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2023-02-24kernel/trace: extract common part in process_fetch_insnSong Chen1-20/+6
Each probe has an instance of process_fetch_insn respectively, but they have something in common. This patch aims to extract the common part into process_common_fetch_insn which can be shared by each probe, and they only need to focus on their special cases. Signed-off-by: Song Chen <chensong_2000@189.cn> Suggested-by: Masami Hiramatsu <mhiramat@kernel.org> Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
2023-02-24kernel/trace: Provide default impelentations defined in trace_probe_tmpl.hSong Chen1-53/+2
There are 6 function definitions in trace_probe_tmpl.h, they are: 1, fetch_store_strlen 2, fetch_store_string 3, fetch_store_strlen_user 4, fetch_store_string_user 5, probe_mem_read 6, probe_mem_read_user Every C file which includes trace_probe_tmpl.h has to implement them, otherwise it gets warnings and errors. However, some of them are identical, like kprobe and eprobe, as a result, there is a lot redundant code in those 2 files. This patch would like to provide default behaviors for those functions which kprobe and eprobe can share by just including trace_probe_kernel.h with trace_probe_tmpl.h together. It removes redundant code, increases readability, and more importantly, makes it easier to introduce a new feature based on trace probe (it's possible). Link: https://lore.kernel.org/all/1672382018-18347-1-git-send-email-chensong_2000@189.cn/ Signed-off-by: Song Chen <chensong_2000@189.cn> Reported-by: kernel test robot <lkp@intel.com> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2023-02-24kernel/trace: Introduce trace_probe_print_args and use it in *probesSong Chen1-1/+1
print_probe_args is currently inplemented in trace_probe_tmpl.h and included by *probes, as a result, each probe has an identical copy. This patch will move it to trace_probe.c as an new API, each probe calls it to print their args in trace file. Link: https://lore.kernel.org/all/1672382000-18304-1-git-send-email-chensong_2000@189.cn/ Signed-off-by: Song Chen <chensong_2000@189.cn> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2023-02-21tracing/eprobe: no need to check for negative ret value for snprintfQuanfa Fu1-8/+4
No need to check for negative return value from snprintf() as the code does not return negative values. Link: https://lore.kernel.org/all/20230109040625.3259642-1-quanfafu@gmail.com/ Signed-off-by: Quanfa Fu <quanfafu@gmail.com> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2022-11-20Merge tag 'trace-probes-v6.1' of ↵Linus Torvalds1-2/+3
git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull tracing/probes fixes from Steven Rostedt: - Fix possible NULL pointer dereference on trace_event_file in kprobe_event_gen_test_exit() - Fix NULL pointer dereference for trace_array in kprobe_event_gen_test_exit() - Fix memory leak of filter string for eprobes - Fix a possible memory leak in rethook_alloc() - Skip clearing aggrprobe's post_handler in kprobe-on-ftrace case which can cause a possible use-after-free - Fix warning in eprobe filter creation - Fix eprobe filter creation as it picked the wrong event for the fields * tag 'trace-probes-v6.1' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: tracing/eprobe: Fix eprobe filter to make a filter correctly tracing/eprobe: Fix warning in filter creation kprobes: Skip clearing aggrprobe's post_handler in kprobe-on-ftrace case rethook: fix a potential memleak in rethook_alloc() tracing/eprobe: Fix memory leak of filter string tracing: kprobe: Fix potential null-ptr-deref on trace_array in kprobe_event_gen_test_exit() tracing: kprobe: Fix potential null-ptr-deref on trace_event_file in kprobe_event_gen_test_exit()
2022-11-20tracing: Fix race where eprobes can be called before the eventSteven Rostedt (Google)1-0/+3
