28 May, 2010
2 commits
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Now that Mike Frysinger unified the FDPIC ptrace code, we can fix the
unsafe usage of child->mm in ptrace_request(PTRACE_GETFDPIC).We have the reference to task_struct, and ptrace_check_attach() verified
the tracee is stopped. But nothing can protect from SIGKILL after that,
we must not assume child->mm != NULL.Signed-off-by: Oleg Nesterov
Acked-by: Mike Frysinger
Acked-by: David Howells
Cc: Paul Mundt
Cc: Greg Ungerer
Acked-by: Roland McGrath
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
The Blackfin/FRV/SuperH guys all have the same exact FDPIC ptrace code in
their arch handlers (since they were probably copied & pasted). Since
these ptrace interfaces are an arch independent aspect of the FDPIC code,
unify them in the common ptrace code so new FDPIC ports don't need to copy
and paste this fundamental stuff yet again.Signed-off-by: Mike Frysinger
Acked-by: Roland McGrath
Acked-by: David Howells
Acked-by: Paul Mundt
Cc: Oleg Nesterov
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
18 May, 2010
1 commit
-
…git/tip/linux-2.6-tip
* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (311 commits)
perf tools: Add mode to build without newt support
perf symbols: symbol inconsistency message should be done only at verbose=1
perf tui: Add explicit -lslang option
perf options: Type check all the remaining OPT_ variants
perf options: Type check OPT_BOOLEAN and fix the offenders
perf options: Check v type in OPT_U?INTEGER
perf options: Introduce OPT_UINTEGER
perf tui: Add workaround for slang < 2.1.4
perf record: Fix bug mismatch with -c option definition
perf options: Introduce OPT_U64
perf tui: Add help window to show key associations
perf tui: Make <- exit menus too
perf newt: Add single key shortcuts for zoom into DSO and threads
perf newt: Exit browser unconditionally when CTRL+C, q or Q is pressed
perf newt: Fix the 'A'/'a' shortcut for annotate
perf newt: Make <- exit the ui_browser
x86, perf: P4 PMU - fix counters management logic
perf newt: Make <- zoom out filters
perf report: Report number of events, not samples
perf hist: Clarify events_stats fields usage
...Fix up trivial conflicts in kernel/fork.c and tools/perf/builtin-record.c
27 Apr, 2010
1 commit
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BKL isn't present anymore into this file thus we can safely remove
smp_lock.h inclusion.Signed-off-by: Alessio Igor Bogani
Cc: Roland McGrath
Cc: Oleg Nesterov
Cc: Andrew Morton
Cc: James Morris
Cc: Ingo Molnar
Signed-off-by: Frederic Weisbecker
10 Apr, 2010
1 commit
-
The comment suggests that this usage is stale. There is no bkl in the
exec path so if there is a race lurking there, the bkl in ptrace is
not going to help in this regard.Overview of the possibility of "accidental" races this bkl might
protect:- ptrace_traceme() is protected against task removal and concurrent
read/write on current->ptrace as it locks write tasklist_lock.- arch_ptrace_attach() is serialized by ptrace_traceme() against
concurrent PTRACE_TRACEME or PTRACE_ATTACH- ptrace_attach() is protected the same way ptrace_traceme() and
in turn serializes arch_ptrace_attach()- ptrace_check_attach() does its own well described serializing too.
There is no obvious race here.
Signed-off-by: Arnd Bergmann
Signed-off-by: Frederic Weisbecker
Acked-by: Oleg Nesterov
Acked-by: Roland McGrath
Cc: Andrew Morton
Cc: Roland McGrath
26 Mar, 2010
1 commit
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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
Signed-off-by: Peter Zijlstra
Cc: Roland McGrath
Cc: Oleg Nesterov
Cc: Markus Metzger
Cc: Steven Rostedt
Cc: Andrew Morton
LKML-Reference:
Signed-off-by: Ingo Molnar
24 Feb, 2010
1 commit
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Return -EINVAL for the bad size and for unrecognized NT_* type in
ptrace_regset() instead of -EIO.Also update the comments for this ptrace interface with more clarifications.
