linux-stable.git/include/linux/kprobes.h, branch v4.11.2

kprobes: move kprobe declarations to asm-generic/kprobes.h

2017-02-28T02:43:45+00:00

Often all is needed is these small helpers, instead of compiler.h or a
full kprobes.h.  This is important for asm helpers, in fact even some
asm/kprobes.h make use of these helpers...  instead just keep a generic
asm file with helpers useful for asm code with the least amount of
clutter as possible.

Likewise we need now to also address what to do about this file for both
when architectures have CONFIG_HAVE_KPROBES, and when they do not.  Then
for when architectures have CONFIG_HAVE_KPROBES but have disabled
CONFIG_KPROBES.

Right now most asm/kprobes.h do not have guards against CONFIG_KPROBES,
this means most architecture code cannot include asm/kprobes.h safely.
Correct this and add guards for architectures missing them.
Additionally provide architectures that not have kprobes support with
the default asm-generic solution.  This lets us force asm/kprobes.h on
the header include/linux/kprobes.h always, but most importantly we can
now safely include just asm/kprobes.h on architecture code without
bringing the full kitchen sink of header files.

Two architectures already provided a guard against CONFIG_KPROBES on its
kprobes.h: sh, arch.  The rest of the architectures needed gaurds added.
We avoid including any not-needed headers on asm/kprobes.h unless
kprobes have been enabled.

In a subsequent atomic change we can try now to remove compiler.h from
include/linux/kprobes.h.

During this sweep I've also identified a few architectures defining a
common macro needed for both kprobes and ftrace, that of the definition
of the breakput instruction up.  Some refer to this as
BREAKPOINT_INSTRUCTION.  This must be kept outside of the #ifdef
CONFIG_KPROBES guard.

[mcgrof@kernel.org: fix arm64 build]
  Link: http://lkml.kernel.org/r/CAB=NE6X1WMByuARS4mZ1g9+W=LuVBnMDnh_5zyN0CLADaVh=Jw@mail.gmail.com
[sfr@canb.auug.org.au: fixup for kprobes declarations moving]
  Link: http://lkml.kernel.org/r/20170214165933.13ebd4f4@canb.auug.org.au
Link: http://lkml.kernel.org/r/20170203233139.32682-1-mcgrof@kernel.org
Signed-off-by: Luis R. Rodriguez 
Signed-off-by: Stephen Rothwell 
Acked-by: Masami Hiramatsu 
Cc: Arnd Bergmann 
Cc: Masami Hiramatsu 
Cc: Ananth N Mavinakayanahalli 
Cc: Anil S Keshavamurthy 
Cc: David S. Miller 
Cc: Ingo Molnar 
Cc: Thomas Gleixner 
Cc: H. Peter Anvin 
Cc: Andy Lutomirski 
Cc: Steven Rostedt 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

kprobes, extable: Identify kprobes trampolines as kernel text area

2017-01-14T07:38:05+00:00

Improve __kernel_text_address()/kernel_text_address() to return
true if the given address is on a kprobe's instruction slot
trampoline.

This can help stacktraces to determine the address is on a
text area or not.

To implement this atomically in is_kprobe_*_slot(), also change
the insn_cache page list to an RCU list.

This changes timings a bit (it delays page freeing to the RCU garbage
collection phase), but none of that is in the hot path.

Note: this change can add small overhead to stack unwinders because
it adds 2 additional checks to __kernel_text_address(). However, the
impact should be very small, because kprobe_insn_pages list has 1 entry
per 256 probes(on x86, on arm/arm64 it will be 1024 probes),
and kprobe_optinsn_pages has 1 entry per 32 probes(on x86).
In most use cases, the number of kprobe events may be less
than 20, which means that is_kprobe_*_slot() will check just one entry.

