4 - Each DSO can now ship an ltrace config file (called prototype
5 library) that ltrace will open when that DSO is loaded to process
6 image. See ltrace(1) for details.
8 - ltrace.conf is no longer part of installation tarball. Instead,
9 we now ship libc.so.conf, libm.so.conf, libacl.so.conf, and
10 syscalls.conf. Those are now istalled to /usr/share/ltrace by
11 default. /etc/ltrace.conf and $HOME/.ltrace.conf are still
12 loaded if present, and can contain arbitrary user configuration.
14 - The option -F was retrofitted to be a colon-separated list of
15 prototype libraries, and directories to look for prototype
16 libraries in. On Linux, ltrace looks into XDG_CONFIG_HOME,
17 XDG_CONFIG_DIRS, and /usr/share/ltrace as well.
19 - Wide character strings are supported in prototypes. Use "string"
20 lens as usual, but use array of integers as underlying type.
21 libc.so.conf now contains prototypes of wide character functions.
23 - Sole void function parameter such as in the following example, is
24 now considered obsolete:
28 This use is still accepted, taken to mean "hide(int)", but
29 produces a warning, and will be removed in future.
31 - Prototypes are now read from DWARF debug info, if available. This
32 complements the data available in config files
34 ** Architectural support
35 - MIPS and MIPSel are now handled by the same backend.
36 - ARMv6, ARMv7 and ARMv8 (AArch64) are supported, including full
37 fetch backend. ARMv8 backend doesn't support tracing of 32-bit
38 binaries, as currently there's no 32-bit userspace available for
40 - Imagination Technologies Meta is now supported.
42 - On Linux, tracing of IFUNC symbols is supported. On i386,
43 x86_64, ppc32 with secure PLT and ppc64, IRELATIVE PLT slots are
46 ** -w output now shows full library path
47 The output format is similar to glibc's backtrace_symbols, e.g.:
48 > /bin/ls(_init+0x19be) [0x40398e]
49 > /lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0xed) [0x7f50cbc3676d]
50 > /bin/ls(_init+0x25fd) [0x4045cd]
52 * Version 0.7.3 [2013-09-15 Sun]
54 *** [MIPS] Fix build on mips big endian
55 This bug caused messages like:
57 | /bin/sh: line 17: cd: mips: No such file or directory
58 *** [MIPS] Fix SIGSEGV on mips big endian
59 This bug caused runtime messages like:
60 | [0x4000000] --- SIGSEGV (Segmentation fault) ---
61 | [0xffffffff] +++ killed by SIGSEGV +++
62 *** Fix build with CLANG on FREEBSD
64 * Version 0.7.2 [2012-12-07 Fri]
66 *** (Again) detect VDSO entry in r_debug linkmap with non-empty name
67 This bug caused messages like:
68 | Couldn't determine base address of linux-vdso32.so.1
69 | Couldn't load ELF object linux-vdso32.so.1: No such file or directory
70 *** Fix building with libunwind 1.1
71 *** Fix prototype lookup for -x symbols from shared libraries
72 Ltrace was unable to find prototypes of static symbols in shared
73 libraries. It changed the symbol name internally to the form
74 name@libfoo.so. Thus mangled, symbols were not found in config
77 * Version 0.7.1 [2012-11-29 Thu]
79 *** ltrace.conf.5 is now installed to man5 as it should be
80 *** [PowerPC] A header file necessary for building is now shipped
81 *** [MIPS] Work around duplicate symbol request bug
82 This fixes the ltrace abort:
83 | ./ltrace: proc.c: 755: breakpoint_for_symbol: Assertion `bp->libsym == ((void *)0)' failed.
85 *** Detect VDSO entry in r_debug linkmap with non-empty name
86 This bug caused messages like:
87 | Couldn't determine base address of linux-vdso32.so.1
88 | Couldn't load ELF object linux-vdso32.so.1: No such file or directory
90 *** Temporary files are wiped properly after the test suite has been run
91 *** Parsing typedefs with common prefix now works as it should
92 More exactly, if there were typedefs X and XY (in this order), and
93 a reference was made to X, ltrace would match XY instead.
