14 Nov, 2018
1 commit
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[ 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
05 Sep, 2018
1 commit
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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
10 Dec, 2017
1 commit
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[ Upstream commit a30b85df7d599f626973e9cd3056fe755bd778e0 ]
We want to wait for all potentially preempted kprobes trampoline
execution to have completed. This guarantees that any freed
trampoline memory is not in use by any task in the system anymore.
synchronize_rcu_tasks() gives such a guarantee, so use it.Also, this guarantees to wait for all potentially preempted tasks
on the instructions which will be replaced with a jump.Since this becomes a problem only when CONFIG_PREEMPT=y, enable
CONFIG_TASKS_RCU=y for synchronize_rcu_tasks() in that case.Signed-off-by: Masami Hiramatsu
Acked-by: Paul E. McKenney
Cc: Ananth N Mavinakayanahalli
Cc: Linus Torvalds
Cc: Naveen N . Rao
Cc: Paul E . McKenney
Cc: Peter Zijlstra
Cc: Steven Rostedt
Cc: Thomas Gleixner
Link: http://lkml.kernel.org/r/150845661962.5443.17724352636247312231.stgit@devbox
Signed-off-by: Ingo Molnar
Signed-off-by: Sasha Levin
Signed-off-by: Greg Kroah-Hartman
08 Jul, 2017
3 commits
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Similar to commit 90ec5e89e393c ("kretprobes: Ensure probe location is
at function entry"), ensure that the jprobe probepoint is at function
entry.Signed-off-by: Naveen N. Rao
Cc: Ananth N Mavinakayanahalli
Cc: Linus Torvalds
Cc: Masami Hiramatsu
Cc: Peter Zijlstra
Cc: Thomas Gleixner
Link: http://lkml.kernel.org/r/a4525af6c5a42df385efa31251246cf7cca73598.1499443367.git.naveen.n.rao@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar -
Re-factor jprobe registration functions as the current version is
getting too unwieldy. Move the actual jprobe registration to
register_jprobe() and re-organize code accordingly.Suggested-by: Ingo Molnar
Signed-off-by: Naveen N. Rao
Cc: Ananth N Mavinakayanahalli
Cc: Linus Torvalds
Cc: Masami Hiramatsu
Cc: Peter Zijlstra
Cc: Thomas Gleixner
Link: http://lkml.kernel.org/r/089cae4bfe73767f765291ee0e6fb0c3d240e5f1.1499443367.git.naveen.n.rao@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar -
Rename function_offset_within_entry() to scope it to kprobe namespace by
using kprobe_ prefix, and to also simplify it.Suggested-by: Ingo Molnar
Suggested-by: Masami Hiramatsu
Signed-off-by: Naveen N. Rao
Cc: Ananth N Mavinakayanahalli
Cc: Linus Torvalds
Cc: Peter Zijlstra
Cc: Thomas Gleixner
Link: http://lkml.kernel.org/r/3aa6c7e2e4fb6e00f3c24fa306496a66edb558ea.1499443367.git.naveen.n.rao@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar
04 Jul, 2017
1 commit
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Pull SMP hotplug updates from Thomas Gleixner:
"This update is primarily a cleanup of the CPU hotplug locking code.The hotplug locking mechanism is an open coded RWSEM, which allows
recursive locking. The main problem with that is the recursive nature
as it evades the full lockdep coverage and hides potential deadlocks.The rework replaces the open coded RWSEM with a percpu RWSEM and
establishes full lockdep coverage that way.The bulk of the changes fix up recursive locking issues and address
the now fully reported potential deadlocks all over the place. Some of
these deadlocks have been observed in the RT tree, but on mainline the
probability was low enough to hide them away."* 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (37 commits)
cpu/hotplug: Constify attribute_group structures
powerpc: Only obtain cpu_hotplug_lock if called by rtasd
ARM/hw_breakpoint: Fix possible recursive locking for arch_hw_breakpoint_init
cpu/hotplug: Remove unused check_for_tasks() function
perf/core: Don't release cred_guard_mutex if not taken
cpuhotplug: Link lock stacks for hotplug callbacks
acpi/processor: Prevent cpu hotplug deadlock
sched: Provide is_percpu_thread() helper
cpu/hotplug: Convert hotplug locking to percpu rwsem
s390: Prevent hotplug rwsem recursion
arm: Prevent hotplug rwsem recursion
arm64: Prevent cpu hotplug rwsem recursion
kprobes: Cure hotplug lock ordering issues
jump_label: Reorder hotplug lock and jump_label_lock
perf/tracing/cpuhotplug: Fix locking order
ACPI/processor: Use cpu_hotplug_disable() instead of get_online_cpus()
PCI: Replace the racy recursion prevention
PCI: Use cpu_hotplug_disable() instead of get_online_cpus()
perf/x86/intel: Drop get_online_cpus() in intel_snb_check_microcode()
x86/perf: Drop EXPORT of perf_check_microcode
...
