Commit Graph

18 Commits

Author SHA1 Message Date
Anshuman Khandual
b98cca444d mm, kprobes: generalize and rename notify_page_fault() as kprobe_page_fault()
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 a980c0ef9f ("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 <anshuman.khandual@arm.com>
Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: James Hogan <jhogan@kernel.org>
Cc: Paul Burton <paul.burton@mips.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-07-16 19:23:22 -07:00
Linus Torvalds
5ad18b2e60 Merge branch 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
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
  ...
2019-07-08 21:48:15 -07:00
Thomas Gleixner
873e65bc09 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 167
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 <tglx@linutronix.de>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070034.021731668@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:39 -07:00
Eric W. Biederman
3cf5d076fb signal: Remove task parameter from force_sig
All of the remaining callers pass current into force_sig so
remove the task parameter to make this obvious and to make
misuse more difficult in the future.

This also makes it clear force_sig passes current into force_sig_info.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2019-05-27 09:36:28 -05:00
Masami Hiramatsu
cce188bd58 bpf/error-inject/kprobes: Clear current_kprobe and enable preempt in kprobe
Clear current_kprobe and enable preemption in kprobe
even if pre_handler returns !0.

This simplifies function override using kprobes.

Jprobe used to require to keep the preemption disabled and
keep current_kprobe until it returned to original function
entry. For this reason kprobe_int3_handler() and similar
arch dependent kprobe handers checks pre_handler result
and exit without enabling preemption if the result is !0.

After removing the jprobe, Kprobes does not need to
keep preempt disabled even if user handler returns !0
anymore.

But since the function override handler in error-inject
and bpf is also returns !0 if it overrides a function,
to balancing the preempt count, it enables preemption
and reset current kprobe by itself.

That is a bad design that is very buggy. This fixes
such unbalanced preempt-count and current_kprobes setting
in kprobes, bpf and error-inject.

Note: for powerpc and x86, this removes all preempt_disable
from kprobe_ftrace_handler because ftrace callbacks are
called under preempt disabled.

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: James Hogan <jhogan@kernel.org>
Cc: Josef Bacik <jbacik@fb.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: linux-arch@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-ia64@vger.kernel.org
Cc: linux-mips@linux-mips.org
Cc: linux-s390@vger.kernel.org
Cc: linux-sh@vger.kernel.org
Cc: linux-snps-arc@lists.infradead.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: sparclinux@vger.kernel.org
Link: https://lore.kernel.org/lkml/152942494574.15209.12323837825873032258.stgit@devbox
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-06-21 12:33:19 +02:00
Masami Hiramatsu
9b85753da7 MIPS/kprobes: Don't call the ->break_handler() in MIPS kprobes code
Don't call the ->break_handler() from the MIPS kprobes code,
because it was only used by jprobes which got removed.

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: James Hogan <jhogan@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: linux-arch@vger.kernel.org
Cc: linux-mips@linux-mips.org
Link: https://lore.kernel.org/lkml/152942482953.15209.843924518200700137.stgit@devbox
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-06-21 12:33:16 +02:00
Masami Hiramatsu
8c2c3f2d40 MIPS/kprobes: Remove jprobe implementation
Remove arch dependent setjump/longjump functions
and unused fields in kprobe_ctlblk for jprobes
from arch/mips.

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: James Hogan <jhogan@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: linux-arch@vger.kernel.org
Cc: linux-mips@linux-mips.org
Link: https://lore.kernel.org/lkml/152942451058.15209.3459785416221980965.stgit@devbox
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-06-21 12:33:09 +02:00
Marcin Nowakowski
d05c513069 MIPS: tracing: disable uprobe/kprobe on compact branch instructions
Current instruction decoder for uprobe/kprobe handler only handles
branches with delay slots. For compact branches the behaviour is rather
unpredictable - and depending on the encoding of a compact branch
instruction may result in one (or more) of:
- executing an instruction that follows a branch which wasn't in a delay
  slot and shouldn't have been executed
- incorrectly emulating a branch leading to a jump to a wrong location
- unexpected branching out of the single-stepped code and never reaching
  the breakpoint that should terminate the probe handler

Results of these actions are generally unpredictable, but can end up
with a probed application or kernel crash, so disable placing probes on
compact branches until they are handled properly.

