valid_vma() rejects the VM_SHARED vmas, but this still allows to insert
a probe into the MAP_SHARED but not VM_MAYWRITE vma.

Currently this is fine, such a mapping doesn't really differ from the
private read-only mmap except mprotect(PROT_WRITE) won't work. However,
get_user_pages(FOLL_WRITE | FOLL_FORCE) doesn't allow to COW in this
case, and it would be safer to follow the same conventions as mm even
if currently this happens to work.

After the recent cda540ac "mm: get_user_pages(write,force) refuse
to COW in shared areas" only uprobes can insert an anon page into the
shared file-backed area, lets stop this and change valid_vma() to check
VM_MAYSHARE instead.
Signed-off-by: NOleg Nesterov <oleg@redhat.com>

uprobe_perf_open()->uprobe_apply() can fail, but this error is wrongly
ignored. Change uprobe_perf_open() to do uprobe_perf_close() and return
the error code in this case.

Change uprobe_perf_close() to propogate the error from uprobe_apply()
as well, although it should not fail.
Signed-off-by: NOleg Nesterov <oleg@redhat.com>
Acked-by: NSteven Rostedt <rostedt@goodmis.org>
Acked-by: NSrikar Dronamraju <srikar@linux.vnet.ibm.com>

Preparation. Move uprobe_perf_close() up before uprobe_perf_open() to
avoid the forward declaration in the next patch and make it readable.
Signed-off-by: NOleg Nesterov <oleg@redhat.com>
Acked-by: NSteven Rostedt <rostedt@goodmis.org>
Acked-by: NSrikar Dronamraju <srikar@linux.vnet.ibm.com>

Ignoring the "correction" logic riprel_pre_xol() and riprel_post_xol()
are very similar but look quite differently.

1. Add the "UPROBE_FIX_RIP_AX | UPROBE_FIX_RIP_CX" check at the start
   of riprel_pre_xol(), like the same check in riprel_post_xol().

2. Add the trivial scratch_reg() helper which returns the address of
   scratch register pre_xol/post_xol need to change.

3. Change these functions to use the new helper and avoid copy-and-paste
   under if/else branches.
Signed-off-by: NOleg Nesterov <oleg@redhat.com>
Acked-by: NSrikar Dronamraju <srikar@linux.vnet.ibm.com>

default_pre_xol_op() passes &current->utask->autask to riprel_pre_xol()
and this is just ugly because it still needs to load current->utask to
read ->vaddr.

Remove this argument, change riprel_pre_xol() to use current->utask.
Signed-off-by: NOleg Nesterov <oleg@redhat.com>
Acked-by: NSrikar Dronamraju <srikar@linux.vnet.ibm.com>

handle_riprel_insn(), pre_xol_rip_insn() and handle_riprel_post_xol()
look confusing and inconsistent. Rename them into riprel_analyze(),
riprel_pre_xol(), and riprel_post_xol() respectively.

No changes in compiled code.
Signed-off-by: NOleg Nesterov <oleg@redhat.com>
Acked-by: NSrikar Dronamraju <srikar@linux.vnet.ibm.com>

Now that UPROBE_FIX_IP/UPROBE_FIX_CALL are mutually exclusive we can
use a single "fix_ip_or_call" enum instead of 2 fix_* booleans. This
way the logic looks more understandable and clean to me.

While at it, join "case 0xea" with other "ip is correct" ret/lret cases.
Also change default_post_xol_op() to use "else if" for the same reason.
Signed-off-by: NOleg Nesterov <oleg@redhat.com>

The only insn which could have both UPROBE_FIX_IP and UPROBE_FIX_CALL
was 0xe8 "call relative", and now it is handled by branch_xol_ops.

So we can change default_post_xol_op(UPROBE_FIX_CALL) to simply push
the address of next insn == utask->vaddr + insn.length, just we need
to record insn.length into the new auprobe->def.ilen member.

Note: if/when we teach branch_xol_ops to support jcxz/loopz we can
remove the "correction" logic, UPROBE_FIX_IP can use the same address.
Signed-off-by: NOleg Nesterov <oleg@redhat.com>

Extract the "push return address" code from branch_emulate_op() into
the new simple helper, push_ret_address(). It will have more users.
Signed-off-by: NOleg Nesterov <oleg@redhat.com>

handle_riprel_insn() assumes that nobody else could modify ->fixups
before. This is correct but fragile, change it to use "|=".

Also make ->fixups u8, we are going to add the new members into the
union. It is not clear why UPROBE_FIX_RIP_.X lived in the upper byte,
redefine them so that they can fit into u8.
Signed-off-by: NOleg Nesterov <oleg@redhat.com>

Finally we can move arch_uprobe->fixups/rip_rela_target_address
into the new "def" struct and place this struct in the union, they
are only used by default_xol_ops paths.

The patch also renames rip_rela_target_address to riprel_target just
to make this name shorter.
Signed-off-by: NOleg Nesterov <oleg@redhat.com>
Reviewed-by: NJim Keniston <jkenisto@us.ibm.com>

UPROBE_FIX_SETF is only needed to handle "popf" correctly but it is
processed by the generic arch_uprobe_post_xol() code. This doesn't
allows us to make ->fixups private for default_xol_ops.

1 Change default_post_xol_op(UPROBE_FIX_SETF) to set ->saved_tf = T.

   "popf" always reads the flags from stack, it doesn't matter if TF
   was set or not before single-step. Ignoring the naming, this is
   even more logical, "saved_tf" means "owned by application" and we
   do not own this flag after "popf".

2. Change arch_uprobe_post_xol() to save ->saved_tf into the local
   "bool send_sigtrap" before ->post_xol().

3. Change arch_uprobe_post_xol() to ignore UPROBE_FIX_SETF and just
   check ->saved_tf after ->post_xol().

With this patch ->fixups and ->rip_rela_target_address are only used
by default_xol_ops hooks, we are ready to remove them from the common
part of arch_uprobe.
Signed-off-by: NOleg Nesterov <oleg@redhat.com>
Reviewed-by: NJim Keniston <jkenisto@us.ibm.com>

014940ba "uprobes/x86: Send SIGILL if arch_uprobe_post_xol() fails"
changed arch_uprobe_post_xol() to use arch_uprobe_abort_xol() if ->post_xol
fails. This was correct and helped to avoid the additional complications,
we need to clear X86_EFLAGS_TF in this case.

However, now that we have uprobe_xol_ops->abort() hook it would be better
to avoid arch_uprobe_abort_xol() here. ->post_xol() should likely do what
->abort() does anyway, we should not do the same work twice. Currently only
handle_riprel_post_xol() can be called twice, this is unnecessary but safe.
Still this is not clean and can lead to the problems in future.

Change arch_uprobe_post_xol() to clear X86_EFLAGS_TF and restore ->ip by
hand and avoid arch_uprobe_abort_xol(). This temporary uglifies the usage
of autask.saved_tf, we will cleanup this later.
Signed-off-by: NOleg Nesterov <oleg@redhat.com>
Reviewed-by: NJim Keniston <jkenisto@us.ibm.com>

arch_uprobe_abort_xol() calls handle_riprel_post_xol() even if
auprobe->ops != default_xol_ops. This is fine correctness wise, only
default_pre_xol_op() can set UPROBE_FIX_RIP_AX|UPROBE_FIX_RIP_CX and
otherwise handle_riprel_post_xol() is nop.

