc_nodes array dynamically bootconfig: Use parse_args() to find bootconfig and '--' tracing/kprobe: Fix uninitialized variable bug bootconfig: Remove unneeded CONFIG_LIBXBC tools/bootconfig: Fix wrong __VA_ARGS__ usage