ptrace_set_debugreg() is only used in this file and should be
static. This also quiets the following sparse warning:
warning: symbol 'ptrace_set_debugreg' was not declared. Should it be static?
Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: hartleys@visionengravers.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The perf_event overflow handler does not receive any caller-derived
argument, so many callers need to resort to looking up the perf_event
in their local data structure. This is ugly and doesn't scale if a
single callback services many perf_events.
Fix by adding a context parameter to perf_event_create_kernel_counter()
(and derived hardware breakpoints APIs) and storing it in the perf_event.
The field can be accessed from the callback as event->overflow_handler_context.
All callers are updated.
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1309362157-6596-2-git-send-email-avi@redhat.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The nmi parameter indicated if we could do wakeups from the current
context, if not, we would set some state and self-IPI and let the
resulting interrupt do the wakeup.
For the various event classes:
- hardware: nmi=0; PMI is in fact an NMI or we run irq_work_run from
the PMI-tail (ARM etc.)
- tracepoint: nmi=0; since tracepoint could be from NMI context.
- software: nmi=[0,1]; some, like the schedule thing cannot
perform wakeups, and hence need 0.
As one can see, there is very little nmi=1 usage, and the down-side of
not using it is that on some platforms some software events can have a
jiffy delay in wakeup (when arch_irq_work_raise isn't implemented).
The up-side however is that we can remove the nmi parameter and save a
bunch of conditionals in fast paths.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Michael Cree <mcree@orcon.net.nz>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Deng-Cheng Zhu <dengcheng.zhu@gmail.com>
Cc: Anton Blanchard <anton@samba.org>
Cc: Eric B Munson <emunson@mgebm.net>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Don Zickus <dzickus@redhat.com>
Link: http://lkml.kernel.org/n/tip-agjev8eu666tvknpb3iaj0fg@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
While the tracer accesses ptrace breakpoints, the child task may
concurrently exit due to a SIGKILL and thus release its breakpoints
at the same time. We can then dereference some freed pointers.
To fix this, hold a reference on the child breakpoints before
manipulating them.
Reported-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Prasad <prasad@linux.vnet.ibm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: v2.6.33.. <stable@kernel.org>
Link: http://lkml.kernel.org/r/1302284067-7860-3-git-send-email-fweisbec@gmail.com
Remove checking @addr less than 0 because @addr is now unsigned and
use new udescp variable in order to remove unnecessary castings.
[akpm@linux-foundation.org: fix unused variable 'udescp']
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix up the arguments to arch_ptrace() to take account of the fact that
@addr and @data are now unsigned long rather than long as of a preceding
patch in this series.
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Cc: <linux-arch@vger.kernel.org>
Acked-by: Roland McGrath <roland@redhat.com>
Acked-by: David Howells <dhowells@redhat.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Tag ptrace breakpoints with the exclude_kernel attribute set. This
will make it easier to set generic policies on breakpoints, when it
comes to ensure nobody unpriviliged try to breakpoint on the kernel.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Paul Mundt <lethal@linux-sh.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Cc: K. Prasad <prasad@linux.vnet.ibm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ingo Molnar <mingo@elte.hu>
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.
percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.
http://userweb.kernel.org/~tj/misc/slabh-sweep.py
The script does the followings.
* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.
* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.
* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.
The conversion was done in the following steps.
1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.
2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.
3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.
4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.
5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.
6. percpu.h was updated not to include slab.h.
7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).
* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig
8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.
Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.
Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
Support for the PMU's BTS features has been upstreamed in
v2.6.32, but we still have the old and disabled ptrace-BTS,
as Linus noticed it not so long ago.
It's buggy: TIF_DEBUGCTLMSR is trampling all over that MSR without
regard for other uses (perf) and doesn't provide the flexibility
needed for perf either.
Its users are ptrace-block-step and ptrace-bts, since ptrace-bts
was never used and ptrace-block-step can be implemented using a
much simpler approach.
So axe all 3000 lines of it. That includes the *locked_memory*()
APIs in mm/mlock.c as well.
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Roland McGrath <roland@redhat.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Markus Metzger <markus.t.metzger@intel.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
LKML-Reference: <20100325135413.938004390@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
When the user enables breakpoints through dr7, he can choose
between "local" or "global" enable bits but given how linux is
implemented, both have the same effect.
That said we don't keep track how the user enabled the breakpoints
so when the user requests the dr7 value, we only translate the
"enabled" status using the global enabled bits. It means that if
the user enabled a breakpoint using the local enabled bit, reading
back dr7 will set the global bit and clear the local one.
Apps like Wine expect a full dr7 POKEUSER/PEEKUSER match for emulated
softwares that implement old reverse engineering protection schemes.
We fix that by keeping track of the whole dr7 value given by the user
in the thread structure to drop this bug. We'll think about
something more proper later.
This fixes a 2.6.32 - 2.6.33-x ptrace regression.
Reported-and-tested-by: Michael Stefaniuc <mstefani@redhat.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: K.Prasad <prasad@linux.vnet.ibm.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Maneesh Soni <maneesh@linux.vnet.ibm.com>
Cc: Alexandre Julliard <julliard@winehq.org>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Maciej Rutecki <maciej.rutecki@gmail.com>
Add the xstate regset support which helps extend the kernel ptrace and the
core-dump interfaces to support AVX state etc.