96 *** The following prototypes in ltrace.conf were added or updated
97 __ctype_get_mb_cur_max, __endmntent, __getmntent_r, __setmntent,
98 a64l, abort, abs, addmntent, getmntent_r, hasmntopt, inet_addr,
99 inet_aton, inet_lnaof, inet_makeaddr, inet_netof, inet_network,
100 inet_ntoa, kill, l64a, labs, memcpy, memmove, setlocale,
101 sigaction, sigaddset, sigandset, sigdelset, sigemptyset,
102 sigfillset, sigisemptyset, sigismember, signal, sigorset,
103 sigpending, sigprocmask, sigsuspend.
105 *** Duplicate typedefs are now guarded against
106 *** It's now possible to define recursive structures
107 Please read ltrace.conf(5) man page, chapter "recursive
108 structures", to learn about this new feature.
110 *** New lens "bitvec" is available
111 This allows displaying various data types as bit vectors. Please
112 read ltrace.conf(5) to learn more.
114 *** Octal lens renamed to "oct"
115 For reasons of consistency with "hex". "octal" is still valid and
116 will be for forseeable future.
118 *** The hex lens can now format floating point arguments
120 * Version 0.7.0 [2012-11-09 Fri]
122 *** Full support for tracing multi-threaded processes
124 Ltrace now understands thread groups, and it stops all threads
125 before manipulating breakpoints. The downside is that performance
126 of multi-threaded processes is rather bad, because handling any
127 event implies stopping the whole job. The upside is that
128 individual threads don't get random SIGILL's and SIGSEGV's and
129 events are not missed.
131 *** Support for tracing inter-library calls
133 -e and -x were extended to allow library selectors. See the man
136 *** Better support for parameter passing ("fetch backend")
138 This version brings more complete support for parameter passing,
139 including passing structures in registers, passing double on i386,
140 and other edge cases that were not handled correctly before. The
141 following architectures now have implementation of fetch backend:
142 i386, x86_64, ppc, ppc64, ia64, s390, s390x, m68k.
144 *** Awareness of deny_ptrace SELinux boolean
146 The deny_ptrace boolean denies all processes from being able to
147 use ptrace to manipulate other processes. Ltrace now understands
148 that this boolean exists, and recommends turning it off, if it is
149 on and ltrace fails to attach to a process.
151 *** Limited support for tracing returns from tail call functions
152 *** -e, -x and -l selectors now allow using globs and regular expressions
154 See the man page for details of the selector syntax. This changes
155 the way -x and -l behave with respect to tracing libraries opened
158 - In 0.6.0, only those -x symbols that were unmatched in main
159 binary were used to search through symbol table of libraries
160 opened with dlopen. In 0.7.0, -x and -e are applied uniformly
161 to each mapped binary: the main binary, dependent DSO's, and any
164 - In 0.6.0, -l argument was a filename to open and inspect. In
165 0.7.0, -l is a glob expression matched against each mapped
168 *** -g command line option dropped
170 This option was introduced in 0.6.0 with the meaning identical to
171 -L, which should be used instead.
173 *** Test suite can now be run under valgrind
175 Use --enable-valgrind to turn this on.
177 *** [ppc] Support both BSS and secure PLTs for 32-bit processes
178 *** [mips] Implement software singlestepping
179 *** [mips] Add support for CPIC main programs
180 *** Support tracing PIE binaries
182 ** Configuration Files
184 *** New abstraction: parameter pack
186 Parameter packs describe zero or more of actual arguments, whose
187 type can be determined in runtime. The only parameter pack
188 currently implemented is "format" for decoding printf-style format
191 In future, it should be relatively straightforward to add more
192 parameter packs for functions like execl, and others.
194 *** New expression: zero
196 When used in array length expressions, it means "this array ends
197 at the first element with zero value". C strings are essentially
200 *** Lenses: change the way that underlying type is rendered
202 Lenses are used similarly to parametrized types, e.g.:
203 | void func(lens(int)); |
207 "octal", which used to be a separate type, is now lens, which can
208 be used to render any underlying type in base 8. Plain "octal"
209 is still valid and means the same thing as "octal(int)".
213 Similarly, "hex" lens was introduced to format as base 16.
214 "hide" was introduced to conceal given argument. "bool" lens was
215 added to format objects as either true, or false.
