Commit Graph

200 Commits

Author SHA1 Message Date
Adam Buchbinder c9404c9c39 Fix misspelling of "should" and "shouldn't" in comments.
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>
2010-02-05 12:22:30 +01:00
Masami Hiramatsu aa5add93e9 x86/ptrace: Remove unused regs_get_argument_nth API
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>
2010-01-13 10:09:12 +01:00
Linus Torvalds 04a1e62c2c x86/ptrace: make genregs[32]_get/set more robust
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>
2009-12-17 07:04:56 -08:00
Oleg Nesterov d519650373 ptrace: x86: change syscall_trace_leave() to rely on tracehook when stepping
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>
2009-12-16 07:20:08 -08:00
Oleg Nesterov 7f38551fc3 ptrace: x86: implement user_single_step_siginfo()
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>
2009-12-16 07:20:08 -08:00
Frederic Weisbecker 44234adcdc hw-breakpoints: Modify breakpoints without unregistering them
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>
2009-12-09 09:48:20 +01:00
Frederic Weisbecker b326e9560a hw-breakpoints: Use overflow handler instead of the event callback
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>
2009-12-06 08:27:18 +01:00
Frederic Weisbecker 2f0993e0fb hw-breakpoints: Drop callback and task parameters from modify helper
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>
2009-12-06 08:27:17 +01:00
Frederic Weisbecker 1cedae7290 hw-breakpoints: Keep track of user disabled breakpoints
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>
2009-12-02 09:59:03 +01:00
Frederic Weisbecker 5fa10b28e5 hw-breakpoints: Use struct perf_event_attr to define user breakpoints
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>
2009-11-27 06:22:58 +01:00
Frederic Weisbecker 605bfaee90 hw-breakpoints: Simplify error handling in breakpoint creation requests
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>
2009-11-26 09:29:21 +01:00
Ingo Molnar 96200591a3 Merge branch 'tracing/hw-breakpoints' into perf/core
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>
2009-11-21 14:07:23 +01:00
Frederic Weisbecker 24f1e32c60 hw-breakpoints: Rewrite the hw-breakpoints layer on top of perf events
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>
2009-11-08 15:34:42 +01:00
Frederic Weisbecker 0f8f86c7bd Merge commit 'perf/core' into perf/hw-breakpoint
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.
2009-10-18 01:12:33 +02:00
Frederic Weisbecker d7a4b414ee Merge commit 'linus/master' into tracing/kprobes
Conflicts:
	kernel/trace/Makefile
	kernel/trace/trace.h
	kernel/trace/trace_event_types.h
	kernel/trace/trace_export.c

Merge reason:
	Sync with latest significant tracing core changes.
2009-09-23 23:08:43 +02:00
Roland McGrath 8cb3ed1393 x86: ptrace: set TS_COMPAT when 32-bit ptrace sets orig_eax>=0
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>
2009-09-22 22:49:24 -07:00
Roland McGrath 08ff18e299 x86: ptrace: do not sign-extend orig_ax on write
The high 32 bits of orig_ax will be ignored when it matters,
so don't fiddle them when setting it.

Signed-off-by: Roland McGrath <roland@redhat.com>
2009-09-22 22:46:48 -07:00
Masami Hiramatsu ad5cafcdb0 x86/ptrace: Fix regs_get_argument_nth() to add correct offset
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>
2009-09-11 04:14:24 +02:00
Ingo Molnar a1922ed661 Merge branch 'tracing/core' into tracing/hw-breakpoints
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>
2009-09-07 08:19:51 +02:00
Masami Hiramatsu b1cf540f0e x86: Add pt_regs register and stack access APIs
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>
2009-08-27 00:35:57 +02:00
Josh Stone 1c569f0264 tracing: Create generic syscall TRACE_EVENTs
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>
2009-08-26 00:41:48 +02:00
Josh Stone 9741987586 tracing: Move tracepoint callbacks from declaration to definition
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>
2009-08-26 00:36:41 +02:00
Josh Stone 6670000119 tracing: Rename FTRACE_SYSCALLS for tracepoints
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>
2009-08-26 00:17:35 +02:00
Jason Baron a871bd33a6 tracing: Add syscall tracepoints
add two tracepoints in syscall exit and entry path, conditioned on
TIF_SYSCALL_FTRACE. Supports the syscall trace event code.