This regset interface is designed to support all the future state that gets
supported using xsave/xrstor infrastructure.
Looking at the memory layout saved by "xsave", one can't say which state
is represented in the memory layout. This is because if a particular state is
in init state, in the xsave hdr it can be represented by bit '0'. And hence
we can't really say by the xsave header wether a state is in init state or
the state is not saved in the memory layout.
And hence the xsave memory layout available through this regset
interface uses SW usable bytes [464..511] to convey what state is represented
in the memory layout.
First 8 bytes of the sw_usable_bytes[464..467] will be set to OS enabled xstate
mask(which is same as the 64bit mask returned by the xgetbv's xCR0).
The note NT_X86_XSTATE represents the extended state information in the
core file, using the above mentioned memory layout.
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
LKML-Reference: <20100211195614.802495327@sbs-t61.sc.intel.com>
Signed-off-by: Hongjiu Lu <hjl.tools@gmail.com>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Some comments misspell "should" or "shouldn't"; this fixes them. No code changes.
Signed-off-by: Adam Buchbinder <adam.buchbinder@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Because of dropping function argument syntax from kprobe-tracer,
we don't need this API anymore.
Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: systemtap <systemtap@sources.redhat.com>
Cc: DLE <dle-develop@lists.sourceforge.net>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Michael Neuling <mikey@neuling.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: linuxppc-dev@ozlabs.org
LKML-Reference: <20100105224656.19431.92588.stgit@dhcp-100-2-132.bos.redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The loop condition is fragile: we compare an unsigned value to zero, and
then decrement it by something larger than one in the loop. All the
callers should be passing in appropriately aligned buffer lengths, but
it's better to just not rely on it, and have some appropriate defensive
loop limits.
Acked-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Suggested by Roland.
Unlike powepc, x86 always calls tracehook_report_syscall_exit(step) with
step = 0, and sends the trap by hand.
This results in unnecessary SIGTRAP when PTRACE_SINGLESTEP follows the
syscall-exit stop.
Change syscall_trace_leave() to pass the correct "step" argument to
tracehook and remove the send_sigtrap() logic.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Roland McGrath <roland@redhat.com>
Cc: <linux-arch@vger.kernel.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Suggested by Roland.
Implement user_single_step_siginfo() for x86. Extract this code from
send_sigtrap().
Since x86 calls tracehook_report_syscall_exit(step => 0) the new helper is
not used yet.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Roland McGrath <roland@redhat.com>
Cc: <linux-arch@vger.kernel.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently, when ptrace needs to modify a breakpoint, like disabling
it, changing its address, type or len, it calls
modify_user_hw_breakpoint(). This latter will perform the heavy and
racy task of unregistering the old breakpoint and registering a new
one.
This is racy as someone else might steal the reserved breakpoint
slot under us, which is undesired as the breakpoint is only
supposed to be modified, sometimes in the middle of a debugging
workflow. We don't want our slot to be stolen in the middle.
So instead of unregistering/registering the breakpoint, just
disable it while we modify its breakpoint fields and re-enable it
after if necessary.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Prasad <prasad@linux.vnet.ibm.com>
LKML-Reference: <1260347148-5519-1-git-send-regression-fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
struct perf_event::event callback was called when a breakpoint
triggers. But this is a rather opaque callback, pretty
tied-only to the breakpoint API and not really integrated into perf
as it triggers even when we don't overflow.
We prefer to use overflow_handler() as it fits into the perf events
rules, being called only when we overflow.
Reported-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: "K. Prasad" <prasad@linux.vnet.ibm.com>
Drop the callback and task parameters from modify_user_hw_breakpoint().
For now we have no user that need to modify a breakpoint to the point
of changing its handler or its task context.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: "K. Prasad" <prasad@linux.vnet.ibm.com>
When we disable a breakpoint through dr7, we unregister it right
away, making us lose track of its corresponding address
register value.
It means that the following sequence would be unsupported:
- set address in dr0
- enable it through dr7
- disable it through dr7
- enable it through dr7
because we lost the address register value when we disabled the
breakpoint.
Don't unregister the disabled breakpoints but rather disable
them.
Reported-by: "K.Prasad" <prasad@linux.vnet.ibm.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <1259735536-9236-1-git-send-regression-fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
In-kernel user breakpoints are created using functions in which
we pass breakpoint parameters as individual variables: address,
length and type.
Although it fits well for x86, this just does not scale across
archictectures that may support this api later as these may have
more or different needs. Pass in a perf_event_attr structure
instead because it is meant to evolve as much as possible into
a generic hardware breakpoint parameter structure.
Reported-by: K.Prasad <prasad@linux.vnet.ibm.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <1259294154-5197-1-git-send-regression-fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This simplifies the error handling when we create a breakpoint.
