linux-stable.git/kernel/kprobes.c, branch v4.4.166

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

2018-11-21T08:27:32+00:00

[ Upstream commit 819319fc93461c07b9cdb3064f154bd8cfd48172 ]

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 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

kprobes: Make list and blacklist root user read only

2018-09-05T07:18:40+00:00

commit f2a3ab36077222437b4826fc76111caa14562b7c upstream.

Since the blacklist and list files on debugfs indicates
a sensitive address information to reader, it should be
restricted to the root user.

Suggested-by: Thomas Richter 
Suggested-by: Ingo Molnar 
Signed-off-by: Masami Hiramatsu 
Cc: Ananth N Mavinakayanahalli 
Cc: Anil S Keshavamurthy 
Cc: Arnd Bergmann 
Cc: David Howells 
Cc: David S . Miller 
Cc: Heiko Carstens 
Cc: Jon Medhurst 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: Tobin C . Harding 
Cc: Will Deacon 
Cc: acme@kernel.org
Cc: akpm@linux-foundation.org
Cc: brueckner@linux.vnet.ibm.com
Cc: linux-arch@vger.kernel.org
Cc: rostedt@goodmis.org
Cc: schwidefsky@de.ibm.com
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/lkml/152491890171.9916.5183693615601334087.stgit@devbox
Signed-off-by: Ingo Molnar 
Signed-off-by: Greg Kroah-Hartman

kprobes/x86: Fix to set RWX bits correctly before releasing trampoline

2018-04-08T09:51:56+00:00

commit c93f5cf571e7795f97d49ef51b766cf25e328545 upstream.

Fix kprobes to set(recover) RWX bits correctly on trampoline
buffer before releasing it. Releasing readonly page to
module_memfree() crash the kernel.

Without this fix, if kprobes user register a bunch of kprobes
in function body (since kprobes on function entry usually
use ftrace) and unregister it, kernel hits a BUG and crash.

Link: http://lkml.kernel.org/r/149570868652.3518.14120169373590420503.stgit@devbox

Signed-off-by: Masami Hiramatsu 
Fixes: d0381c81c2f7 ("kprobes/x86: Set kprobes pages read-only")
Signed-off-by: Steven Rostedt (VMware) 
Cc: Ben Hutchings 
Signed-off-by: Greg Kroah-Hartman

tracing/kprobes: Enforce kprobes teardown after testing

2017-05-25T12:30:17+00:00

commit 30e7d894c1478c88d50ce94ddcdbd7f9763d9cdd upstream.

Enabling the tracer selftest triggers occasionally the warning in
text_poke(), which warns when the to be modified page is not marked
reserved.

The reason is that the tracer selftest installs kprobes on functions marked
__init for testing. These probes are removed after the tests, but that
removal schedules the delayed kprobes_optimizer work, which will do the
actual text poke. If the work is executed after the init text is freed,
then the warning triggers. The bug can be reproduced reliably when the work
delay is increased.

Flush the optimizer work and wait for the optimizing/unoptimizing lists to
become empty before returning from the kprobes tracer selftest. That
ensures that all operations which were queued due to the probes removal
have completed.

Link: http://lkml.kernel.org/r/20170516094802.76a468bb@gandalf.local.home

Signed-off-by: Thomas Gleixner 
Acked-by: Masami Hiramatsu 
Fixes: 6274de498 ("kprobes: Support delayed unoptimizing")
Signed-off-by: Steven Rostedt (VMware) 
Signed-off-by: Greg Kroah-Hartman

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: makes kprobes/enabled works correctly for optimized kprobes.

2015-02-14T05:21:42+00:00

debugfs/kprobes/enabled doesn't work correctly on optimized kprobes.
Masami Hiramatsu has a test report on x86_64 platform:

https://lkml.org/lkml/2015/1/19/274

This patch forces it to unoptimize kprobe if kprobes_all_disarmed is set.
It also checks the flag in unregistering path for skipping unneeded
disarming process when kprobes globally disarmed.

Signed-off-by: Wang Nan 
Signed-off-by: Masami Hiramatsu 
Cc: Ingo Molnar 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

kprobes: set kprobes_all_disarmed earlier to enable re-optimization.

