uprobe_register() or uprobe_mmap() requires VM_READ | VM_EXEC, this
is not right. An apllication can do mprotect(PROT_EXEC) later and
execute this code.
Change valid_vma(is_register => true) to check VM_MAYEXEC instead.
No need to check VM_MAYREAD, it is always set.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
write_opcode()->get_user_pages() needs FOLL_FORCE to ensure we can
read the page even if the probed task did mprotect(PROT_NONE) after
uprobe_register(). Without FOLL_WRITE, FOLL_FORCE doesn't have any
side effect but allows to read the !VM_READ memory.
Otherwiese the subsequent uprobe_unregister()->set_orig_insn() fails
and we leak "int3". If that task does mprotect(PROT_READ | EXEC) and
execute the probed insn later it will be killed.
Note: in fact this is also needed for _register, see the next patch.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Kill UTASK_BP_HIT state, it buys nothing but complicates the code.
It is only used in uprobe_notify_resume() to decide who should be
called, we can check utask->active_uprobe != NULL instead. And this
allows us to simplify handle_swbp(), no need to clear utask->state.
Likewise we could kill UTASK_SSTEP, but UTASK_BP_HIT is worse and
imho should die. The problem is, it creates the special case when
task->utask is NULL, we can't distinguish RUNNING and BP_HIT. With
this patch utask == NULL always means RUNNING.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
If handle_swbp()->add_utask() fails but UPROBE_SKIP_SSTEP is set,
cleanup_ret: path do not restart the insn, this is wrong. Remove
this check and add the additional label for can_skip_sstep() = T
case.
Note also that UPROBE_SKIP_SSTEP can be false positive, we simply
can not trust it unless arch_uprobe_skip_sstep() was already called.
Also, move another UPROBE_SKIP_SSTEP check before can_skip_sstep()
into this helper, this looks more clean and understandable.
Note: probably we should rename "skip" to "emulate" and I think
that "clear UPROBE_SKIP_SSTEP" should be moved to arch_can_skip.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
handle_swbp() sets utask->active_uprobe before handler_chain(),
and UTASK_SSTEP before pre_ssout(). This complicates the code
for no reason, arch_ hooks or consumer->handler() should not
(and can't) use this info.
Change handle_swbp() to initialize them after pre_ssout(), and
remove the no longer needed cleanup-utask code.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
cked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
If handle_swbp()->find_active_uprobe() fails we return with
utask->state = UTASK_BP_HIT.
Change handle_swbp() to reset utask->state at the start. Note
that we do this unconditionally, see the next patch(es).
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Pull perf/core improvements and fixes from Arnaldo Carvalho de Melo:
* Improve listing of accessible enum perf probe variables, from Hyeoncheol Lee.
* Don't stop the build if the audit libraries are not installed, fix from Namhyung Kim.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The newly added trace command requires an external audit library.
However it can cause a build error because it's not checked whether the
libaudit is installed on system:
CC builtin-trace.o
builtin-trace.c:7:22: fatal error: libaudit.h: No such file or directory
compilation terminated.
make: *** [builtin-trace.o] Error 1
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1348745018-21744-1-git-send-email-namhyung@kernel.org
[ committer note: Added ", disables 'trace tool' to the feature warning msg ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Initially should look loosely like the venerable 'strace' tool, but
using the infrastructure in the perf tools to allow tracing extra
targets:
[acme@sandy linux]$ perf trace --hell
Error: unknown option `hell'
usage: perf trace <PID>
-p, --pid <pid> trace events on existing process id
--tid <tid> trace events on existing thread id
--all-cpus system-wide collection from all CPUs
--cpu <cpu> list of cpus to monitor
--no-inherit child tasks do not inherit counters
--mmap-pages <n> number of mmap data pages
--uid <user> user to profile
[acme@sandy linux]$
Those should have the same semantics as when using with 'perf record'.
It gets stuck sometimes, but hey, it works sometimes too!
In time it should support perf.data based workloads, i.e. it should have
a:
-o filename
Command line option that will produce a perf.data file that can then be
used with 'perf trace' or any of the other perf tools (script, report,
etc).
It will also eventually have the set of functionalities described in the
previous 'trace' prototype by Thomas Gleixner:
"Announcing a new utility: 'trace'"
http://lwn.net/Articles/415728/
Also planned is to have some of the features suggested in the comments
of that LWN article.
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/n/tip-v9x3q9rv4caxtox7wtjpchq5@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
It will set up a syscall open tracepoint event, generate an open with
invalid flags, then check those flags were the ones reported in the
tracepoint fired.
For the filename we need vfs:getname, but that will go thru some more
iterations as the vfs getname codebase is going thru changes lately.
When that is in I'll just check that the perf_evsel__newtp constructor
is not bailing out and then add it to the evlist, catch the event and
check the filename against the one used in the 'open' call used to
trigger the event.
Cc: David Ahern <dsahern@gmail.com>
Cc: Eric Paris <eparis@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jeff Layton <jlayton@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-p5w9aq0jcbb91ghzqomowm16@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
We were relying on the info in pevent, but since we have it in
perf_evsel, set up by the perf_session routine if read from a perf.data
file or by whoever creates the evsels, use it.
New 'perf test' entries will use it to parse locally generated events,
in a non perf.data centered workflow.
As well as use byteswap.h to get per arch optimized swap routines, like
other parts of perf (header, perf_evsel__parse_sample, symbol, etc)
already do.
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-8tjuxk09mlsfmh7macgkxsip@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