The flag that tells the event to call its triggers after reading the event is set for eprobes after the eprobe is enabled. This leads to a race where the eprobe may be triggered at the beginning of the event where the record information is NULL. The eprobe then dereferences the NULL record causing a NULL kernel pointer bug. Test for a NULL record to keep this from happening. Link: https://lore.kernel.org/linux-trace-kernel/20221116192552.1066630-1-rafaelmendsr@gmail.com/ Link: https://lore.kernel.org/linux-trace-kernel/20221117214249.2addbe10@gandalf.local.home Cc: Linux Trace Kernel <linux-trace-kernel@vger.kernel.org> Cc: Tzvetomir Stoyanov <tz.stoyanov@gmail.com> Cc: Tom Zanussi <zanussi@kernel.org> Cc: stable@vger.kernel.org Fixes: 7491e2c442781 ("tracing: Add a probe that attaches to trace events") Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Reported-by: Rafael Mendonca <rafaelmendsr@gmail.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-11-18tracing/eprobe: Fix eprobe filter to make a filter correctlyMasami Hiramatsu (Google)1-1/+1
Since the eprobe filter was defined based on the eprobe's trace event itself, it doesn't work correctly. Use the original trace event of the eprobe when making the filter so that the filter works correctly. Without this fix: # echo 'e syscalls/sys_enter_openat \ flags_rename=$flags:u32 if flags < 1000' >> dynamic_events # echo 1 > events/eprobes/sys_enter_openat/enable [ 114.551550] event trace: Could not enable event sys_enter_openat -bash: echo: write error: Invalid argument With this fix: # echo 'e syscalls/sys_enter_openat \ flags_rename=$flags:u32 if flags < 1000' >> dynamic_events # echo 1 > events/eprobes/sys_enter_openat/enable # tail trace cat-241 [000] ...1. 266.498449: sys_enter_openat: (syscalls.sys_enter_openat) flags_rename=0 cat-242 [000] ...1. 266.977640: sys_enter_openat: (syscalls.sys_enter_openat) flags_rename=0 Link: https://lore.kernel.org/all/166823166395.1385292.8931770640212414483.stgit@devnote3/ Fixes: 752be5c5c910 ("tracing/eprobe: Add eprobe filter support") Reported-by: Rafael Mendonca <rafaelmendsr@gmail.com> Tested-by: Rafael Mendonca <rafaelmendsr@gmail.com> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2022-11-18tracing/eprobe: Fix warning in filter creationRafael Mendonca1-1/+1
The filter pointer (filterp) passed to create_filter() function must be a pointer that references a NULL pointer, otherwise, we get a warning when adding a filter option to the event probe: root@localhost:/sys/kernel/tracing# echo 'e:egroup/stat_runtime_4core sched/sched_stat_runtime \ runtime=$runtime:u32 if cpu < 4' >> dynamic_events [ 5034.340439] ------------[ cut here ]------------ [ 5034.341258] WARNING: CPU: 0 PID: 223 at kernel/trace/trace_events_filter.c:1939 create_filter+0x1db/0x250 [...] stripped [ 5034.345518] RIP: 0010:create_filter+0x1db/0x250 [...] stripped [ 5034.351604] Call Trace: [ 5034.351803] <TASK> [ 5034.351959] ? process_preds+0x1b40/0x1b40 [ 5034.352241] ? rcu_read_lock_bh_held+0xd0/0xd0 [ 5034.352604] ? kasan_set_track+0x29/0x40 [ 5034.352904] ? kasan_save_alloc_info+0x1f/0x30 [ 5034.353264] create_event_filter+0x38/0x50 [ 5034.353573] __trace_eprobe_create+0x16f4/0x1d20 [ 5034.353964] ? eprobe_dyn_event_release+0x360/0x360 [ 5034.354363] ? mark_held_locks+0xa6/0xf0 [ 5034.354684] ? _raw_spin_unlock_irqrestore+0x35/0x60 [ 5034.355105] ? trace_hardirqs_on+0x41/0x120 [ 5034.355417] ? _raw_spin_unlock_irqrestore+0x35/0x60 [ 5034.355751] ? __create_object+0x5b7/0xcf0 [ 5034.356027] ? lock_is_held_type+0xaf/0x120 [ 5034.356362] ? rcu_read_lock_bh_held+0xb0/0xd0 [ 5034.356716] ? rcu_read_lock_bh_held+0xd0/0xd0 [ 5034.357084] ? kasan_set_track+0x29/0x40 [ 5034.357411] ? kasan_save_alloc_info+0x1f/0x30 [ 5034.357715] ? __kasan_kmalloc+0xb8/0xc0 [ 5034.357985] ? write_comp_data+0x2f/0x90 [ 5034.358302] ? __sanitizer_cov_trace_pc+0x25/0x60 [ 5034.358691] ? argv_split+0x381/0x460 [ 5034.358949] ? write_comp_data+0x2f/0x90 [ 5034.359240] ? eprobe_dyn_event_release+0x360/0x360 [ 5034.359620] trace_probe_create+0xf6/0x110 [ 5034.359940] ? trace_probe_match_command_args+0x240/0x240 [ 5034.360376] eprobe_dyn_event_create+0x21/0x30 [ 5034.360709] create_dyn_event+0xf3/0x1a0 [ 