06 Mar, 2009
1 commit
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Use the mutual exclusion provided by the text edit lock in the kprobes code. It
allows coherent manipulation of the kernel code by other subsystems.Changelog:
Move the kernel_text_lock/unlock out of the for loops.
Use text_mutex directly instead of a function.
Remove whitespace modifications.(note : kprobes_mutex is always taken outside of text_mutex)
Signed-off-by: Mathieu Desnoyers
Acked-by: Ananth N Mavinakayanahalli
Acked-by: Masami Hiramatsu
LKML-Reference:
Signed-off-by: Ingo Molnar
17 Jan, 2009
1 commit
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Check CONFIG_FREEZER instead of CONFIG_PM because kprobe booster
depends on freeze_processes() and thaw_processes() when CONFIG_PREEMPT=y.This fixes a linkage error which occurs when CONFIG_PREEMPT=y, CONFIG_PM=y
and CONFIG_FREEZER=n.Reported-by: Cheng Renquan
Signed-off-by: Masami Hiramatsu
Signed-off-by: Rafael J. Wysocki
Acked-by: Ingo Molnar
Signed-off-by: Len Brown
07 Jan, 2009
6 commits
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Allow kprobes to probe module __init routines. When __init functions are
freed, kprobes which probe those functions are set to "Gone" flag. These
"Gone" probes are disarmed from the code and never be enabled.Signed-off-by: Masami Hiramatsu
Acked-by: Ananth N Mavinakayanahalli
Cc: Anil S Keshavamurthy
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Remove called_from argument from kprobes which had been used for
preventing self-refering of kernel module. However, since we don't keep
module's refcount after registering kprobe any more, there is no reason to
check that.This patch also simplifies registering/unregistering functions because we
don't need to use __builtin_return_address(0) which was passed to
called_from.[ananth@in.ibm.com: build fix]
Signed-off-by: Masami Hiramatsu
Acked-by: Ananth N Mavinakayanahalli
Cc: Anil S Keshavamurthy
Signed-off-by: Ananth N Mavinakayanahalli
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Allows kprobes to probe __exit routine. This adds flags member to struct
kprobe. When module is freed(kprobes hooks module_notifier to get this
event), kprobes which probe the functions in that module are set to "Gone"
flag to the flags member. These "Gone" probes are never be enabled.
Users can check the GONE flag through debugfs.This also removes mod_refcounted, because we couldn't free a module if
kprobe incremented the refcount of that module.[akpm@linux-foundation.org: document some locking]
[mhiramat@redhat.com: bugfix: pass aggr_kprobe to arch_remove_kprobe]
[mhiramat@redhat.com: bugfix: release old_p's insn_slot before error return]
Signed-off-by: Masami Hiramatsu
Acked-by: Ananth N Mavinakayanahalli
Cc: Anil S Keshavamurthy
Signed-off-by: Masami Hiramatsu
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Add __kprobes to kprobes internal functions for protecting from probing by
kprobes itself.Signed-off-by: Masami Hiramatsu
Acked-by: Ananth N Mavinakayanahalli
Cc: Anil S Keshavamurthy
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Add kprobe_insn_mutex for protecting kprobe_insn_pages hlist, and remove
kprobe_mutex from architecture dependent code.This allows us to call arch_remove_kprobe() (and free_insn_slot) while
holding kprobe_mutex.Signed-off-by: Masami Hiramatsu
Acked-by: Ananth N Mavinakayanahalli
Cc: Anil S Keshavamurthy
Cc: Russell King
Cc: "Luck, Tony"
Cc: Paul Mackerras
Cc: Benjamin Herrenschmidt
Cc: Martin Schwidefsky
Cc: Heiko Carstens
Cc: Ingo Molnar
Cc: Thomas Gleixner
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
When someone called register_*probe() from kernel-core code(not from
module) and that probes a kernel module, users can remove the probed
module because kprobe doesn't increment reference counter of the module.
