linux.git/kernel/kprobes.c, branch v5.2-rc4

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156

2019-05-30T18:26:35+00:00

Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version this program is distributed in the
  hope that it will be useful but without any warranty without even
  the implied warranty of merchantability or fitness for a particular
  purpose see the gnu general public license for more details you
  should have received a copy of the gnu general public license along
  with this program if not write to the free software foundation inc
  59 temple place suite 330 boston ma 02111 1307 usa

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 1334 file(s).

Signed-off-by: Thomas Gleixner 
Reviewed-by: Allison Randal 
Reviewed-by: Richard Fontana 
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070033.113240726@linutronix.de
Signed-off-by: Greg Kroah-Hartman

kprobes: Fix error check when reusing optimized probes

2019-04-16T07:38:16+00:00

The following commit introduced a bug in one of our error paths:

  819319fc9346 ("kprobes: Return error if we fail to reuse kprobe instead of BUG_ON()")

it missed to handle the return value of kprobe_optready() as
error-value. In reality, the kprobe_optready() returns a bool
result, so "true" case must be passed instead of 0.

This causes some errors on kprobe boot-time selftests on ARM:

 [   ] Beginning kprobe tests...
 [   ] Probe ARM code
 [   ]     kprobe
 [   ]     kretprobe
 [   ] ARM instruction simulation
 [   ]     Check decoding tables
 [   ]     Run test cases
 [   ] FAIL: test_case_handler not run
 [   ] FAIL: Test andge	r10, r11, r14, asr r7
 [   ] FAIL: Scenario 11
 ...
 [   ] FAIL: Scenario 7
 [   ] Total instruction simulation tests=1631, pass=1433 fail=198
 [   ] kprobe tests failed

This can happen if an optimized probe is unregistered and next
kprobe is registered on same address until the previous probe
is not reclaimed.

If this happens, a hidden aggregated probe may be kept in memory,
and no new kprobe can probe same address. Also, in that case
register_kprobe() will return "1" instead of minus error value,
which can mislead caller logic.

Signed-off-by: Masami Hiramatsu 
Cc: Anil S Keshavamurthy 
Cc: David S . Miller 
Cc: Linus Torvalds 
Cc: Naveen N . Rao 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: stable@vger.kernel.org # v5.0+
Fixes: 819319fc9346 ("kprobes: Return error if we fail to reuse kprobe instead of BUG_ON()")
Link: http://lkml.kernel.org/r/155530808559.32517.539898325433642204.stgit@devnote2
Signed-off-by: Ingo Molnar

kprobes: Search non-suffixed symbol in blacklist

2019-02-13T07:16:40+00:00

Newer GCC versions can generate some different instances of a function
with suffixed symbols if the function is optimized and only
has a part of that. (e.g. .constprop, .part etc.)

In this case, it is not enough to check the entry of kprobe
blacklist because it only records non-suffixed symbol address.

To fix this issue, search non-suffixed symbol in blacklist if
given address is within a symbol which has a suffix.

Note that this can cause false positive cases if a kprobe-safe
function is optimized to suffixed instance and has same name
symbol which is blacklisted.
But I would like to chose a fail-safe design for this issue.

Signed-off-by: Masami Hiramatsu 
Reviewed-by: Steven Rostedt (VMware) 
Cc: Alexander Shishkin 
Cc: Andrea Righi 
Cc: Arnaldo Carvalho de Melo 
Cc: Jiri Olsa 
Cc: Linus Torvalds 
Cc: Mathieu Desnoyers 
Cc: Peter Zijlstra 
Cc: Steven Rostedt 
Cc: Thomas Gleixner 
Link: http://lkml.kernel.org/r/154998799234.31052.6136378903570418008.stgit@devbox
Signed-off-by: Ingo Molnar

Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2018-12-26T22:45:18+00:00

Pull perf updates from Ingo Molnar:
 "The main changes in this cycle on the kernel side:

   - rework kprobes blacklist handling (Masami Hiramatsu)

   - misc cleanups

  on the tooling side these areas were the main focus:

   - 'perf trace'     enhancements (Arnaldo Carvalho de Melo)

   - 'perf bench'     enhancements (Davidlohr Bueso)

   - 'perf record'    enhancements (Alexey Budankov)

   - 'perf annotate'  enhancements (Jin Yao)

   - 'perf top'       enhancements (Jiri Olsa)

   - Intel hw tracing enhancements (Adrian Hunter)

   - ARM hw tracing   enhancements (Leo Yan, Mathieu Poirier)

   - ... plus lots of other enhancements, cleanups and fixes"

* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (171 commits)
  tools uapi asm: Update asm-generic/unistd.h copy
  perf symbols: Relax checks on perf-PID.map ownership
  perf trace: Wire up the fadvise 'advice' table generator
  perf beauty: Add generator for fadvise64's 'advice' arg constants
  tools headers uapi: Grab a copy of fadvise.h
  perf beauty mmap: Print mmap's 'offset' arg in hexadecimal
  perf beauty mmap: Print PROT_READ before PROT_EXEC to match strace output
  perf trace beauty: Beautify arch_prctl()'s arguments
  perf trace: When showing string prefixes show prefix + ??? for unknown entries
  perf trace: Move strarrays to beauty.h for further reuse
  perf beauty: Wire up the x86_arch prctl code table generator
  perf beauty: Add a string table generator for x86's 'arch_prctl' codes
  tools include arch: Grab a copy of x86's prctl.h
  perf trace: Show NULL when syscall pointer args are 0
  perf trace: Enclose the errno strings with ()
  perf augmented_raw_syscalls: Copy 'access' arg as well
  perf trace: Add alignment spaces after the closing parens
  perf trace beauty: Print O_RDONLY when (flags & O_ACCMODE) == 0
  perf trace: Allow asking for not suppressing common string prefixes
  perf trace: Add a prefix member to the strarray class
  ...

kprobes: Blacklist symbols in arch-defined prohibited area

2018-12-17T16:48:38+00:00

Blacklist symbols in arch-defined probe-prohibited areas.
With this change, user can see all symbols which are prohibited
to probe in debugfs.

All archtectures which have custom prohibit areas should define
its own arch_populate_kprobe_blacklist() function, but unless that,
all symbols marked __kprobes are blacklisted.

Reported-by: Andrea Righi 
Tested-by: Andrea Righi 
Signed-off-by: Masami Hiramatsu 
Cc: Andy Lutomirski 
Cc: Anil S Keshavamurthy 
Cc: Borislav Petkov 
Cc: David S. Miller 
Cc: Linus Torvalds 
Cc: Naveen N. Rao 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: Yonghong Song 
Link: http://lkml.kernel.org/r/154503485491.26176.15823229545155174796.stgit@devbox
Signed-off-by: Ingo Molnar

kprobes: Replace synchronize_sched() with synchronize_rcu()

2018-11-27T17:21:42+00:00

Now that synchronize_rcu() waits for preempt-disable regions of code
as well as RCU read-side critical sections, synchronize_sched() can be
replaced by synchronize_rcu().  This commit therefore makes this change.

Signed-off-by: Paul E. McKenney 
Cc: "Naveen N. Rao" 
Cc: Anil S Keshavamurthy 
Cc: "David S. Miller" 
Acked-by: Masami Hiramatsu

kprobes: Don't call BUG_ON() if there is a kprobe in use on free list

2018-09-12T06:01:16+00:00

Instead of calling BUG_ON(), if we find a kprobe in use on free kprobe
list, just remove it from the list and keep it on kprobe hash list
as same as other in-use kprobes.

Signed-off-by: Masami Hiramatsu 
Cc: Anil S Keshavamurthy 
Cc: David S . Miller 
Cc: Linus Torvalds 
Cc: Naveen N . Rao 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Link: http://lkml.kernel.org/r/153666126882.21306.10738207224288507996.stgit@devbox
Signed-off-by: Ingo Molnar

kprobes: Return error if we fail to reuse kprobe instead of BUG_ON()

2018-09-12T06:01:16+00:00

Make reuse_unused_kprobe() to return error code if
it fails to reuse unused kprobe for optprobe instead
of calling BUG_ON().

Signed-off-by: Masami Hiramatsu 
Cc: Anil S Keshavamurthy 
Cc: David S . Miller 
Cc: Linus Torvalds 
Cc: Naveen N . Rao 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Link: http://lkml.kernel.org/r/153666124040.21306.14150398706331307654.stgit@devbox
Signed-off-by: Ingo Molnar

kprobes: Remove pointless BUG_ON() from reuse_unused_kprobe()

2018-09-12T06:01:16+00:00

Since reuse_unused_kprobe() is called when the given kprobe
is unused, checking it inside again with BUG_ON() is
pointless. Remove it.

Signed-off-by: Masami Hiramatsu 
Cc: Anil S Keshavamurthy 
Cc: David S . Miller 
Cc: Linus Torvalds 
Cc: Naveen N . Rao 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Link: http://lkml.kernel.org/r/153666121154.21306.17540752948574483565.stgit@devbox
Signed-off-by: Ingo Molnar

kprobes: Remove pointless BUG_ON() from add_new_kprobe()

2018-09-12T06:01:15+00:00

Before calling add_new_kprobe(), aggr_probe's GONE
flag and kprobe GONE flag are cleared. We don't need
to worry about that flag at this point.

Signed-off-by: Masami Hiramatsu 
Cc: Anil S Keshavamurthy 
Cc: David S . Miller 
Cc: Linus Torvalds 
Cc: Naveen N . Rao 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Link: http://lkml.kernel.org/r/153666118298.21306.4915366706875652652.stgit@devbox
Signed-off-by: Ingo Molnar