Signed-off-by: Marcin Nowakowski <marcin.nowakowski@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14336/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-10-06 17:37:40 +02:00
Marcin Nowakowski
e3031b3284 MIPS: tracing: move insn_has_delay_slot to a shared header
Currently both kprobes and uprobes code have definitions of the
insn_has_delay_slot method. Move it to a separate header as an inline
method that each probe-specific method can later use.
No functional change intended, although the methods slightly varied in
the constraints they set for the methods - the uprobes one was chosen as
it is slightly more specific when filtering opcode fields.

Signed-off-by: Marcin Nowakowski <marcin.nowakowski@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14335/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-10-06 17:36:39 +02:00
Christoph Lameter
35898716b4 mips: Replace __get_cpu_var uses
__get_cpu_var() is used for multiple purposes in the kernel source. One of
them is address calculation via the form &__get_cpu_var(x).  This calculates
the address for the instance of the percpu variable of the current processor
based on an offset.

Other use cases are for storing and retrieving data from the current
processors percpu area.  __get_cpu_var() can be used as an lvalue when
writing data or on the right side of an assignment.

__get_cpu_var() is defined as :

#define __get_cpu_var(var) (*this_cpu_ptr(&(var)))

__get_cpu_var() always only does an address determination. However, store
and retrieve operations could use a segment prefix (or global register on
other platforms) to avoid the address calculation.

this_cpu_write() and this_cpu_read() can directly take an offset into a
percpu area and use optimized assembly code to read and write per cpu
variables.

This patch converts __get_cpu_var into either an explicit address
calculation using this_cpu_ptr() or into a use of this_cpu operations that
use the offset.  Thereby address calculations are avoided and less registers
are used when code is generated.

At the end of the patch set all uses of __get_cpu_var have been removed so
the macro is removed too.

The patch set includes passes over all arches as well. Once these operations
are used throughout then specialized macros can be defined in non -x86
arches as well in order to optimize per cpu access by f.e.  using a global
register that may be set to the per cpu base.

Transformations done to __get_cpu_var()

1. Determine the address of the percpu instance of the current processor.

	DEFINE_PER_CPU(int, y);
	int *x = &__get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(&y);

2. Same as #1 but this time an array structure is involved.

	DEFINE_PER_CPU(int, y[20]);
	int *x = __get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(y);

3. Retrieve the content of the current processors instance of a per cpu
variable.

	DEFINE_PER_CPU(int, y);
	int x = __get_cpu_var(y)

   Converts to

	int x = __this_cpu_read(y);

4. Retrieve the content of a percpu struct

	DEFINE_PER_CPU(struct mystruct, y);
	struct mystruct x = __get_cpu_var(y);

   Converts to

	memcpy(&x, this_cpu_ptr(&y), sizeof(x));

5. Assignment to a per cpu variable

	DEFINE_PER_CPU(int, y)
	__get_cpu_var(y) = x;

   Converts to

	__this_cpu_write(y, x);

6. Increment/Decrement etc of a per cpu variable

	DEFINE_PER_CPU(int, y);
	__get_cpu_var(y)++

   Converts to

	__this_cpu_inc(y)

Cc: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2014-08-26 13:45:51 -04:00
Masami Hiramatsu
22047b8517 kprobes/mips: Fix to check double free of insn slot
Fix to check double free of insn_slot at arch_remove_kprobe
as other arches do.

Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: David Daney <ddaney@caviumnetworks.com>
Cc: Maneesh Soni <manesoni@cisco.com>
Cc: Victor Kamensky <kamensky@cisco.com>
Cc: linux-mips@linux-mips.org
Cc: Ingo Molnar <mingo@redhat.com>
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Cc: yrl.pp-manager.tt@hitachi.com
Cc: systemtap@sourceware.org
Patchwork: https://patchwork.linux-mips.org/patch/5293/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2013-05-22 12:48:30 +02:00
Linus Torvalds
aebb2afd54 Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus
Pull MIPS updates from Ralf Baechle:

 o Add basic support for the Mediatek/Ralink Wireless SoC family.

 o The Qualcomm Atheros platform is extended by support for the new
   QCA955X SoC series as well as a bunch of patches that get the code
   ready for OF support.

 o Lantiq and BCM47XX platform have a few improvements and bug fixes.

 o MIPS has sent a few patches that get the kernel ready for the
   upcoming microMIPS support.

 o The rest of the series is made up of small bug fixes and cleanups
   that relate to various parts of the MIPS code.  The biggy in there is
   a whitespace cleanup.  After I was sent another set of whitespace
   cleanup patches I decided it was the time to clean the whitespace
   "issues" for once and and that touches many files below arch/mips/.

