04 Feb, 2010
1 commit
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Disable kprobe booster when CONFIG_PREEMPT=y at this time,
because it can't ensure that all kernel threads preempted on
kprobe's boosted slot run out from the slot even using
freeze_processes().The booster on preemptive kernel will be resumed if
synchronize_tasks() or something like that is introduced.Signed-off-by: Masami Hiramatsu
Cc: systemtap
Cc: DLE
Cc: Ananth N Mavinakayanahalli
Cc: Frederic Weisbecker
Cc: Jim Keniston
Cc: Mathieu Desnoyers
Cc: Steven Rostedt
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
08 Jan, 2009
1 commit
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* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (24 commits)
trivial: chack -> check typo fix in main Makefile
trivial: Add a space (and a comma) to a printk in 8250 driver
trivial: Fix misspelling of "firmware" in docs for ncr53c8xx/sym53c8xx
trivial: Fix misspelling of "firmware" in powerpc Makefile
trivial: Fix misspelling of "firmware" in usb.c
trivial: Fix misspelling of "firmware" in qla1280.c
trivial: Fix misspelling of "firmware" in a100u2w.c
trivial: Fix misspelling of "firmware" in megaraid.c
trivial: Fix misspelling of "firmware" in ql4_mbx.c
trivial: Fix misspelling of "firmware" in acpi_memhotplug.c
trivial: Fix misspelling of "firmware" in ipw2100.c
trivial: Fix misspelling of "firmware" in atmel.c
trivial: Fix misspelled firmware in Kconfig
trivial: fix an -> a typos in documentation and comments
trivial: fix then -> than typos in comments and documentation
trivial: update Jesper Juhl CREDITS entry with new email
trivial: fix singal -> signal typo
trivial: Fix incorrect use of "loose" in event.c
trivial: printk: fix indentation of new_text_line declaration
trivial: rtc-stk17ta8: fix sparse warning
...
07 Jan, 2009
1 commit
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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
06 Jan, 2009
1 commit
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- (better, more, bigger ...) then -> (...) than
Signed-off-by: Frederik Schwarzer
Signed-off-by: Jiri Kosina
26 Jul, 2008
1 commit
-
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
10 Apr, 2008
1 commit
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Add kprobe-booster support on ia64.
Kprobe-booster improves the performance of kprobes by eliminating single-step,
where possible. Currently, kprobe-booster is implemented on x86 and x86-64.
This is an ia64 port.On ia64, kprobe-booster executes a copied bundle directly, instead of single
stepping. Bundles which have B or X unit and which may cause an exception
(including break) are not executed directly. And also, to prevent hitting
break exceptions on the copied bundle, only the hindmost kprobe is executed
directly if several kprobes share a bundle and are placed in different slots.
Note: set_brl_inst() is used for preparing an instruction buffer(it does not
modify any active code), so it does not need any atomic operation.Signed-off-by: Masami Hiramatsu
Cc: Anil S Keshavamurthy
Cc: Ananth N Mavinakayanahalli
Cc: bibo,mao
Cc: Rusty Lynch
Cc: Prasanna S Panchamukhi
Cc: Jim Keniston
Cc: Shaohua Li
Signed-off-by: Andrew Morton
Signed-off-by: Tony Luck
07 Mar, 2008
1 commit
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ia64 named their handler kprobes_fault_handler while all other
arches used kprobe_fault_handler. Change the function definition
and header declaration.Signed-off-by: Harvey Harrison
Signed-off-by: Tony Luck
05 Mar, 2008
1 commit
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This patch fixes the following compile error with a recent gcc:
CC kernel/kprobes.o
/home/bunk/linux/kernel-2.6/git/linux-2.6/kernel/kprobes.c:1066: error: __ksymtab_jprobe_return causes a section type conflictSigned-off-by: Adrian Bunk
Signed-off-by: Tony Luck
05 Feb, 2008
1 commit
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Fix the order of atomic operations to prevent overwriting prev_kprobe[0].