We don't need to check the NULL return value corner case anymore
since we have improved perf_event_create_kernel_counter() to
always return an error code in the failure case.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Prasad <prasad@linux.vnet.ibm.com>
LKML-Reference: <1259210142-5714-3-git-send-regression-fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Conflicts:
arch/x86/kernel/kprobes.c
kernel/trace/Makefile
Merge reason: hw-breakpoints perf integration is looking
good in testing and in reviews, plus conflicts
are mounting up - so merge & resolve.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This patch rebase the implementation of the breakpoints API on top of
perf events instances.
Each breakpoints are now perf events that handle the
register scheduling, thread/cpu attachment, etc..
The new layering is now made as follows:
ptrace kgdb ftrace perf syscall
\ | / /
\ | / /
/
Core breakpoint API /
/
| /
| /
Breakpoints perf events
|
|
Breakpoints PMU ---- Debug Register constraints handling
(Part of core breakpoint API)
|
|
Hardware debug registers
Reasons of this rewrite:
- Use the centralized/optimized pmu registers scheduling,
implying an easier arch integration
- More powerful register handling: perf attributes (pinned/flexible
events, exclusive/non-exclusive, tunable period, etc...)
Impact:
- New perf ABI: the hardware breakpoints counters
- Ptrace breakpoints setting remains tricky and still needs some per
thread breakpoints references.
Todo (in the order):
- Support breakpoints perf counter events for perf tools (ie: implement
perf_bpcounter_event())
- Support from perf tools
Changes in v2:
- Follow the perf "event " rename
- The ptrace regression have been fixed (ptrace breakpoint perf events
weren't released when a task ended)
- Drop the struct hw_breakpoint and store generic fields in
perf_event_attr.
- Separate core and arch specific headers, drop
asm-generic/hw_breakpoint.h and create linux/hw_breakpoint.h
- Use new generic len/type for breakpoint
- Handle off case: when breakpoints api is not supported by an arch
Changes in v3:
- Fix broken CONFIG_KVM, we need to propagate the breakpoint api
changes to kvm when we exit the guest and restore the bp registers
to the host.
Changes in v4:
- Drop the hw_breakpoint_restore() stub as it is only used by KVM
- EXPORT_SYMBOL_GPL hw_breakpoint_restore() as KVM can be built as a
module
- Restore the breakpoints unconditionally on kvm guest exit:
TIF_DEBUG_THREAD doesn't anymore cover every cases of running
breakpoints and vcpu->arch.switch_db_regs might not always be
set when the guest used debug registers.
(Waiting for a reliable optimization)
Changes in v5:
- Split-up the asm-generic/hw-breakpoint.h moving to
linux/hw_breakpoint.h into a separate patch
- Optimize the breakpoints restoring while switching from kvm guest
to host. We only want to restore the state if we have active
breakpoints to the host, otherwise we don't care about messed-up
address registers.
- Add asm/hw_breakpoint.h to Kbuild
- Fix bad breakpoint type in trace_selftest.c
Changes in v6:
- Fix wrong header inclusion in trace.h (triggered a build
error with CONFIG_FTRACE_SELFTEST
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Prasad <prasad@linux.vnet.ibm.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Jan Kiszka <jan.kiszka@web.de>
Cc: Jiri Slaby <jirislaby@gmail.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Avi Kivity <avi@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Conflicts:
kernel/Makefile
kernel/trace/Makefile
kernel/trace/trace.h
samples/Makefile
Merge reason: We need to be uptodate with the perf events development
branch because we plan to rewrite the breakpoints API on top of
perf events.
The 32-bit ptrace syscall on a 64-bit kernel (32-bit debugger on
32-bit task) behaves differently than a native 32-bit kernel. When
setting a register state of orig_eax>=0 and eax=-ERESTART* when the
debugged task is NOT on its way out of a 32-bit syscall, the task will
fail to do the syscall restart logic that it should do.
Test case available at http://sources.redhat.com/cgi-bin/cvsweb.cgi/~checkout~/tests/ptrace-tests/tests/erestartsys-trap.c?cvsroot=systemtap
This happens because the 32-bit ptrace syscall sets eax=0xffffffff
when it sets orig_eax>=0. The resuming task will not sign-extend this
for the -ERESTART* check because TS_COMPAT is not set. (So the task
thinks it is restarting after a 64-bit syscall, not a 32-bit one.)
The fix is to have 32-bit ptrace calls set TS_COMPAT when setting
orig_eax>=0. This ensures that the 32-bit syscall restart logic
will apply when the child resumes.
Signed-off-by: Roland McGrath <roland@redhat.com>
Fix regs_get_argument_nth() to add correct offset bytes. Because
offset_of() returns offset in byte, the offset should be added
to char * instead of unsigned long *.
Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Jim Keniston <jkenisto@us.ibm.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Frank Ch. Eigler <fche@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Jason Baron <jbaron@redhat.com>
Cc: K.Prasad <prasad@linux.vnet.ibm.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Tom Zanussi <tzanussi@gmail.com>
LKML-Reference: <20090910235306.22412.31613.stgit@dhcp-100-2-132.bos.redhat.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Conflicts:
arch/Kconfig
kernel/trace/trace.h
Merge reason: resolve the conflicts, plus adopt to the new
ring-buffer APIs.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Add following APIs for accessing registers and stack entries from
pt_regs.