Requested-by: Roland McGrath
Requested-by: Oleg Nesterov
Signed-off-by: Suresh Siddha
LKML-Reference:
Acked-by: Roland McGrath
Signed-off-by: H. Peter Anvin
12 Feb, 2010
1 commit
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Generic support for PTRACE_GETREGSET/PTRACE_SETREGSET commands which
export the regsets supported by each architecture using the correponding
NT_* types. These NT_* types are already part of the userland ABI, used
in representing the architecture specific register sets as different NOTES
in an ELF core file.'addr' parameter for the ptrace system call encode the REGSET type (using
the corresppnding NT_* type) and the 'data' parameter points to the
struct iovec having the user buffer and the length of that buffer.struct iovec iov = { buf, len};
ret = ptrace(PTRACE_GETREGSET/PTRACE_SETREGSET, pid, NT_XXX_TYPE, &iov);On successful completion, iov.len will be updated by the kernel specifying
how much the kernel has written/read to/from the user's iov.buf.x86 extended state registers are primarily exported using this interface.
Signed-off-by: Suresh Siddha
LKML-Reference:
Acked-by: Hongjiu Lu
Cc: Roland McGrath
Signed-off-by: H. Peter Anvin
24 Sep, 2009
1 commit
-
The bug is old, it wasn't cause by recent changes.
Test case:
static void *tfunc(void *arg)
{
int pid = (long)arg;assert(ptrace(PTRACE_ATTACH, pid, NULL, NULL) == 0);
kill(pid, SIGKILL);sleep(1);
return NULL;
}int main(void)
{
pthread_t th;
long pid = fork();if (!pid)
pause();signal(SIGCHLD, SIG_IGN);
assert(pthread_create(&th, NULL, tfunc, (void*)pid) == 0);int r = waitpid(-1, NULL, __WNOTHREAD);
printf("waitpid: %d %m\n", r);return 0;
}Before the patch this program hangs, after this patch waitpid() correctly
fails with errno == -ECHILD.The problem is, __ptrace_detach() reaps the EXIT_ZOMBIE tracee if its
->real_parent is our sub-thread and we ignore SIGCHLD. But in this case
we should wake up other threads which can sleep in do_wait().Signed-off-by: Oleg Nesterov
Cc: Roland McGrath
Cc: Vitaly Mayatskikh
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
13 Jul, 2009
1 commit
-
Conflicts:
include/linux/personality.hUse Linus' version.
Signed-off-by: James Morris
07 Jul, 2009
1 commit
-
do_execve() and ptrace_attach() return -EINTR if
mutex_lock_interruptible(->cred_guard_mutex) fails.This is not right, change the code to return ERESTARTNOINTR.
Perhaps we should also change proc_pid_attr_write().
Signed-off-by: Oleg Nesterov
Cc: David Howells
Acked-by: Roland McGrath
Cc: James Morris
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
24 Jun, 2009
1 commit
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The ->ptrace_may_access() methods are named confusingly - the real
ptrace_may_access() returns a bool, while these security checks have
a retval convention.Rename it to ptrace_access_check, to reduce the confusion factor.
[ Impact: cleanup, no code changed ]
Signed-off-by: Ingo Molnar
Signed-off-by: James Morris
19 Jun, 2009
5 commits
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Change ptrace_getsiginfo/ptrace_setsiginfo to use lock_task_sighand()
without tasklist_lock. Perhaps it makes sense to make a single helper
with "bool rw" argument.Signed-off-by: Oleg Nesterov
Acked-by: Roland McGrath
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
- Use rcu_read_lock() instead of tasklist_lock to find/get the task
in ptrace_get_task_struct().- Make it static, it has no callers outside of ptrace.c.