Fix up silly conflicts, mostly due to whitespace cleanups.

* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus: (105 commits)
  MIPS: Quit exporting kernel internel break codes to uapi/asm/break.h
  MIPS: remove broken conditional inside vpe loader code
  MIPS: SMTC: fix implicit declaration of set_vi_handler
  MIPS: early_printk: drop __init annotations
  MIPS: Probe for and report hardware virtualization support.
  MIPS: ath79: add support for the Qualcomm Atheros AP136-010 board
  MIPS: ath79: add USB controller registration code for the QCA955X SoCs
  MIPS: ath79: add PCI controller registration code for the QCA955X SoCs
  MIPS: ath79: add WMAC registration code for the QCA955X SoCs
  MIPS: ath79: register UART for the QCA955X SoCs
  MIPS: ath79: add QCA955X specific glue to ath79_device_reset_{set, clear}
  MIPS: ath79: add GPIO setup code for the QCA955X SoCs
  MIPS: ath79: add IRQ handling code for the QCA955X SoCs
  MIPS: ath79: add clock setup code for the QCA955X SoCs
  MIPS: ath79: add SoC detection code for the QCA955X SoCs
  MIPS: ath79: add early printk support for the QCA955X SoCs
  MIPS: ath79: fix WMAC IRQ resource assignment
  mips: reserve elfcorehdr
  mips: Make sure kernel memory is in iomem
  MIPS: ath79: use dynamically allocated USB platform devices
  ...
2013-03-02 07:44:16 -08:00
Sasha Levin
b67bfe0d42 hlist: drop the node parameter from iterators
I'm not sure why, but the hlist for each entry iterators were conceived

        list_for_each_entry(pos, head, member)

The hlist ones were greedy and wanted an extra parameter:

        hlist_for_each_entry(tpos, pos, head, member)

Why did they need an extra pos parameter? I'm not quite sure. Not only
they don't really need it, it also prevents the iterator from looking
exactly like the list iterator, which is unfortunate.

Besides the semantic patch, there was some manual work required:

 - Fix up the actual hlist iterators in linux/list.h
 - Fix up the declaration of other iterators based on the hlist ones.
 - A very small amount of places were using the 'node' parameter, this
 was modified to use 'obj->member' instead.
 - Coccinelle didn't handle the hlist_for_each_entry_safe iterator
 properly, so those had to be fixed up manually.

The semantic patch which is mostly the work of Peter Senna Tschudin is here:

@@
iterator name hlist_for_each_entry, hlist_for_each_entry_continue, hlist_for_each_entry_from, hlist_for_each_entry_rcu, hlist_for_each_entry_rcu_bh, hlist_for_each_entry_continue_rcu_bh, for_each_busy_worker, ax25_uid_for_each, ax25_for_each, inet_bind_bucket_for_each, sctp_for_each_hentry, sk_for_each, sk_for_each_rcu, sk_for_each_from, sk_for_each_safe, sk_for_each_bound, hlist_for_each_entry_safe, hlist_for_each_entry_continue_rcu, nr_neigh_for_each, nr_neigh_for_each_safe, nr_node_for_each, nr_node_for_each_safe, for_each_gfn_indirect_valid_sp, for_each_gfn_sp, for_each_host;