27 May, 2017
1 commit
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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)
26 May, 2017
1 commit
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Converting the cpu hotplug locking to a percpu rwsem unearthed hidden lock
ordering problems.There is a wide range of locks involved in this: kprobe_mutex,
jump_label_mutex, ftrace_lock, text_mutex, event_mutex, module_mutex,
func_hash->regex_lock and a gazillion of lock order permutations with
nested get_online_cpus() calls.Some of those permutations are potential deadlocks even with the current
nesting hotplug locking scheme, but they can't be discovered by lockdep.The conversion of the hotplug locking to a percpu rwsem requires to prevent
nested locking, so it's required to take the hotplug rwsem early in the
call chain and establish a proper lock order.After quite some analysis and going down the wrong road severa times the
following lock order has been chosen:kprobe_mutex -> cpus_rwsem -> jump_label_mutex -> text_mutex
For kprobes which hook on an ftrace function trace point, it's required to
drop cpus_rwsem before calling into the ftrace code to avoid a deadlock on
the func_hash->regex_lock.[ Steven: Ftrace interaction fixes ]
Signed-off-by: Thomas Gleixner
Signed-off-by: Steven Rostedt
Signed-off-by: Thomas Gleixner
Acked-by: Ingo Molnar
Acked-by: Masami Hiramatsu
Cc: Paul E. McKenney
Cc: Peter Zijlstra
Cc: Sebastian Siewior
Link: http://lkml.kernel.org/r/20170524081549.104864779@linutronix.de
18 May, 2017
2 commits
-
Thomas discovered a bug where the kprobe trace tests had a race
condition where the kprobe_optimizer called from a delayed work queue
that does the optimizing and "unoptimizing" of a kprobe, can try to
modify the text after it has been freed by the init code.The kprobe trace selftest is a special case, and Thomas and myself
investigated to see if there's a chance that this could also be a bug
with module unloading, as the code is not obvious to how it handles
this. After adding lots of printks, I figured it out. Thomas suggested
that this should be commented so that others will not have to go
through this exercise again.Link: http://lkml.kernel.org/r/20170516145835.3827d3aa@gandalf.local.home
Acked-by: Masami Hiramatsu
Suggested-by: Thomas Gleixner
Signed-off-by: Steven Rostedt (VMware) -
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
Cc: stable@vger.kernel.org
Fixes: 6274de498 ("kprobes: Support delayed unoptimizing")
Signed-off-by: Steven Rostedt (VMware)
06 May, 2017
1 commit
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Pull powerpc updates from Michael Ellerman:
"Highlights include:- Larger virtual address space on 64-bit server CPUs. By default we
use a 128TB virtual address space, but a process can request access
to the full 512TB by passing a hint to mmap().- Support for the new Power9 "XIVE" interrupt controller.
- TLB flushing optimisations for the radix MMU on Power9.
- Support for CAPI cards on Power9, using the "Coherent Accelerator
Interface Architecture 2.0".- The ability to configure the mmap randomisation limits at build and
runtime.- Several small fixes and cleanups to the kprobes code, as well as
support for KPROBES_ON_FTRACE.- Major improvements to handling of system reset interrupts,
correctly treating them as NMIs, giving them a dedicated stack and
using a new hypervisor call to trigger them, all of which should
aid debugging and robustness.- Many fixes and other minor enhancements.