Signed-off-by: Jason Baron <jbaron@redhat.com>
Cc: Lai Jiangshan <laijs@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: Li Zefan <lizf@cn.fujitsu.com>
Cc: Masami Hiramatsu <mhiramat@redhat.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2009-08-11 20:35:26 +02:00
Jaswinder Singh Rajput 9d22b53660 x86: Mark ptrace_get_debugreg() as static
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>
2009-07-01 16:53:27 +02:00
K.Prasad 72f674d203 hw-breakpoints: modify Ptrace routines to access breakpoint registers
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>
2009-06-02 22:46:59 +02:00
K.Prasad b332828c39 hw-breakpoints: prepare the code for Hardware Breakpoint interfaces
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>
2009-06-02 22:46:57 +02:00
Markus Metzger 1cb81b143f x86, bts, mm: clean up buffer allocation
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>
2009-04-24 10:18:52 +02:00
Ingo Molnar 416dfdcdb8 Merge commit 'v2.6.30-rc3' into tracing/hw-branch-tracing
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>
2009-04-24 10:11:23 +02:00
Frederic Weisbecker 47788c58e6 tracing/syscalls: use a dedicated file header
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>
2009-04-09 05:43:32 +02:00
Markus Metzger 0f4814065f x86, ptrace: add bts context unconditionally
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>
2009-04-07 13:36:31 +02:00
Markus Metzger de79f54f53 x86, bts, hw-branch-tracer: add _noirq variants to the debug store interface
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>
2009-04-07 13:36:20 +02:00
Markus Metzger e2b371f00a mm, x86, ptrace, bts: defer branch trace stopping
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>
2009-04-07 13:36:13 +02:00
Linus Torvalds 714f83d5d9 Merge branch 'tracing-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* '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
2009-04-05 11:04:19 -07:00
Oleg Nesterov 43918f2bf4 signals: remove 'handler' parameter to tracehook functions
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>
2009-04-02 19:04:58 -07:00
Ingo Molnar 8302294f43 Merge branch 'tracing/core-v2' into tracing-for-linus
Conflicts:
	include/linux/slub_def.h
	lib/Kconfig.debug
	mm/slob.c
	mm/slub.c
2009-04-02 00:49:02 +02:00
Américo Wang 5a8ac9d28d x86: ptrace, bts: fix an unreachable statement
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>
2009-03-13 10:27:57 +01:00
Frederic Weisbecker 1b3fa2ce64 tracing/x86: basic implementation of syscall tracing for x86
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>
2009-03-13 06:25:44 +01:00
Ingo Molnar 8b0e5860cb Merge branches 'x86/apic', 'x86/cpu', 'x86/fixmap', 'x86/mm', 'x86/sched', 'x86/setup-lzma', 'x86/signal' and 'x86/urgent' into x86/core 2009-03-04 02:22:31 +01:00
Roland McGrath ccbe495caa x86-64: syscall-audit: fix 32/64 syscall hole
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>
2009-03-02 15:41:30 -08:00
Ingo Molnar d951734654 x86, mm: rename TASK_SIZE64 => TASK_SIZE_MAX
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>
2009-02-21 00:09:44 +01:00
Ingo Molnar 7032e86967 Merge branches 'x86/paravirt', 'x86/pat', 'x86/setup-v2', 'x86/subarch', 'x86/uaccess' and 'x86/urgent' into x86/core 2009-02-13 09:47:32 +01:00
Markus Metzger 9f339e7028 x86, ptrace, mm: fix double-free on race
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>
2009-02-11 15:44:20 +01:00
Tejun Heo ccbeed3a05 x86: make lazy %gs optional on x86_32
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>
2009-02-10 00:42:00 +01:00
Tejun Heo d9a89a26e0 x86: add %gs accessors for x86_32
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>
2009-02-10 00:41:58 +01:00
Markus Metzger c5dee6177f x86, bts: memory accounting
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>
2008-12-20 09:15:47 +01:00
Markus Metzger bf53de907d x86, bts: add fork and exit handling
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>
2008-12-20 09:15:46 +01:00
Markus Metzger c2724775ce x86, bts: provide in-kernel branch-trace interface
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>
2008-12-12 08:08:12 +01:00
Markus Metzger b0884e25fe x86, bts: turn BUG_ON into WARN_ON_ONCE
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>
2008-12-12 08:08:10 +01:00
Markus Metzger 6abb11aecd x86, bts, ptrace: move BTS buffer allocation from ds.c into ptrace.c
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>
2008-11-25 17:31:12 +01:00
Markus Metzger ca0002a179 x86, bts: base in-kernel ds interface on handles
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>
2008-11-25 17:31:11 +01:00
Markus Metzger f4166c54bf x86, bts: DS and BTS initialization
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>
2008-11-10 08:50:32 +01:00
Ingo Molnar 8daf14cf56 Merge branches 'x86/xen', 'x86/build', 'x86/microcode', 'x86/mm-debug-v2', 'x86/memory-corruption-check', 'x86/early-printk', 'x86/xsave', 'x86/ptrace-v2', 'x86/quirks', 'x86/setup', 'x86/spinlocks' and 'x86/signal' into x86/core-v2 2008-10-12 15:50:02 +02:00
Roland McGrath 325af5fb14 x86: ioperm user_regset
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> ]
2008-10-12 12:05:55 +02:00
Ingo Molnar 206855c321 Merge branch 'x86/urgent' into core/signal
Conflicts:
	arch/x86/kernel/signal_64.c
2008-10-12 11:32:17 +02:00
Ingo Molnar b159d7a989 Merge branch 'x86/tracehook' into x86-v28-for-linus-phase1
Conflicts:
	arch/x86/kernel/signal_64.c