These APIs are required by kprobes-based event tracer on ftrace.
Some other debugging tools might be able to use it too.
- regs_query_register_offset(const char *name)
Query the offset of "name" register.
- regs_query_register_name(unsigned int offset)
Query the name of register by its offset.
- regs_get_register(struct pt_regs *regs, unsigned int offset)
Get the value of a register by its offset.
- regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr)
Check the address is in the kernel stack.
- regs_get_kernel_stack_nth(struct pt_regs *reg, unsigned int nth)
Get Nth entry of the kernel stack. (N >= 0)
- regs_get_argument_nth(struct pt_regs *reg, unsigned int nth)
Get Nth argument at function call. (N >= 0)
Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Cc: linux-arch@vger.kernel.org
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Avi Kivity <avi@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Frank Ch. Eigler <fche@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Jason Baron <jbaron@redhat.com>
Cc: Jim Keniston <jkenisto@us.ibm.com>
Cc: K.Prasad <prasad@linux.vnet.ibm.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Przemysław Pawełczyk <przemyslaw@pawelczyk.it>
Cc: Roland McGrath <roland@redhat.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Tom Zanussi <tzanussi@gmail.com>
Cc: Vegard Nossum <vegard.nossum@gmail.com>
LKML-Reference: <20090813203444.31965.26374.stgit@localhost.localdomain>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
This converts the syscall_enter/exit tracepoints into TRACE_EVENTs, so
you can have generic ftrace events that capture all system calls with
arguments and return values. These generic events are also renamed to
sys_enter/exit, so they're more closely aligned to the specific
sys_enter_foo events.
Signed-off-by: Josh Stone <jistone@redhat.com>
Cc: Jason Baron <jbaron@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Jiaying Zhang <jiayingz@google.com>
Cc: Martin Bligh <mbligh@google.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
LKML-Reference: <1251150194-1713-5-git-send-email-jistone@redhat.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
It's not strictly correct for the tracepoint reg/unreg callbacks to
occur when a client is hooking up, because the actual tracepoint may not
be present yet. This happens to be fine for syscall, since that's in
the core kernel, but it would cause problems for tracepoints defined in
a module that hasn't been loaded yet. It also means the reg/unreg has
to be EXPORTed for any modules to use the tracepoint (as in SystemTap).
This patch removes DECLARE_TRACE_WITH_CALLBACK, and instead introduces
DEFINE_TRACE_FN which stores the callbacks in struct tracepoint. The
callbacks are used now when the active state of the tracepoint changes
in set_tracepoint & disable_tracepoint.
This also introduces TRACE_EVENT_FN, so ftrace events can also provide
registration callbacks if needed.
Signed-off-by: Josh Stone <jistone@redhat.com>
Cc: Jason Baron <jbaron@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Jiaying Zhang <jiayingz@google.com>
Cc: Martin Bligh <mbligh@google.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
LKML-Reference: <1251150194-1713-4-git-send-email-jistone@redhat.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
s/HAVE_FTRACE_SYSCALLS/HAVE_SYSCALL_TRACEPOINTS/g
s/TIF_SYSCALL_FTRACE/TIF_SYSCALL_TRACEPOINT/g
The syscall enter/exit tracing is no longer specific to just ftrace, so
they now have names that reflect their tie to tracepoints instead.
Signed-off-by: Josh Stone <jistone@redhat.com>
Cc: Jason Baron <jbaron@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Jiaying Zhang <jiayingz@google.com>
Cc: Martin Bligh <mbligh@google.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
LKML-Reference: <1251150194-1713-2-git-send-email-jistone@redhat.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
This sparse warning:
arch/x86/kernel/ptrace.c:560:15: warning: symbol 'ptrace_get_debugreg' was not declared. Should it be static?
triggers because ptrace_get_debugreg() is global but is only
used in a single .c file. change ptrace_get_debugreg() to
static to fix that - this also addresses the sparse warning.
Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <1246458150.6940.19.camel@hpdv5.satnam>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This patch modifies the ptrace code to use the new wrapper routines around the
debug/breakpoint registers.
[ Impact: adapt x86 ptrace to the new breakpoint Api ]
Original-patch-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: K.Prasad <prasad@linux.vnet.ibm.com>
Signed-off-by: Maneesh Soni <maneesh@linux.vnet.ibm.com>
Reviewed-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
The generic hardware breakpoint interface provides an abstraction of
hardware breakpoints in front of specific arch implementations for both kernel
and user side breakpoints.
This includes execution breakpoints and read/write breakpoints, also known as
"watchpoints".
This patch introduces header files containing constants, structure definitions
and declaration of functions used by the hardware breakpoint core and x86
specific code.
It also introduces an array based storage for the debug-register values in
'struct thread_struct', while modifying all users of debugreg<n> member in the
structure.
[ Impact: add headers for new hardware breakpoint interface ]
Original-patch-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: K.Prasad <prasad@linux.vnet.ibm.com>
Reviewed-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
The current mm interface is asymetric. One function allocates a locked
buffer, another function only refunds the memory.
Change this to have two functions for accounting and refunding locked
memory, respectively; and do the actual buffer allocation in ptrace.