But this doesn't look clean and this doesn't allow us to move ->fixups
into the union in arch_uprobe. Move this handle_riprel_post_xol() call
into the new default_abort_op() hook and change arch_uprobe_abort_xol()
accordingly.
Signed-off-by: NOleg Nesterov <oleg@redhat.com>
Reviewed-by: NJim Keniston <jkenisto@us.ibm.com>

Currently this doesn't matter, the only ->pre_xol() hook can't fail,
but we need to fix arch_uprobe_pre_xol() anyway. If ->pre_xol() fails
we should not change regs->ip/flags, we should just return the error
to make restart actually possible.
Signed-off-by: NOleg Nesterov <oleg@redhat.com>
Reviewed-by: NJim Keniston <jkenisto@us.ibm.com>

is_64bit_mm() assumes that mm->context.ia32_compat means the 32-bit
instruction set, this is not true if the task is TIF_X32.

Change set_personality_ia32() to initialize mm->context.ia32_compat
by TIF_X32 or TIF_IA32 instead of 1. This allows to fix is_64bit_mm()
without affecting other users, they all treat ia32_compat as "bool".

TIF_ in ->ia32_compat looks a bit strange, but this is grep-friendly
and avoids the new define's.
Signed-off-by: NOleg Nesterov <oleg@redhat.com>
Reviewed-by: NJim Keniston <jkenisto@us.ibm.com>
Acked-by: NSrikar Dronamraju <srikar@linux.vnet.ibm.com>

Add the suitable ifdef's around good_insns_* arrays. We do not want
to add the ugly ifdef's into their only user, uprobe_init_insn(), so
the "#else" branch simply defines them as NULL. This doesn't generate
the extra code, gcc is smart enough, although the code is fine even if
it could not detect that (without CONFIG_IA32_EMULATION) is_64bit_mm()
is __builtin_constant_p().

The patch looks more complicated because it also moves good_insns_64
up close to good_insns_32.
Signed-off-by: NOleg Nesterov <oleg@redhat.com>
Reviewed-by: NJim Keniston <jkenisto@us.ibm.com>
Acked-by: NSrikar Dronamraju <srikar@linux.vnet.ibm.com>

Change uprobe_init_insn() to make insn_complete() == T, this makes
other insn_get_*() calls unnecessary.
Signed-off-by: NOleg Nesterov <oleg@redhat.com>
Reviewed-by: NJim Keniston <jkenisto@us.ibm.com>
Acked-by: NSrikar Dronamraju <srikar@linux.vnet.ibm.com>

1. Extract the ->ia32_compat check from 64bit validate_insn_bits()
   into the new helper, is_64bit_mm(), it will have more users.

   TODO: this checks is actually wrong if mm owner is X32 task,
   we need another fix which changes set_personality_ia32().

   TODO: even worse, the whole 64-or-32-bit logic is very broken
   and the fix is not simple, we need the nontrivial changes in
   the core uprobes code.

2. Kill validate_insn_bits() and change its single caller to use
   uprobe_init_insn(is_64bit_mm(mm).
Signed-off-by: NOleg Nesterov <oleg@redhat.com>
Reviewed-by: NJim Keniston <jkenisto@us.ibm.com>
Acked-by: NSrikar Dronamraju <srikar@linux.vnet.ibm.com>

validate_insn_32bits() and validate_insn_64bits() are very similar,
turn them into the single uprobe_init_insn() which has the additional
"bool x86_64" argument which can be passed to insn_init() and used to
choose between good_insns_64/good_insns_32.

Also kill UPROBE_FIX_NONE, it has no users.

Note: the current code doesn't use ifdef's consistently, good_insns_64
depends on CONFIG_X86_64 but good_insns_32 is unconditional. This patch
removes ifdef around good_insns_64, we will add it back later along with
the similar one for good_insns_32.
Signed-off-by: NOleg Nesterov <oleg@redhat.com>
Reviewed-by: NJim Keniston <jkenisto@us.ibm.com>
Acked-by: NSrikar Dronamraju <srikar@linux.vnet.ibm.com>

All branch insns on x86 can be prefixed with the operand-size
override prefix, 0x66. It was only ever useful for performing
jumps to 32-bit offsets in 16-bit code segments.

In 32-bit code, such instructions are useless since
they cause IP truncation to 16 bits, and in case of call insns,
they save only 16 bits of return address and misalign
the stack pointer as a "bonus".