- The comment doesn't match the reality, this helper does not do
any checks. Beacuse it is really trivial and static I removed the
whole comment.Signed-off-by: Oleg Nesterov
Acked-by: Roland McGrath
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Remove the "Nasty, nasty" lock dance in ptrace_attach()/ptrace_traceme() -
from now task_lock() has nothing to do with ptrace at all.With the recent changes nobody uses task_lock() to serialize with ptrace,
but in fact it was never needed and it was never used consistently.However ptrace_attach() calls __ptrace_may_access() and needs task_lock()
to pin task->mm for get_dumpable(). But we can call __ptrace_may_access()
before we take tasklist_lock, ->cred_exec_mutex protects us against
do_execve() path which can change creds and MMF_DUMP* flags.(ugly, but we can't use ptrace_may_access() because it hides the error
code, so we have to take task_lock() and use __ptrace_may_access()).NOTE: this change assumes that LSM hooks, security_ptrace_may_access() and
security_ptrace_traceme(), can be called without task_lock() held.Signed-off-by: Oleg Nesterov
Cc: Chris Wright
Acked-by: Roland McGrath
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
ptrace_attach() and ptrace_traceme() are the last functions which look as
if the untraced task can have task->ptrace != 0, this must not be
possible. Change the code to just check ->ptrace != 0 and s/|=/=/ to set
PT_PTRACED.Also, a couple of trivial whitespace cleanups in ptrace_attach().
And move ptrace_traceme() up near ptrace_attach() to keep them close to
each other.Signed-off-by: Oleg Nesterov
Cc: Chris Wright
Acked-by: Roland McGrath
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
- Add PF_KTHREAD check to prevent attaching to the kernel thread
with a borrowed ->mm.With or without this change we can race with daemonize() which
can set PF_KTHREAD or clear ->mm after ptrace_attach() does the
check, but this doesn't matter because reparent_to_kthreadd()
does ptrace_unlink().- Kill "!task->mm" check. We don't really care about ->mm != NULL,
and the task can call exit_mm() right after we drop task_lock().
What we need is to make sure we can't attach after exit_notify(),
check task->exit_state != 0 instead.Also, move the "already traced" check down for cosmetic reasons.
Signed-off-by: Oleg Nesterov
Cc: Chris Wright
Acked-by: Roland McGrath
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
12 Jun, 2009
1 commit
-
…s/security-testing-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6: (44 commits)
nommu: Provide mmap_min_addr definition.
TOMOYO: Add description of lists and structures.
TOMOYO: Remove unused field.
integrity: ima audit dentry_open failure
TOMOYO: Remove unused parameter.
security: use mmap_min_addr indepedently of security models
TOMOYO: Simplify policy reader.
TOMOYO: Remove redundant markers.
SELinux: define audit permissions for audit tree netlink messages
TOMOYO: Remove unused mutex.
tomoyo: avoid get+put of task_struct
smack: Remove redundant initialization.
integrity: nfsd imbalance bug fix
rootplug: Remove redundant initialization.
smack: do not beyond ARRAY_SIZE of data
integrity: move ima_counts_get
integrity: path_check update
IMA: Add __init notation to ima functions
IMA: Minimal IMA policy and boot param for TCB IMA policy
selinux: remove obsolete read buffer limit from sel_read_bool
...
11 Jun, 2009
1 commit
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* 'tracing-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (244 commits)
Revert "x86, bts: reenable ptrace branch trace support"
tracing: do not translate event helper macros in print format
ftrace/documentation: fix typo in function grapher name
tracing/events: convert block trace points to TRACE_EVENT(), fix !CONFIG_BLOCK
tracing: add protection around module events unload
tracing: add trace_seq_vprint interface
tracing: fix the block trace points print size
tracing/events: convert block trace points to TRACE_EVENT()
ring-buffer: fix ret in rb_add_time_stamp
ring-buffer: pass in lockdep class key for reader_lock
tracing: add annotation to what type of stack trace is recorded
tracing: fix multiple use of __print_flags and __print_symbolic
tracing/events: fix output format of user stack
tracing/events: fix output format of kernel stack
tracing/trace_stack: fix the number of entries in the header
ring-buffer: discard timestamps that are at the start of the buffer
ring-buffer: try to discard unneeded timestamps
ring-buffer: fix bug in ring_buffer_discard_commit
ftrace: do not profile functions when disabled
tracing: make trace pipe recognize latency format flag
...