Thanks to: Alastair D'Silva, Alexey Kardashevskiy, Alistair Popple,
Andrew Donnellan, Aneesh Kumar K.V, Anshuman Khandual, Anton
Blanchard, Balbir Singh, Ben Hutchings, Benjamin Herrenschmidt,
Bhupesh Sharma, Chris Packham, Christian Zigotzky, Christophe Leroy,
Christophe Lombard, Daniel Axtens, David Gibson, Gautham R. Shenoy,
Gavin Shan, Geert Uytterhoeven, Guilherme G. Piccoli, Hamish Martin,
Hari Bathini, Kees Cook, Laurent Dufour, Madhavan Srinivasan, Mahesh J
Salgaonkar, Mahesh Salgaonkar, Masami Hiramatsu, Matt Brown, Matthew
R. Ochs, Michael Neuling, Naveen N. Rao, Nicholas Piggin, Oliver
O'Halloran, Pan Xinhui, Paul Mackerras, Rashmica Gupta, Russell
Currey, Sukadev Bhattiprolu, Thadeu Lima de Souza Cascardo, Tobin C.
Harding, Tyrel Datwyler, Uma Krishnan, Vaibhav Jain, Vipin K Parashar,
Yang Shi"* tag 'powerpc-4.12-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (214 commits)
powerpc/64s: Power9 has no LPCR[VRMASD] field so don't set it
powerpc/powernv: Fix TCE kill on NVLink2
powerpc/mm/radix: Drop support for CPUs without lockless tlbie
powerpc/book3s/mce: Move add_taint() later in virtual mode
powerpc/sysfs: Move #ifdef CONFIG_HOTPLUG_CPU out of the function body
powerpc/smp: Document irq enable/disable after migrating IRQs
powerpc/mpc52xx: Don't select user-visible RTAS_PROC
powerpc/powernv: Document cxl dependency on special case in pnv_eeh_reset()
powerpc/eeh: Clean up and document event handling functions
powerpc/eeh: Avoid use after free in eeh_handle_special_event()
cxl: Mask slice error interrupts after first occurrence
cxl: Route eeh events to all drivers in cxl_pci_error_detected()
cxl: Force context lock during EEH flow
powerpc/64: Allow CONFIG_RELOCATABLE if COMPILE_TEST
powerpc/xmon: Teach xmon oops about radix vectors
powerpc/mm/hash: Fix off-by-one in comment about kernel contexts ids
powerpc/pseries: Enable VFIO
powerpc/powernv: Fix iommu table size calculation hook for small tables
powerpc/powernv: Check kzalloc() return value in pnv_pci_table_alloc
powerpc: Add arch/powerpc/tools directory
...
20 Apr, 2017
3 commits
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commit 239aeba76409 ("perf powerpc: Fix kprobe and kretprobe handling with
kallsyms on ppc64le") changed how we use the offset field in struct kprobe on
ABIv2. perf now offsets from the global entry point if an offset is specified
and otherwise chooses the local entry point.Fix the same in kernel for kprobe API users. We do this by extending
kprobe_lookup_name() to accept an additional parameter to indicate the offset
specified with the kprobe registration. If offset is 0, we return the local
function entry and return the global entry point otherwise.With:
# cd /sys/kernel/debug/tracing/
# echo "p _do_fork" >> kprobe_events
# echo "p _do_fork+0x10" >> kprobe_eventsbefore this patch:
# cat ../kprobes/list
c0000000000d0748 k _do_fork+0x8 [DISABLED]
c0000000000d0758 k _do_fork+0x18 [DISABLED]
c0000000000412b0 k kretprobe_trampoline+0x0 [OPTIMIZED]and after:
# cat ../kprobes/list
c0000000000d04c8 k _do_fork+0x8 [DISABLED]
c0000000000d04d0 k _do_fork+0x10 [DISABLED]
c0000000000412b0 k kretprobe_trampoline+0x0 [OPTIMIZED]Acked-by: Ananth N Mavinakayanahalli
Signed-off-by: Naveen N. Rao
Signed-off-by: Michael Ellerman -
The macro is now pretty long and ugly on powerpc. In the light of further
changes needed here, convert it to a __weak variant to be over-ridden with a
nicer looking function.Suggested-by: Masami Hiramatsu
Acked-by: Masami Hiramatsu
Signed-off-by: Naveen N. Rao
Signed-off-by: Michael Ellerman -
Skip preparing optprobe if the probe is ftrace-based, since anyway, it
must not be optimized (or already optimized by ftrace).Tested-by: Naveen N. Rao
Signed-off-by: Masami Hiramatsu
Signed-off-by: Michael Ellerman
16 Mar, 2017
1 commit
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perf specifies an offset from _text and since this offset is fed
directly into the arch-specific helper, kprobes tracer rejects
installation of kretprobes through perf. Fix this by looking up the
actual offset from a function for the specified sym+offset.Refactor and reuse existing routines to limit code duplication -- we
repurpose kprobe_addr() for determining final kprobe address and we
split out the function entry offset determination into a separate
generic helper.Before patch:
naveen@ubuntu:~/linux/tools/perf$ sudo ./perf probe -v do_open%return
probe-definition(0): do_open%return
symbol:do_open file:(null) line:0 offset:0 return:1 lazy:(null)
0 arguments
Looking at the vmlinux_path (8 entries long)
Using /boot/vmlinux for symbols
Open Debuginfo file: /boot/vmlinux
Try to find probe point from debuginfo.
