linux-stable.git/kernel/trace, branch linux-4.15.y

trace/bpf: remove helper bpf_perf_prog_read_value from tracepoint type programs

2018-03-28T16:23:04+00:00

commit f005afede992e265bb98534b86912bb669ccd0d2 upstream.

Commit 4bebdc7a85aa ("bpf: add helper bpf_perf_prog_read_value")
added helper bpf_perf_prog_read_value so that perf_event type program
can read event counter and enabled/running time.
This commit, however, introduced a bug which allows this helper
for tracepoint type programs. This is incorrect as bpf_perf_prog_read_value
needs to access perf_event through its bpf_perf_event_data_kern type context,
which is not available for tracepoint type program.

This patch fixed the issue by separating bpf_func_proto between tracepoint
and perf_event type programs and removed bpf_perf_prog_read_value
from tracepoint func prototype.

Fixes: 4bebdc7a85aa ("bpf: add helper bpf_perf_prog_read_value")
Reported-by: Alexei Starovoitov 
Signed-off-by: Yonghong Song 
Signed-off-by: Daniel Borkmann 
Signed-off-by: Greg Kroah-Hartman

tracing: probeevent: Fix to support minus offset from symbol

2018-03-28T16:23:01+00:00

commit c5d343b6b7badd1f5fe0873eff2e8d63a193e732 upstream.

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) 
Signed-off-by: Greg Kroah-Hartman

tracing: Fix parsing of globs with a wildcard at the beginning

2018-02-22T14:40:08+00:00

commit 07234021410bbc27b7c86c18de98616c29fbe667 upstream.

Al Viro reported:

    For substring - sure, but what about something like "*a*b" and "a*b"?
    AFAICS, filter_parse_regex() ends up with identical results in both
    cases - MATCH_GLOB and *search = "a*b".  And no way for the caller
    to tell one from another.

Testing this with the following:

 # cd /sys/kernel/tracing
 # echo '*raw*lock' > set_ftrace_filter
 bash: echo: write error: Invalid argument

With this patch:

 # echo '*raw*lock' > set_ftrace_filter
 # cat set_ftrace_filter
_raw_read_trylock
_raw_write_trylock
_raw_read_unlock
_raw_spin_unlock
_raw_write_unlock
_raw_spin_trylock
_raw_spin_lock
_raw_write_lock
_raw_read_lock

Al recommended not setting the search buffer to skip the first '*' unless we
know we are not using MATCH_GLOB. This implements his suggested logic.

Link: http://lkml.kernel.org/r/20180127170748.GF13338@ZenIV.linux.org.uk

Cc: stable@vger.kernel.org
Fixes: 60f1d5e3bac44 ("ftrace: Support full glob matching")
Reviewed-by: Masami Hiramatsu 
Reported-by: Al Viro 
Suggsted-by: Al Viro 
Signed-off-by: Steven Rostedt (VMware) 
Signed-off-by: Greg Kroah-Hartman

trace_uprobe: Display correct offset in uprobe_events

2018-02-22T14:39:55+00:00

commit 0e4d819d0893dc043ea7b7cb6baf4be1e310bd96 upstream.

Recently, how the pointers being printed with %p has been changed
by commit ad67b74d2469 ("printk: hash addresses printed with %p").
This is causing a regression while showing offset in the
uprobe_events file. Instead of %p, use %px to display offset.

Before patch:

  # perf probe -vv -x /tmp/a.out main
  Opening /sys/kernel/debug/tracing//uprobe_events write=1
  Writing event: p:probe_a/main /tmp/a.out:0x58c

  # cat /sys/kernel/debug/tracing/uprobe_events
  p:probe_a/main /tmp/a.out:0x0000000049a0f352

After patch:

  # cat /sys/kernel/debug/tracing/uprobe_events
  p:probe_a/main /tmp/a.out:0x000000000000058c

Link: http://lkml.kernel.org/r/20180106054246.15375-1-ravi.bangoria@linux.vnet.ibm.com

Cc: stable@vger.kernel.org
Fixes: ad67b74d2469 ("printk: hash addresses printed with %p")
Acked-by: Srikar Dronamraju 
Signed-off-by: Ravi Bangoria 
Signed-off-by: Steven Rostedt (VMware) 
Signed-off-by: Greg Kroah-Hartman

ftrace: Remove incorrect setting of glob search field

2018-02-16T19:07:01+00:00

commit 7b6586562708d2b3a04fe49f217ddbadbbbb0546 upstream.

__unregister_ftrace_function_probe() will incorrectly parse the glob filter
because it resets the search variable that was setup by filter_parse_regex().

Al Viro reported this:

    After that call of filter_parse_regex() we could have func_g.search not
    equal to glob only if glob started with '!' or '*'.  In the former case
    we would've buggered off with -EINVAL (not = 1).  In the latter we
    would've set func_g.search equal to glob + 1, calculated the length of
    that thing in func_g.len and proceeded to reset func_g.search back to
    glob.

    Suppose the glob is e.g. *foo*.  We end up with
	    func_g.type = MATCH_MIDDLE_ONLY;
	    func_g.len = 3;
	    func_g.search = "*foo";
    Feeding that to ftrace_match_record() will not do anything sane - we
    will be looking for names containing "*foo" (->len is ignored for that
    one).

