Commit Graph

36 Commits

Author SHA1 Message Date
Brooks Davis
41fc64c259 Be consistent about temporary variable use in adjacent loops.
Obtained from:	CheriBSD
MFC after:	1 week
Sponsored by:	DARPA, AFRL
2019-07-22 18:27:17 +00:00
Mark Johnston
5aa9b11b61 Take the mapping's segment offset into account when resolving symbols.
Reported by:	Jenkins, via asomers
MFC after:	2 weeks
2018-07-21 22:15:48 +00:00
Pedro F. Giffuni
5e53a4f90f lib: further adoption of SPDX licensing ID tags.
Mainly focus on files that use BSD 2-Clause license, however the tool I
was using mis-identified many licenses so this was mostly a manual - error
prone - task.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.
2017-11-26 02:00:33 +00:00
Mark Johnston
1bdc41d252 Refine symtab sorting in libproc.
Add some rules to more closely match what illumos does when an address
resolves to multiple symbols:
- prefer non-local symbols
- prefer symbols with fewer leading underscores and no leading '$'

Add some regression tests to verify these rules.
2017-11-21 16:03:21 +00:00
Mark Johnston
2c73c414eb Avoid keeping a dangling pointer when the mappings array is resized.
Sponsored by:	Dell EMC Isilon
2017-09-06 16:24:34 +00:00
Mark Johnston
3573cf3376 Ensure that the mappings table is populated in proc_objname().
MFC after:	1 week
Sponsored by:	Dell EMC Isilon
2017-05-22 23:21:24 +00:00
Mark Johnston
1f7967e13b Add a reasonable bound on the symbol table index size. 2017-01-05 02:33:10 +00:00
Mark Johnston
c156354ff8 libproc: Cache symbol tables for mapped objects upon access.
Extend the file handle cache entries to include symbol tables as well. An
index is used to implement binary search by symbol value. Lookups by
name are comparatively rare and are thus still implemented with a linear
search, but support for a binary search by name would be straightforward
to add if needed.
2016-12-06 04:21:35 +00:00
Mark Johnston
d42df2a447 libproc: Match prefixes when looking up mapped object by name.
When looking up an object by name, allow prefix matches if no direct match
is found. This allows one to, for example, match libc entry probes with:

 # dtrace -n 'pid$target:libc.so::entry' -c ./foo

instead of requiring "libc.so.7" or a glob.

Also remove proc_obj2map() as it currently just duplicates the
functionality of proc_name2map(). It's supposed to take a Solaris
link-map ID as a paramter, but support for this isn't implemented and
isn't required to support DTrace's pid provider.
2016-12-06 04:20:32 +00:00
Mark Johnston
07a9c2e65d libproc: Cache ELF handles for loaded objects.
libproc previously created a new handle for each symbol lookup, which
gives rather egregious performance for DTrace's ustack() action. With
this change libproc will cache the libelf descriptor upon access, making
lookups much faster in the common case.
2016-12-06 04:19:08 +00:00
Mark Johnston
76c6531c65 libproc: Improve .gnu_debuglink support.
As of r278658 libproc looks for debug files under /usr/lib/debug and will
use them if available. This change fleshes out that support a bit further:
- Check for a .gnu_debuglink section and use the file name specified
  there if one is present.
- Validate external debug files with the CRC in the .gnu_debuglink
  section so as to avoid using stale or corrupt debug files.
- Search for debug files in the directory containing the referencing
  object or in the .debug subdirectory, as GDB does.
2016-12-06 04:18:09 +00:00
Mark Johnston
b1bb30e5c5 libproc: Make proc_getpid() an accessor for struct proc_handle.
This allows librtld_db to fetch the PID from a handle without calling into
libproc. Together with r303531, this means that librtld_db no longer
references symbols from libproc.
2016-12-06 04:14:20 +00:00
Stanislav Sedov
0faaddb8db Fix debug symbols loading in libproc: 0 is a valid file descriptor.
Reported by:	Chris Torek <chris.torek@gmail.com>
2015-03-13 04:26:48 +00:00
Rui Paulo
eda94c07de Teach libproc how to find debugging symbols in /usr/lib/debug.
MFC after:	1 week
2015-02-13 03:18:29 +00:00
Mark Johnston
c7fa6f0bb0 Stop iterating and return if the caller-supplied callback function returns
a non-zero value.

MFC after:	1 week
2015-01-31 03:22:00 +00:00
Mark Johnston
cd9c993950 Ensure that we don't try to demangle a symbol name if we failed to look
up the symbol. Add a test to exercise this code path.

Reviewed by:	adrian
2015-01-25 00:34:43 +00:00
Mark Johnston
3f1cbdbeb1 Fix a memory leak that occured when looking up CTF info for a symbol. 2014-12-23 15:40:57 +00:00
Mark Johnston
ec04549052 Remove an incorrect and useless debug print.
X-MFC-With:	r272488
2014-10-04 02:34:30 +00:00
Mark Johnston
41da933c87 Hook up support for userland CTF support in DTrace. This required some
modifications to libproc to support fetching the CTF info for a given file.

