user/sven/linux.git/kernel/trace/trace_events_trigger.c, branch v6.7.3

tracing: Fix kernel-doc warnings in trace_events_trigger.c

2023-07-28T23:59:03Z

Fix kernel-doc warnings: kernel/trace/trace_events_trigger.c:59: warning: Function parameter or member 'buffer' not described in 'event_triggers_call' kernel/trace/trace_events_trigger.c:59: warning: Function parameter or member 'event' not described in 'event_triggers_call' Link: https://lkml.kernel.org/r/20230724140827.1023266-4-cuigaosheng1@huawei.com Cc: Signed-off-by: Gaosheng Cui Signed-off-by: Steven Rostedt (Google)

tracing: Do not synchronize freeing of trigger filter on boot up

2022-12-14T13:50:56Z

If a trigger filter on the kernel command line fails to apply (due to syntax error), it will be freed. The freeing will call tracepoint_synchronize_unregister(), but this is not needed during early boot up, and will even trigger a lockdep splat. Avoid calling the synchronization function when system_state is SYSTEM_BOOTING. Link: https://lore.kernel.org/linux-trace-kernel/20221213172429.7774f4ba@gandalf.local.home Cc: Andrew Morton Acked-by: Masami Hiramatsu (Google) Signed-off-by: Steven Rostedt (Google)

tracing: Have trigger filter parsing errors show up in error_log

2022-12-13T20:46:05Z

It is annoying that the filter parsing of triggers do not show up in the error_log. Trying to figure out what is incorrect in the input is difficult when it fails for a typo. Have the errors of filter parsing show up in error_log as well. Link: https://lore.kernel.org/linux-trace-kernel/20221213095602.083fa9fd@gandalf.local.home Cc: Masami Hiramatsu Cc: Tom Zanussi Signed-off-by: Steven Rostedt (Google)

tracing: Fix to check event_mutex is held while accessing trigger list

2022-09-07T02:26:00Z

Since the check_user_trigger() is called outside of RCU read lock, this list_for_each_entry_rcu() caused a suspicious RCU usage warning. # echo hist:keys=pid > events/sched/sched_stat_runtime/trigger # cat events/sched/sched_stat_runtime/trigger [ 43.167032] [ 43.167418] ============================= [ 43.167992] WARNING: suspicious RCU usage [ 43.168567] 5.19.0-rc5-00029-g19ebe4651abf #59 Not tainted [ 43.169283] ----------------------------- [ 43.169863] kernel/trace/trace_events_trigger.c:145 RCU-list traversed in non-reader section!! ... However, this file->triggers list is safe when it is accessed under event_mutex is held. To fix this warning, adds a lockdep_is_held check to the list_for_each_entry_rcu(). Link: https://lkml.kernel.org/r/166226474977.223837.1992182913048377113.stgit@devnote2 Cc: stable@vger.kernel.org Fixes: 7491e2c44278 ("tracing: Add a probe that attaches to trace events") Signed-off-by: Masami Hiramatsu (Google) Signed-off-by: Steven Rostedt (Google)

tracing: Fix comments for event_trigger_separate_filter()

2022-05-27T02:03:52Z

The parameter name in comments of event_trigger_separate_filter() is inconsistent with actual parameter name, fix it. Link: https://lkml.kernel.org/r/20220526072957.165655-1-sunliming@kylinos.cn Signed-off-by: sunliming Signed-off-by: Steven Rostedt (Google)

tracing: Replace usage of found with dedicated list iterator variable

2022-04-27T21:19:31Z

To move the list iterator variable into the list_for_each_entry_*() macro in the future it should be avoided to use the list iterator variable after the loop body. To *never* use the list iterator variable after the loop it was concluded to use a separate iterator variable instead of a found boolean [1]. This removes the need to use a found variable and simply checking if the variable was set, can determine if the break/goto was hit. Link: https://lkml.kernel.org/r/20220427170734.819891-4-jakobkoschel@gmail.com Cc: Ingo Molnar Link: https://lore.kernel.org/all/CAHk-=wgRr_D8CB-D9Kg-c=EHreAsk5SqXPwr9Y7k9sA6cWXJ6w@mail.gmail.com/ [1] Signed-off-by: Jakob Koschel Signed-off-by: Steven Rostedt (Google)

tracing: Have existing event_command.parse() implementations use helpers

2022-04-26T21:58:50Z

Simplify the existing event_command.parse() implementations by having them make use of the helper functions previously introduced. Link: https://lkml.kernel.org/r/b353e3427a81f9d3adafd98fd7d73e78a8209f43.1644010576.git.zanussi@kernel.org Signed-off-by: Tom Zanussi Signed-off-by: Steven Rostedt (Google)