Matched function: do_open [2d0c7ff]
Probe point found: do_open+0
Matched function: do_open [35d76dc]
found inline addr: 0xc0000000004ba9c4
Failed to find "do_open%return",
because do_open is an inlined function and has no return point.
An error occurred in debuginfo analysis (-22).
Trying to use symbols.
Opening /sys/kernel/debug/tracing//README write=0
Opening /sys/kernel/debug/tracing//kprobe_events write=1
Writing event: r:probe/do_open _text+4469776
Failed to write event: Invalid argument
Error: Failed to add events. Reason: Invalid argument (Code: -22)
naveen@ubuntu:~/linux/tools/perf$ dmesg | tail
[ 33.568656] Given offset is not valid for return probe.After patch:
naveen@ubuntu:~/linux/tools/perf$ sudo ./perf probe -v do_open%return
probe-definition(0): do_open%return
symbol:do_open file:(null) line:0 offset:0 return:1 lazy:(null)
0 arguments
Looking at the vmlinux_path (8 entries long)
Using /boot/vmlinux for symbols
Open Debuginfo file: /boot/vmlinux
Try to find probe point from debuginfo.
Matched function: do_open [2d0c7d6]
Probe point found: do_open+0
Matched function: do_open [35d76b3]
found inline addr: 0xc0000000004ba9e4
Failed to find "do_open%return",
because do_open is an inlined function and has no return point.
An error occurred in debuginfo analysis (-22).
Trying to use symbols.
Opening /sys/kernel/debug/tracing//README write=0
Opening /sys/kernel/debug/tracing//kprobe_events write=1
Writing event: r:probe/do_open _text+4469808
Writing event: r:probe/do_open_1 _text+4956344
Added new events:
probe:do_open (on do_open%return)
probe:do_open_1 (on do_open%return)You can now use it in all perf tools, such as:
perf record -e probe:do_open_1 -aR sleep 1
naveen@ubuntu:~/linux/tools/perf$ sudo cat /sys/kernel/debug/kprobes/list
c000000000041370 k kretprobe_trampoline+0x0 [OPTIMIZED]
c0000000004ba0b8 r do_open+0x8 [DISABLED]
c000000000443430 r do_open+0x0 [DISABLED]Signed-off-by: Naveen N. Rao
Acked-by: Masami Hiramatsu
Cc: Ananth N Mavinakayanahalli
Cc: Michael Ellerman
Cc: Steven Rostedt
Cc: linuxppc-dev@lists.ozlabs.org
Link: http://lkml.kernel.org/r/d8cd1ef420ec22e3643ac332fdabcffc77319a42.1488961018.git.naveen.n.rao@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo
15 Mar, 2017
1 commit
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commit fc62d0207ae0 ("kprobes: Introduce weak variant of
kprobe_exceptions_notify()") used the __kprobes annotation to exclude
kprobe_exceptions_notify from being probed. Since NOKPROBE_SYMBOL() is a
better way to do this enabling the symbol to be discovered as being
blacklisted, change over to using NOKPROBE_SYMBOL().Signed-off-by: Naveen N. Rao
Acked-by: Masami Hiramatsu
Cc: Ananth N Mavinakayanahalli
Link: http://lkml.kernel.org/r/3f25bf400da5c222cd9b10eec6ded2d6b58209f8.1488991670.git.naveen.n.rao@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo
04 Mar, 2017
1 commit
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kretprobes can be registered by specifying an absolute address or by
specifying offset to a symbol. However, we need to ensure this falls at
function entry so as to be able to determine the return address.Validate the same during kretprobe registration. By default, there
should not be any offset from a function entry, as determined through a
kallsyms_lookup(). Introduce arch_function_offset_within_entry() as a
way for architectures to override this.Signed-off-by: Naveen N. Rao
Acked-by: Masami Hiramatsu
Cc: Ananth N Mavinakayanahalli
Cc: Michael Ellerman
Cc: Steven Rostedt
Cc: linuxppc-dev@lists.ozlabs.org
Link: http://lkml.kernel.org/r/f1583bc4839a3862cfc2acefcc56f9c8837fa2ba.1487770934.git.naveen.n.rao@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo
23 Feb, 2017
1 commit
-
Pull powerpc updates from Michael Ellerman:
"Highlights include:- Support for direct mapped LPC on POWER9, giving Linux direct access
to devices that may be on there such as a UART.- Memory hotplug support for the Power9 Radix MMU.