5034.360983] trace_parse_run_command+0x1a9/0x2e0 [ 5034.361297] ? dyn_event_release+0x500/0x500 [ 5034.361591] dyn_event_write+0x39/0x50 [ 5034.361851] vfs_write+0x311/0xe50 [ 5034.362091] ? dyn_event_seq_next+0x40/0x40 [ 5034.362376] ? kernel_write+0x5b0/0x5b0 [ 5034.362637] ? write_comp_data+0x2f/0x90 [ 5034.362937] ? __sanitizer_cov_trace_pc+0x25/0x60 [ 5034.363258] ? ftrace_syscall_enter+0x544/0x840 [ 5034.363563] ? write_comp_data+0x2f/0x90 [ 5034.363837] ? __sanitizer_cov_trace_pc+0x25/0x60 [ 5034.364156] ? write_comp_data+0x2f/0x90 [ 5034.364468] ? write_comp_data+0x2f/0x90 [ 5034.364770] ksys_write+0x158/0x2a0 [ 5034.365022] ? __ia32_sys_read+0xc0/0xc0 [ 5034.365344] __x64_sys_write+0x7c/0xc0 [ 5034.365669] ? syscall_enter_from_user_mode+0x53/0x70 [ 5034.366084] do_syscall_64+0x60/0x90 [ 5034.366356] entry_SYSCALL_64_after_hwframe+0x63/0xcd [ 5034.366767] RIP: 0033:0x7ff0b43938f3 [...] stripped [ 5034.371892] </TASK> [ 5034.374720] ---[ end trace 0000000000000000 ]--- Link: https://lore.kernel.org/all/20221108202148.1020111-1-rafaelmendsr@gmail.com/ Fixes: 752be5c5c910 ("tracing/eprobe: Add eprobe filter support") Signed-off-by: Rafael Mendonca <rafaelmendsr@gmail.com> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2022-11-18tracing/eprobe: Fix memory leak of filter stringRafael Mendonca1-0/+1
The filter string doesn't get freed when a dynamic event is deleted. If a filter is set, then memory is leaked: root@localhost:/sys/kernel/tracing# echo 'e:egroup/stat_runtime_4core \ sched/sched_stat_runtime runtime=$runtime:u32 if cpu < 4' >> dynamic_events root@localhost:/sys/kernel/tracing# echo "-:egroup/stat_runtime_4core" >> dynamic_events root@localhost:/sys/kernel/tracing# echo scan > /sys/kernel/debug/kmemleak [ 224.416373] kmemleak: 1 new suspected memory leaks (see /sys/kernel/debug/kmemleak) root@localhost:/sys/kernel/tracing# cat /sys/kernel/debug/kmemleak unreferenced object 0xffff88810156f1b8 (size 8): comm "bash", pid 224, jiffies 4294935612 (age 55.800s) hex dump (first 8 bytes): 63 70 75 20 3c 20 34 00 cpu < 4. backtrace: [<000000009f880725>] __kmem_cache_alloc_node+0x18e/0x720 [<0000000042492946>] __kmalloc+0x57/0x240 [<0000000034ea7995>] __trace_eprobe_create+0x1214/0x1d30 [<00000000d70ef730>] trace_probe_create+0xf6/0x110 [<00000000915c7b16>] eprobe_dyn_event_create+0x21/0x30 [<000000000d894386>] create_dyn_event+0xf3/0x1a0 [<00000000e9af57d5>] trace_parse_run_command+0x1a9/0x2e0 [<0000000080777f18>] dyn_event_write+0x39/0x50 [<0000000089f0ec73>] vfs_write+0x311/0xe50 [<000000003da1bdda>] ksys_write+0x158/0x2a0 [<00000000bb1e616e>] __x64_sys_write+0x7c/0xc0 [<00000000e8aef1f7>] do_syscall_64+0x60/0x90 [<00000000fe7fe8ba>] entry_SYSCALL_64_after_hwframe+0x63/0xcd Additionally, in __trace_eprobe_create() function, if an error occurs after the call to trace_eprobe_parse_filter(), which allocates the filter string, then memory is also leaked. That can be reproduced by creating the same event probe twice: root@localhost:/sys/kernel/tracing# echo 'e:egroup/stat_runtime_4core \ sched/sched_stat_runtime runtime=$runtime:u32 if cpu < 4' >> dynamic_events root@localhost:/sys/kernel/tracing# echo 'e:egroup/stat_runtime_4core \ sched/sched_stat_runtime runtime=$runtime:u32 if cpu < 4' >> dynamic_events -bash: echo: write error: File exists root@localhost:/sys/kernel/tracing# echo scan > /sys/kernel/debug/kmemleak [ 207.871584] kmemleak: 1 new suspected memory leaks (see /sys/kernel/debug/kmemleak) root@localhost:/sys/kernel/tracing# cat /sys/kernel/debug/kmemleak unreferenced object 0xffff8881020d17a8 (size 8): comm "bash", pid 223, jiffies 4294938308 (age 31.000s) hex dump (first 8 bytes): 63 70 75 20 3c 20 34 00 cpu < 4. backtrace: [<000000000e4f5f31>] __kmem_cache_alloc_node+0x18e/0x720 [<0000000024f0534b>] __kmalloc+0x57/0x240 [<000000002930a28e>] __trace_eprobe_create+0x1214/0x1d30 [<0000000028387903>] trace_probe_create+0xf6/0x110 [<00000000a80d6a9f>] eprobe_dyn_event_create+0x21/0x30 [<000000007168698c>] create_dyn_event+0xf3/0x1a0 [<00000000f036bf6a>] trace_parse_run_command+0x1a9/0x2e0 [<00000000014bde8b>] dyn_event_write+0x39/0x50 [<0000000078a097f7>] vfs_write+0x311/0xe50 [<00000000996cb208>] ksys_write+0x158/0x2a0 [<00000000a3c2acb0>] __x64_sys_write+0x7c/0xc0 [<0000000006b5d698>] do_syscall_64+0x60/0x90 [<00000000780e8ecf>] entry_SYSCALL_64_after_hwframe+0x63/0xcd Fix both issues by releasing the filter string in trace_event_probe_cleanup(). Link: https://lore.kernel.org/all/20221108235738.1021467-1-rafaelmendsr@gmail.com/ Fixes: 752be5c5c910 ("tracing/eprobe: Add eprobe filter support") Signed-off-by: Rafael Mendonca <rafaelmendsr@gmail.com> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2022-10-12tracing: Move duplicate code of trace_kprobe/eprobe.c into headerSteven Rostedt (Google)1-55/+5
The functions: fetch_store_strlen_user() fetch_store_strlen() fetch_store_string_user() fetch_store_string() are identical in both trace_kprobe.c and trace_eprobe.c. Move them into a new header file trace_probe_kernel.h to share it. This code will later be used by the synthetic events as well. Marked for stable as a fix for a crash in synthetic events requires it. Link: https://lkml.kernel.org/r/20221012104534.467668078@goodmis.org Cc: stable@vger.kernel.org Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Tom Zanussi <zanussi@kernel.org> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Reviewed-by: Tom Zanussi <zanussi@kernel.org> Fixes: bd82631d7ccdc ("tracing: Add support for dynamic strings to synthetic events") Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-09-27tracing/eprobe: Fix alloc event dir failed when event name no setTao Chen1-2/+1
The event dir will alloc failed when event name no set, using the command: "echo "e:esys/ syscalls/sys_enter_openat file=\$filename:string" >> dynamic_events" It seems that dir name="syscalls/sys_enter_openat" is not allowed in debugfs. So just use the "sys_enter_openat" as the event name. Link: https://lkml.kernel.org/r/1664028814-45923-1-git-send-email-chentao.kernel@linux.alibaba.com Cc: Ingo Molnar <mingo@redhat.com> Cc: Tom Zanussi <zanussi@kernel.org> Cc: Linyu Yuan <quic_linyyuan@quicinc.com> Cc: Tao Chen <chentao.kernel@linux.alibaba.com Cc: stable@vger.kernel.org Fixes: 95c104c378dc ("tracing: Auto generate event name when creating a group of events") Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Tao Chen <chentao.kernel@linux.alibaba.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-09-26tracing/eprobe: Add eprobe filter supportMasami Hiramatsu (Google)1-8/+96
Add the filter option to the event probe. This is useful if user wants to derive a new event based on the condition of the original event. E.g. echo 'e:egroup/stat_runtime_4core sched/sched_stat_runtime \ runtime=$runtime:u32 if cpu < 4' >> ../dynamic_events Then it can filter the events only on first 4 cores. Note that the fields used for 'if' must be the fields in the original events, not eprobe events. Link: https://lkml.kernel.org/r/165932114513.2850673.2592206685744598080.stgit@devnote2 Cc: Tzvetomir Stoyanov <tz.stoyanov@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-08-21tracing/eprobes: Have event probes be consistent with kprobes and uprobesSteven Rostedt (Google)1-6/+64
Currently, if a symbol "@" is attempted to be used with an event probe (eprobes), it will cause a NULL pointer dereference crash. Both kprobes and uprobes can reference data other than the main registers. Such as immediate address, symbols and the current task name. Have eprobes do the same thing. For "comm", if "comm" is used and the event being attached to does not have the "comm" field, then make it the "$comm" that kprobes has. This is consistent to the way histograms and filters work. Link: https://lkml.kernel.org/r/20220820134401.136924220@goodmis.org Cc: stable@vger.kernel.org Cc: Ingo Molnar <mingo@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Tzvetomir Stoyanov <tz.stoyanov@gmail.com> Cc: Tom Zanussi <zanussi@kernel.org> Fixes: 7491e2c44278 ("tracing: Add a probe that attaches to trace events") Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-08-21tracing/eprobes: Fix reading of string fieldsSteven Rostedt (Google)1-0/+21
Currently when an event probe (eprobe) hooks to a string field, it does not display it as a string, but instead as a number. This makes the field rather useless. Handle the different kinds of strings, dynamic, static, relational/dynamic etc. Now when a string field is used, the ":string" type can be used to display it: echo "e:sw sched/sched_switch comm=$next_comm:string" > dynamic_events Link: https://lkml.kernel.org/r/20220820134400.959640191@goodmis.org Cc: stable@vger.kernel.org Cc: Ingo Molnar <mingo@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Tzvetomir Stoyanov <tz.stoyanov@gmail.com> Cc: Tom Zanussi <zanussi@kernel.org> Fixes: 7491e2c44278 ("tracing: Add a probe that attaches to trace events") Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-08-21tracing: React to error return from traceprobe_parse_event_name()Lukas Bulwahn1-1/+1
The function traceprobe_parse_event_name() may set the first two function arguments to a non-null value and still return -EINVAL to indicate an unsuccessful completion of the function. Hence, it is not sufficient to just check the result of the two function arguments for being not null, but the return value also needs to be checked. Commit 95c104c378dc ("tracing: Auto generate event name when creating a group of events") changed the error-return-value checking of the second traceprobe_parse_event_name() invocation in __trace_eprobe_create() and removed checking the return value to jump to the error handling case. Reinstate using the return value in the error-return-value checking. Link: https://lkml.kernel.org/r/20220811071734.20700-1-lukas.bulwahn@gmail.com Fixes: 95c104c378dc ("tracing: Auto generate event name when creating a group of events") Acked-by: Linyu Yuan <quic_linyyuan@quicinc.com> Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-08-02tracing/eprobe: Show syntax error logs in error_log fileMasami Hiramatsu (Google)1-2/+9
Show the syntax errors for event probes in error_log file as same as other dynamic events, so that user can understand what is the problem. Link: https://lkml.kernel.org/r/165932113556.2850673.3483079297896607612.stgit@devnote2 Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-07-24tracing: Auto generate event name when creating a group of eventsLinyu Yuan1-12/+13
Currently when creating a specific group of trace events, take kprobe event as example, the user must use the following format: p:GRP/EVENT [MOD:]KSYM[+OFFS]|KADDR [FETCHARGS], which means user must enter EVENT name, one example is: echo 'p:usb_gadget/config_usb_cfg_link config_usb_cfg_link $arg1' >> kprobe_events It is not simple if there are too many entries because the event name is the same as symbol name. This change allows user to specify no EVENT name, format changed as: p:GRP/ [MOD:]KSYM[+OFFS]|KADDR [FETCHARGS] It will generate event name automatically and one example is: echo 'p:usb_gadget/ config_usb_cfg_link $arg1' >> kprobe_events. Link: https://lore.kernel.org/all/1656296348-16111-4-git-send-email-quic_linyyuan@quicinc.com/ Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Reviewed-by: Tom Zanussi <zanussi@kernel.org> Signed-off-by: Linyu Yuan <quic_linyyuan@quicinc.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-07-24tracing: eprobe: Remove duplicate is_good_name() operationLinyu Yuan1-2/+0
traceprobe_parse_event_name() already validate SYSTEM and EVENT name, there is no need to call is_good_name() after it. Link: https://lore.kernel.org/all/1656296348-16111-3-git-send-email-quic_linyyuan@quicinc.com/ Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Reviewed-by: Tom Zanussi <zanussi@kernel.org> Signed-off-by: Linyu Yuan <quic_linyyuan@quicinc.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-07-24tracing: eprobe: Add missing log indexLinyu Yuan1-0/+1
