linux-toradex.git/arch/mips/kernel/kprobes.c, branch v6.7

MIPS: Use NOKPROBE_SYMBOL() instead of __kprobes annotation

2022-05-12T16:00:51+00:00

If define CONFIG_KPROBES, __kprobes annotation forces the whole function
into the ".kprobes.text" section, NOKPROBE_SYMBOL() only stores the given
function address in the "_kprobe_blacklist" section which is introduced
to maintain kprobes blacklist.

Modify the related code to use NOKPROBE_SYMBOL() to protect functions from
kprobes instead of __kprobes annotation under arch/mips.

No obvious functional change in this patch, some more work needs to be done
to fix the kernel panic when execute the following testcase on mips:

  # cd tools/testing/selftests/ftrace
  # ./ftracetest test.d/kprobe/multiple_kprobes.tc

Signed-off-by: Tiezhu Yang 
Acked-by: Masami Hiramatsu 
Signed-off-by: Thomas Bogendoerfer

kprobes: treewide: Make it harder to refer kretprobe_trampoline directly

2021-10-01T01:24:06+00:00

Since now there is kretprobe_trampoline_addr() for referring the
address of kretprobe trampoline code, we don't need to access
kretprobe_trampoline directly.

Make it harder to refer by renaming it to __kretprobe_trampoline().

Link: https://lkml.kernel.org/r/163163045446.489837.14510577516938803097.stgit@devnote2

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

kprobes: treewide: Remove trampoline_address from kretprobe_trampoline_handler()

2021-10-01T01:24:06+00:00

The __kretprobe_trampoline_handler() callback, called from low level
arch kprobes methods, has the 'trampoline_address' parameter, which is
entirely superfluous as it basically just replicates:

  dereference_kernel_function_descriptor(kretprobe_trampoline)

In fact we had bugs in arch code where it wasn't replicated correctly.

So remove this superfluous parameter and use kretprobe_trampoline_addr()
instead.

Link: https://lkml.kernel.org/r/163163044546.489837.13505751885476015002.stgit@devnote2

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

kprobes: treewide: Cleanup the error messages for kprobes

2021-10-01T01:24:05+00:00

This clean up the error/notification messages in kprobes related code.
Basically this defines 'pr_fmt()' macros for each files and update
the messages which describes

 - what happened,
 - what is the kernel going to do or not do,
 - is the kernel fine,
 - what can the user do about it.

Also, if the message is not needed (e.g. the function returns unique
error code, or other error message is already shown.) remove it,
and replace the message with WARN_*() macros if suitable.

Link: https://lkml.kernel.org/r/163163036568.489837.14085396178727185469.stgit@devnote2

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

kprobes: Remove kprobe::fault_handler

2021-06-01T14:00:08+00:00

The reason for kprobe::fault_handler(), as given by their comment:

 * We come here because instructions in the pre/post
 * handler caused the page_fault, this could happen
 * if handler tries to access user space by
 * copy_from_user(), get_user() etc. Let the
 * user-specified handler try to fix it first.

Is just plain bad. Those other handlers are ran from non-preemptible
context and had better use _nofault() functions. Also, there is no
upstream usage of this.

Signed-off-by: Peter Zijlstra (Intel) 
Reviewed-by: Christoph Hellwig 
Acked-by: Masami Hiramatsu 
Link: https://lore.kernel.org/r/20210525073213.561116662@infradead.org

mips: kprobes: Use generic kretprobe trampoline handler

2020-09-08T09:52:33+00:00

Use the generic kretprobe trampoline handler. Don't use
framepointer verification.

Signed-off-by: Masami Hiramatsu 
Signed-off-by: Ingo Molnar 
Link: https://lore.kernel.org/r/159870607968.1229682.12100697467108845587.stgit@devnote2

maccess: rename probe_kernel_{read,write} to copy_{from,to}_kernel_nofault

2020-06-17T17:57:41+00:00

Better describe what these functions do.

Suggested-by: Linus Torvalds 
Signed-off-by: Christoph Hellwig 
Signed-off-by: Linus Torvalds

mm, kprobes: generalize and rename notify_page_fault() as kprobe_page_fault()

2019-07-17T02:23:22+00:00

Architectures which support kprobes have very similar boilerplate around
calling kprobe_fault_handler().  Use a helper function in kprobes.h to
unify them, based on the x86 code.

