17 Oct, 2007
2 commits
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Introduce architecture dependent kretprobe blacklists to prohibit users
from inserting return probes on the function in which kprobes can be
inserted but kretprobes can not.This patch also removes "__kprobes" mark from "__switch_to" on x86_64 and
registers "__switch_to" to the blacklist on x86-64, because that mark is to
prohibit user from inserting only kretprobe.Signed-off-by: Masami Hiramatsu
Cc: Prasanna S Panchamukhi
Acked-by: Ananth N Mavinakayanahalli
Cc: Anil S Keshavamurthy
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
x86(-64) are the last architectures still using the page fault notifier
cruft for the kprobes page fault hook. This patch converts them to the
proper direct calls, and removes the now unused pagefault notifier bits
aswell as the cruft in kprobes.c that was related to this mess.I know Andi didn't really like this, but all other architecture maintainers
agreed the direct calls are much better and besides the obvious cruft
removal a common way of dealing with kprobes across architectures is
important aswell.[akpm@linux-foundation.org: build fix]
[akpm@linux-foundation.org: fix sparc64]
Signed-off-by: Christoph Hellwig
Cc: Andi Kleen
Cc:
Cc: Prasanna S Panchamukhi
Cc: Ananth N Mavinakayanahalli
Cc: Anil S Keshavamurthy
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
12 Aug, 2007
1 commit
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gcc-4.2 is a lot more picky about its symbol handling. EXPORT_SYMBOL no
longer works on symbols that are undefined or defined with static scope.For example, with CONFIG_PROFILE off, I see:
kernel/profile.c:206: error: __ksymtab_profile_event_unregister causes a section type conflict
kernel/profile.c:205: error: __ksymtab_profile_event_register causes a section type conflictThis patch moves the EXPORTs inside the #ifdef CONFIG_PROFILE, so we
only try to export symbols that are defined.Also, in kernel/kprobes.c there's an EXPORT_SYMBOL_GPL() for
jprobes_return, which if CONFIG_JPROBES is undefined is a static
inline and gives the same error.And in drivers/acpi/resources/rsxface.c, there's an
ACPI_EXPORT_SYMBOPL() for a static symbol. If it's static, it's not
accessible from outside the compilation unit, so should bot be exported.These three changes allow building a zx1_defconfig kernel with gcc 4.2
on IA64.[akpm@linux-foundation.org: export jpobe_return properly]
Signed-off-by: Peter Chubb
Cc: Prasanna S Panchamukhi
Cc: Ananth N Mavinakayanahalli
Cc: Anil S Keshavamurthy
Cc: "Luck, Tony"
Cc: Len Brown
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
20 Jul, 2007
1 commit
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I realise jprobes are a razor-blades-included type of interface, but that
doesn't mean we can't try and make them safer to use. This guy I know once
wrote code like this:struct jprobe jp = { .kp.symbol_name = "foo", .entry = "jprobe_foo" };
And then his kernel exploded. Oops.
This patch adds an arch hook, arch_deref_entry_point() (I don't like it
either) which takes the void * in a struct jprobe, and gives back the text
address that it represents.We can then use that in register_jprobe() to check that the entry point we're
passed is actually in the kernel text, rather than just some random value.Signed-off-by: Michael Ellerman
Cc: Prasanna S Panchamukhi
Acked-by: Ananth N Mavinakayanahalli
Cc: Anil S Keshavamurthy
Cc: David S. Miller
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
09 May, 2007
7 commits
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This patch provides a debugfs knob to turn kprobes on/off
o A new file /debug/kprobes/enabled indicates if kprobes is enabled or
not (default enabled)
o Echoing 0 to this file will disarm all installed probes
o Any new probe registration when disabled will register the probe but
not arm it. A message will be printed out in such a case.
o When a value 1 is echoed to the file, all probes (including ones
registered in the intervening period) will be enabled
o Unregistration will happen irrespective of whether probes are globally
enabled or not.
o Update Documentation/kprobes.txt to reflect these changes. While there
also update the doc to make it current.We are also looking at providing sysrq key support to tie to the disabling
feature provided by this patch.[akpm@linux-foundation.org: Use bool like a bool!]