09 Jun, 2009
1 commit
05 Jun, 2009
1 commit
-
Commit 95a3540da9c81a5987be810e1d9a83640a366bd5 ("ptrace_detach: the wrong
wakeup breaks the ERESTARTxxx logic") removed the "extra"
wake_up_process() from ptrace_detach(), but as Jan pointed out this breaks
the compatibility.I believe the changelog is right and this wake_up() is wrong in many
ways, but GDB assumes that ptrace(PTRACE_DETACH, child, 0, 0) always
wakes up the tracee.Despite the fact this breaks SIGNAL_STOP_STOPPED/group_stop_count logic,
and despite the fact this wake_up_process() can break another
assumption: PTRACE_DETACH with SIGSTOP should leave the tracee in
TASK_STOPPED case. Because the untraced child can dequeue SIGSTOP and
call do_signal_stop() before ptrace_detach() calls wake_up_process().Revert this change for now. We need some fixes even if we we want to keep
the current behaviour, but these fixes are not for 2.6.30.Signed-off-by: Oleg Nesterov
Acked-by: Roland McGrath
Cc: Jan Kratochvil
Cc: Denys Vlasenko
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
11 May, 2009
1 commit
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Rename cred_exec_mutex to reflect that it's a guard against foreign
intervention on a process's credential state, such as is made by ptrace(). The
attachment of a debugger to a process affects execve()'s calculation of the new
credential state - _and_ also setprocattr()'s calculation of that state.Signed-off-by: David Howells
Signed-off-by: James Morris
07 May, 2009
1 commit
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Merge reason: this topic is ready for upstream now. It passed
Oleg's review and Andrew had no further mm/*
objections/observations either.Signed-off-by: Ingo Molnar
27 Apr, 2009
1 commit
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ptrace_attach() needs task->cred_exec_mutex, not current->cred_exec_mutex.
Signed-off-by: Oleg Nesterov
Acked-by: Roland McGrath
Acked-by: David Howells
Signed-off-by: James Morris
24 Apr, 2009
1 commit
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Conflicts:
arch/x86/kernel/ptrace.cMerge 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
14 Apr, 2009
1 commit
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Pointed out by Roland. The bug was recently introduced by me in
"forget_original_parent: split out the un-ptrace part", commit
39c626ae47c469abdfd30c6e42eff884931380d6.Since that patch we have a window after exit_ptrace() drops tasklist and
before forget_original_parent() takes it again. In this window the child
can do ptrace(PTRACE_TRACEME) and nobody can untrace this child after
that.Change ptrace_traceme() to not attach to the exiting ->real_parent. We
don't report the error in this case, we pretend we attach right before
->real_parent calls exit_ptrace() which should untrace us anyway.Signed-off-by: Oleg Nesterov
Acked-by: Roland McGrath
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
09 Apr, 2009
1 commit
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This fixes all the checkpatch --file complaints about kernel/ptrace.c
and also removes an unused #include. I've verified that there are no
changes to the compiled code on x86_64.Signed-off-by: Roland McGrath
[ Removed the parts that just split a line - Linus ]
Signed-off-by: Linus Torvalds
07 Apr, 2009
1 commit
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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
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:
Signed-off-by: Ingo Molnar
04 Apr, 2009
1 commit
-
…nel/git/tip/linux-2.6-tip
* 'core-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
ptrace: remove a useless goto
03 Apr, 2009
5 commits
-
This bug is ancient too. ptrace_untrace() must not resume the task
if the group stop in progress, we should set TASK_STOPPED instead.Unfortunately, we still have problems here:
- if the process/thread was traced, SIGNAL_STOP_STOPPED
does not necessary means this thread group is stopped.- ptrace breaks the bookkeeping of ->group_stop_count.
Signed-off-by: Oleg Nesterov
Cc: Jerome Marchand
Cc: Roland McGrath
Cc: Denys Vlasenko
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Another ancient bug. Consider this trivial test-case,
int main(void)
{
int pid = fork();if (pid) {
ptrace(PTRACE_ATTACH, pid, NULL, NULL);
wait(NULL);
ptrace(PTRACE_DETACH, pid, NULL, NULL);
} else {
pause();
printf("WE HAVE A KERNEL BUG!!!\n");
}return 0;
}the child must not "escape" for sys_pause(), but it can and this was seen
in practice.This is because ptrace_detach does:
if (!child->exit_state)
wake_up_process(child);this wakeup can happen after this child has already restarted sys_pause(),
because it gets another wakeup from ptrace_untrace().With or without this patch, perhaps sys_pause() needs a fix. But this
wakeup also breaks the SIGNAL_STOP_STOPPED logic in ptrace_untrace().Remove this wakeup. The caller saw this task in TASK_TRACED state, and
unless it was SIGKILL'ed in between __ptrace_unlink()->ptrace_untrace()
should handle this case correctly. If it was SIGKILL'ed, we don't need to
wakup the dying tracee too.Signed-off-by: Oleg Nesterov
Cc: Jerome Marchand
Acked-by: Roland McGrath
Cc: Denys Vlasenko
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
By discussion with Roland.