(on the other hand, if the kernel-module calls register_*probe, kprobe
increments refcount of the probed module.)Currently, we have no register_*probe() calling from kernel-core(except
smoke-test, but the smoke-test doesn't probe module), so there is no real
bugs. But the logic is wrong(or not fair) and it can causes a problem
when someone might want to probe module from kernel.After this patch is applied, even if someone put register_*probe() call in
the kernel-core code, it increments the reference counter of the probed
module, and it prevents user to remove the module until stopping probing
it.Signed-off-by: Masami Hiramatsu
Cc: Lai Jiangshan
Cc: Ananth N Mavinakayanahalli
Cc: Hiroshi Shimamoto
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
13 Nov, 2008
2 commits
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We only need the cacheline padding on SMP kernels. Saves 6k:
text data bss dec hex filename
5713 388 8840 14941 3a5d kernel/kprobes.o
5713 388 2632 8733 221d kernel/kprobes.oAcked-by: Masami Hiramatsu
Cc: Ananth N Mavinakayanahalli
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
__register_kprobe() can be preempted after checking probing address but
before module_text_address() or try_module_get(), and in this interval
the module can be unloaded. In that case, try_module_get(probed_mod)
will access to invalid address, or kprobe will probe invalid address.This patch uses preempt_disable() to protect it and uses
__module_text_address() and __kernel_text_address().Signed-off-by: Lai Jiangshan
Signed-off-by: Masami Hiramatsu
Cc: Ananth N Mavinakayanahalli
Cc: Hiroshi Shimamoto
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
17 Oct, 2008
1 commit
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Make the needlessly global kretprobe_table_lock() static.
Signed-off-by: Adrian Bunk
Acked-by: Ananth N Mavinakayanahalli
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
26 Jul, 2008
2 commits
-
I noticed that there's a CONFIG_KPROBES check inside kernel/kprobes.c,
which is redundant.Signed-off-by: Abhishek Sagar
Acked-by: Masami Hiramatsu
Cc: Ananth N Mavinakayanahalli
Cc: Anil S Keshavamurthy
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Currently list of kretprobe instances are stored in kretprobe object (as
used_instances,free_instances) and in kretprobe hash table. We have one
global kretprobe lock to serialise the access to these lists. This causes
only one kretprobe handler to execute at a time. Hence affects system
performance, particularly on SMP systems and when return probe is set on
lot of functions (like on all systemcalls).Solution proposed here gives fine-grain locks that performs better on SMP
system compared to present kretprobe implementation.Solution:
1) Instead of having one global lock to protect kretprobe instances
present in kretprobe object and kretprobe hash table. We will have
two locks, one lock for protecting kretprobe hash table and another
lock for kretporbe object.2) We hold lock present in kretprobe object while we modify kretprobe
instance in kretprobe object and we hold per-hash-list lock while
modifying kretprobe instances present in that hash list. To prevent
deadlock, we never grab a per-hash-list lock while holding a kretprobe
lock.3) We can remove used_instances from struct kretprobe, as we can
track used instances of kretprobe instances using kretprobe hash
table.Time duration for kernel compilation ("make -j 8") on a 8-way ppc64 system
with return probes set on all systemcalls looks like this.cacheline non-cacheline Un-patched kernel
aligned patch aligned patch
===============================================================================
real 9m46.784s 9m54.412s 10m2.450s
user 40m5.715s 40m7.142s 40m4.273s
sys 2m57.754s 2m58.583s 3m17.430s
===========================================================Time duration for kernel compilation ("make -j 8) on the same system, when
kernel is not probed.
=========================
real 9m26.389s
user 40m8.775s
sys 2m7.283s
=========================Signed-off-by: Srinivasa DS
Signed-off-by: Jim Keniston
Acked-by: Ananth N Mavinakayanahalli
Cc: Anil S Keshavamurthy
Cc: David S. Miller
Cc: Masami Hiramatsu
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
11 Jul, 2008
1 commit
-
Signed-off-by: Daniel Guilak
Signed-off-by: Linus Torvalds
13 Jun, 2008
1 commit
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Fix error checking routine to catch an error which occurs in first
__register_*probe().Signed-off-by: Masami Hiramatsu
Cc: Ananth N Mavinakayanahalli
Cc: Jim Keniston
Cc: David Miller
Cc: Anil S Keshavamurthy
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
28 Apr, 2008
4 commits
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Introduce unregister_/register_jprobes() for jprobe batch registration.