- Add new AUX vectors describing the processor's cache geometry, to
be used by glibc.- The ability for a guest to ask the hypervisor to resize the guest's
hash table, and in addition support for doing so automatically when
memory is hotplugged into/out-of the guest. This allows the hash
table to be sized based on the current memory usage of the guest,
rather than the maximum possible memory usage.- Implementation of optprobes (kprobe optimisation) for powerpc.
In addition there's the topic branch shared with the KVM tree, which
includes support for guests to use the Radix MMU on Power9.Thanks to:
Alistair Popple, Andrew Donnellan, Aneesh Kumar K.V, Anju T, Anton
Blanchard, Benjamin Herrenschmidt, Chris Packham, Daniel Axtens,
Daniel Borkmann, David Gibson, Finn Thain, Gautham R. Shenoy, Gavin
Shan, Greg Kurz, Joel Stanley, John Allen, Madhavan Srinivasan,
Mahesh Salgaonkar, Markus Elfring, Michael Neuling, Nathan Fontenot,
Naveen N. Rao, Nicholas Piggin, Paul Mackerras, Ravi Bangoria, Reza
Arbab, Shailendra Singh, Vaibhav Jain, Wei Yongjun"* tag 'powerpc-4.11-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (129 commits)
powerpc/mm/radix: Skip ptesync in pte update helpers
powerpc/mm/radix: Use ptep_get_and_clear_full when clearing pte for full mm
powerpc/mm/radix: Update pte update sequence for pte clear case
powerpc/mm: Update PROTFAULT handling in the page fault path
powerpc/xmon: Fix data-breakpoint
powerpc/mm: Fix build break with BOOK3S_64=n and MEMORY_HOTPLUG=y
powerpc/mm: Fix build break when CMA=n && SPAPR_TCE_IOMMU=y
powerpc/mm: Fix build break with RADIX=y & HUGETLBFS=n
powerpc/pseries: Fix typo in parameter description
powerpc/kprobes: Remove kprobe_exceptions_notify()
kprobes: Introduce weak variant of kprobe_exceptions_notify()
powerpc/ftrace: Fix confusing help text for DISABLE_MPROFILE_KERNEL
powerpc/powernv: Fix opal_exit tracepoint opcode
powerpc: Add a prototype for mcount() so it can be versioned
powerpc: Drop GPL from of_node_to_nid() export to match other arches
powerpc/kprobes: Optimize kprobe in kretprobe_trampoline()
powerpc/kprobes: Implement Optprobes
powerpc/kprobes: Fixes for kprobe_lookup_name() on BE
powerpc: Add helper to check if offset is within relative branch range
powerpc/bpf: Introduce __PPC_SH64()
...
10 Feb, 2017
1 commit
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kprobe_exceptions_notify() is not used on some of the architectures such
as arm[64] and powerpc anymore. Introduce a weak variant for such
architectures.Signed-off-by: Naveen N. Rao
Acked-by: Masami Hiramatsu
Signed-off-by: Michael Ellerman
14 Jan, 2017
1 commit
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Improve __kernel_text_address()/kernel_text_address() to return
true if the given address is on a kprobe's instruction slot
trampoline.This can help stacktraces to determine the address is on a
text area or not.To implement this atomically in is_kprobe_*_slot(), also change
the insn_cache page list to an RCU list.This changes timings a bit (it delays page freeing to the RCU garbage
collection phase), but none of that is in the hot path.Note: this change can add small overhead to stack unwinders because
it adds 2 additional checks to __kernel_text_address(). However, the
impact should be very small, because kprobe_insn_pages list has 1 entry
per 256 probes(on x86, on arm/arm64 it will be 1024 probes),
and kprobe_optinsn_pages has 1 entry per 32 probes(on x86).