To pop values from stack, we must decrement stack index right AFTER
reading values.Signed-off-by: Masami Hiramatsu
Signed-off-by: Tony Luck
08 Dec, 2007
2 commits
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Restore regs->ccr_iip before kreturn probe handler runs. In this way, if
probe handler does unwind, unwind can correctly get the stack trace.Fixes: http://sourceware.org/bugzilla/show_bug.cgi?id=5051
Signed-off-by: Shaohua Li
Signed-off-by: Tony Luck -
Signed-off-by: Joe Perches
Signed-off-by: Tony Luck
17 Oct, 2007
1 commit
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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
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
17 May, 2007
1 commit
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Get rid of the notifier list and call the kprobes code directly
if compiled in. This mirrors the changes that recently went
into powerpc, s390 and sparc64.Signed-off-by: Christoph Hellwig
Signed-off-by: Tony Luck
12 May, 2007
2 commits
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Spelling and apostrophe fixes in arch/ia64/.
Signed-off-by: Simon Arlott
Signed-off-by: Tony Luck -
In case of reentrance i.e when a probe handler calls a functions which
inturn has a probe, we save a previous kprobe information and just single
step the reentrant probe without calling the actual probe handler. During
this reentracy period, if an interrupt occurs and if probe happens to
trigger in the inturrupt path, then we were corrupting the previous kprobe(
as we were overriding the previous kprobe info) info their by crashing the
system. This patch fixes this issues by having a an array of previous
kprobe info struct(with the array size of 2).This similar technique is not needed on i386 and x86_64 because by default
interrupts are turn off in the break/int3 exception handler.Signed-off-by: Anil S Keshavamurthy
Signed-off-by: Andrew Morton
Signed-off-by: Tony Luck
09 May, 2007
4 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 -
In certain cases like when the real return address can't be found or when
the number of tracked calls to a kretprobed function is less than the
number of returns, we may not be able to find the correct return address
after processing a kretprobe. Currently we just do a BUG_ON, but no
information is provided about the actual failing kretprobe.Print out details of the kretprobe before calling BUG().
Signed-off-by: Ananth N Mavinakayanahalli
Cc: Prasanna S Panchamukhi
Cc: Jim Keniston
Cc: Anil S Keshavamurthy
Cc: Maneesh Soni
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
13 Dec, 2006
2 commits
-
On IA64 there exists some special instructions which
always need to be executed regradless of qp bits, such
as com.crel.unc, tbit.trel.unc etc.
This patch clears qp bits when inserting kprobe trap code
and disables probepoint on slot 1 for these special
instructions.Signed-off-by: bibo,mao
Signed-off-by: Tony Luck -
Because slot 1 of one instr bundle crosses border of two consecutive
8-bytes, kprobe on slot 1 is disabled. This patch enables kprobe on
slot1, it only replaces higher 8-bytes of the instruction bundle and
changes the exception code to ignore the low 12 bits of the break
number (which is across the border in the lower 8-bytes of the bundle).For those instructions which must execute regardless qp bits,
kprobe on slot 1 is still disabled.Signed-off-by: bibo,mao
Signed-off-by: Tony Luck
08 Dec, 2006
3 commits
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* 'release' of master.kernel.org:/pub/scm/linux/kernel/git/aegl/linux-2.6:
[IA64] replace kmalloc+memset with kzalloc
[IA64] resolve name clash by renaming is_available_memory()
[IA64] Need export for csum_ipv6_magic
[IA64] Fix DISCONTIGMEM without VIRTUAL_MEM_MAP
[PATCH] Add support for type argument in PAL_GET_PSTATE
[IA64] tidy up return value of ip_fast_csum
[IA64] implement csum_ipv6_magic for ia64.
[IA64] More Itanium PAL spec updates
[IA64] Update processor_info features
[IA64] Add se bit to Processor State Parameter structure
[IA64] Add dp bit to cache and bus check structs
[IA64] SN: Correctly update smp_affinty mask
[IA64] sparse cleanups
[IA64] IA64 Kexec/kdump -
0/NULL confusion and some missing UL on constants.