Link: http://lkml.kernel.org/r/20180127031706.GE13338@ZenIV.linux.org.uk

Fixes: 3ba009297149f ("ftrace: Introduce ftrace_glob structure")
Reviewed-by: Dmitry Safonov <0x7f454c46@gmail.com>
Reviewed-by: Masami Hiramatsu 
Reported-by: Al Viro 
Signed-off-by: Steven Rostedt (VMware) 
Signed-off-by: Greg Kroah-Hartman

tracing: Update stack trace skipping for ORC unwinder

2018-01-23T20:57:00+00:00

With the addition of ORC unwinder and FRAME POINTER unwinder, the stack
trace skipping requirements have changed.

I went through the tracing stack trace dumps with ORC and with frame
pointers and recalculated the proper values.

Signed-off-by: Steven Rostedt (VMware)

ftrace, orc, x86: Handle ftrace dynamically allocated trampolines

2018-01-23T20:56:55+00:00

The function tracer can create a dynamically allocated trampoline that is
called by the function mcount or fentry hook that is used to call the
function callback that is registered. The problem is that the orc undwinder
will bail if it encounters one of these trampolines. This breaks the stack
trace of function callbacks, which include the stack tracer and setting the
stack trace for individual functions.

Since these dynamic trampolines are basically copies of the static ftrace
trampolines defined in ftrace_*.S, we do not need to create new orc entries
for the dynamic trampolines. Finding the return address on the stack will be
identical as the functions that were copied to create the dynamic
trampolines. When encountering a ftrace dynamic trampoline, we can just use
the orc entry of the ftrace static function that was copied for that
trampoline.

Signed-off-by: Steven Rostedt (VMware)

tracing: Fix converting enum's from the map in trace_event_eval_update()

2018-01-18T20:53:10+00:00

Since enums do not get converted by the TRACE_EVENT macro into their values,
the event format displaces the enum name and not the value. This breaks
tools like perf and trace-cmd that need to interpret the raw binary data. To
solve this, an enum map was created to convert these enums into their actual
numbers on boot up. This is done by TRACE_EVENTS() adding a
TRACE_DEFINE_ENUM() macro.

Some enums were not being converted. This was caused by an optization that
had a bug in it.

All calls get checked against this enum map to see if it should be converted
or not, and it compares the call's system to the system that the enum map
was created under. If they match, then they call is processed.

To cut down on the number of iterations needed to find the maps with a
matching system, since calls and maps are grouped by system, when a match is
made, the index into the map array is saved, so that the next call, if it
belongs to the same system as the previous call, could start right at that
array index and not have to scan all the previous arrays.

The problem was, the saved index was used as the variable to know if this is
a call in a new system or not. If the index was zero, it was assumed that
the call is in a new system and would keep incrementing the saved index
until it found a matching system. The issue arises when the first matching
system was at index zero. The next map, if it belonged to the same system,
would then think it was the first match and increment the index to one. If
the next call belong to the same system, it would begin its search of the
maps off by one, and miss the first enum that should be converted. This left
a single enum not converted properly.

Also add a comment to describe exactly what that index was for. It took me a
bit too long to figure out what I was thinking when debugging this issue.

Link: http://lkml.kernel.org/r/717BE572-2070-4C1E-9902-9F2E0FEDA4F8@oracle.com

Cc: stable@vger.kernel.org
Fixes: 0c564a538aa93 ("tracing: Add TRACE_DEFINE_ENUM() macro to map enums to their values")
Reported-by: Chuck Lever 
Teste-by: Chuck Lever 
Signed-off-by: Steven Rostedt (VMware)

ring-buffer: Fix duplicate results in mapping context to bits in recursive lock

2018-01-18T20:45:48+00:00

In bringing back the context checks, the code checks first if its normal
(non-interrupt) context, and then for NMI then IRQ then softirq. The final
check is redundant. Since the if branch is only hit if the context is one of
NMI, IRQ, or SOFTIRQ, if it's not NMI or IRQ there's no reason to check if
it is SOFTIRQ. The current code returns the same result even if its not a
SOFTIRQ. Which is confusing.

  pc & SOFTIRQ_OFFSET ? 2 : RB_CTX_SOFTIRQ

Is redundant as RB_CTX_SOFTIRQ *is* 2!

Fixes: a0e3a18f4baf ("ring-buffer: Bring back context level recursive checks")
Signed-off-by: Steven Rostedt (VMware)

tracing: Prevent PROFILE_ALL_BRANCHES when FORTIFY_SOURCE=y

2018-01-15T19:15:31+00:00

I regularly get 50 MB - 60 MB files during kernel randconfig builds.
These large files mostly contain (many repeats of; e.g., 124,594):

In file included from ../include/linux/string.h:6:0,
                 from ../include/linux/uuid.h:20,
                 from ../include/linux/mod_devicetable.h:13,
                 from ../scripts/mod/devicetable-offsets.c:3:
../include/linux/compiler.h:64:4: warning: '______f' is static but declared in inline function 'strcpy' which is not static [enabled by default]
    ______f = {     \
    ^
../include/linux/compiler.h:56:23: note: in expansion of macro '__trace_if'
                       ^
../include/linux/string.h:425:2: note: in expansion of macro 'if'
  if (p_size == (size_t)-1 && q_size == (size_t)-1)
  ^

This only happens when CONFIG_FORTIFY_SOURCE=y and
CONFIG_PROFILE_ALL_BRANCHES=y, so prevent PROFILE_ALL_BRANCHES if
FORTIFY_SOURCE=y.

Link: http://lkml.kernel.org/r/9199446b-a141-c0c3-9678-a3f9107f2750@infradead.org

Signed-off-by: Randy Dunlap 
Signed-off-by: Steven Rostedt (VMware)