- Rename ptrace_exit() to exit_ptrace(), and change it to do all the
necessary work with ->ptraced list by its own.- Move this code from exit.c to ptrace.c
- Update the comment in ptrace_detach() to explain the rechecking of
the child->ptrace.Signed-off-by: Oleg Nesterov
Cc: "Eric W. Biederman"
Cc: "Metzger, Markus T"
Cc: Roland McGrath
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
When ptrace_detach() takes tasklist, the tracee can be SIGKILL'ed. If it
has already passed exit_notify() we can leak a zombie, because a) ptracing
disables the auto-reaping logic, and b) ->real_parent was not notified
about the child's death.ptrace_detach() should follow the ptrace_exit's logic, change the code
accordingly.Signed-off-by: Oleg Nesterov
Cc: Jerome Marchand
Cc: Roland McGrath
Tested-by: Denys Vlasenko
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Move the code from __ptrace_detach() to its single caller and kill this
helper.Also, fix the ->exit_state check, we shouldn't wake up EXIT_DEAD tasks.
Actually, I think task_is_stopped_or_traced() makes more sense, but this
needs another patch.Signed-off-by: Oleg Nesterov
Cc: Jerome Marchand
Cc: Roland McGrath
Cc: Denys Vlasenko
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
10 Mar, 2009
1 commit
-
Impact: cleanup
Obviously, this goto is useless. Remove it.
Signed-off-by: WANG Cong
Cc: Andrew Morton
Cc: Roland McGrath
LKML-Reference:
Signed-off-by: Ingo Molnar
14 Jan, 2009
1 commit
-
Signed-off-by: Heiko Carstens
29 Dec, 2008
1 commit
-
…el/git/tip/linux-2.6-tip
* 'tracing-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (241 commits)
sched, trace: update trace_sched_wakeup()
tracing/ftrace: don't trace on early stage of a secondary cpu boot, v3
Revert "x86: disable X86_PTRACE_BTS"
ring-buffer: prevent false positive warning
ring-buffer: fix dangling commit race
ftrace: enable format arguments checking
x86, bts: memory accounting
x86, bts: add fork and exit handling
ftrace: introduce tracing_reset_online_cpus() helper
tracing: fix warnings in kernel/trace/trace_sched_switch.c
tracing: fix warning in kernel/trace/trace.c
tracing/ring-buffer: remove unused ring_buffer size
trace: fix task state printout
ftrace: add not to regex on filtering functions
trace: better use of stack_trace_enabled for boot up code
trace: add a way to enable or disable the stack tracer
x86: entry_64 - introduce FTRACE_ frame macro v2
tracing/ftrace: add the printk-msg-only option
tracing/ftrace: use preempt_enable_no_resched_notrace in ring_buffer_time_stamp()
x86, bts: correctly report invalid bts records
...Fixed up trivial conflict in scripts/recordmcount.pl due to SH bits
being already partly merged by the SH merge.
20 Dec, 2008
1 commit
-
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
Signed-off-by: Ingo Molnar
04 Dec, 2008
1 commit
-
Conflicts:
fs/nfsd/nfs4recover.cManually fixed above to use new creds API functions, e.g.
nfs4_save_creds().Signed-off-by: James Morris
01 Dec, 2008
1 commit
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All architectures now use the generic compat_sys_ptrace, as should every
new architecture that needs 32bit compat (if we'll ever get another).Remove the now superflous __ARCH_WANT_COMPAT_SYS_PTRACE define, and also
kill a comment about __ARCH_SYS_PTRACE that was added after
__ARCH_SYS_PTRACE was already gone.Signed-off-by: Christoph Hellwig
Acked-by: David S. Miller
Signed-off-by: Linus Torvalds