[ Impact: refactor BTS buffer allocation code ]
Signed-off-by: Markus Metzger <markus.t.metzger@intel.com>
Acked-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20090424095143.A30265@sedona.ch.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Conflicts:
arch/x86/kernel/ptrace.c
Merge reason: fix the conflict above, and also pick up the CONFIG_BROKEN
dependency change from upstream so that we can remove it
here.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: fix build warnings and possibe compat misbehavior on IA64
Building a kernel on ia64 might trigger these ugly build warnings:
CC arch/ia64/ia32/sys_ia32.o
In file included from arch/ia64/ia32/sys_ia32.c:55:
arch/ia64/ia32/ia32priv.h:290:1: warning: "elf_check_arch" redefined
In file included from include/linux/elf.h:7,
from include/linux/module.h:14,
from include/linux/ftrace.h:8,
from include/linux/syscalls.h:68,
from arch/ia64/ia32/sys_ia32.c:18:
arch/ia64/include/asm/elf.h:19:1: warning: this is the location of the previous definition
[...]
sys_ia32.c includes linux/syscalls.h which in turn includes linux/ftrace.h
to import the syscalls tracing prototypes.
But including ftrace.h can pull too much things for a low level file,
especially on ia64 where the ia32 private headers conflict with higher
level headers.
Now we isolate the syscall tracing headers in their own lightweight file.
Reported-by: Tony Luck <tony.luck@intel.com>
Tested-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Jason Baron <jbaron@redhat.com>
Cc: "Frank Ch. Eigler" <fche@redhat.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Jiaying Zhang <jiayingz@google.com>
Cc: Michael Rubin <mrubin@google.com>
Cc: Martin Bligh <mbligh@google.com>
Cc: Michael Davidson <md@google.com>
LKML-Reference: <20090408184058.GB6017@nowhere>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Add the ptrace bts context field to task_struct unconditionally.
Initialize the field directly in copy_process().
Remove all the unneeded functionality used to initialize that field.
Signed-off-by: Markus Metzger <markus.t.metzger@intel.com>
Cc: roland@redhat.com
Cc: eranian@googlemail.com
Cc: oleg@redhat.com
Cc: juan.villacis@intel.com
Cc: ak@linux.jf.intel.com
LKML-Reference: <20090403144603.292754000@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The hw-branch-tracer uses debug store functions from an on_each_cpu()
context, which is simply wrong since the functions may sleep.
Add _noirq variants for most functions, which may be called with
interrupts disabled.
Separate per-cpu and per-task tracing and allow per-cpu tracing to be
controlled from any cpu.
Make the hw-branch-tracer use the new debug store interface, synchronize
with hotplug cpu event using get/put_online_cpus(), and remove the
unnecessary spinlock.
Make the ptrace bts and the ds selftest code use the new interface.
Defer the ds selftest.
Signed-off-by: Markus Metzger <markus.t.metzger@intel.com>
Cc: roland@redhat.com
Cc: eranian@googlemail.com
Cc: oleg@redhat.com
Cc: juan.villacis@intel.com
Cc: ak@linux.jf.intel.com
LKML-Reference: <20090403144555.658136000@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
When a ptraced task is unlinked, we need to stop branch tracing for
that task.
Since the unlink is called with interrupts disabled, and we need
interrupts enabled to stop branch tracing, we defer the work.
Collect all branch tracing related stuff in a branch tracing context.
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Markus Metzger <markus.t.metzger@intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: roland@redhat.com
Cc: eranian@googlemail.com
Cc: juan.villacis@intel.com
Cc: ak@linux.jf.intel.com
LKML-Reference: <20090403144550.712401000@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* 'tracing-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (413 commits)
tracing, net: fix net tree and tracing tree merge interaction
tracing, powerpc: fix powerpc tree and tracing tree interaction
ring-buffer: do not remove reader page from list on ring buffer free
function-graph: allow unregistering twice
trace: make argument 'mem' of trace_seq_putmem() const
tracing: add missing 'extern' keywords to trace_output.h
tracing: provide trace_seq_reserve()
blktrace: print out BLK_TN_MESSAGE properly
blktrace: extract duplidate code
blktrace: fix memory leak when freeing struct blk_io_trace
blktrace: fix blk_probes_ref chaos
blktrace: make classic output more classic
blktrace: fix off-by-one bug
blktrace: fix the original blktrace
blktrace: fix a race when creating blk_tree_root in debugfs
blktrace: fix timestamp in binary output
tracing, Text Edit Lock: cleanup
tracing: filter fix for TRACE_EVENT_FORMAT events
ftrace: Using FTRACE_WARN_ON() to check "freed record" in ftrace_release()
x86: kretprobe-booster interrupt emulation code fix
...
Fix up trivial conflicts in
arch/parisc/include/asm/ftrace.h
include/linux/memory.h
kernel/extable.c
kernel/module.c
Container-init must behave like global-init to processes within the
container and hence it must be immune to unhandled fatal signals from
within the container (i.e SIG_DFL signals that terminate the process).
But the same container-init must behave like a normal process to processes
in ancestor namespaces and so if it receives the same fatal signal from a
process in ancestor namespace, the signal must be processed.