2015-02-14T05:21:42+00:00

In original code, the probed instruction doesn't get optimized after

echo 0 > /sys/kernel/debug/kprobes/enabled
echo 1 > /sys/kernel/debug/kprobes/enabled

This is because original code checks kprobes_all_disarmed in
optimize_kprobe(), but this flag is turned off after calling that
function.  Therefore, optimize_kprobe() will see kprobes_all_disarmed ==
true and doesn't do the optimization.

This patch simply turns off kprobes_all_disarmed earlier to enable
optimization.

Signed-off-by: Wang Nan 
Signed-off-by: Masami Hiramatsu 
Cc: Ingo Molnar 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Merge branch 'for-linus' of git://ftp.arm.linux.org.uk/~rmk/linux-arm

2015-02-12T16:51:56+00:00

Pull ARM updates from Russell King:

 - clang assembly fixes from Ard

 - optimisations and cleanups for Aurora L2 cache support

 - efficient L2 cache support for secure monitor API on Exynos SoCs

 - debug menu cleanup from Daniel Thompson to allow better behaviour for
   multiplatform kernels

 - StrongARM SA11x0 conversion to irq domains, and pxa_timer

 - kprobes updates for older ARM CPUs

 - move probes support out of arch/arm/kernel to arch/arm/probes

 - add inline asm support for the rbit (reverse bits) instruction

 - provide an ARM mode secondary CPU entry point (for Qualcomm CPUs)

 - remove the unused ARMv3 user access code

 - add driver_override support to AMBA Primecell bus

* 'for-linus' of git://ftp.arm.linux.org.uk/~rmk/linux-arm: (55 commits)
  ARM: 8256/1: driver coamba: add device binding path 'driver_override'
  ARM: 8301/1: qcom: Use secondary_startup_arm()
  ARM: 8302/1: Add a secondary_startup that assumes ARM mode
  ARM: 8300/1: teach __asmeq that r11 == fp and r12 == ip
  ARM: kprobes: Fix compilation error caused by superfluous '*'
  ARM: 8297/1: cache-l2x0: optimize aurora range operations
  ARM: 8296/1: cache-l2x0: clean up aurora cache handling
  ARM: 8284/1: sa1100: clear RCSR_SMR on resume
  ARM: 8283/1: sa1100: collie: clear PWER register on machine init
  ARM: 8282/1: sa1100: use handle_domain_irq
  ARM: 8281/1: sa1100: move GPIO-related IRQ code to gpio driver
  ARM: 8280/1: sa1100: switch to irq_domain_add_simple()
  ARM: 8279/1: sa1100: merge both GPIO irqdomains
  ARM: 8278/1: sa1100: split irq handling for low GPIOs
  ARM: 8291/1: replace magic number with PAGE_SHIFT macro in fixup_pv code
  ARM: 8290/1: decompressor: fix a wrong comment
  ARM: 8286/1: mm: Fix dma_contiguous_reserve comment
  ARM: 8248/1: pm: remove outdated comment
  ARM: 8274/1: Fix DEBUG_LL for multi-platform kernels (without PL01X)
  ARM: 8273/1: Seperate DEBUG_UART_PHYS from DEBUG_LL on EP93XX
  ...

module: remove mod arg from module_free, rename module_memfree().

2015-01-20T01:08:33+00:00

Nothing needs the module pointer any more, and the next patch will
call it from RCU, where the module itself might no longer exist.
Removing the arg is the safest approach.

This just codifies the use of the module_alloc/module_free pattern
which ftrace and bpf use.

Signed-off-by: Rusty Russell 
Acked-by: Alexei Starovoitov 
Cc: Mikael Starvik 
Cc: Jesper Nilsson 
Cc: Ralf Baechle 
Cc: Ley Foon Tan 
Cc: Benjamin Herrenschmidt 
Cc: Chris Metcalf 
Cc: Steven Rostedt 
Cc: x86@kernel.org
Cc: Ananth N Mavinakayanahalli 
Cc: Anil S Keshavamurthy 
Cc: Masami Hiramatsu 
Cc: linux-cris-kernel@axis.com
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Cc: nios2-dev@lists.rocketboards.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: sparclinux@vger.kernel.org
Cc: netdev@vger.kernel.org

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