type T;
expression a,c,d,e;
identifier b;
statement S;
@@

-T b;
    <+... when != b
(
hlist_for_each_entry(a,
- b,
c, d) S
|
hlist_for_each_entry_continue(a,
- b,
c) S
|
hlist_for_each_entry_from(a,
- b,
c) S
|
hlist_for_each_entry_rcu(a,
- b,
c, d) S
|
hlist_for_each_entry_rcu_bh(a,
- b,
c, d) S
|
hlist_for_each_entry_continue_rcu_bh(a,
- b,
c) S
|
for_each_busy_worker(a, c,
- b,
d) S
|
ax25_uid_for_each(a,
- b,
c) S
|
ax25_for_each(a,
- b,
c) S
|
inet_bind_bucket_for_each(a,
- b,
c) S
|
sctp_for_each_hentry(a,
- b,
c) S
|
sk_for_each(a,
- b,
c) S
|
sk_for_each_rcu(a,
- b,
c) S
|
sk_for_each_from
-(a, b)
+(a)
S
+ sk_for_each_from(a) S
|
sk_for_each_safe(a,
- b,
c, d) S
|
sk_for_each_bound(a,
- b,
c) S
|
hlist_for_each_entry_safe(a,
- b,
c, d, e) S
|
hlist_for_each_entry_continue_rcu(a,
- b,
c) S
|
nr_neigh_for_each(a,
- b,
c) S
|
nr_neigh_for_each_safe(a,
- b,
c, d) S
|
nr_node_for_each(a,
- b,
c) S
|
nr_node_for_each_safe(a,
- b,
c, d) S
|
- for_each_gfn_sp(a, c, d, b) S
+ for_each_gfn_sp(a, c, d) S
|
- for_each_gfn_indirect_valid_sp(a, c, d, b) S
+ for_each_gfn_indirect_valid_sp(a, c, d) S
|
for_each_host(a,
- b,
c) S
|
for_each_host_safe(a,
- b,
c, d) S
|
for_each_mesh_entry(a,
- b,
c, d) S
)
    ...+>

[akpm@linux-foundation.org: drop bogus change from net/ipv4/raw.c]
[akpm@linux-foundation.org: drop bogus hunk from net/ipv6/raw.c]
[akpm@linux-foundation.org: checkpatch fixes]
[akpm@linux-foundation.org: fix warnings]
[akpm@linux-foudnation.org: redo intrusive kvm changes]
Tested-by: Peter Senna Tschudin <peter.senna@gmail.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-27 19:10:24 -08:00
Ralf Baechle
7034228792 MIPS: Whitespace cleanup.
Having received another series of whitespace patches I decided to do this
once and for all rather than dealing with this kind of patches trickling
in forever.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2013-02-01 10:00:22 +01:00
Maneesh Soni
6457a396bb MIPS Kprobes: Support branch instructions probing
This patch provides support for kprobes on branch instructions. The branch
instruction at the probed address is actually emulated and not executed
out-of-line like other normal instructions. Instead the delay-slot instruction
is copied and single stepped out of line.

At the time of probe hit, the original branch instruction is evaluated
and the target cp0_epc is computed similar to compute_retrun_epc(). It
is also checked if the delay slot instruction can be skipped, which is
true if there is a NOP in delay slot or branch is taken in case of
branch likely instructions. Once the delay slot instruction is single
stepped the normal execution resume with the cp0_epc updated the earlier
computed cp0_epc as per the branch instructions.

Signed-off-by: Maneesh Soni <manesoni@cisco.com>
Signed-off-by: Victor Kamensky <kamensky@cisco.com>
Cc: David Daney <david.daney@cavium.com>
Cc: ananth@in.ibm.com
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/2914/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2011-12-07 22:04:03 +00:00
Maneesh Soni
9233c1ee71 MIPS Kprobes: Deny probes on ll/sc instructions
As ll/sc instruction are for atomic read-modify-write operations, allowing
probes on top of these insturctions is a bad idea.

Signed-off-by: Victor Kamensky <kamensky@cisco.com>
Signed-off-by: Maneesh Soni <manesoni@cisco.com>
Cc: David Daney <david.daney@cavium.com>
Cc: ananth@in.ibm.com
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/2912/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2011-12-07 22:04:03 +00:00
Maneesh Soni
41dde781f5 MIPS Kprobes: Fix OOPS in arch_prepare_kprobe()
This patch fixes the arch_prepare_kprobe() on MIPS when it tries to find the
instruction at the previous address to the probed address. The oops happens
when the probed address is the first address in a kernel module and there is
no previous address. The patch uses probe_kernel_read() to safely read the
previous instruction.