Signed-off-by: Matthew Wilcox
Signed-off-by: Tony Luck -
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
2 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
27 Sep, 2006
2 commits
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If the user-specified kprobe handler causes the page fault when accessing
user space address, fixup this fault since do_page_fault() should not
continue as the kprobe handler are run with preemption disabled.Signed-off-by: Anil S Keshavamurthy
Signed-off-by: Andrew Morton
Signed-off-by: Tony Luck -
On IA64 instruction opcode must be 16 bytes alignment, in kprobe structure
there is one element to save original instruction, currently saved opcode
is not statically allocated in kprobe structure, that can not assure
16 bytes alignment. This patch dynamically allocated kprobe instruction
opcode to assure 16 bytes alignment.Signed-off-by: bibo mao
Acked-by: Anil S Keshavamurthy
Signed-off-by: Tony Luck
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
01 Jul, 2006
1 commit
-
Signed-off-by: Jörn Engel
Signed-off-by: Adrian Bunk
20 Apr, 2006
1 commit
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Andrew Morton pointed out that compiler might not inline the functions
marked for inline in kprobes. There-by allowing the insertion of probes
on these kprobes routines, which might cause recursion.This patch removes all such inline and adds them to kprobes section
there by disallowing probes on all such routines. Some of the routines
can even still be inlined, since these routines gets executed after the
kprobes had done necessay setup for reentrancy.Signed-off-by: Prasanna S Panchamukhi
Cc: "Luck, Tony"
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
27 Mar, 2006
2 commits
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Provide proper kprobes fault handling, if a user-specified pre/post handlers
tries to access user address space, through copy_from_user(), get_user() etc.The user-specified fault handler gets called only if the fault occurs while
executing user-specified handlers. In such a case user-specified handler is
allowed to fix it first, later if the user-specifed fault handler does not fix
it, we try to fix it by calling fix_exception().The user-specified handler will not be called if the fault happens when single
stepping the original instruction, instead we reset the current probe and
allow the system page fault handler to fix it up.Signed-off-by: Prasanna S Panchamukhi
Acked-by: Anil S Keshavamurthy
Cc: "Luck, Tony"
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Currently kprobe handler traps only happen in kernel space, so function
kprobe_exceptions_notify should skip traps which happen in user space.
This patch modifies this, and it is based on 2.6.16-rc4.Signed-off-by: bibo mao
Cc: Ananth N Mavinakayanahalli
Cc: "Keshavamurthy, Anil S"
Cc:
Signed-off-by: Prasanna S Panchamukhi
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
14 Jan, 2006
1 commit
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When jprobe is hit, the function parameters of the original function
should be saved before jprobe handler is executed, and restored it after
jprobe handler is executed, because jprobe handler might change the
register values due to tail call optimization by the gcc.Signed-off-by: Zhang Yanmin
Signed-off-by: Anil S Keshavamurthy
Signed-off-by: Tony Luck
12 Jan, 2006
1 commit
-
There is a window where a probe gets removed right after the probe is hit
on some different cpu. In this case probe handlers can't find a matching
probe instance related to break address. In this case we need to read the
original instruction at break address to see if that is not a break/int3
instruction and recover safely.Previous code had a bug where we were not checking for the above race in
case of reentrant probes and the below patch fixes this race.Tested on IA64, Powerpc, x86_64.
Signed-off-by: Anil S Keshavamurthy
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
11 Jan, 2006
1 commit
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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
13 Dec, 2005
1 commit
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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
30 Nov, 2005
1 commit
-
break.b always sets cr.iim to 0 and the current code tries to
get the break_num by decoding instruction. However, their
seems to be a race condition while reading the regs->cr_iip,
as on other cpu the break.b at regs->cr_iip might have been
replaced with the original instruction as a result of
unregister_kprobe() and hence decoding instruction to
obtain break_num will result in wrong value in this case.Also includes changes to kprobes.c which now has to handle
break number zero.Signed-off-by: Anil S Keshavamurthy
Signed-off-by: Tony Luck