tracing: Remove redundant trigger_ops params

2022-04-26T21:58:50Z

Since event_trigger_data contains the .ops trigger_ops field, there's no reason to pass the trigger_ops separately. Remove it as a param from functions whenever event_trigger_data is passed. Link: https://lkml.kernel.org/r/9856c9bc81bde57077f5b8d6f8faa47156c6354a.1644010575.git.zanussi@kernel.org Signed-off-by: Tom Zanussi Signed-off-by: Steven Rostedt (Google)

tracing: Remove logic for registering multiple event triggers at a time

2022-04-26T21:58:50Z

Code for registering triggers assumes it's possible to register more than one trigger at a time. In fact, it's unimplemented and there doesn't seem to be a reason to do that. Remove the n_registered param from event_trigger_register() and fix up callers. Doing so simplifies the logic in event_trigger_register to the point that it just becomes a wrapper calling event_command.reg(). It also removes the problematic call to event_command.unreg() in case of failure. A new function, event_trigger_unregister() is also added for callers to call themselves. The changes to trace_events_hist.c simply allow compilation; a separate patch follows which updates the hist triggers to work correctly with the new changes. Link: https://lkml.kernel.org/r/6149fec7a139d93e84fa4535672fb5bef88006b0.1644010575.git.zanussi@kernel.org Signed-off-by: Tom Zanussi Signed-off-by: Steven Rostedt (Google)

tracing: Uninline trace_trigger_soft_disabled() partly

2022-02-25T17:07:01Z

On a powerpc32 build with CONFIG_CC_OPTIMISE_FOR_SIZE, the inline keyword is not honored and trace_trigger_soft_disabled() appears approx 50 times in vmlinux. Adding -Winline to the build, the following message appears: ./include/linux/trace_events.h:712:1: error: inlining failed in call to 'trace_trigger_soft_disabled': call is unlikely and code size would grow [-Werror=inline] That function is rather big for an inlined function: c003df60 : c003df60: 94 21 ff f0 stwu r1,-16(r1) c003df64: 7c 08 02 a6 mflr r0 c003df68: 90 01 00 14 stw r0,20(r1) c003df6c: bf c1 00 08 stmw r30,8(r1) c003df70: 83 e3 00 24 lwz r31,36(r3) c003df74: 73 e9 01 00 andi. r9,r31,256 c003df78: 41 82 00 10 beq c003df88 c003df7c: 38 60 00 00 li r3,0 c003df80: 39 61 00 10 addi r11,r1,16 c003df84: 4b fd 60 ac b c0014030 <_rest32gpr_30_x> c003df88: 73 e9 00 80 andi. r9,r31,128 c003df8c: 7c 7e 1b 78 mr r30,r3 c003df90: 41 a2 00 14 beq c003dfa4 c003df94: 38 c0 00 00 li r6,0 c003df98: 38 a0 00 00 li r5,0 c003df9c: 38 80 00 00 li r4,0 c003dfa0: 48 05 c5 f1 bl c009a590 c003dfa4: 73 e9 00 40 andi. r9,r31,64 c003dfa8: 40 82 00 28 bne c003dfd0 c003dfac: 73 ff 02 00 andi. r31,r31,512 c003dfb0: 41 82 ff cc beq c003df7c c003dfb4: 80 01 00 14 lwz r0,20(r1) c003dfb8: 83 e1 00 0c lwz r31,12(r1) c003dfbc: 7f c3 f3 78 mr r3,r30 c003dfc0: 83 c1 00 08 lwz r30,8(r1) c003dfc4: 7c 08 03 a6 mtlr r0 c003dfc8: 38 21 00 10 addi r1,r1,16 c003dfcc: 48 05 6f 6c b c0094f38 c003dfd0: 38 60 00 01 li r3,1 c003dfd4: 4b ff ff ac b c003df80 However it is located in a hot path so inlining it is important. But forcing inlining of the entire function by using __always_inline leads to increasing the text size by approx 20 kbytes. Instead, split the fonction in two parts, one part with the likely fast path, flagged __always_inline, and a second part out of line. With this change, on a powerpc32 with CONFIG_CC_OPTIMISE_FOR_SIZE vmlinux text increases by only 1,4 kbytes, which is partly compensated by a decrease of vmlinux data by 7 kbytes. On ppc64_defconfig which has CONFIG_CC_OPTIMISE_FOR_SPEED, this change reduces vmlinux text by more than 30 kbytes. Link: https://lkml.kernel.org/r/69ce0986a52d026d381d612801d978aa4f977460.1644563295.git.christophe.leroy@csgroup.eu Signed-off-by: Christophe Leroy Signed-off-by: Steven Rostedt (Google)