CPU 3 Unable to handle kernel paging request at virtual address ffffffffc0211ffc, epc == ffffffff81113204, ra == ffffffff8111511c
Oops[#1]:
Cpu 3
$ 0   : 0000000000000000 0000000000000001 ffffffffc0212000 0000000000000000
$ 4   : ffffffffc0220030 0000000000000000 0000000000000adf ffffffff81a3f898
$ 8   : ffffffffc0220030 ffffffffffffffff 000000000000ffff 0000000000004821
$12   : 000000000000000a ffffffff81105ddc ffffffff812927d0 0000000000000000
$16   : ffffffff81a40000 ffffffffc0220030 ffffffffc0220030 ffffffffc0212660
$20   : 0000000000000000 0000000000000008 efffffffffffffff ffffffffc0220000
$24   : 0000000000000002 ffffffff8139f5b0
$28   : a800000072adc000 a800000072adfca0 ffffffffc0220000 ffffffff8111511c
Hi    : 0000000000000000
Lo    : 0000000000000000
epc   : ffffffff81113204 arch_prepare_kprobe+0x1c/0xe8
    Tainted: P
ra    : ffffffff8111511c register_kprobe+0x33c/0x730
Status: 10008ce3    KX SX UX KERNEL EXL IE
Cause : 00800008
BadVA : ffffffffc0211ffc
PrId  : 000d9008 (Cavium Octeon II)
Modules linked in: bpa_mem crashinfo pds tun cpumem ipv6 exportfs nfsd OOBnd(P) OOBhal(P) cvmx_mdio cvmx_gpio aipcmod(P) mtsmod procfs(P) utaker_mod dplr_pci hello atomicm_foo [last unloaded: sysmgr_hb]
Process stapio (pid: 5603, threadinfo=a800000072adc000, task=a8000000722e0438, tls=000000002b4bcda0)
Stack : ffffffff81a40000 ffffffff81a40000 ffffffffc0220030 ffffffff8111511c
        ffffffffc0218008 0000000000000001 ffffffffc0218008 0000000000000001
        ffffffffc0220000 ffffffffc021efe8 1000000000000000 0000000000000008
        efffffffffffffff ffffffffc0220000 ffffffffc0220000 ffffffffc021d500
        0000000000000022 0000000000000002 1111000072be02b8 0000000000000000
        00000000000015e6 00000000000015e6 00000000007d0f00 a800000072be02b8
        0000000000000000 ffffffff811d16c8 a80000000382e3b0 ffffffff811d5ba0
        ffffffff81b0a270 ffffffff81b0a270 ffffffffc0212000 0000000000000013
        ffffffffc0220030 ffffffffc021ed00 a800000089114c80 000000007f90d590
        a800000072adfe38 a800000089114c80 0000000010020000 0000000010020000
        ...
Call Trace:
[<ffffffff81113204>] arch_prepare_kprobe+0x1c/0xe8
[<ffffffff8111511c>] register_kprobe+0x33c/0x730
[<ffffffffc021d500>] _stp_ctl_write_cmd+0x8e8/0xa88 [atomicm_foo]
[<ffffffff812925cc>] vfs_write+0xb4/0x178
[<ffffffff81292828>] SyS_write+0x58/0x148
[<ffffffff81103844>] handle_sysn32+0x44/0x84

Code: ffb20010  ffb00000  dc820028 <8c44fffc> 8c500000  0c4449e0  0004203c  14400029  3c048199

Signed-off-by: Maneesh Soni <manesoni@cisco.com>
Signed-off-by: Victor Kamensky <kamensky@cisco.com>
Cc: David Daney <david.daney@cavium.com>
Cc: ananth@in.ibm.com
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/2915/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2011-12-07 22:04:03 +00:00
David Daney
c1bf207d6e MIPS: kprobe: Add support.
This patch is based on previous work by Sony and Himanshu Chauhan.

I have done some cleanup and implemented JProbes and KRETPROBES.  The
KRETPROBES part is pretty much copied verbatim from powerpc.  A possible
future enhance might be to factor out the common code.

Signed-off-by: David Daney <ddaney@caviumnetworks.com>
Cc: Himanshu Chauhan <hschauhan@nulltrace.org>
To: linux-mips@linux-mips.org
To: ananth@in.ibm.com,
To: anil.s.keshavamurthy@intel.com
To: davem@davemloft.net
To: masami.hiramatsu.pt@hitachi.com
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/1525/
Patchwork: https://patchwork.linux-mips.org/patch/1530/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2010-08-05 13:26:29 +01:00