[akpm@linux-foundation.org: add printk facility levels]
[cornelia.huck@de.ibm.com: Add the missing arch_trampoline_kprobe() for s390]
Signed-off-by: Ananth N Mavinakayanahalli
Signed-off-by: Srinivasa DS
Signed-off-by: Cornelia Huck
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
- consolidate duplicate code in all arch_prepare_kretprobe instances
into common code
- replace various odd helpers that use hlist_for_each_entry to get
the first elemenet of a list with either a hlist_for_each_entry_save
or an opencoded access to the first element in the caller
- inline add_rp_inst into it's only remaining caller
- use kretprobe_inst_table_head instead of opencoding itSigned-off-by: Christoph Hellwig
Cc: Prasanna S Panchamukhi
Acked-by: Ananth N Mavinakayanahalli
Cc: Anil S Keshavamurthy
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Remove superflous braces and fix indentation aswell as comments.
Signed-off-by: Christoph Hellwig
Cc: Prasanna S Panchamukhi
Cc: Ananth N Mavinakayanahalli
Cc: Anil S Keshavamurthy
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Signed-off-by: Christoph Hellwig
Cc: Prasanna S Panchamukhi
Cc: Ananth N Mavinakayanahalli
Cc: Anil S Keshavamurthy
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Several kallsyms_lookup() pass dummy arguments but only need, say, module's
name. Make kallsyms_lookup() accept NULLs where possible.Also, makes picture clearer about what interfaces are needed for all symbol
resolving business.Signed-off-by: Alexey Dobriyan
Cc: Rusty Russell
Acked-by: Ingo Molnar
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
This patch moves the die notifier handling to common code. Previous
various architectures had exactly the same code for it. Note that the new
code is compiled unconditionally, this should be understood as an appel to
the other architecture maintainer to implement support for it aswell (aka
sprinkling a notify_die or two in the proper place)arm had a notifiy_die that did something totally different, I renamed it to
arm_notify_die as part of the patch and made it static to the file it's
declared and used at. avr32 used to pass slightly less information through
this interface and I brought it into line with the other architectures.[akpm@linux-foundation.org: build fix]
[akpm@linux-foundation.org: fix vmalloc_sync_all bustage]
[bryan.wu@analog.com: fix vmalloc_sync_all in nommu]
Signed-off-by: Christoph Hellwig
Cc:
Cc: Russell King
Signed-off-by: Bryan Wu
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Fix sparse NULL warnings:
kernel/kprobes.c:915:49: warning: Using plain integer as NULL pointerSigned-off-by: Randy Dunlap
Acked-by: Ananth N Mavinakayanahalli
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
21 Feb, 2007
1 commit
-
This patch lists all active probes in the system by scanning through
kprobe_table[]. It takes care of aggregate handlers and prints the type of
the probe. Letter "k" for kprobes, "j" for jprobes, "r" for kretprobes.
It also lists address of the instruction,its symbolic name(function name +
offset) and the module name. One can access this file through
/sys/kernel/debug/kprobes/list.Output looks like this
=====================
llm40:~/a # cat /sys/kernel/debug/kprobes/list
c0169ae3 r sys_read+0x0
c0169ae3 k sys_read+0x0
c01694c8 k vfs_write+0x0
c0167d20 r sys_open+0x0
f8e658a6 k reiserfs_delete_inode+0x0 reiserfs
c0120f4a k do_fork+0x0
c0120f4a j do_fork+0x0
c0169b4a r sys_write+0x0
c0169b4a k sys_write+0x0
c0169622 r vfs_read+0x0
=================================[akpm@linux-foundation.org: cleanup]
[ananth@in.ibm.com: sparc build fix]
Signed-off-by: Srinivasa DS
Cc: Prasanna S Panchamukhi
Cc: Ananth N Mavinakayanahalli
Cc: Anil S Keshavamurthy
Signed-off-by: Ananth N Mavinakayanahalli
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
31 Jan, 2007
1 commit
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Replace the magic numbers with an enum, and gets rid of a warning on the
specific architectures (ex. powerpc) on which the compiler considers
'char' as 'unsigned char'.Signed-off-by: Masami Hiramatsu
Cc: Prasanna S Panchamukhi
Cc: Ananth N Mavinakayanahalli
Cc: Anil S Keshavamurthy
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
08 Dec, 2006
1 commit
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When we are unregistering a kprobe-booster, we can't release its
instruction buffer immediately on the preemptive kernel, because some
processes might be preempted on the buffer. The freeze_processes() and
thaw_processes() functions can clean most of processes up from the buffer.