219 "enum" became lens as well. Because enum already uses
220 parentheses to denote the list of enumeration values, the
221 underlying type is selected by square brackets:
223 | void func(enum[short](RED,GREEN,BLUE)); |
227 "string" was also turned to lens. The argument can be either a
228 char*, or pointer to array of char, or array of char. The latter
229 is useful in cases like the following:
231 | void func_struct_2(struct(string(array(char, 6)))); |
233 *** Misspelling of "int" as "itn" temporarily accepted, but deprecated
235 Pre-0.7 ltrace shipped a buggy version of ltrace.conf that
236 contained the following prototype:
238 | itn acl_valid(addr); |
240 To support extant versions of ltrace.conf, that use is now
241 considered valid, and "itn" is a synonym of "int". It is however
242 deprecated, and will produce a warning in future.
244 *** Using void as top-level function argument now deprecated
246 Functions that take no arguments shouldn't pretend to take one
247 parameter of void type. For example the following:
251 ... should be declared like this:
255 To support extant versions of ltrace.conf, that use is now
256 considered valid. It is however deprecated, and will produce a
259 *** Using void to hide one argument is now obsolete
261 Ltrace needs to know the exact underlying type to decide what the
262 calling convention is. The use of void to mean "hide this
263 argument", such as the following example, is therefore obsolete:
265 | void func(void, array(int, arg1)); |
267 Instead, rewrite the prototype depending on the exact underlying
270 | void func(hide(int), array(int, arg1)); |
271 | void func(hide(long), array(int, arg1)); |
273 To support extant versions of ltrace.conf, this use is still
274 accepted, and "void" is taken to mean "hide(int)". It is however
275 obsolete, produces a warning, and will be removed in future.
279 *** New manual page ltrace.conf(5)
280 *** README, INSTALL brought up to date
281 *** New file CREDITS with a list of contributors
285 *** Fix detaching from a process
287 Earlier, a process that ltrace detached from would sometimes die
288 of SIGSEGV, SIGTRAP, or SIGILL. These were caused by ltrace
289 detaching from the process just after that process hit a
290 breakpoint. Program counter would thus be left pointing
291 mid-instruction, or signals would be left pending.
293 *** Argument to -n is now checked for validity
294 *** Fix tracing across exec in a stripped binary
295 *** [x86] ORIG_RAX/ORIG_EAX may not contain original syscall number
297 In cases where the system call shouldn't be restarted, these are
298 set to -1. In that case assume that the return is from the
299 topmost syscall. This gets rid of some "unexpected breakpoint"
300 messages on x86_64 and i386.
302 *** [ppc] Fix races in tracing -e events in 64-bit processes
304 On ppc, the contents of PLT table change after the first call.
305 Ltrace used to handle this by reinserting the (now overwritten)
306 breakpoint after the function returns. This introduced a window
307 where calls to the same function from the same binary (either a
308 recursive calls, or calls from another thread) weren't traced.
309 This is fixed as of 0.7.0.
311 As a side effect, events requested via -e now only hit when a PLT
312 call is made, which is consistent with other architectures.
314 *** [ppc] Allow stepping over lwarx instruction
318 *** [arm] Tracing is not supported at all on ARM
320 ltrace might work on older kernels, but no attempt was made to
321 fully support it. Newer kernels don't support PTRACE_SINGLESTEP,
322 which ltrace depends on. Before singlestepping is implemented in
323 software, ARM is considered unsupported.
325 * Version 0.6.0 [2011-01-06 Thu]
329 *** Use autotools for building
330 *** New option -b: disables output of signals received by the tracee
331 *** New option -w: print stack trace of events
333 Pass --with-libunwind to configure to enable the feature. This
336 *** Support tracing of symbols from libraries opened with dlopen
338 These symbols are selected by -x.
340 ** Architecture-specific Changes
342 *** Various fixes for MIPS and PowerPC
343 *** Support for ARM Thumb mode
344 *** Implement fetching of 5th and further function arguments on s390
345 *** Support fork/exec syscalls on 31-bit s390
346 *** Support for float and double arguments on x86_64
347 *** Fixes for return arguments (after '+') in nested calls on x86_64
350 -------------------------------------------------------------------------------
351 Copyright (C) 2012-2014 Petr Machata <pmachata@redhat.com>
352 This file is part of ltrace.
354 ltrace is free software; you can redistribute it and/or modify it
355 under the terms of the GNU General Public License as published by the
356 Free Software Foundation; either version 2 of the License, or (at your
357 option) any later version.
359 ltrace is distributed in the hope that it will be useful, but WITHOUT
360 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
361 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
364 You should have received a copy of the GNU General Public License
365 along with this program. If not, see <http://www.gnu.org/licenses/>.