In most use cases, the number of kprobe events may be less
than 20, which means that is_kprobe_*_slot() will check just one entry.Tested-by: Josh Poimboeuf
Signed-off-by: Masami Hiramatsu
Acked-by: Peter Zijlstra
Cc: Alexander Shishkin
Cc: Ananth N Mavinakayanahalli
Cc: Andrew Morton
Cc: Andrey Konovalov
Cc: Arnaldo Carvalho de Melo
Cc: Jiri Olsa
Cc: Linus Torvalds
Cc: Thomas Gleixner
Link: http://lkml.kernel.org/r/148388747896.6869.6354262871751682264.stgit@devbox
[ Improved the changelog and coding style. ]
Signed-off-by: Ingo Molnar
25 Dec, 2016
1 commit
-
This was entirely automated, using the script by Al:
PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*'
sed -i -e "s!$PATT!#include !" \
$(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h)to do the replacement at the end of the merge window.
Requested-by: Al Viro
Signed-off-by: Linus Torvalds
12 Oct, 2016
1 commit
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asm-generic headers are generic implementations for architecture specific
code and should not be included by common code. Thus use the asm/ version
of sections.h to get at the linker sections.Link: http://lkml.kernel.org/r/1473602302-6208-1-git-send-email-hch@lst.de
Signed-off-by: Christoph Hellwig
Acked-by: Masami Hiramatsu
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
04 Aug, 2015
1 commit
-
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
14 Feb, 2015
2 commits
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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 -
In original code, the probed instruction doesn't get optimized after
echo 0 > /sys/kernel/debug/kprobes/enabled
echo 1 > /sys/kernel/debug/kprobes/enabledThis 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
13 Feb, 2015
1 commit
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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
...
20 Jan, 2015
1 commit
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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
14 Jan, 2015
1 commit
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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
12 Dec, 2014
1 commit
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Pull s390 updates from Martin Schwidefsky:
"The most notable change for this pull request is the ftrace rework
from Heiko. It brings a small performance improvement and the ground
work to support a new gcc option to replace the mcount blocks with a
single nop.Two new s390 specific system calls are added to emulate user space
mmio for PCI, an artifact of the how PCI memory is accessed.Two patches for the memory management with changes to common code.
For KVM mm_forbids_zeropage is added which disables the empty zero
page for an mm that is used by a KVM process. And an optimization,
pmdp_get_and_clear_full is added analog to ptep_get_and_clear_full.Some micro optimization for the cmpxchg and the spinlock code.
And as usual bug fixes and cleanups"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (46 commits)
s390/cputime: fix 31-bit compile
s390/scm_block: make the number of reqs per HW req configurable
s390/scm_block: handle multiple requests in one HW request
s390/scm_block: allocate aidaw pages only when necessary
s390/scm_block: use mempool to manage aidaw requests
s390/eadm: change timeout value
s390/mm: fix memory leak of ptlock in pmd_free_tlb
s390: use local symbol names in entry[64].S
s390/ptrace: always include vector registers in core files
s390/simd: clear vector register pointer on fork/clone
s390: translate cputime magic constants to macros
s390/idle: convert open coded idle time seqcount
s390/idle: add missing irq off lockdep annotation
s390/debug: avoid function call for debug_sprintf_*
s390/kprobes: fix instruction copy for out of line execution
s390: remove diag 44 calls from cpu_relax()
s390/dasd: retry partition detection
s390/dasd: fix list corruption for sleep_on requests
s390/dasd: fix infinite term I/O loop
s390/dasd: remove unused code
...
22 Nov, 2014
1 commit
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Add FTRACE_OPS_FL_IPMODIFY flag to kprobe_ftrace_ops
since kprobes can changes regs->ip.Link: http://lkml.kernel.org/r/20141121102523.11844.21298.stgit@localhost.localdomain
Signed-off-by: Masami Hiramatsu
Signed-off-by: Steven Rostedt
27 Oct, 2014
1 commit
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Introduce weak arch_check_ftrace_location() helper function which
architectures can override in order to implement handling of kprobes
on function tracer call sites on their own, without depending on
common code or implementing the KPROBES_ON_FTRACE feature.Signed-off-by: Heiko Carstens
Acked-by: Masami Hiramatsu
Acked-by: Steven Rostedt
Signed-off-by: Martin Schwidefsky
08 Aug, 2014
1 commit
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Skip kretprobe hit in NMI context, because if an NMI happens
inside the critical section protected by kretprobe_table.lock
and another(or same) kretprobe hit, pre_kretprobe_handler
tries to lock kretprobe_table.lock again.