Tested-by: Josh Poimboeuf 
Signed-off-by: Masami Hiramatsu 
Acked-by: Peter Zijlstra 
Cc: Alexander Shishkin 
Cc: Ananth N Mavinakayanahalli 
Cc: Andrew Morton 
Cc: Andrey Konovalov 
Cc: Arnaldo Carvalho de Melo 
Cc: Jiri Olsa 
Cc: Linus Torvalds 
Cc: Thomas Gleixner 
Link: http://lkml.kernel.org/r/148388747896.6869.6354262871751682264.stgit@devbox
[ Improved the changelog and coding style. ]
Signed-off-by: Ingo Molnar

perf/x86/hw_breakpoints: Disallow kernel breakpoints unless kprobe-safe

2015-08-04T08:16:54+00:00

Code on the kprobe blacklist doesn't want unexpected int3
exceptions. It probably doesn't want unexpected debug exceptions
either. Be safe: disallow breakpoints in nokprobes code.

On non-CONFIG_KPROBES kernels, there is no kprobe blacklist.  In
that case, disallow kernel breakpoints entirely.

It will be particularly important to keep hw breakpoints out of the
entry and NMI code once we move debug exceptions off the IST stack.

Signed-off-by: Andy Lutomirski 
Signed-off-by: Peter Zijlstra (Intel) 
Cc: Borislav Petkov 
Cc: Brian Gerst 
Cc: Linus Torvalds 
Cc: Masami Hiramatsu 
Cc: Peter Zijlstra 
Cc: Steven Rostedt 
Cc: Thomas Gleixner 
Link: http://lkml.kernel.org/r/e14b152af99640448d895e3c2a8c2d5ee19a1325.1438312874.git.luto@kernel.org
Signed-off-by: Ingo Molnar

kprobes: Pass the original kprobe for preparing optimized kprobe

2015-01-13T16:10:16+00:00

Pass the original kprobe for preparing an optimized kprobe arch-dep
part, since for some architecture (e.g. ARM32) requires the information
in original kprobe.

Signed-off-by: Masami Hiramatsu 
Signed-off-by: Wang Nan 
Signed-off-by: Jon Medhurst

kprobes: introduce weak arch_check_ftrace_location() helper function

2014-10-27T12:27:27+00:00

Introduce weak arch_check_ftrace_location() helper function which
architectures can override in order to implement handling of kprobes
on function tracer call sites on their own, without depending on
common code or implementing the KPROBES_ON_FTRACE feature.

Signed-off-by: Heiko Carstens 
Acked-by: Masami Hiramatsu 
Acked-by: Steven Rostedt 
Signed-off-by: Martin Schwidefsky

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

2014-06-13T02:18:49+00:00

Pull more perf updates from Ingo Molnar:
 "A second round of perf updates:

   - wide reaching kprobes sanitization and robustization, with the hope
     of fixing all 'probe this function crashes the kernel' bugs, by
     Masami Hiramatsu.

   - uprobes updates from Oleg Nesterov: tmpfs support, corner case
     fixes and robustization work.

   - perf tooling updates and fixes from Jiri Olsa, Namhyung Ki, Arnaldo
     et al:
        * Add support to accumulate hist periods (Namhyung Kim)
        * various fixes, refactorings and enhancements"

* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (101 commits)
  perf: Differentiate exec() and non-exec() comm events
  perf: Fix perf_event_comm() vs. exec() assumption
  uprobes/x86: Rename arch_uprobe->def to ->defparam, minor comment updates
  perf/documentation: Add description for conditional branch filter
  perf/x86: Add conditional branch filtering support
  perf/tool: Add conditional branch filter 'cond' to perf record
  perf: Add new conditional branch filter 'PERF_SAMPLE_BRANCH_COND'
  uprobes: Teach copy_insn() to support tmpfs
  uprobes: Shift ->readpage check from __copy_insn() to uprobe_register()
  perf/x86: Use common PMU interrupt disabled code
  perf/ARM: Use common PMU interrupt disabled code
  perf: Disable sampled events if no PMU interrupt
  perf: Fix use after free in perf_remove_from_context()
  perf tools: Fix 'make help' message error
  perf record: Fix poll return value propagation
  perf tools: Move elide bool into perf_hpp_fmt struct
  perf tools: Remove elide setup for SORT_MODE__MEMORY mode
  perf tools: Fix "==" into "=" in ui_browser__warning assignment
  perf tools: Allow overriding sysfs and proc finding with env var
  perf tools: Consider header files outside perf directory in tags target
  ...

tracing: Replace __get_cpu_var uses with this_cpu_ptr

2014-05-06T02:40:53+00:00

Replace uses of &__get_cpu_var for address calculation with this_cpu_ptr.

