Граф коммитов

10 Коммитов

Автор SHA1 Сообщение Дата
Tom Zanussi 2378a2d6b6 tracing: Remove ops param from event_command reg()/unreg() callbacks
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>
2022-01-10 11:09:11 -05:00
Tom Zanussi fb339e531b tracing: Change event_trigger_ops func() to trigger()
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>
2022-01-10 11:09:10 -05:00
Tom Zanussi 9ec5a7d168 tracing: Change event_command func() to parse()
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>
2022-01-10 11:09:10 -05:00
Steven Rostedt (VMware) 3e8b1a29a0 tracing: Have eprobes use filtering logic of trace events
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>
2021-12-06 15:37:22 -05:00
Steven Rostedt (VMware) ddcf906fe5 tracing: Fix misspelling of "missing"
My snake instinct was on and I wrote "misssing" instead of "missing".

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-10-29 09:54:14 -04:00
Steven Rostedt (VMware) 7fa598f970 tracing: Do not warn when connecting eprobe to non existing event
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: 7491e2c442 ("tracing: Add a probe that attaches to trace events")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-10-27 21:47:55 -04:00
Steven Rostedt (VMware) 7d5fda1c84 tracing: Fix event probe removal from dynamic events
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: 7491e2c442 ("tracing: Add a probe that attaches to trace events")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-10-13 19:26:57 -04:00
Vamshi K Sthambamkadi 6675880fc4 tracing: Fix memory leak in eprobe_register()
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: 7491e2c442 ("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>
2021-10-10 22:26:55 -04:00
Dan Carpenter 5615e088b4 tracing: Fix some alloc_event_probe() error handling bugs
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: 7491e2c442 ("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>
2021-09-07 20:58:23 -04:00
Tzvetomir Stoyanov (VMware) 7491e2c442 tracing: Add a probe that attaches to trace events
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>
2021-08-20 14:18:40 -04:00