This changes the behaviour for other architectures when preemption is
enabled.  Previously, they would have disabled preemption while calling
the kprobe handler.  However, preemption would be disabled if this fault
was due to a kprobe, so we know the fault was not due to a kprobe
handler and can simply return failure.

This behaviour was introduced in commit a980c0ef9f6d ("x86/kprobes:
Refactor kprobes_fault() like kprobe_exceptions_notify()")

[anshuman.khandual@arm.com: export kprobe_fault_handler()]
  Link: http://lkml.kernel.org/r/1561133358-8876-1-git-send-email-anshuman.khandual@arm.com
Link: http://lkml.kernel.org/r/1560420444-25737-1-git-send-email-anshuman.khandual@arm.com
Signed-off-by: Anshuman Khandual 
Reviewed-by: Dave Hansen 
Cc: Michal Hocko 
Cc: Matthew Wilcox 
Cc: Mark Rutland 
Cc: Christophe Leroy 
Cc: Stephen Rothwell 
Cc: Andrey Konovalov 
Cc: Michael Ellerman 
Cc: Paul Mackerras 
Cc: Russell King 
Cc: Catalin Marinas 
Cc: Will Deacon 
Cc: Tony Luck 
Cc: Fenghua Yu 
Cc: Martin Schwidefsky 
Cc: Heiko Carstens 
Cc: Yoshinori Sato 
Cc: "David S. Miller" 
Cc: Thomas Gleixner 
Cc: Peter Zijlstra 
Cc: Ingo Molnar 
Cc: Andy Lutomirski 
Cc: Vineet Gupta 
Cc: James Hogan 
Cc: Paul Burton 
Cc: Ralf Baechle 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Merge branch 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace

2019-07-09T04:48:15+00:00

Pull force_sig() argument change from Eric Biederman:
 "A source of error over the years has been that force_sig has taken a
  task parameter when it is only safe to use force_sig with the current
  task.

  The force_sig function is built for delivering synchronous signals
  such as SIGSEGV where the userspace application caused a synchronous
  fault (such as a page fault) and the kernel responded with a signal.

  Because the name force_sig does not make this clear, and because the
  force_sig takes a task parameter the function force_sig has been
  abused for sending other kinds of signals over the years. Slowly those
  have been fixed when the oopses have been tracked down.

  This set of changes fixes the remaining abusers of force_sig and
  carefully rips out the task parameter from force_sig and friends
  making this kind of error almost impossible in the future"

* 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (27 commits)
  signal/x86: Move tsk inside of CONFIG_MEMORY_FAILURE in do_sigbus
  signal: Remove the signal number and task parameters from force_sig_info
  signal: Factor force_sig_info_to_task out of force_sig_info
  signal: Generate the siginfo in force_sig
  signal: Move the computation of force into send_signal and correct it.
  signal: Properly set TRACE_SIGNAL_LOSE_INFO in __send_signal
  signal: Remove the task parameter from force_sig_fault
  signal: Use force_sig_fault_to_task for the two calls that don't deliver to current
  signal: Explicitly call force_sig_fault on current
  signal/unicore32: Remove tsk parameter from __do_user_fault
  signal/arm: Remove tsk parameter from __do_user_fault
  signal/arm: Remove tsk parameter from ptrace_break
  signal/nds32: Remove tsk parameter from send_sigtrap
  signal/riscv: Remove tsk parameter from do_trap
  signal/sh: Remove tsk parameter from force_sig_info_fault
  signal/um: Remove task parameter from send_sigtrap
  signal/x86: Remove task parameter from send_sigtrap
  signal: Remove task parameter from force_sig_mceerr
  signal: Remove task parameter from force_sig
  signal: Remove task parameter from force_sigsegv
  ...

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 167

2019-05-30T18:26:39+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 version 2 of the license 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-only

has been chosen to replace the boilerplate/reference in 83 file(s).

Signed-off-by: Thomas Gleixner 
Reviewed-by: Richard Fontana 
Reviewed-by: Kate Stewart 
Reviewed-by: Allison Randal 
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070034.021731668@linutronix.de
Signed-off-by: Greg Kroah-Hartman