Link: http://lkml.kernel.org/p/alpine.DEB.2.10.1404291415560.18364@gentwo.org

Acked-by: Masami Hiramatsu 
Signed-off-by: Christoph Lameter 
Signed-off-by: Steven Rostedt

kprobes: Introduce NOKPROBE_SYMBOL() macro to maintain kprobes blacklist

2014-04-24T08:02:56+00:00

Introduce NOKPROBE_SYMBOL() macro which builds a kprobes
blacklist at kernel build time.

The usage of this macro is similar to EXPORT_SYMBOL(),
placed after the function definition:

  NOKPROBE_SYMBOL(function);

Since this macro will inhibit inlining of static/inline
functions, this patch also introduces a nokprobe_inline macro
for static/inline functions. In this case, we must use
NOKPROBE_SYMBOL() for the inline function caller.

When CONFIG_KPROBES=y, the macro stores the given function
address in the "_kprobe_blacklist" section.

Since the data structures are not fully initialized by the
macro (because there is no "size" information),  those
are re-initialized at boot time by using kallsyms.

Signed-off-by: Masami Hiramatsu 
Link: http://lkml.kernel.org/r/20140417081705.26341.96719.stgit@ltc230.yrl.intra.hitachi.co.jp
Cc: Alok Kataria 
Cc: Ananth N Mavinakayanahalli 
Cc: Andrew Morton 
Cc: Anil S Keshavamurthy 
Cc: Arnd Bergmann 
Cc: Christopher Li 
Cc: Chris Wright 
Cc: David S. Miller 
Cc: Jan-Simon Möller 
Cc: Jeremy Fitzhardinge 
Cc: Linus Torvalds 
Cc: Randy Dunlap 
Cc: Rusty Russell 
Cc: linux-arch@vger.kernel.org
Cc: linux-doc@vger.kernel.org
Cc: linux-sparse@vger.kernel.org
Cc: virtualization@lists.linux-foundation.org
Signed-off-by: Ingo Molnar

kprobes: Prohibit probing on .entry.text code

2014-04-24T08:02:56+00:00

.entry.text is a code area which is used for interrupt/syscall
entries, which includes many sensitive code.
Thus, it is better to prohibit probing on all of such code
instead of a part of that.
Since some symbols are already registered on kprobe blacklist,
this also removes them from the blacklist.

Signed-off-by: Masami Hiramatsu 
Reviewed-by: Steven Rostedt 
Cc: Ananth N Mavinakayanahalli 
Cc: Anil S Keshavamurthy 
Cc: Borislav Petkov 
Cc: David S. Miller 
Cc: Frederic Weisbecker 
Cc: Jan Kiszka 
Cc: Jiri Kosina 
Cc: Jonathan Lebon 
Cc: Seiji Aguchi 
Link: http://lkml.kernel.org/r/20140417081658.26341.57354.stgit@ltc230.yrl.intra.hitachi.co.jp
Signed-off-by: Ingo Molnar

kprobes: allow to specify custom allocator for insn caches

2013-09-11T22:58:52+00:00

The current two insn slot caches both use module_alloc/module_free to
allocate and free insn slot cache pages.

For s390 this is not sufficient since there is the need to allocate insn
slots that are either within the vmalloc module area or within dma memory.

Therefore add a mechanism which allows to specify an own allocator for an
own insn slot cache.

Signed-off-by: Heiko Carstens 
Acked-by: Masami Hiramatsu 
Cc: Ananth N Mavinakayanahalli 
Cc: Ingo Molnar 
Cc: Martin Schwidefsky 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds