Abegail Jakop [Tue, 25 Aug 2015 15:00:51 +0000 (11:00 -0400)]
PR18455: suggest type in const_folder binary expr
elaborate.cxx: within const_folder::visit_binary_expression(), for cases
like {println(i+0)} where part of the binary expression is elided, suggest
what the type (pe_long) should be to the remaining part of the expression.
Fix BZ1264678 by updating the networking tapset for the 4.1 kernel.
* tapset/linux/networking.stp (netdev.transmit): Prefer
__dev_queue_xmit() if available.
(netdev.hard_transmit): Handle the change in argument name from 'skb' to
'first'.
David Smith [Mon, 14 Sep 2015 15:35:36 +0000 (10:35 -0500)]
Fix PR18944 by updating runtime/linux/autoconf-blk-types.c.
* runtime/linux/autoconf-blk-types.c: Add linux/blkdev.h that hopefully
includes linux/rh_kabi.h. We can't include it directly since it doesn't
exist on non-RHEL kernels.
David Smith [Wed, 9 Sep 2015 15:47:57 +0000 (10:47 -0500)]
Fixed PR18942 by avoiding the inclusion of unused global variables.
* tapset/linux/aux_syscalls.stp (__count_envp): Changed the name of the
'argc' local variable to '__argc' to avoid confusing the translator with
the global 'argc' variable from tapset/argv.stp.
(__count_compat_envp): Ditto.
Josh Stone [Tue, 8 Sep 2015 21:24:36 +0000 (14:24 -0700)]
PR18936: extend the lifetime of synthesized DW_OP_addr
In dwflpp::literal_stmt_for_local(), a fake addr_loc is created for
variables we find in the symbol table. But this addr_loc had tight
scope on the stack, and its contents were clobbered by the time the
pointer was read by emit_header().
Just extending the lifetime to the whole function scope is enough.
Josh Stone [Fri, 4 Sep 2015 18:11:53 +0000 (11:11 -0700)]
Switch to SSL_GetImplementedCiphers()
When nss rebases, the size of SSL_ImplementedCiphers[] may change. If
we have a copy relocation, this could mean we'll get an incomplete copy
of the array. Use the accessor function instead for a simple pointer.
See also: https://bugzilla.mozilla.org/show_bug.cgi?id=496993
Martin Cermak [Fri, 4 Sep 2015 07:38:45 +0000 (09:38 +0200)]
PR18649: Add tests for the new --prologue-searching option
* NEWS: Add entry describing the new option.
* hash.cxx: Add the option index into the script hash.
* testsuite/parseko/cmdline23.stp: New testcase.
* testsuite/parseok/cmdline03.stp: Ditto.
* testsuite/systemtap.base/pr18649.exp: Ditto.
PR18889: switch to STP_TRACEPOINT* frontend for kernel tracepoint registration
jistone kindly reminded that the runtime/stp_tracepoint.[ch] machinery
allows us to attach to kernel tracepoints, whether on string- or
tp*-based kernel APIs, and whether or not the tp* objects are
EXPORT_TRACEPOINT_SYMBOL_GPL'd. Let's use those; presto we get
module-init probing back on kernels oldish and newish.
Frank Ch. Eigler [Mon, 31 Aug 2015 21:46:43 +0000 (17:46 -0400)]
PR18889 part: module-init notification via module_{load,free} tracepoints
Investigating RHBZ1257399 et al., we found that module_notifier is
being called too early after kernel commit #4982223e51. This
precludes normal module section-address computation and thus kprobe
emplacement. This patch adds hooking into the module_{load,free}
tracepoints in parallel, because on some kernels (RHEL7.1.Z+) they
occur at just the right time.
On the downside, on recent LKML kernels, attaching to those
tracepoints requires EXPORT_TRACEPOINT_SYMBOL_GPL's, so until that is
done (or another workaround made), LKML kernels will still miss out on
module-init probing.
Jose Castillo [Wed, 22 Jan 2014 10:40:27 +0000 (10:40 +0000)]
Add a new command line option to enable print backtraces under some conditions.