Add trace_probe_log_set_index(1) to allow report correct error if user input wrong SYSTEM.EVENT format. Link: https://lore.kernel.org/all/1656296348-16111-2-git-send-email-quic_linyyuan@quicinc.com/ Reviewed-by: Tom Zanussi <zanussi@kernel.org> Signed-off-by: Linyu Yuan <quic_linyyuan@quicinc.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-04-27tracing: Remove check of list iterator against head past the loop bodyJakob Koschel1-6/+8
When list_for_each_entry() completes the iteration over the whole list without breaking the loop, the iterator value will be a bogus pointer computed based on the head element. While it is safe to use the pointer to determine if it was computed based on the head element, either with list_entry_is_head() or &pos->member == head, using the iterator variable after the loop should be avoided. In preparation to limit the scope of a list iterator to the list traversal loop, use a dedicated pointer to point to the found element [1]. Link: https://lkml.kernel.org/r/20220427170734.819891-5-jakobkoschel@gmail.com Cc: Ingo Molnar <mingo@redhat.com> Link: https://lore.kernel.org/all/CAHk-=wgRr_D8CB-D9Kg-c=EHreAsk5SqXPwr9Y7k9sA6cWXJ6w@mail.gmail.com/ Signed-off-by: Jakob Koschel <jakobkoschel@gmail.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-04-26tracing: Have existing event_command.parse() implementations use helpersTom Zanussi1-1/+2
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 <zanussi@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-04-26tracing: Remove redundant trigger_ops paramsTom Zanussi1-5/+2
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 <zanussi@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-02-25eprobes: Remove redundant event type informationSteven Rostedt (Google)1-9/+7
Currently, the event probes save the type of the event they are attached to when recording the event. For example: # echo 'e:switch sched/sched_switch prev_state=$prev_state prev_prio=$prev_prio next_pid=$next_pid next_prio=$next_prio' > dynamic_events # cat events/eprobes/switch/format name: switch ID: 1717 format: field:unsigned short common_type; offset:0; size:2; signed:0; field:unsigned char common_flags; offset:2; size:1; signed:0; field:unsigned char common_preempt_count; offset:3; size:1; signed:0; field:int common_pid; offset:4; size:4; signed:1; field:unsigned int __probe_type; offset:8; size:4; signed:0; field:u64 prev_state; offset:12; size:8; signed:0; field:u64 prev_prio; offset:20; size:8; signed:0; field:u64 next_pid; offset:28; size:8; signed:0; field:u64 next_prio; offset:36; size:8; signed:0; print fmt: "(%u) prev_state=0x%Lx prev_prio=0x%Lx next_pid=0x%Lx next_prio=0x%Lx", REC->__probe_type, REC->prev_state, REC->prev_prio, REC->next_pid, REC->next_prio The __probe_type adds 4 bytes to every event. One of the reasons for creating eprobes is to limit what is traced in an event to be able to limit what is written into the ring buffer. Having this redundant 4 bytes to every event takes away from this. The event that is recorded can be retrieved from the event probe itself, that is available when the trace is happening. For user space tools, it could simply read the dynamic_event file to find the event they are for. So there is really no reason to write this information into the ring buffer for every event. Link: https://lkml.kernel.org/r/20220218190057.2f5a19a8@gandalf.local.home Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Reviewed-by: Joel Fernandes <joel@joelfernandes.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-01-10tracing: Remove ops param from event_command reg()/unreg() callbacksTom Zanussi1-6/+6
The event_trigger_ops for an event_command are already accessible via event_trigger_data.ops so remove the redundant ops from the callback. Link: https://lkml.kernel.org/r/4c6f2a41820452f9cacddc7634ad442928aa2aa6.1641823001.git.zanussi@kernel.org Signed-off-by: Tom Zanussi <zanussi@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2022-01-10tracing: Change event_trigger_ops func() to trigger()Tom Zanussi1-1/+1