There are still some non-frozen threads who have the PF_NOFREEZE flag. If
those threads are sleeping (not preempted) at the known place outside the
buffer, we can ensure safety of freeing.However, the processing of this check routine takes a long time. So, this
patch introduces the garbage collection mechanism of insn_slot. It also
introduces the "dirty" flag to free_insn_slot because of efficiency.The "clean" instruction slots (dirty flag is cleared) are released
immediately. But the "dirty" slots which are used by boosted kprobes, are
marked as garbages. collect_garbage_slots() will be invoked to release
"dirty" slots if there are more than INSNS_PER_PAGE garbage slots or if
there are no unused slots.Cc: "Keshavamurthy, Anil S"
Cc: Ananth N Mavinakayanahalli
Cc: "bibo,mao"
Cc: Prasanna S Panchamukhi
Cc: Yumiko Sugita
Cc: Satoshi Oshima
Cc: Hideo Aoki
Signed-off-by: Masami Hiramatsu
Acked-by: Ingo Molnar
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
02 Oct, 2006
3 commits
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kprobe_flush_task() possibly calls kfree function during holding
kretprobe_lock spinlock, if kfree function is probed by kretprobe that will
incur spinlock deadlock. This patch moves kfree function out scope of
kretprobe_lock.Signed-off-by: bibo, mao
Signed-off-by: Ananth N Mavinakayanahalli
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Whitespace is used to indent, this patch cleans up these sentences by
kernel coding style.Signed-off-by: bibo, mao
Signed-off-by: Ananth N Mavinakayanahalli
Cc: "Luck, Tony"
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
In an effort to make kprobe modules more portable, here is a patch that:
o Introduces the "symbol_name" field to struct kprobe.
The symbol->address resolution now happens in the kernel in an
architecture agnostic manner. 64-bit powerpc users no longer have
to specify the ".symbols"
o Introduces the "offset" field to struct kprobe to allow a user to
specify an offset into a symbol.
o The legacy mechanism of specifying the kprobe.addr is still supported.
However, if both the kprobe.addr and kprobe.symbol_name are specified,
probe registration fails with an -EINVAL.
o The symbol resolution code uses kallsyms_lookup_name(). So
CONFIG_KPROBES now depends on CONFIG_KALLSYMS
o Apparantly kprobe modules were the only legitimate out-of-tree user of
the kallsyms_lookup_name() EXPORT. Now that the symbol resolution
happens in-kernel, remove the EXPORT as suggested by Christoph Hellwig
o Modify tcp_probe.c that uses the kprobe interface so as to make it
work on multiple platforms (in its earlier form, the code wouldn't
work, say, on powerpc)Signed-off-by: Ananth N Mavinakayanahalli
Signed-off-by: Prasanna S Panchamukhi
Signed-off-by: Christoph Hellwig
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
01 Aug, 2006
1 commit
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Kprobe inserts breakpoint instruction in probepoint and then jumps to
instruction slot when breakpoint is hit, the instruction slot icache must
be consistent with dcache. Here is the patch which invalidates instruction
slot icache area.Without this patch, in some machines there will be fault when executing
instruction slot where icache content is inconsistent with dcache.Signed-off-by: bibo,mao
Acked-by: "Luck, Tony"
Acked-by: Keshavamurthy Anil S
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
27 Jun, 2006
3 commits
-
With this patch Kprobes now registers for page fault notifications only when
their is an active probe registered. Once all the active probes are
unregistered their is no need to be notified of page faults and kprobes
unregisters itself from the page fault notifications. Hence we will have ZERO
side effects when no probes are active.Signed-off-by: Anil S Keshavamurthy
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Kprobes now registers for page fault notifications.