Implementing these semantics requires that send_signal() determine pid
namespace of the sender but since signals can originate from workqueues/
interrupt-handlers, determining pid namespace of sender may not always be
possible or safe.
This patchset implements the design/simplified semantics suggested by
Oleg Nesterov. The simplified semantics for container-init are:
- container-init must never be terminated by a signal from a
descendant process.
- container-init must never be immune to SIGKILL from an ancestor
namespace (so a process in parent namespace must always be able
to terminate a descendant container).
- container-init may be immune to unhandled fatal signals (like
SIGUSR1) even if they are from ancestor namespace. SIGKILL/SIGSTOP
are the only reliable signals to a container-init from ancestor
namespace.
This patch:
Based on an earlier patch submitted by Oleg Nesterov and comments from
Roland McGrath (http://lkml.org/lkml/2008/11/19/258).
The handler parameter is currently unused in the tracehook functions.
Besides, the tracehook functions are called with siglock held, so the
functions can check the handler if they later need to.
Removing the parameter simiplifies changes to sig_ignored() in a follow-on
patch.
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Acked-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Daniel Lezcano <daniel.lezcano@free.fr>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit c2724775ce put a statement
after return, which makes that statement unreachable.
Move that statement before return.
Signed-off-by: WANG Cong <xiyou.wangcong@gmail.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: Markus Metzger <markus.t.metzger@intel.com>
LKML-Reference: <20090313075622.GB8933@hack>
Cc: <stable@kernel.org> # .29 only
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Provide the x86 trace callbacks to trace syscalls.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
LKML-Reference: <1236401580-5758-3-git-send-email-fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
On x86-64, a 32-bit process (TIF_IA32) can switch to 64-bit mode with
ljmp, and then use the "syscall" instruction to make a 64-bit system
call. A 64-bit process make a 32-bit system call with int $0x80.
In both these cases, audit_syscall_entry() will use the wrong system
call number table and the wrong system call argument registers. This
could be used to circumvent a syscall audit configuration that filters
based on the syscall numbers or argument details.
Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Impact: cleanup
Rename TASK_SIZE64 to TASK_SIZE_MAX, and provide the
define on 32-bit too. (mapped to TASK_SIZE)
This allows 32-bit code to make use of the (former-) TASK_SIZE64
symbol as well, in a clean way.
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Ptrace_detach() races with __ptrace_unlink() if the traced task is
reaped while detaching. This might cause a double-free of the BTS
buffer.
Change the ptrace_detach() path to only do the memory accounting in
ptrace_bts_detach() and leave the buffer free to ptrace_bts_untrace()
which will be called from __ptrace_unlink().
The fix follows a proposal from Oleg Nesterov.
Reported-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Markus Metzger <markus.t.metzger@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: pt_regs changed, lazy gs handling made optional, add slight
overhead to SAVE_ALL, simplifies error_code path a bit
On x86_32, %gs hasn't been used by kernel and handled lazily. pt_regs
doesn't have place for it and gs is saved/loaded only when necessary.
In preparation for stack protector support, this patch makes lazy %gs
handling optional by doing the followings.
* Add CONFIG_X86_32_LAZY_GS and place for gs in pt_regs.
* Save and restore %gs along with other registers in entry_32.S unless
LAZY_GS. Note that this unfortunately adds "pushl $0" on SAVE_ALL
even when LAZY_GS. However, it adds no overhead to common exit path
and simplifies entry path with error code.
* Define different user_gs accessors depending on LAZY_GS and add
lazy_save_gs() and lazy_load_gs() which are noop if !LAZY_GS. The
lazy_*_gs() ops are used to save, load and clear %gs lazily.
* Define ELF_CORE_COPY_KERNEL_REGS() which always read %gs directly.
xen and lguest changes need to be verified.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: cleanup
On x86_32, %gs is handled lazily. It's not saved and restored on
kernel entry/exit but only when necessary which usually is during task
switch but there are few other places. Currently, it's done by
calling savesegment() and loadsegment() explicitly. Define
get_user_gs(), set_user_gs() and task_user_gs() and use them instead.
While at it, clean up register access macros in signal.c.
This cleans up code a bit and will help future changes.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: move the BTS buffer accounting to the mlock bucket
Add alloc_locked_buffer() and free_locked_buffer() functions to mm/mlock.c
to kalloc a buffer and account the locked memory to current.
Account the memory for the BTS buffer to the tracer.
Signed-off-by: Markus Metzger <markus.t.metzger@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: introduce new ptrace facility
Add arch_ptrace_untrace() function that is called when the tracer
detaches (either voluntarily or when the tracing task dies);
ptrace_disable() is only called on a voluntary detach.
Add ptrace_fork() and arch_ptrace_fork(). They are called when a
traced task is forked.
Clear DS and BTS related fields on fork.
Release DS resources and reclaim memory in ptrace_untrace(). This
releases resources already when the tracing task dies. We used to do
that when the traced task dies.
Signed-off-by: Markus Metzger <markus.t.metzger@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: cleanup
Move the BTS bits from ptrace.c into ds.c.