Normal interrupts have no problem because they are disabled
with the lock.Signed-off-by: Masami Hiramatsu
Acked-by: Ananth N Mavinakayanahalli
Cc: David S. Miller
Link: http://lkml.kernel.org/r/20140804031016.11433.65539.stgit@kbuild-fedora.novalocal
[ Minor edits for clarity. ]
Signed-off-by: Ingo Molnar
18 Jul, 2014
1 commit
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On ia64 and ppc64, function pointers do not point to the
entry address of the function, but to the address of a
function descriptor (which contains the entry address and misc
data).Since the kprobes code passes the function pointer stored
by NOKPROBE_SYMBOL() to kallsyms_lookup_size_offset() for
initalizing its blacklist, it fails and reports many errors,
such as:Failed to find blacklist 0001013168300000
Failed to find blacklist 0001013000f0a000
[...]To fix this bug, use arch_deref_entry_point() to get the
function entry address for kallsyms_lookup_size_offset()
instead of the raw function pointer.Suzuki also pointed out that blacklist entries should also
be updated as well.Reported-by: Tony Luck
Fixed-by: Suzuki K. Poulose
Tested-by: Tony Luck
Tested-by: Michael Ellerman
Signed-off-by: Masami Hiramatsu
Acked-by: Michael Ellerman (for powerpc)
Acked-by: Benjamin Herrenschmidt
Cc: Jeremy Fitzhardinge
Cc: sparse@chrisli.org
Cc: Paul Mackerras
Cc: akataria@vmware.com
Cc: anil.s.keshavamurthy@intel.com
Cc: Fenghua Yu
Cc: Arnd Bergmann
Cc: Rusty Russell
Cc: Chris Wright
Cc: yrl.pp-manager.tt@hitachi.com
Cc: Kevin Hao
Cc: Ananth N Mavinakayanahalli
Cc: rdunlap@infradead.org
Cc: dl9pf@gmx.de
Cc: Linus Torvalds
Cc: David S. Miller
Cc: linux-ia64@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Link: http://lkml.kernel.org/r/20140717114411.13401.2632.stgit@kbuild-fedora.novalocal
Signed-off-by: Ingo Molnar
24 Apr, 2014
5 commits
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Show blacklist entries (function names with the address
range) via /sys/kernel/debug/kprobes/blacklist.Note that at this point the blacklist supports only
in vmlinux, not module. So the list is fixed and
not updated.Signed-off-by: Masami Hiramatsu
Cc: Ananth N Mavinakayanahalli
Cc: Anil S Keshavamurthy
Cc: David S. Miller
Link: http://lkml.kernel.org/r/20140417081849.26341.11609.stgit@ltc230.yrl.intra.hitachi.co.jp
Signed-off-by: Ingo Molnar -
Use NOKPROBE_SYMBOL macro to protect functions from
kprobes instead of __kprobes annotation.Signed-off-by: Masami Hiramatsu
Reviewed-by: Steven Rostedt
Cc: Ananth N Mavinakayanahalli
Cc: Anil S Keshavamurthy
Cc: David S. Miller
Link: http://lkml.kernel.org/r/20140417081821.26341.40362.stgit@ltc230.yrl.intra.hitachi.co.jp
Signed-off-by: Ingo Molnar -
There is no need to prohibit probing on the functions
used for preparation, registeration, optimization,
controll etc. Those are safely probed because those are
not invoked from breakpoint/fault/debug handlers,
there is no chance to cause recursive exceptions.Following functions are now removed from the kprobes blacklist:
add_new_kprobe
aggr_kprobe_disabled
alloc_aggr_kprobe
alloc_aggr_kprobe
arm_all_kprobes
__arm_kprobe
arm_kprobe
arm_kprobe_ftrace
check_kprobe_address_safe
collect_garbage_slots
collect_garbage_slots
collect_one_slot
debugfs_kprobe_init
__disable_kprobe
disable_kprobe
disarm_all_kprobes
__disarm_kprobe
disarm_kprobe
disarm_kprobe_ftrace
do_free_cleaned_kprobes
do_optimize_kprobes
do_unoptimize_kprobes
enable_kprobe
force_unoptimize_kprobe
free_aggr_kprobe
free_aggr_kprobe
__free_insn_slot
__get_insn_slot
get_optimized_kprobe