Signed-off-by: Anil S Keshavamurthy
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
If there are multi kprobes on the same probepoint, there will be one extra
aggr_kprobe on the head of kprobe list. The aggr_kprobe has
aggr_post_handler/aggr_break_handler whether the other kprobe
post_hander/break_handler is NULL or not. This patch modifies this, only
when there is one or more kprobe in the list whose post_handler is not
NULL, post_handler of aggr_kprobe will be set as aggr_post_handler.[soshima@redhat.com: !CONFIG_PREEMPT fix]
Signed-off-by: bibo, mao
Cc: Masami Hiramatsu
Cc: Ananth N Mavinakayanahalli
Cc: "Keshavamurthy, Anil S"
Cc: Prasanna S Panchamukhi
Cc: Jim Keniston
Cc: Yumiko Sugita
Cc: Hideo Aoki
Signed-off-by: Satoshi Oshima
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
20 Apr, 2006
1 commit
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In cases where a struct kretprobe's *_handler fields are non-NULL, it is
possible to cause a system crash, due to the possibility of calls ending up
in zombie functions. Documentation clearly states that unused *_handlers
should be set to NULL, but kprobe users sometimes fail to do so.Fix it by setting the non-relevant fields of the struct kretprobe to NULL.
Signed-off-by: Ananth N Mavinakayanahalli
Acked-by: Jim Keniston
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
27 Mar, 2006
1 commit
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When kretprobe probes the schedule() function, if the probed process exits
then schedule() will never return, so some kretprobe instances will never
be recycled.In this patch the parent process will recycle retprobe instances of the
probed function and there will be no memory leak of kretprobe instances.Signed-off-by: bibo mao
Cc: Masami Hiramatsu
Cc: Prasanna S Panchamukhi
Cc: Ananth N Mavinakayanahalli
Cc: Anil S Keshavamurthy
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
23 Mar, 2006
1 commit
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Semaphore to mutex conversion.
The conversion was generated via scripts, and the result was validated
automatically via a script as well.Signed-off-by: Ingo Molnar
Acked-by: Anil S Keshavamurthy
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
04 Feb, 2006
2 commits
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When two function-return probes are inserted on kfree()[1] and the second
on say, sys_link()[2], and later [2] is unregistered, we have a deadlock as
kfree is called with the kretprobe_lock held and the function-return probe
on kfree will also try to grab the same lock.However, we can move the kfree() during unregistration to outside the
spinlock as we are sure that no instances from the free list will be used
after synchronized_sched() returns during the unregistration process.
Thanks to Masami Hiramatsu for spotting this.Signed-off-by: Ananth N Mavinakayanahalli
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
kernel/kprobes.c:353: warning: 'pre_handler_kretprobe' defined but not used
Signed-off-by: Adrian Bunk
Acked-by: Ananth N Mavinakayanahalli
Acked-by: "Keshavamurthy, Anil S"
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
12 Jan, 2006
1 commit
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When a kprobes modules is written in such a way that probes are inserted on
itself, then unload of that moudle was not possible due to reference
couning on the same module.The below patch makes a check and incrementes the module refcount only if
it is not a self probed module.We need to allow modules to probe themself for kprobes performance
measurementsThis patch has been tested on several x86_64, ppc64 and IA64 architectures.