Signed-off-by: Masami Hiramatsu
Cc: Ananth N Mavinakayanahalli
Cc: Jim Keniston
Cc: Prasanna S Panchamukhi
Cc: Shaohua Li
Cc: David Miller
Cc: "Frank Ch. Eigler"
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Introduce unregister_/register_kretprobes() for kretprobe batch registration.
Signed-off-by: Masami Hiramatsu
Cc: Ananth N Mavinakayanahalli
Cc: Jim Keniston
Cc: Prasanna S Panchamukhi
Cc: Shaohua Li
Cc: David Miller
Cc: "Frank Ch. Eigler"
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Introduce unregister_/register_kprobes() for kprobe batch registration. This
can reduce waiting time for synchronized_sched() when a lot of probes have to
be unregistered at once.Signed-off-by: Masami Hiramatsu
Cc: Ananth N Mavinakayanahalli
Cc: Jim Keniston
Cc: Prasanna S Panchamukhi
Cc: Shaohua Li
Cc: David Miller
Cc: "Frank Ch. Eigler"
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Prohibit users from probing preempt_schedule(). One way of prohibiting the
user from probing functions is by marking such functions with __kprobes. But
this method doesn't work for those functions, which are already marked to
different section like preempt_schedule() (belongs to __sched section). So we
use blacklist approach to refuse user from probing these functions.In blacklist approach we populate the blacklisted function's starting address
and its size in kprobe_blacklist structure. Then we verify the user specified
address against start and end of the blacklisted function. So any attempt to
register probe on blacklisted functions will be rejected.[akpm@linux-foundation.org: build fix]
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Srinivasa DS
Signed-off-by: Ananth N Mavinakayanahalli
Signed-off-by: Jim Keniston
Cc: Dave Hansen
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
05 Mar, 2008
2 commits
-
Fix a bug in regiseter_kretprobe() which does not check rp->kp.symbol_name ==
NULL before calling kprobe_lookup_name.For maintainability, this introduces kprobe_addr helper function which
resolves addr field. It is used by register_kprobe and register_kretprobe.Signed-off-by: Masami Hiramatsu
Cc: Ananth N Mavinakayanahalli
Cc: Jim Keniston
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Add CONFIG_HAVE_KRETPROBES to the arch//Kconfig file for relevant
architectures with kprobes support. This facilitates easy handling of
in-kernel modules (like samples/kprobes/kretprobe_example.c) that depend on
kretprobes being present in the kernel.Thanks to Sam Ravnborg for helping make the patch more lean.
Per Mathieu's suggestion, added CONFIG_KRETPROBES and fixed up dependencies.
Signed-off-by: Ananth N Mavinakayanahalli
Acked-by: Mathieu Desnoyers
Acked-by: Ingo Molnar
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
07 Feb, 2008
1 commit
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Provide support to add an optional user defined callback to be run at
function entry of a kretprobe'd function. Also modify the kprobe smoke
tests to include an entry-handler during the kretprobe sanity test.Signed-off-by: Abhishek Sagar
Cc: Prasanna S Panchamukhi
Cc: Ananth N Mavinakayanahalli
Cc: Anil S Keshavamurthy
Acked-by: Jim Keniston
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
30 Jan, 2008
1 commit
-
Here is a quick and naive smoke test for kprobes. This is intended to
just verify if some unrelated change broke the *probes subsystem. It is
self contained, architecture agnostic and isn't of any great use by itself.This needs to be built in the kernel and runs a basic set of tests to
verify if kprobes, jprobes and kretprobes run fine on the kernel. In case
of an error, it'll print out a message with a "BUG" prefix.This is a start; we intend to add more tests to this bucket over time.
Thanks to Jim Keniston and Masami Hiramatsu for comments and suggestions.
Tested on x86 (32/64) and powerpc.
Signed-off-by: Ananth N Mavinakayanahalli
Acked-by: Masami Hiramatsu
Signed-off-by: Thomas Gleixner
Signed-off-by: Ingo Molnar
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
-
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
-
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
-
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
-
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
-
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
