linux-toradex.git/arch/arm64/include/asm/kprobes.h, branch v6.10

kprobes: unify kprobes_exceptions_nofify() prototypes

2023-11-10T10:59:05+00:00

Most architectures that support kprobes declare this function in their
own asm/kprobes.h header and provide an override, but some are missing
the prototype, which causes a warning for the __weak stub implementation:

kernel/kprobes.c:1865:12: error: no previous prototype for 'kprobe_exceptions_notify' [-Werror=missing-prototypes]
 1865 | int __weak kprobe_exceptions_notify(struct notifier_block *self,

Move the prototype into linux/kprobes.h so it is visible to all
the definitions.

Link: https://lore.kernel.org/all/20231108125843.3806765-4-arnd@kernel.org/

Acked-by: Masami Hiramatsu (Google) 
Signed-off-by: Arnd Bergmann 
Signed-off-by: Masami Hiramatsu (Google)

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)

arm64: kprobes: Remove redundant kprobe_step_ctx

2020-11-10T17:12:30+00:00

The kprobe_step_ctx (kcb->ss_ctx) has ss_pending and match_addr, but
those are redundant because those can be replaced by KPROBE_HIT_SS and
&cur_kprobe->ainsn.api.insn[1] respectively.
To simplify the code, remove the kprobe_step_ctx.

Signed-off-by: Masami Hiramatsu 
Reviewed-by: Jean-Philippe Brucker 
Acked-by: Will Deacon 
Link: https://lore.kernel.org/r/20201103134900.337243-2-jean-philippe@linaro.org
Signed-off-by: Catalin Marinas

arm64: kprobes: Use BRK instead of single-step when executing instructions out-of-line

2020-11-03T14:03:38+00:00

Commit 36dadef23fcc ("kprobes: Init kprobes in early_initcall") enabled
using kprobes from early_initcall. Unfortunately at this point the
hardware debug infrastructure is not operational. The OS lock may still
be locked, and the hardware watchpoints may have unknown values when
kprobe enables debug monitors to single-step instructions.

Rather than using hardware single-step, append a BRK instruction after
the instruction to be executed out-of-line.

Fixes: 36dadef23fcc ("kprobes: Init kprobes in early_initcall")
Suggested-by: Will Deacon 
Signed-off-by: Jean-Philippe Brucker 
Acked-by: Masami Hiramatsu 
Link: https://lore.kernel.org/r/20201103134900.337243-1-jean-philippe@linaro.org
Signed-off-by: Will Deacon

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 174

2019-05-30T18:26:41+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 version 2 as
  published by the free software foundation 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

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 655 file(s).

Signed-off-by: Thomas Gleixner 
Reviewed-by: Allison Randal 
Reviewed-by: Kate Stewart 
Reviewed-by: Richard Fontana 
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070034.575739538@linutronix.de
Signed-off-by: Greg Kroah-Hartman

arm64: kprobes: Avoid calling kprobes debug handlers explicitly

2019-04-09T10:21:13+00:00

Kprobes bypasses our debug hook registration code so that it doesn't
get tangled up with recursive debug exceptions from things like lockdep:

  http://lists.infradead.org/pipermail/linux-arm-kernel/2015-February/324385.html

However, since then, (a) the hook list has become RCU protected and (b)
the kprobes hooks were found not to filter out exceptions from userspace
correctly. On top of that, the step handler is invoked directly from
single_step_handler(), which *does* use the debug hook list, so it's
clearly not the end of the world.

For now, have kprobes use the debug hook registration API like everybody
else. We can revisit this in the future if this is found to limit
coverage significantly.

Reviewed-by: Mark Rutland 
Signed-off-by: Will Deacon

arm64/kprobes: Remove jprobe implementation

2018-06-21T10:33:07+00:00

Remove arch dependent setjump/longjump functions
and unused fields in kprobe_ctlblk for jprobes
from arch/arm64.

Signed-off-by: Masami Hiramatsu 
Acked-by: Thomas Gleixner 
Acked-by: Will Deacon 
Cc: Ananth N Mavinakayanahalli 
Cc: Andrew Morton 
Cc: Catalin Marinas 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Steven Rostedt 
Cc: linux-arch@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lore.kernel.org/lkml/152942442318.15209.17767976282305601884.stgit@devbox
Signed-off-by: Ingo Molnar

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

arm64: Remove stack duplicating code from jprobes

2016-08-11T16:38:16+00:00

Because the arm64 calling standard allows stacked function arguments to be
anywhere in the stack frame, do not attempt to duplicate the stack frame for
jprobes handler functions.

Documentation changes to describe this issue have been broken out into a
separate patch in order to simultaneously address them in other
architecture(s).

Signed-off-by: David A. Long 
Acked-by: Masami Hiramatsu 
Acked-by: Marc Zyngier 
Signed-off-by: Catalin Marinas

arm64: Add trampoline code for kretprobes

2016-07-19T14:03:22+00:00

The trampoline code is used by kretprobes to capture a return from a probed
function.  This is done by saving the registers, calling the handler, and
restoring the registers. The code then returns to the original saved caller
return address. It is necessary to do this directly instead of using a
software breakpoint because the code used in processing that breakpoint
could itself be kprobe'd and cause a problematic reentry into the debug
exception handler.

Signed-off-by: William Cohen 
Signed-off-by: David A. Long 
Acked-by: Masami Hiramatsu 
[catalin.marinas@arm.com: removed unnecessary masking of the PSTATE bits]
Signed-off-by: Catalin Marinas