Signed-off-by: Markus Metzger <markus.t.metzger@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: make the ds code more debuggable
Turn BUG_ON's into WARN_ON_ONCE.
Signed-off-by: Markus Metzger <markus.t.metzger@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: restructure DS memory allocation to be done by the usage site of DS
Require pre-allocated buffers in ds.h.
Move the BTS buffer allocation for ptrace into ptrace.c.
The pointer to the allocated buffer is stored in the traced task's
task_struct together with the handle returned by ds_request_bts().
Removes memory accounting code.
Signed-off-by: Markus Metzger <markus.t.metzger@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: generalize the DS code to shared buffers
Change the in-kernel ds.h interface to identify the tracer via a
handle returned on ds_request_~().
Tracers used to be identified via their task_struct.
The changes are required to allow DS to be shared between different
tasks, which is needed for perfmon2 and for ftrace.
For ptrace, the handle is stored in the traced task's task_struct.
This should probably go into a (arch-specific) ptrace context some
time.
Signed-off-by: Markus Metzger <markus.t.metzger@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: widen BTS/PEBS ptrace enablement to more CPU models
Move BTS initialisation out of an #ifdef CONFIG_X86_64 guard.
Assume core2 BTS and DS layout for future models of family 6 processors.
Signed-off-by: Markus Metzger <markus.t.metzger@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This adds a user_regset type for the x86 io permissions bitmap.
This makes it appear in core dumps (when ioperm has been used).
It will also make it visible to debuggers in the future.
Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
[conflict resolutions: Signed-off-by: Ingo Molnar <mingo@elte.hu> ]
fix:
arch/x86/kernel/ptrace.c:763:29: warning: Using plain integer as NULL pointer
arch/x86/kernel/ptrace.c:777:46: warning: Using plain integer as NULL pointer
arch/x86/kernel/ptrace.c:1115:45: warning: Using plain integer as NULL pointer
arch/x86/kernel/ds.c:482:26: warning: Using plain integer as NULL pointer
arch/x86/kernel/ds.c:487:25: warning: Using plain integer as NULL pointer
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Acked-by: Cyrill Gorcunov <gorcunov@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Currently a SIGTRAP can denote any one of below reasons.
- Breakpoint hit
- H/W debug register hit
- Single step
- Signal sent through kill() or rasie()
Architectures like powerpc/parisc provides infrastructure to demultiplex
SIGTRAP signal by passing down the information for receiving SIGTRAP through
si_code of siginfot_t structure. Here is an attempt is generalise this
infrastructure by extending it to x86 and x86_64 archs.
Signed-off-by: Srinivasa DS <srinivasa@in.ibm.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: akpm@linux-foundation.org
Cc: paulus@samba.org
Cc: linuxppc-dev@ozlabs.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This changes x86 syscall tracing to use the new tracehook.h entry points.
There is no change, only cleanup.
Signed-off-by: Roland McGrath <roland@redhat.com>
This closes some arcane holes in single-step handling that can arise
only when user programs set TF directly (via popf or sigreturn) and
then use vDSO (syscall/sysenter) system call entry. In those entry
paths, the clear_TF_reenable case hits and we must check TIF_SINGLESTEP
to be sure our bookkeeping stays correct wrt the user's view of TF.
Signed-off-by: Roland McGrath <roland@redhat.com>
This unifies and cleans up the syscall tracing code on i386 and x86_64.
Using a single function for entry and exit tracing on 32-bit made the
do_syscall_trace() into some terrible spaghetti. The logic is clear and
simple using separate syscall_trace_enter() and syscall_trace_leave()
functions as on 64-bit.
The unification adds PTRACE_SYSEMU and PTRACE_SYSEMU_SINGLESTEP support
on x86_64, for 32-bit ptrace() callers and for 64-bit ptrace() callers
tracing either 32-bit or 64-bit tasks. It behaves just like 32-bit.
Changing syscall_trace_enter() to return the syscall number shortens
all the assembly paths, while adding the SYSEMU feature in a simple way.
Signed-off-by: Roland McGrath <roland@redhat.com>
ptrace has always returned only -EIO for all failures to access
registers. The user_regset calls are allowed to return a more
meaningful variety of errors. The REGSET_XFP calls use -ENODEV
for !cpu_has_fxsr hardware. Make ptrace return the traditional
-EIO instead of the error code from the user_regset call.
Signed-off-by: Roland McGrath <roland@redhat.com>
Cc: stable@kernel.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The user_regset_view table for the 32-bit regsets on the 64-bit build had
the wrong sizes for the FP regsets. This bug had no user-visible effect
(just on kernel modules using the user_regset interfaces and the like).
But the fix is trivial and risk-free.
Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Polish the ds.h interface and add support for PEBS.
Ds.c is meant to be the resource allocator for per-thread and per-cpu
BTS and PEBS recording.
It is used by ptrace/utrace to provide execution tracing of debugged tasks.
It will be used by profilers (e.g. perfmon2).
It may be used by kernel debuggers to provide a kernel execution trace.