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-06 18:16:40 +02:00
Ingo Molnar 0962f402af Merge branch 'x86/prototypes' into x86-v28-for-linus-phase1
Conflicts:
	arch/x86/kernel/process_32.c

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-06 18:06:53 +02:00
Harvey Harrison 493cd9122a x86: ds.c ptrace.c integer as NULL pointer sparse fixes
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>
2008-09-24 09:57:47 +02:00
Srinivasa Ds da654b74bd signals: demultiplexing SIGTRAP signal
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>
2008-09-23 13:26:52 +02:00
Ingo Molnar 046fd53773 Merge branches 'x86/tracehook', 'x86/xsave' and 'x86/prototypes' into x86/signal
Conflicts:
	arch/x86/kernel/signal_64.c

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-06 14:53:01 +02:00
Roland McGrath eeea3c3ff8 x86: tracehook syscall
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>
2008-07-26 14:38:00 -07:00
Ingo Molnar 0e2f65ee30 Merge branch 'linus' into x86/pebs
Conflicts:

	arch/x86/Kconfig.cpu
	arch/x86/kernel/cpu/intel.c
	arch/x86/kernel/setup_64.c

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-25 11:37:07 +02:00
Jaswinder Singh 4fe702c7e4 X86_32: declare pt_regs_access as unsigned long
Fixed pt_regs_access to unsigned long as per X86_64

Signed-off-by: Jaswinder Singh <jaswinder@infradead.org>
2008-07-25 11:56:15 +05:30
Roland McGrath 380fdd7585 x86 ptrace: user-sets-TF nits
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>
2008-07-16 12:15:17 -07:00
Roland McGrath d4d6715016 x86 ptrace: unify syscall tracing
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>
2008-07-16 12:15:17 -07:00
Roland McGrath 45fdc3a762 x86 ptrace: fix PTRACE_GETFPXREGS error
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>
2008-07-01 11:03:31 +02:00
Thomas Gleixner 0e50a4c6ab Merge branch 'linus' into x86/pebs 2008-05-17 16:01:05 +02:00
Roland McGrath 1f465f4e47 x86: user_regset_view table fix for ia32 on 64-bit
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>
2008-05-13 19:40:20 +02:00
Markus Metzger 93fa7636df x86, ptrace: PEBS support
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>
2008-05-12 21:27:53 +02:00
Roland McGrath 562b80baff x86_64 ia32 ptrace: convert to compat_arch_ptrace
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>
2008-04-26 17:35:47 +02:00
Roland McGrath cdb6990479 x86_64 ia32 ptrace: use compat_ptrace_request for siginfo
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>
2008-04-26 17:35:47 +02:00
Harvey Harrison c3e6ff87a3 x86: regparm(3) is mandatory, no need to annotate
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-04-17 17:40:45 +02:00
Andrew Morton d8d4f157b8 x86: ptrace.c: fix defined-but-unused warnings
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>
2008-03-27 16:08:44 +01:00
Roland McGrath 40f0933d51 x86: ia32 syscall restart fix
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>
2008-03-11 17:11:54 +01:00
Roland McGrath 84c6f6046c x86_64: make ptrace always sign-extend orig_ax to 64 bits
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>
2008-03-07 19:05:58 -08:00
Ingo Molnar b4ef95de00 x86: disable BTS ptrace extensions for now
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>
2008-02-29 18:55:42 +01:00
Roland McGrath f9cb02b0be x86 ptrace: fix compat PTRACE_SETREGS
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>
2008-02-22 07:35:06 -08:00
Roland McGrath c63855d040 x86 ptrace: disallow null cs/ss
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>
2008-02-06 22:39:44 +01:00
Markus Metzger 87e8407f9a x86, ptrace: add bts_struct size to status command
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>
2008-01-30 13:32:54 +01:00
Markus Metzger cba4b65d35 x86, ptrace: add buffer size checks
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>
2008-01-30 13:32:03 +01:00
Markus Metzger e6ae5d9540 x86, ptrace: support 32bit-cross-64bit BTS recording
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>
2008-01-30 13:32:03 +01:00
Markus Metzger da35c37198 x86, ptrace: rlimit BTS buffer allocation
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>
2008-01-30 13:32:03 +01:00
Roland McGrath fdadd54db5 x86: x86 ptrace generic requests
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>
2008-01-30 13:31:56 +01:00
Roland McGrath bb61682b3f x86: x86 core dump TLS
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>
2008-01-30 13:31:56 +01:00
Roland McGrath 5a4646a4ef x86: x86 ptrace user_regset
This cleans up the PTRACE_*REGS* request code so each one is just a
simple call to copy_regset_to_user or copy_regset_from_user.  The
ptrace layouts already match the user_regset formats (core dump formats).

Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:31:54 +01:00
Roland McGrath 070459d95e x86: x86 user_regset_view
This defines task_user_regset_view and the tables
describing the x86 user_regset layouts for 32 and 64.

Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:31:53 +01:00
Roland McGrath 91e7b707a4 x86: x86 user_regset general regs
This adds accessor functions in the user_regset style for
the general registers (struct user_regs_struct).

Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:31:52 +01:00
Roland McGrath 4421011120 x86: x86 i387 user_regset
This revamps the i387 code to be shared across 32-bit, 64-bit,
and 32-on-64.  It does so by consolidating the code in one place
based on the user_regset accessor interfaces.  This switches
32-bit to using the i387_64.h header and 64-bit to using the
i387.c that was previously i387_32.c, but that's what took the
least cleanup in each file.  Here i387.h is stubbed to always
include i387_64.h rather than renaming the file, to keep this
diff smaller and easier to read.

Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:31:50 +01:00
Markus Metzger a95d67f87e x86, ptrace: new ptrace BTS API
Here's the new ptrace BTS API that supports two different overflow handling mechanisms (wrap-around and buffer-full-signal) to support two different use cases (debugging and profiling).

It further combines buffer allocation and configuration.

Opens:
- memory rlimit
- overflow signal

What would be the right signal to use?

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>
2008-01-30 13:31:20 +01:00
Markus Metzger e4811f2568 x86, ptrace: change BTS GET ptrace interface
Change the ptrace interface to mimick an array from newst to oldest.

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>
2008-01-30 13:31:20 +01:00
Markus Metzger 3c68904fee x86, ptrace: use jiffies for BTS timestamps
Replace sched_clock() with jiffies for BTS timestamps.

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>
2008-01-30 13:31:20 +01:00
Markus Metzger eee3af4a2c x86, ptrace: support for branch trace store(BTS)
Resend using different mail client

Changes to the last version:
- split implementation into two layers: ds/bts and ptrace
- renamed TIF's
- save/restore ds save area msr in __switch_to_xtra()
- make block-stepping only look at BTF bit

Signed-off-by: Markus Metzger <markus.t.metzger@intel.com>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:31:09 +01:00
Roland McGrath 099cd6e9da x86: x86 ia32 ptrace arch merge
This moves the sys32_ptrace code into arch/x86/kernel/ptrace.c,
verbatim except for a few hard-coded sizes replaced with sizeof.
Here this code can use the shared local functions in this file.

Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:31:01 +01:00
Roland McGrath cb757c41f3 x86: x86 ia32 ptrace getreg/putreg merge
This reimplements the 64-bit IA32-emulation register access
functions in arch/x86/kernel/ptrace.c, where they can share
some guts with the native access functions directly.

These functions are not used yet, but this paves the way to move
IA32 ptrace support into this file to share its local functions.

[akpm@linuxfoundation.org: Build fix]

Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:31:01 +01:00
Roland McGrath 86976cd805 x86: x86 ptrace merge syscall trace
This moves the 64-bit syscall tracing functions into ptrace.c,
so that ptrace_64.c becomes entirely obsolete.

Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:31:01 +01:00
Roland McGrath e9c86c789f x86: x86 ptrace arch merge
This adds 64-bit support to arch_ptrace in arch/x86/kernel/ptrace.c,
so this function can be used for native ptrace on both 32 and 64.

Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:31:01 +01:00
Roland McGrath 2047b08be6 x86: x86 ptrace getreg/putreg merge
This merges 64-bit support into the low-level register access
functions in arch/x86/kernel/ptrace.c, paving the way to share
this file between 32-bit and 64-bit builds.

Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:31:01 +01:00
Roland McGrath 06ee1b687a x86: x86 ptrace getreg/putreg cleanup
This cleans up the getreg/putreg functions to move the special cases
(segment registers and eflags) out into their own subroutines.

Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:31:01 +01:00
Roland McGrath e39c289141 x86: ptrace FLAG_MASK cleanup
This cleans up the FLAG_MASK macro to use symbolic constants instead of a
magic number.

Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:31:01 +01:00
Roland McGrath d52e9d690f x86: ptrace_32 renamed
This renames ptrace_32.c back to ptrace.c, in preparation
for merging the 32/64 versions of these files.

Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:31:01 +01:00