The name of the func() callback on event_trigger_ops is too generic and is easily confused with other callbacks with that name, so change it to something that reflects its actual purpose. In this case, the main purpose of the callback is to implement an event trigger, so call it trigger() instead. Also add some more documentation to event_trigger_ops describing the callbacks a bit better. Link: https://lkml.kernel.org/r/36ab812e3ee74ee03ae0043fda41a858ee728c00.1641823001.git.zanussi@kernel.org Signed-off-by: Tom Zanussi <zanussi@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2022-01-10tracing: Change event_command func() to parse()Tom Zanussi1-4/+4
The name of the func() callback on event_command is too generic and is easily confused with other callbacks with that name, so change it to something that reflects its actual purpose. In this case, the main purpose of the callback is to parse an event command, so call it parse() instead. Link: https://lkml.kernel.org/r/7784e321840752ed88aac0b349c0c685fc9247b1.1641823001.git.zanussi@kernel.org Signed-off-by: Tom Zanussi <zanussi@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2021-12-06tracing: Have eprobes use filtering logic of trace eventsSteven Rostedt (VMware)1-11/+5
The eprobes open code the reserving of the event on the ring buffer for ftrace instead of using the ftrace event wrappers, which means that it doesn't get affected by the filters, breaking the filtering logic on user space. Link: https://lkml.kernel.org/r/20211130024319.068451680@goodmis.org Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-10-29tracing: Fix misspelling of "missing"Steven Rostedt (VMware)1-1/+1
My snake instinct was on and I wrote "misssing" instead of "missing". Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-10-27tracing: Do not warn when connecting eprobe to non existing eventSteven Rostedt (VMware)1-2/+2
When the syscall trace points are not configured in, the kselftests for ftrace will try to attach an event probe (eprobe) to one of the system call trace points. This triggered a WARNING, because the failure only expects to see memory issues. But this is not the only failure. The user may attempt to attach to a non existent event, and the kernel must not warn about it. Link: https://lkml.kernel.org/r/20211027120854.0680aa0f@gandalf.local.home Fixes: 7491e2c442781 ("tracing: Add a probe that attaches to trace events") Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-10-13tracing: Fix event probe removal from dynamic eventsSteven Rostedt (VMware)1-3/+51
When an event probe is to be removed via the API that created it via the dynamic events, an -ENOENT error is returned. This is because the removal of the event probe does not expect to see the event system and name that the event probe is attached to, even though that's part of the API to create it. As the removal of probes is to use the same API as they are created. In fact, the removal is not consistent with the kprobes and uprobes removal. Fix that by allowing various ways to remove the eprobe. The eprobe is created with: e:[GROUP/]NAME SYSTEM/EVENT [OPTIONS] Have it get removed by echoing in the following into dynamic_events: # Remove all eprobes with NAME echo '-:NAME' >> dynamic_events # Remove a specific eprobe echo '-:GROUP/NAME' >> dynamic_events echo '-:GROUP/NAME SYSTEM/EVENT' >> dynamic_events echo '-:NAME SYSTEM/EVENT' >> dynamic_events echo '-:GROUP/NAME SYSTEM/EVENT OPTIONS' >> dynamic_events echo '-:NAME SYSTEM/EVENT OPTIONS' >> dynamic_events Link: https://lkml.kernel.org/r/20211012081925.0e19cc4f@gandalf.local.home Link: https://lkml.kernel.org/r/20211013205533.630722129@goodmis.org Suggested-by: Masami Hiramatsu <mhiramat@kernel.org> Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Fixes: 7491e2c442781 ("tracing: Add a probe that attaches to trace events") Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-10-10tracing: Fix memory leak in eprobe_register()Vamshi K Sthambamkadi1-0/+7