Changes in detail:
- guard DS and ptrace by CONFIG macros
- separate DS and BTS more clearly
- simplify field accesses
- add functions to manage PEBS buffers
- add simple protection/allocation mechanism
- added support for Atom
Opens:
- buffer overflow handling
Currently, only circular buffers are supported. This is all we need
for debugging. Profilers would want an overflow notification.
This is planned to be added when perfmon2 is made to use the ds.h
interface.
- utrace intermediate layer
Signed-off-by: Markus Metzger <markus.t.metzger@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Now that there are no more special cases in sys32_ptrace, we
can convert to using the generic compat_sys_ptrace entry point.
The sys32_ptrace function gets simpler and becomes compat_arch_ptrace.
Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This removes the special-case handling for PTRACE_GETSIGINFO
and PTRACE_SETSIGINFO from x86_64's sys32_ptrace. The generic
compat_ptrace_request code handles these.
Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
arch/x86/kernel/ptrace.c:548: warning: 'ptrace_bts_get_size' defined but not used
arch/x86/kernel/ptrace.c:558: warning: 'ptrace_bts_read_record' defined but not used
arch/x86/kernel/ptrace.c:607: warning: 'ptrace_bts_clear' defined but not used
arch/x86/kernel/ptrace.c:617: warning: 'ptrace_bts_drain' defined but not used
arch/x86/kernel/ptrace.c:720: warning: 'ptrace_bts_config' defined but not used
arch/x86/kernel/ptrace.c:788: warning: 'ptrace_bts_status' defined but not used
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
The code to restart syscalls after signals depends on checking for a
negative orig_ax, and for particular negative -ERESTART* values in ax.
These fields are 64 bits and for a 32-bit task they get zero-extended.
The syscall restart behavior is lost, a regression from a native 32-bit
kernel and from 64-bit tasks' behavior.
This patch fixes the problem by doing sign-extension where it matters.
For orig_ax, the only time the value should be -1 but winds up as
0x0ffffffff is via a 32-bit ptrace call. So the patch changes ptrace to
sign-extend the 32-bit orig_eax value when it's stored; it doesn't
change the checks on orig_ax, though it uses the new current_syscall()
inline to better document the subtle importance of the used of
signedness there.
The ax value is stored a lot of ways and it seems hard to get them all
sign-extended at their origins. So for that, we use the
current_syscall_ret() to sign-extend it only for 32-bit tasks at the
time of the -ERESTART* comparisons.
Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This makes 64-bit ptrace calls setting the 64-bit orig_ax field for a
32-bit task sign-extend the low 32 bits up to 64. This matches what a
64-bit debugger expects when tracing a 32-bit task.
This follows on my "x86_64 ia32 syscall restart fix". This didn't
matter until that was fixed.
The debugger ignores or zeros the high half of every register slot it
sets (including the orig_rax pseudo-register) uniformly. It expects
that the setting of the low 32 bits always has the same meaning as a
32-bit debugger setting those same 32 bits with native 32-bit
facilities.
This never arose before because the syscall restart check never
matched any -ERESTART* values due to lack of sign extension. Before
that fix, even 32-bit ptrace setting orig_eax to -1 failed to trigger
the restart check anyway. So this was never noticed as a regression
of 64-bit debuggers vs 32-bit debuggers on the same 64-bit kernel.
Signed-off-by: Roland McGrath <roland@redhat.com>
[ Changed to just do the sign-extension unconditionally on x86-64,
since orig_ax is always just a small integer and doesn't need
the full 64-bit range ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
revert the BTS ptrace extension for now.
based on general objections from Roland McGrath:
http://lkml.org/lkml/2008/2/21/323
we'll let the BTS functionality cook some more and re-enable
it in v2.6.26. We'll leave the dead code around to help the
development of this code.
(X86_BTS is not defined at the moment)
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Simple typo fix for regression introduced by the user_regset changes.
Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In my revamp of the x86 ptrace code for setting register values,
I accidentally omitted a check that was there in the old code.
Allowing %cs to be 0 causes a bad crash in recovery from iret failure.
This patch fixes that regression against 2.6.24, and adds a comment
that should help prevent this subtlety from being overlooked again.
Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Return the size of bts_struct in the PTRACE_BTS_STATUS command.
Change types to u32.
Signed-off-by: Markus Metzger <markus.t.metzger@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Pass the buffer size for (most) ptrace commands that pass user-allocated buffers and check that size before accessing the buffer. Unfortunately, PTRACE_BTS_GET already uses all 4 parameters.
Commands that access user buffers return the number of bytes or records read or written.
Signed-off-by: Markus Metzger <markus.t.metzger@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Support BTS recording of 32bit and 64bit tasks from 32bit or 64bit tasks.
Signed-off-by: Markus Metzger <markus.t.metzger@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Check the rlimit of the tracing task for total and locked memory when allocating the BTS buffer.
Signed-off-by: Markus Metzger <markus.t.metzger@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This removes duplicated code by calling the generic ptrace_request and
compat_ptrace_request functions for the things they already handle.
Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This makes ELF core dumps of 32-bit processes include a new
note type NT_386_TLS (0x200) giving the contents of the TLS
slots in struct user_desc format. This lets post mortem
examination figure out what the segment registers mean like
the debugger does with get_thread_area on a live process.
Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
