Commit Graph

8 Commits

Author SHA1 Message Date
Thomas Gleixner
1a59d1b8e0 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156
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 either version 2 of the license or at
  your option any later version 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-or-later

has been chosen to replace the boilerplate/reference in 1334 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070033.113240726@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:35 -07:00
Naveen N. Rao
2dea1d9c38 powerpc/uprobes: Implement arch_uretprobe_is_alive()
This helper is used to detect if a uprobe'd function has returned
through a setjmp/longjmp, rather than branching to the LR that was
updated previously by us. This fixes a SIGSEGV that gets generated when
programs use setjmp/longjmp with uretprobes.

We use the arm64 model (arch/arm64/kernel/probes/uprobes.c:
arch_uretprobe_is_alive()) for detecting when stack frames have been
removed from under us.

Reference:
https://marc.info/?l=linux-kernel&m=143748610330073
commit 7b868e4802 ("uprobes/x86: Reimplement arch_uretprobe_is_alive()")
commit db087ef69a ("uprobes/x86: Make arch_uretprobe_is_alive(RP_CHECK_CALL) more
clever")

Tested with the test program from:
https://sourceware.org/git/gitweb.cgi?p=systemtap.git;a=blob;f=testsuite/systemtap.base/bz5274.c;hb=HEAD

And this script:
    $ cat test.sh
    #!/bin/bash

    perf probe -x ./bz5274 -a bz5274_main_return=main%return
    perf probe -x ./bz5274 -a bz5274_funca_return=funca%return
    perf probe -x ./bz5274 -a bz5274_funcb_return=funcb%return
    perf probe -x ./bz5274 -a bz5274_funcc_return=funcc%return
    perf probe -x ./bz5274 -a bz5274_funcd_return=funcd%return

    perf record -e 'probe_bz5274:*' -aR ./bz5274

Reported-by: Gustavo Luiz Duarte <gduarte@redhat.com>
Reported-by: zsun@redhat.com
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-08-24 16:19:21 +10:00
Oleg Nesterov
3d78e945b6 uprobes/powerpc: Kill arch_uprobe->ainsn
powerpc has both arch_uprobe->insn and arch_uprobe->ainsn to
make the generic code happy. This is no longer needed after
the previous change, powerpc can just use "u32 insn".

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
2013-11-20 16:31:01 +01:00
Anton Arapov
f15706b79d uretprobes/powerpc: Hijack return address
Hijack the return address and replace it with a trampoline address.
PowerPC implementation.

Signed-off-by: Anton Arapov <anton@redhat.com>
Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
2013-04-13 15:31:56 +02:00
Ananth N Mavinakayanahalli
3c9eb54f71 uprobes/powerpc: Remove additional trap instruction check
prepare_uprobe() already checks if the underlying unstruction
(on file) is a trap variant. We don't need to check this again.

Signed-off-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
2013-04-04 13:57:04 +02:00
Ananth N Mavinakayanahalli
ab07e807be uprobes/powerpc: Teach uprobes to ignore gdb breakpoints
Powerpc has many trap variants that could be used by entities like gdb.
Currently, running gdb on a program being traced by uprobes causes an
endless loop since uprobes doesn't understand that the trap was inserted
by some other entity and a SIGTRAP needs to be delivered.

Teach uprobes to ignore breakpoints that do not belong to it.

Signed-off-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
2013-04-04 13:57:04 +02:00
Oleg Nesterov
65b2c8f0e5 uprobes/powerpc: Do not use arch_uprobe_*_step() helpers
No functional changes.

powerpc is the only user of arch_uprobe_enable/disable_step() helpers,
but they should die. They can not be used correctly, every arch needs
its own implementation (like x86 does). And they do not really help
even as initial-and-almost-working code, arch_uprobe_*_xol() hooks can
easily use user_enable/disable_single_step() directly.

Change arch_uprobe_*_step() to do nothing, and convert powerpc to use
ptrace helpers. This is equally wrong, powerpc needs the arch-specific
fixes.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
2012-11-03 17:15:12 +01:00
Ananth N Mavinakayanahalli
8b7b80b9eb powerpc: Uprobes port to powerpc
This is the port of uprobes to powerpc. Usage is similar to x86.

[root@xxxx ~]# ./bin/perf probe -x /lib64/libc.so.6 malloc
Added new event:
  probe_libc:malloc    (on 0xb4860)

You can now use it in all perf tools, such as:

	perf record -e probe_libc:malloc -aR sleep 1

[root@xxxx ~]# ./bin/perf record -e probe_libc:malloc -aR sleep 20
[ perf record: Woken up 22 times to write data ]
[ perf record: Captured and wrote 5.843 MB perf.data (~255302 samples) ]
[root@xxxx ~]# ./bin/perf report --stdio
...

    69.05%           tar  libc-2.12.so   [.] malloc
    28.57%            rm  libc-2.12.so   [.] malloc
     1.32%  avahi-daemon  libc-2.12.so   [.] malloc
     0.58%          bash  libc-2.12.so   [.] malloc
     0.28%          sshd  libc-2.12.so   [.] malloc
     0.08%    irqbalance  libc-2.12.so   [.] malloc
     0.05%         bzip2  libc-2.12.so   [.] malloc
     0.04%         sleep  libc-2.12.so   [.] malloc
     0.03%    multipathd  libc-2.12.so   [.] malloc
     0.01%      sendmail  libc-2.12.so   [.] malloc
     0.01%     automount  libc-2.12.so   [.] malloc

The trap_nr addition patch is a prereq.

Signed-off-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-09-05 15:35:19 +10:00