Most of the times, when we use bkl.stp to investigate BKL issues, we've found useful to have
the backtrace of the function that holds the BKL. This patch adds a new command line option,
"backtrace=N", that when used enables the use of print_backtrace(). The value of <N>, if present,
is taken as useconds, and it is the limit of time the task or tasks have been waiting to acquire
the lock i.e.:
# stap blk.stp backtrace=100
That would enable printing of backtrace on all tasks holding the kernel
big lock for more than 100us.
Signed-off-by: Jose Castillo <jcastillo@redhat.com>
David Smith [Thu, 20 Aug 2015 16:27:53 +0000 (11:27 -0500)]
Fix PR18856 by making nfsd.close optional.
* tapset/linux/nfsd.stp: Make nfsd.close optional in nfsd.entries (and add
it optionally to nfsd.return), since the underlying probe point no
longer exists in kernels 4.2+. Also add nfsd.proc.commit.return to
nfsd.proc.return (to match nfsd.proc).
* testsuite/buildok/nfsd-detailed.stp: Make nfsd.close tests optional.
Josh Stone [Thu, 20 Aug 2015 01:38:08 +0000 (18:38 -0700)]
runtime: only compare line records at "commit" states
The state machine for line records may go through intermediate states
which are not proper to compare address against. Only at DW_LNS_copy,
DW_LNE_end_sequence, and special opcodes are we supposed to "append a
row to the matrix", as the DWARF specification tells us.
The usymfileline testcase didn't hit problems, because its C target only
outputted a simple sequence of special opcodes. It's now C++, as that's
a very easy way to get code generated from a lot of different files and
lines. A simple std::find creates pretty complicated line records, even
in an unoptimized build.
Abegail Jakop [Wed, 19 Aug 2015 22:04:36 +0000 (18:04 -0400)]
stringtable.h: add logical ops and to_string if needed
when it comes to string_ref, boost 1.53 doesn't contain all the
logical operations that we need, nor to_string(). so we'll fill in
the gaps with our own defintions for interned_string.
Martin Cermak [Wed, 19 Aug 2015 18:20:36 +0000 (20:20 +0200)]
Update syscall tapset documentation to use cached content.
Before this update syscall tapset autodocumentation has been
generated dynamically at the build time using stap -L call.
This way stap requires kernel-devel RPM matching `uname -r`
which is tricky to achieve in koji. For this reason the content
is cached from now on:
jistone pointed out a possible problem in the interned_string
implementation; we break the tie in favour of trivial c_str()
(since commit 3e4547ad096d showed its value).
Abegail Jakop [Fri, 14 Aug 2015 20:42:33 +0000 (16:42 -0400)]
alternate interned_string if no boost::string_ref
string_ref was only introduced in boost 1.53, meaning rhel 5 and 6
might not have a recent enough version. to account for this, if
string_ref is not available, fall back on an alternate definition
of interned_string that uses std::string instead.
Some of the tapset*cxx functions were used to representing empty
function / file names with NULL char*s. As these are transitioned to
interned_strings, the latter's ctors must be willing to accept those
NULLs and convert them to empty strings. (Adjusting all the callers
to pass "" instead of NULL in those slots is also possible.)
interned_string: drop magic c_str() implementation
It turns out that while it was right for boost::string_ref not to
provide it, we can, because our interned_string's backing stores
are full (read-only) std::strings, which always carry a \0. This
shrinks down our interned_string to 2*sizeof(void*) bytes.
With the richer interned_string API, one can return to the previous
way of finding line boundaries in the input string. While in the
area, we tweak spacing of parse error message lines.
With INTERNED_STRING_INSTRUMENT set, a /tmp/hash.log file is written
out to record each string being interned. Looking through that is a
good way of tuning the hash function, as well as what
staptree/etc. variables are reverted to std::string form. (The hint
is that if strings are hardly ever interned in the log, then maybe
they are not reused either. But that could instead be because they're
being reused exclusively in interned string_ref form, so don't need to
be rehashed.)