In 64-bit code, such instructions are treated differently by Intel
and AMD CPUs: Intel ignores the prefix altogether,
AMD treats them the same as in 32-bit mode.

Before this patch, the emulation code would execute
the instructions as if they have no 0x66 prefix.

With this patch, we refuse to attach uprobes to such insns.
Signed-off-by: NDenys Vlasenko <dvlasenk@redhat.com>
Acked-by: NJim Keniston <jkenisto@us.ibm.com>
Acked-by: NMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: NOleg Nesterov <oleg@redhat.com>

Merge tag 'perf-core-for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/jolsa/perf into perf/core

Pull perf/core improvements and fixes from Jiri Olsa:

  * Add a test case for hists filtering (Namhyung Kim)

  * Share map_groups among threads of the same group (Arnaldo Carvalho de Melo, Jiri Olsa)
Signed-off-by: NJiri Olsa <jolsa@kernel.org>
Signed-off-by: NIngo Molnar <mingo@kernel.org>

This test create 2 processes abstractions, with several threads
and checks they properly share and maintain map groups info.
Acked-by: NNamhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1397490723-1992-6-git-send-email-jolsa@redhat.comSigned-off-by: NJiri Olsa <jolsa@kernel.org>

Sharing map groups within all process threads. This way
there's only one copy of mmap info and it's reachable
from any thread within the process.
Original-patch-by: NArnaldo Carvalho de Melo <acme@kernel.org>
Acked-by: NNamhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1397490723-1992-5-git-send-email-jolsa@redhat.comSigned-off-by: NJiri Olsa <jolsa@kernel.org>

We will share it among threads in the same process.
Adding map_groups__get/map_groups__put interface for that.
Signed-off-by: NArnaldo Carvalho de Melo <acme@kernel.org>
Acked-by: NNamhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1397490723-1992-4-git-send-email-jolsa@redhat.comSigned-off-by: NJiri Olsa <jolsa@kernel.org>

Moving towards sharing map groups within a process threads.

Because of this we need the map groups to be dynamically allocated. No
other functional change is intended in here.

Based on a patch by Jiri Olsa, but this time _just_ making the
conversion from statically allocating thread->mg to turning it into a
pointer and instead of initializing it at thread's constructor,
introduce a constructor/destructor for the map_groups class and
call at thread creation time.

Later we will introduce the get/put methods when we move to sharing
those map_groups, when the get/put refcounting semantics will be needed.
Signed-off-by: NArnaldo Carvalho de Melo <acme@kernel.org>
Acked-by: NNamhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1397490723-1992-3-git-send-email-jolsa@redhat.comSigned-off-by: NJiri Olsa <jolsa@kernel.org>

Adding automated test for memory maps lookup within multiple machines
threads.

The test creates 4 threads and separated memory maps. It checks that we
could use thread__find_addr_map function with thread object based on TID
to find memory maps.
Acked-by: NNamhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1397490723-1992-2-git-send-email-jolsa@redhat.comSigned-off-by: NJiri Olsa <jolsa@kernel.org>

Now we have changed how hists stats are accounted especially when
filter(s) applied.  So add a test case to verify it.
Signed-off-by: NNamhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/r/1398396494-12811-2-git-send-email-namhyung@kernel.orgSigned-off-by: NJiri Olsa <jolsa@kernel.org>

The fake_setup_machine() is for setting up a environment for testing
various hists operations. As it'll be used for other test cases it'd
better factoring it out.
Signed-off-by: NNamhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/r/1398396494-12811-1-git-send-email-namhyung@kernel.orgSigned-off-by: NJiri Olsa <jolsa@kernel.org>

Merge tag 'perf-core-for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/jolsa/perf into perf/core

Pull perf/core improvements and fixes from Jiri Olsa:

  * Factor hists statistics counts processing which in turn also
    fixes several bugs in TUI report command (Namhyung Kim)
Signed-off-by: NJiri Olsa <jolsa@kernel.org>
Signed-off-by: NIngo Molnar <mingo@kernel.org>

Signed-off-by: NIngo Molnar <mingo@kernel.org>

When TUI hist browser expands/collapses callchains it accounted number
of callchain nodes into total entries to show.  However this code
ignores filtering so that it can make the cursor go to out of screen.