kmemleak report: unreferenced object 0xffff900a70ec7ec0 (size 32): comm "ftracetest", pid 2770, jiffies 4295042510 (age 311.464s) hex dump (first 32 bytes): c8 31 23 45 0a 90 ff ff 40 85 c7 6e 0a 90 ff ff .1#E....@..n.... 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [<000000009d3751fd>] kmem_cache_alloc_trace+0x2a2/0x440 [<0000000088b8124b>] eprobe_register+0x1e3/0x350 [<000000002a9a0517>] __ftrace_event_enable_disable+0x7c/0x240 [<0000000019109321>] event_enable_write+0x93/0xe0 [<000000007d85b320>] vfs_write+0xb9/0x260 [<00000000b94c5e41>] ksys_write+0x67/0xe0 [<000000005a08c81d>] __x64_sys_write+0x1a/0x20 [<00000000240bf576>] do_syscall_64+0x3b/0xc0 [<0000000043d5d9f6>] entry_SYSCALL_64_after_hwframe+0x44/0xae unreferenced object 0xffff900a56bbf280 (size 128): comm "ftracetest", pid 2770, jiffies 4295042510 (age 311.464s) hex dump (first 32 bytes): ff ff ff ff ff ff ff ff 00 00 00 00 01 00 00 00 ................ 80 69 3b b2 ff ff ff ff 20 69 3b b2 ff ff ff ff .i;..... i;..... backtrace: [<000000009d3751fd>] kmem_cache_alloc_trace+0x2a2/0x440 [<00000000c4e90fad>] eprobe_register+0x1fc/0x350 [<000000002a9a0517>] __ftrace_event_enable_disable+0x7c/0x240 [<0000000019109321>] event_enable_write+0x93/0xe0 [<000000007d85b320>] vfs_write+0xb9/0x260 [<00000000b94c5e41>] ksys_write+0x67/0xe0 [<000000005a08c81d>] __x64_sys_write+0x1a/0x20 [<00000000240bf576>] do_syscall_64+0x3b/0xc0 [<0000000043d5d9f6>] entry_SYSCALL_64_after_hwframe+0x44/0xae In new_eprobe_trigger(), allocated edata and trigger variables are never freed. To fix, free memory in disable_eprobe(). Link: https://lkml.kernel.org/r/20211008071802.GA2098@cosmos Fixes: 7491e2c442781 ("tracing: Add a probe that attaches to trace events") Signed-off-by: Vamshi K Sthambamkadi <vamshi.k.sthambamkadi@gmail.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-09-07tracing: Fix some alloc_event_probe() error handling bugsDan Carpenter1-2/+3
There are two bugs in this code. First, if the kzalloc() fails it leads to a NULL dereference of "ep" on the next line. Second, if the alloc_event_probe() function returns an error then it leads to an error pointer dereference in the caller. Link: https://lkml.kernel.org/r/20210824115150.GI31143@kili Fixes: 7491e2c44278 ("tracing: Add a probe that attaches to trace events") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-08-20tracing: Add a probe that attaches to trace eventsTzvetomir Stoyanov (VMware)1-0/+903
A new dynamic event is introduced: event probe. The event is attached to an existing tracepoint and uses its fields as arguments. The user can specify custom format string of the new event, select what tracepoint arguments will be printed and how to print them. An event probe is created by writing configuration string in 'dynamic_events' ftrace file: e[:[SNAME/]ENAME] SYSTEM/EVENT [FETCHARGS] - Set an event probe -:SNAME/ENAME - Delete an event probe Where: SNAME - System name, if omitted 'eprobes' is used. ENAME - Name of the new event in SNAME, if omitted the SYSTEM_EVENT is used. SYSTEM - Name of the system, where the tracepoint is defined, mandatory. EVENT - Name of the tracepoint event in SYSTEM, mandatory. FETCHARGS - Arguments: <name>=$<field>[:TYPE] - Fetch given filed of the tracepoint and print it as given TYPE with given name. Supported types are: (u8/u16/u32/u64/s8/s16/s32/s64), basic type (x8/x16/x32/x64), hexadecimal types "string", "ustring" and bitfield. Example, attach an event probe on openat system call and print name of the file that will be opened: echo "e:esys/eopen syscalls/sys_enter_openat file=\$filename:string" >> dynamic_events A new dynamic event is created in events/esys/eopen/ directory. It can be deleted with: echo "-:esys/eopen" >> dynamic_events Filters, triggers and histograms can be attached to the new event, it can be matched in synthetic events. There is one limitation - an event probe can not be attached to kprobe, uprobe or another event probe. Link: https://lkml.kernel.org/r/20210812145805.2292326-1-tz.stoyanov@gmail.com Link: https://lkml.kernel.org/r/20210819152825.142428383@goodmis.org Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Co-developed-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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