Signed-off-by: Anil S Keshavamurthy
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
11 Jan, 2006
6 commits
-
Signed-of-by: Anil S Keshavamurthy
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
The following patch (against 2.6.15-rc5-mm3) fixes a kprobes build break
due to changes introduced in the kprobe locking in 2.6.15-rc5-mm3. In
addition, the patch reverts back the open-coding of kprobe_mutex.Signed-off-by: Ananth N Mavinakayanahalli
Acked-by: Anil S Keshavamurthy
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Currently arch_remove_kprobes() is only implemented/required for x86_64 and
powerpc. All other architecture like IA64, i386 and sparc64 implementes a
dummy function which is being called from arch independent kprobes.c file.This patch removes the dummy functions and replaces it with
#define arch_remove_kprobe(p, s) do { } while(0)Signed-off-by: Anil S Keshavamurthy
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Based on some feedback from Oleg Nesterov, I have made few changes to
previously posted patch.Signed-off-by: Anil S Keshavamurthy
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Since Kprobes runtime exception handlers is now lock free as this code path is
now using RCU to walk through the list, there is no need for the
register/unregister{_kprobe} to use spin_{lock/unlock}_isr{save/restore}. The
serialization during registration/unregistration is now possible using just a
mutex.In the above process, this patch also fixes a minor memory leak for x86_64 and
powerpc.Signed-off-by: Anil S Keshavamurthy
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Kernel/kprobes.c defines get_insn_slot() and free_insn_slot() which are
currently required _only_ for x86_64 and powerpc (which has no-exec support).FYI, get{free}_insn_slot() functions manages the memory page which is mapped
as executable, required for instruction emulation.This patch moves those two functions under __ARCH_WANT_KPROBES_INSN_SLOT and
defines __ARCH_WANT_KPROBES_INSN_SLOT in arch specific kprobes.h file.Signed-off-by: Anil S Keshavamurthy
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
13 Dec, 2005
3 commits
-
When multiple probes are registered at the same address and if due to some
recursion (probe getting triggered within a probe handler), we skip calling
pre_handlers and just increment nmissed field.The below patch make sure it walks the list for multiple probes case.
Without the below patch we get incorrect results of nmissed count for
multiple probe case.Signed-off-by: Anil S Keshavamurthy
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
When registering multiple kprobes at the same address, we leave a small
window where the kprobe hlist will not contain a reference to the
registered kprobe, leading to potentially, a system crash if the breakpoint
is hit on another processor.Patch below now automically relpace the old kprobe with the new
kprobe from the hash list.Signed-off-by: Anil S Keshavamurthy
Acked-by: Ananth N Mavinakayanahalli
Cc: "Paul E. McKenney"
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
When a Kprobes are inserted/removed on a modules, the modules must be ref
counted so as not to allow to unload while probes are registered on that
module.Without this patch, the probed module is free to unload, and when the
probing module unregister the probe, the kpobes code while trying to
replace the original instruction might crash.Signed-off-by: Anil S Keshavamurthy
Signed-off-by: Mao Bibo
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
07 Nov, 2005
3 commits
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Reorganize the preempt_disable/enable calls to eliminate the extra preempt
depth. Changes based on Paul McKenney's review suggestions for the kprobes
RCU changeset.Signed-off-by: Ananth N Mavinakayanahalli
Signed-off-by: Anil S Keshavamurthy
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Changes to the base kprobes infrastructure to use RCU for synchronization
during kprobe registration and unregistration. These changes coupled with the
arch kprobe changes (next in series):a. serialize registration and unregistration of kprobes.
b. enable lockless execution of handlers. Handlers can now run in parallel.Signed-off-by: Ananth N Mavinakayanahalli
Signed-off-by: Anil S Keshavamurthy
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Changes to the base kprobe infrastructure to track kprobe execution on a
per-cpu basis.Signed-off-by: Ananth N Mavinakayanahalli
Signed-off-by: Anil S Keshavamurthy
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
31 Oct, 2005
1 commit
-
I recently picked up my older work to remove unnecessary #includes of
sched.h, starting from a patch by Dave Jones to not include sched.h
from module.h. This reduces the number of indirect includes of sched.h
by ~300. Another ~400 pointless direct includes can be removed after
this disentangling (patch to follow later).
However, quite a few indirect includes need to be fixed up for this.In order to feed the patches through -mm with as little disturbance as
possible, I've split out the fixes I accumulated up to now (complete for
i386 and x86_64, more archs to follow later) and post them before the real
patch. This way this large part of the patch is kept simple with only
adding #includes, and all hunks are independent of each other. So if any
hunk rejects or gets in the way of other patches, just drop it. My scripts
will pick it up again in the next round.Signed-off-by: Tim Schmielau
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