Thanks to Jiri Olsa for pointing out a bug (and a fix) in the code.
Signed-off-by: NNamhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/r/1398327843-31845-12-git-send-email-namhyung@kernel.orgSigned-off-by: NJiri Olsa <jolsa@kernel.org>

The hist_browser__reset() is only called right after a filter is
applied so it needs to udpate browser->nr_entries properly.  We cannot
use hists->nr_non_filtered_entreis directly since it's possible that
such entries are also filtered out by minimum percentage limit.

In addition when a filter is used for perf top, hist browser's
nr_entries field was not updated after applying the filter.  But it
needs to be updated as new samples are coming.
Signed-off-by: NNamhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/r/1398327843-31845-11-git-send-email-namhyung@kernel.orgSigned-off-by: NJiri Olsa <jolsa@kernel.org>

Rename ->nr_pcnt_entries and hist_browser__update_pcnt_entries() to
->nr_non_filtered_entries and hist_browser__update_nr_entries() since
it's now used for filtering as well.
Signed-off-by: NNamhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/r/1398327843-31845-10-git-send-email-namhyung@kernel.orgSigned-off-by: NJiri Olsa <jolsa@kernel.org>

The nr_entries variable is increased inside the loop in the function
but it always count the first entry regardless of it's filtered or
not; caused an off-by-one error.

It'd become a problem especially there's no entry at all - it'd get a
segfault during referencing a NULL pointer.
Signed-off-by: NNamhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/r/1398327843-31845-9-git-send-email-namhyung@kernel.orgSigned-off-by: NJiri Olsa <jolsa@kernel.org>

When a filter is used for perf top, its hists->nr_non_filtered_entries
was not updated after it removed an entry in hists__decay_entries().
Also hists->stats.total_non_filtered_period was missed too.
Signed-off-by: NNamhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/r/1398327843-31845-8-git-send-email-namhyung@kernel.orgSigned-off-by: NJiri Olsa <jolsa@kernel.org>

Currently, accounting each sample is done in multiple places - once
when adding them to the input tree, other when adding them to the
output tree.  It's not only confusing but also can cause a subtle
problem since concurrent processing like in perf top might see the
updated stats before adding entries into the output tree - like seeing
more (blank) lines at the end and/or slight inaccurate percentage.

To fix this, only account the entries when it's moved into the output
tree so that they cannot be seen prematurely.  There're some
exceptional cases here and there - they should be addressed separately
with comments.
Signed-off-by: NNamhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/r/1398327843-31845-7-git-send-email-namhyung@kernel.orgSigned-off-by: NJiri Olsa <jolsa@kernel.org>

When a filter is applied a hist entry checks whether its callchain was
folded and account it to the output stat.  But this is rather hacky
and only TUI-specific.  Simply fold the callchains for the entry looks
like a simpler and more generic solution IMHO.
Signed-off-by: NNamhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/r/1398327843-31845-6-git-send-email-namhyung@kernel.orgSigned-off-by: NJiri Olsa <jolsa@kernel.org>

Add hists__{reset,inc}_[filter_]stats() functions to cleanup accesses
to hist stats (for output).  Note that number of samples in the stat
is not handled here since it belongs to the input stage.
Signed-off-by: NNamhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/r/1398327843-31845-5-git-send-email-namhyung@kernel.orgSigned-off-by: NJiri Olsa <jolsa@kernel.org>

It's not the part of logic of hists__inc_stats() so it'd be better to
move it out of the function.
Signed-off-by: NNamhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/r/1398327843-31845-4-git-send-email-namhyung@kernel.orgSigned-off-by: NJiri Olsa <jolsa@kernel.org>