__get_valid_kprobe
init_aggr_kprobe
init_aggr_kprobe
in_nokprobe_functions
kick_kprobe_optimizer
kill_kprobe
kill_optimized_kprobe
kprobe_addr
kprobe_optimizer
kprobe_queued
kprobe_seq_next
kprobe_seq_start
kprobe_seq_stop
kprobes_module_callback
kprobes_open
optimize_all_kprobes
optimize_kprobe
prepare_kprobe
prepare_optimized_kprobe
register_aggr_kprobe
register_jprobe
register_jprobes
register_kprobe
register_kprobes
register_kretprobe
register_kretprobe
register_kretprobes
register_kretprobes
report_probe
show_kprobe_addr
try_to_optimize_kprobe
unoptimize_all_kprobes
unoptimize_kprobe
unregister_jprobe
unregister_jprobes
unregister_kprobe
__unregister_kprobe_bottom
unregister_kprobes
__unregister_kprobe_top
unregister_kretprobe
unregister_kretprobe
unregister_kretprobes
unregister_kretprobes
wait_for_kprobe_optimizerI tested those functions by putting kprobes on all
instructions in the functions with the bash script
I sent to LKML. See:https://lkml.org/lkml/2014/3/27/33
Signed-off-by: Masami Hiramatsu
Link: http://lkml.kernel.org/r/20140417081753.26341.57889.stgit@ltc230.yrl.intra.hitachi.co.jp
Cc: Ananth N Mavinakayanahalli
Cc: Anil S Keshavamurthy
Cc: David S. Miller
Cc: fche@redhat.com
Cc: systemtap@sourceware.org
Signed-off-by: Ingo Molnar -
Introduce NOKPROBE_SYMBOL() macro which builds a kprobes
blacklist at kernel build time.The usage of this macro is similar to EXPORT_SYMBOL(),
placed after the function definition:NOKPROBE_SYMBOL(function);
Since this macro will inhibit inlining of static/inline
functions, this patch also introduces a nokprobe_inline macro
for static/inline functions. In this case, we must use
NOKPROBE_SYMBOL() for the inline function caller.When CONFIG_KPROBES=y, the macro stores the given function
address in the "_kprobe_blacklist" section.Since the data structures are not fully initialized by the
macro (because there is no "size" information), those
are re-initialized at boot time by using kallsyms.Signed-off-by: Masami Hiramatsu
Link: http://lkml.kernel.org/r/20140417081705.26341.96719.stgit@ltc230.yrl.intra.hitachi.co.jp
Cc: Alok Kataria
Cc: Ananth N Mavinakayanahalli
Cc: Andrew Morton
Cc: Anil S Keshavamurthy
Cc: Arnd Bergmann
Cc: Christopher Li
Cc: Chris Wright
Cc: David S. Miller
Cc: Jan-Simon Möller
Cc: Jeremy Fitzhardinge
Cc: Linus Torvalds
Cc: Randy Dunlap
Cc: Rusty Russell
Cc: linux-arch@vger.kernel.org
Cc: linux-doc@vger.kernel.org
Cc: linux-sparse@vger.kernel.org
Cc: virtualization@lists.linux-foundation.org
Signed-off-by: Ingo Molnar -
.entry.text is a code area which is used for interrupt/syscall
entries, which includes many sensitive code.
Thus, it is better to prohibit probing on all of such code
instead of a part of that.
Since some symbols are already registered on kprobe blacklist,
this also removes them from the blacklist.Signed-off-by: Masami Hiramatsu
Reviewed-by: Steven Rostedt
Cc: Ananth N Mavinakayanahalli
Cc: Anil S Keshavamurthy
Cc: Borislav Petkov
Cc: David S. Miller
Cc: Frederic Weisbecker
Cc: Jan Kiszka
Cc: Jiri Kosina
Cc: Jonathan Lebon
Cc: Seiji Aguchi
Link: http://lkml.kernel.org/r/20140417081658.26341.57354.stgit@ltc230.yrl.intra.hitachi.co.jp
Signed-off-by: Ingo Molnar
13 Nov, 2013
1 commit
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Use KSYM_NAME_LEN to size identifier buffers, so that it can be easier
increased.Signed-off-by: Joe Mario
Signed-off-by: Andi Kleen
Acked-by: Ananth N Mavinakayanahalli
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