With this change, dtrace(1) is able to resolve type info for function and
USDT probe arguments, and function return values. In particular, the args[n]
syntax should now work for referencing arguments of userland probes,
provided that the requisite CTF info is available.

The uctf tests pass if the test programs are compiled with CTF info. The
current infrastructure around the DTrace test suite doesn't support this
yet.

Differential Revision:	https://reviews.freebsd.org/D891
MFC after:		1 month
Relnotes:		yes
Sponsored by:		EMC / Isilon Storage Division
2014-10-03 23:20:37 +00:00
Mark Johnston
540cc663b1 Factor out some of the duplicated code in the symbol lookup functions, in
preparation for adding userland CTF support to DTrace.

MFC after:	1 month
Sponsored by:	EMC / Isilon Storage Division
2014-09-25 19:08:06 +00:00
Mark Johnston
24a08d303e Fix a bug in r265255: only return NULL if the requested map wasn't found.
Submitted by:	Luke Chang-Hsien Tsai <luke.tw@gmail.com>
MFC after:	1 week
2014-08-24 17:02:27 +00:00
Dimitry Andric
96ec3cdd8e In r268463, I misplaced a return in demangle(), causing the function to
erroneously skip symbols that were not mangled at all.  Fix this by
moving the return into the preceding if block.

While here, simplify the code by letting __cxa_demangle() allocate the
needed space for the demangled symbol.  This also fixes a memory leak,
which would occur whenever __cxa_demangle() failed.

Reported by:	pgj
MFC after:	3 days
2014-08-09 12:25:06 +00:00
Dimitry Andric
3d12a34380 In libproc, avoid calling __cxa_demangle(), and thus depending on either
libcxxrt or libsupc++, if WITHOUT_CXX is defined.

Noticed by:	sbruno
MFC after:	1 week
2014-07-09 17:31:57 +00:00
Mark Johnston
acc0eea6b0 Allow "a.out" as an alias for the executable if no other matching entries
are found. This improves compatibility with Solaris' libproc and fixes a
number of failing DTrace tests that rely on this feature.

MFC after:	3 weeks
2014-05-03 04:44:03 +00:00
Mark Johnston
1e6b385830 Fix some off-by-one errors. The kve_end and rdl_eaddr fields contain the
first address after the end of the map entry and should therefore be
excluded.

MFC after:	2 weeks
2014-04-14 00:24:04 +00:00
Mark Johnston
fbce8e1683 Consistently add the relocation offset only when the ELF type is not
ET_EXEC. This fixes several problems with the DTrace pid provider not
being able to match probes.

Reviewed by:	rpaulo
MFC after:	2 weeks
2013-11-11 16:57:57 +00:00
Mark Johnston
4ec6017e0b Fix an off-by-one error when checking whether a given address is within
the extent of a symbol.

Submitted by:	Prashanth Kumar <pra_udupi@yahoo.co.in>
Reviewed by:	rpaulo
MFC after:	1 week
2013-10-29 03:52:05 +00:00
Mark Johnston
7a514b6277 Remove an incorrect debug printf. 2013-10-28 01:41:59 +00:00
Mark Johnston
30e81f7e3b Clean up the debug printing in libproc a bit. In particular:
* Don't print any error messages to stderr unless DEBUG is defined.
* Add a DPRINTFX macro for use when errno isn't set.
* Print the error string from libelf when appropriate.
2013-10-27 20:39:10 +00:00
Rui Paulo
7bc9877d20 Fix the return value when we found a symbol in .dynstr. This nasty bug was
preventing a lot of symbol lookups in dtruss -s, for example.
2013-08-10 07:39:15 +00:00
Rui Paulo
404087cc06 When calling the C++ demangler, make sure to free the returned buffer,
which might have been reallocated.

Pointed out by:	stefanf
2012-09-07 02:38:07 +00:00
Rui Paulo
cd906041ea Add support for demangling C++ symbols. This requires linking libproc with
libc++rt/libsupc++.

Discussed with:	theraven
2012-09-06 03:19:48 +00:00
Rui Paulo
19a75aff51 Make sure we visit both symbol sections even if one of them doesn't
exist. This makes it possible to dtrace some C++ programs like devd.
2012-09-02 18:14:01 +00:00
Rui Paulo
4c74b2455d Several fixes for libproc:
o return the correct status in proc_wstatus()
o proc_read takes a void *
o correctly allocate the objs structure array

Sponsored by:	The FreeBSD Foundation
2010-08-11 17:33:26 +00:00
Rui Paulo
8eb20f364f New version of libproc. Changes are:
* breakpoint setup support
* register query
* symbol to address mapping and vice-versa
* more misc utility functions based on their Solaris counterpart

Also, I've written some test cases.

Sponsored by:	The FreeBSD Foundation
2010-07-31 16:10:20 +00:00
John Birrell
2c633af461 Add a process library with some stubs that the DTrace client needs.
These will be fleshed out as part of the DTrace userland tracing
development.

For now, the kernel tracing part of DTrace requires minimal functionality
for this library.

The API for this library is deliberately different from the libproc in
OpenSolaris due to licensing restrictions.
2008-05-22 02:09:21 +00:00