linux-toradex.git/kernel/trace/trace_probe.c, branch v4.18-rc4

tracing: probeevent: Fix to support minus offset from symbol

2018-03-23T16:02:37+00:00

In Documentation/trace/kprobetrace.txt, it says

 @SYM[+|-offs] : Fetch memory at SYM +|- offs (SYM should be a data symbol)

However, the parser doesn't parse minus offset correctly, since
commit 2fba0c8867af ("tracing/kprobes: Fix probe offset to be
unsigned") drops minus ("-") offset support for kprobe probe
address usage.

This fixes the traceprobe_split_symbol_offset() to parse minus
offset again with checking the offset range, and add a minus
offset check in kprobe probe address usage.

Link: http://lkml.kernel.org/r/152129028983.31874.13419301530285775521.stgit@devbox

Cc: Ingo Molnar 
Cc: Tom Zanussi 
Cc: Arnaldo Carvalho de Melo 
Cc: Ravi Bangoria 
Cc: stable@vger.kernel.org
Fixes: 2fba0c8867af ("tracing/kprobes: Fix probe offset to be unsigned")
Acked-by: Namhyung Kim 
Signed-off-by: Masami Hiramatsu 
Signed-off-by: Steven Rostedt (VMware)

tracing: Make traceprobe parsing code reusable

2017-10-04T17:06:44+00:00

traceprobe_probes_write() and traceprobe_command() actually contain
nothing that ties them to kprobes - the code is generically useful for
similar types of parsing elsewhere, so separate it out and move it to
trace.c/trace.h.

Other than moving it, the only change is in naming:
traceprobe_probes_write() becomes trace_parse_run_command() and
traceprobe_command() becomes trace_run_command().

Link: http://lkml.kernel.org/r/ae5c26ea40c196a8986854d921eb6e713ede7e3f.1506105045.git.tom.zanussi@linux.intel.com

Signed-off-by: Tom Zanussi 
Signed-off-by: Steven Rostedt (VMware)

tracing/probes: Fix a warning message to show correct maximum length

2017-02-15T15:32:48+00:00

Since tracing/*probe_events will accept a probe definition
up to 4096 - 2 ('\n' and '\0') bytes, it must show 4094 instead
of 4096 in warning message.

Note that there is one possible case of exceed 4094. If user
prepare 4096 bytes null-terminated string and syscall write
it with the count == 4095, then it can be accepted. However,
if user puts a '\n' after that, it must rejected.
So IMHO, the warning message should indicate shorter one,
since it is safer.

Link: http://lkml.kernel.org/r/148673290462.2579.7966778294009665632.stgit@devbox

Signed-off-by: Masami Hiramatsu 
Signed-off-by: Steven Rostedt (VMware)

tracing/probe: Show subsystem name in messages

2017-02-15T14:02:25+00:00

Show "trace_probe:", "trace_kprobe:" and "trace_uprobe:"
headers for each warning/error/info message. This will
help people to notice that kprobe/uprobe events caused
those messages.

Link: http://lkml.kernel.org/r/148646647813.24658.16705315294927615333.stgit@devbox

Signed-off-by: Masami Hiramatsu 
Signed-off-by: Steven Rostedt (VMware)

tracing: Have traceprobe_probes_write() not access userspace unnecessarily

2017-02-15T14:00:55+00:00

The code in traceprobe_probes_write() reads up to 4096 bytes from userpace
for each line. If userspace passes in several lines to execute, the code
will do a large read for each line, even though, it is highly likely that
the first read from userspace received all of the lines at once.

I changed the logic to do a single read from userspace, and to only read
from userspace again if not all of the read from userspace made it in.

I tested this by adding printk()s and writing files that would test -1, ==,
and +1 the buffer size, to make sure that there's no overflows and that if a
single line is written with +1 the buffer size, that it fails properly.

Link: http://lkml.kernel.org/r/20170209180458.5c829ab2@gandalf.local.home

Acked-by: Masami Hiramatsu 
Acked-by: Namhyung Kim 
Signed-off-by: Steven Rostedt (VMware)

ftrace: kprobe: uprobe: Show u8/u16/u32/u64 types in decimal

2016-08-23T20:06:38+00:00

Change kprobe/uprobe-tracer to show the arguments type-casted
with u8/u16/u32/u64 in decimal digits instead of hexadecimal.

To minimize compatibility issue, the arguments without type
casting are typed by x64 (or x32 for 32bit arch) by default.

Note: all arguments set by old perf probe without types are
shown in decimal by default.

Signed-off-by: Masami Hiramatsu 
Acked-by: Steven Rostedt 
Cc: Alexander Shishkin 
Cc: Hemant Kumar 
Cc: Naohiro Aota 
Cc: Peter Zijlstra 
Cc: Wang Nan 
Link: http://lkml.kernel.org/r/147151076135.12957.14684546093034343894.stgit@devbox
Signed-off-by: Arnaldo Carvalho de Melo

ftrace: kprobe: uprobe: Add x8/x16/x32/x64 for hexadecimal types

2016-08-23T18:38:09+00:00

Add x8/x16/x32/x64 for hexadecimal type casting to kprobe/uprobe event
tracer.

These type casts can be used for integer arguments for explicitly
showing them in hexadecimal digits in formatted text.

Signed-off-by: Masami Hiramatsu 
Acked-by: Steven Rostedt 
Cc: Alexander Shishkin 
Cc: Hemant Kumar 
Cc: Naohiro Aota 
Cc: Peter Zijlstra 
Cc: Wang Nan 
Link: http://lkml.kernel.org/r/147151067029.12957.11591314629326414783.stgit@devbox
Signed-off-by: Arnaldo Carvalho de Melo

tracing: expose current->comm to [ku]probe events

2016-06-20T13:54:19+00:00

ftrace is very quick to give up on saving the task command line (see
`trace_save_cmdline()`). The workaround for events which really care
about the command line is to explicitly assign it as part of the entry.
However, this doesn't work for kprobe events, as there's no
straightforward way to get access to current->comm. Add a kprobe/uprobe
event variable $comm which provides exactly that.

Link: http://lkml.kernel.org/r/f59b472033b943a370f5f48d0af37698f409108f.1465435894.git.osandov@fb.com

Acked-by: Masami Hiramatsu 
Signed-off-by: Omar Sandoval 
Signed-off-by: Steven Rostedt

kernel/...: convert pr_warning to pr_warn

2016-03-22T22:36:02+00:00

Use the more common logging method with the eventual goal of removing
pr_warning altogether.

Miscellanea:

 - Realign arguments
 - Coalesce formats
 - Add missing space between a few coalesced formats

Signed-off-by: Joe Perches 
Acked-by: Rafael J. Wysocki 	[kernel/power/suspend.c]
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

trace: Don't use __weak in header files

2015-03-25T12:57:23+00:00

The commit that added a check for this to checkpatch says:

"Using weak declarations can have unintended link defects.  The __weak on
the declaration causes non-weak definitions to become weak."

In this case, when a PowerPC kernel is built with CONFIG_KPROBE_EVENT
but not CONFIG_UPROBE_EVENT, it generates the following warning:

WARNING: 1 bad relocations
c0000000014f2190 R_PPC64_ADDR64    uprobes_fetch_type_table

This is fixed by passing the fetch_table arrays to
traceprobe_parse_probe_arg() which also means that they can never be NULL.

Link: http://lkml.kernel.org/r/20150312165834.4482cb48@canb.auug.org.au

Acked-by: Masami Hiramatsu 
Signed-off-by: Stephen Rothwell 
Signed-off-by: Steven Rostedt