Experimentation indicates that the sizeof(interned_string)=24
is so much larger than that of an empty sizeof(std::string)=8
that for mostly-empty slots it's a loss! A 1-byte std::string
causes a 26-byte malloc, so the interned_string is probably
good for nonempty strings.
Converting many many classes' use of std::string to interned_string.
Largely mechanical, and driven by the desire to (a) store long-lived
duplicate strings only once (in the stringtable), and (b) avoid
instantiating std::strings unnecessarily (in temporary variables
or function parameters).
Motivated by frustratingly easy-to-miss memory corruption errors of
the direct boost::string_ref model, switching gears to a new derived
class interned_string. This one performs proper interning when
converting in from a std::string for all copy/assignment operations.
In many cases, it can simply replace std::string through automatic
conversions in/out, naturally paying a CPU / temporary-memory cost.
Replacing many std::string types, focusing on those stored in
high-cardinality data structures, with boost::string_ref.
Largely mechanical work, with valgrind runs identifying some
persistent trouble-spots of the form
string_ref FOO = (some_temp_string_value);
which makes them dangle the moment the temp goes out of scope.
string_ref usage correction: drop string_ref->to_string()->c_str() chain
This construct generates stale char* pointers that valgrind notices.
We use a first-class temporary string object for these uses. (They
should probably be rewritten in terms of string_ref native
operations.)
The obstacks used for storing piecemeal-printf'd $context functions
could leak if inferior functions threw exceptions. We now use a
RAII type widget to assure their destruction.
It turns out that c++11's unordered_set<> makes the stringtable
dramatically faster. Since that is a c++11-only facility, we switch
the translator (stap) to conditionally compile with that flag.
Returning partly to an older model of parser input processing: the
parser::input_contents goes back to a plain string, which may be
modified gradually by $/@ expansion etc. While string_refs cannot be
made based on that, they don't need to be either, since the
input_contents is a temporary member variable and will be disposed of
when the parser dies.
So we switch back to the prior general logic of
lexer::input_{put,get,peek}, which worked OK. To populate token
content string_refs, we use a global stringtable (a *set<string>)
against which long-lived string_refs may be issued with a new intern()
call. The input file contents are amongst those strings interned.
(Many other repeated string uses in the translator could probably
benefit from intern/string_ref'ing, and there are optimization
opportunities within the stringtable implementation proper.)
(While en route, mass-dropped a bunch of unnecessary namespace
prefixes in some affected files. Sorry for the diff noise.)
parse::parse_probe_point(): store new token's content
in parse_porbe_point() the content for a new token is created by
appending to an existing token's content. the string for the new
token's content needs to be stored somewhere, so we'll store it in
the the probe_point, since we can't access the (private) stapfile.
store file contents as strings in systemtap_session
since we need input_contents and file_contents to last longer
than the lexer, store the input_contents in a vector in a
systemtap_session. change lexer->input_contents and
stapfile->file_contents to string* so they will point to part of
some string in session->input_contents. will need to change to
string_ref in another commit
parse.cxx: new append_to_content() and set_token_content() to hide
the logic of work of setting up a token's content.
staptree.h: a vector to contain all the mangled strings that tok->content
will point to
since tok->content are now boost::string_refs, some portions of the
code don't play well with the fact that string_refs can't be
automatically converted into a std::string, so we need to manually add
in a to_string() call to do the conversion.
Note: can't use .data() since the string_ref is proabably not null terminated.
session.*: store lex_cast() versions of the stap arguments passed
through the command line.
parse.cxx: if the scanner encounters [$|@]<NN> in a stap script, use
the pre-lex_cast() stap arguments instead of calling lex_cast() each
time the scanner encounters [$|@]<NN>.
parse.cxx: instead of keeping track of a seperate set of file_contents
(lexer->input_contents) in which [$|@]<NN> are replaced by script args,
we'll keep file_contents and input_contents identical to one another
and parse the scripts args strings when we encouter [$|@]<NN>
git://sourceware.org / systemtap.git / log