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.
21 ** Architectural support
22 - MIPS and MIPSel are now handled by the same backend.
23 - ARMv6 and ARMv7 are supported, including full fetch backend.
24 - Imagination Technologies Meta is now supported.
26 - On Linux, tracing of IFUNC symbols is supported. On i386,
27 x86_64, ppc32 with secure PLT and ppc64, IRELATIVE PLT slots are
30 ** -w output now shows full library path
31 The output format is similar to glibc's backtrace_symbols, e.g.:
32 > /bin/ls(_init+0x19be) [0x40398e]
33 > /lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0xed) [0x7f50cbc3676d]
34 > /bin/ls(_init+0x25fd) [0x4045cd]
36 * Version 0.7.3 [2013-09-15 Sun]
38 *** [MIPS] Fix build on mips big endian
39 This bug caused messages like:
41 | /bin/sh: line 17: cd: mips: No such file or directory
42 *** [MIPS] Fix SIGSEGV on mips big endian
43 This bug caused runtime messages like:
44 | [0x4000000] --- SIGSEGV (Segmentation fault) ---
45 | [0xffffffff] +++ killed by SIGSEGV +++
46 *** Fix build with CLANG on FREEBSD
48 * Version 0.7.2 [2012-12-07 Fri]
50 *** (Again) detect VDSO entry in r_debug linkmap with non-empty name
51 This bug caused messages like:
52 | Couldn't determine base address of linux-vdso32.so.1
53 | Couldn't load ELF object linux-vdso32.so.1: No such file or directory
54 *** Fix building with libunwind 1.1
55 *** Fix prototype lookup for -x symbols from shared libraries
56 Ltrace was unable to find prototypes of static symbols in shared
57 libraries. It changed the symbol name internally to the form
58 name@libfoo.so. Thus mangled, symbols were not found in config
61 * Version 0.7.1 [2012-11-29 Thu]
63 *** ltrace.conf.5 is now installed to man5 as it should be
64 *** [PowerPC] A header file necessary for building is now shipped
65 *** [MIPS] Work around duplicate symbol request bug
66 This fixes the ltrace abort:
67 | ./ltrace: proc.c: 755: breakpoint_for_symbol: Assertion `bp->libsym == ((void *)0)' failed.
69 *** Detect VDSO entry in r_debug linkmap with non-empty name
70 This bug caused messages like:
71 | Couldn't determine base address of linux-vdso32.so.1
72 | Couldn't load ELF object linux-vdso32.so.1: No such file or directory
74 *** Temporary files are wiped properly after the test suite has been run
75 *** Parsing typedefs with common prefix now works as it should
76 More exactly, if there were typedefs X and XY (in this order), and
77 a reference was made to X, ltrace would match XY instead.
80 *** The following prototypes in ltrace.conf were added or updated
81 __ctype_get_mb_cur_max, __endmntent, __getmntent_r, __setmntent,
82 a64l, abort, abs, addmntent, getmntent_r, hasmntopt, inet_addr,
83 inet_aton, inet_lnaof, inet_makeaddr, inet_netof, inet_network,
84 inet_ntoa, kill, l64a, labs, memcpy, memmove, setlocale,
85 sigaction, sigaddset, sigandset, sigdelset, sigemptyset,
86 sigfillset, sigisemptyset, sigismember, signal, sigorset,
87 sigpending, sigprocmask, sigsuspend.
89 *** Duplicate typedefs are now guarded against
90 *** It's now possible to define recursive structures
91 Please read ltrace.conf(5) man page, chapter "recursive
92 structures", to learn about this new feature.
94 *** New lens "bitvec" is available
95 This allows displaying various data types as bit vectors. Please
96 read ltrace.conf(5) to learn more.
98 *** Octal lens renamed to "oct"
99 For reasons of consistency with "hex". "octal" is still valid and
100 will be for forseeable future.
102 *** The hex lens can now format floating point arguments
104 * Version 0.7.0 [2012-11-09 Fri]
106 *** Full support for tracing multi-threaded processes
108 Ltrace now understands thread groups, and it stops all threads
109 before manipulating breakpoints. The downside is that performance
110 of multi-threaded processes is rather bad, because handling any
111 event implies stopping the whole job. The upside is that
112 individual threads don't get random SIGILL's and SIGSEGV's and
113 events are not missed.
115 *** Support for tracing inter-library calls
117 -e and -x were extended to allow library selectors. See the man
120 *** Better support for parameter passing ("fetch backend")
122 This version brings more complete support for parameter passing,
123 including passing structures in registers, passing double on i386,
124 and other edge cases that were not handled correctly before. The
125 following architectures now have implementation of fetch backend:
126 i386, x86_64, ppc, ppc64, ia64, s390, s390x, m68k.
128 *** Awareness of deny_ptrace SELinux boolean
130 The deny_ptrace boolean denies all processes from being able to
131 use ptrace to manipulate other processes. Ltrace now understands
132 that this boolean exists, and recommends turning it off, if it is
133 on and ltrace fails to attach to a process.
135 *** Limited support for tracing returns from tail call functions
136 *** -e, -x and -l selectors now allow using globs and regular expressions
138 See the man page for details of the selector syntax. This changes
139 the way -x and -l behave with respect to tracing libraries opened
142 - In 0.6.0, only those -x symbols that were unmatched in main
143 binary were used to search through symbol table of libraries
144 opened with dlopen. In 0.7.0, -x and -e are applied uniformly
145 to each mapped binary: the main binary, dependent DSO's, and any
148 - In 0.6.0, -l argument was a filename to open and inspect. In
149 0.7.0, -l is a glob expression matched against each mapped
152 *** -g command line option dropped
154 This option was introduced in 0.6.0 with the meaning identical to
155 -L, which should be used instead.
157 *** Test suite can now be run under valgrind
159 Use --enable-valgrind to turn this on.
161 *** [ppc] Support both BSS and secure PLTs for 32-bit processes
162 *** [mips] Implement software singlestepping
163 *** [mips] Add support for CPIC main programs
164 *** Support tracing PIE binaries
166 ** Configuration Files
168 *** New abstraction: parameter pack
170 Parameter packs describe zero or more of actual arguments, whose
171 type can be determined in runtime. The only parameter pack
172 currently implemented is "format" for decoding printf-style format
175 In future, it should be relatively straightforward to add more
176 parameter packs for functions like execl, and others.
178 *** New expression: zero
180 When used in array length expressions, it means "this array ends
181 at the first element with zero value". C strings are essentially
184 *** Lenses: change the way that underlying type is rendered
186 Lenses are used similarly to parametrized types, e.g.:
187 | void func(lens(int)); |
191 "octal", which used to be a separate type, is now lens, which can
192 be used to render any underlying type in base 8. Plain "octal"
193 is still valid and means the same thing as "octal(int)".
197 Similarly, "hex" lens was introduced to format as base 16.
198 "hide" was introduced to conceal given argument. "bool" lens was
199 added to format objects as either true, or false.
203 "enum" became lens as well. Because enum already uses
204 parentheses to denote the list of enumeration values, the
205 underlying type is selected by square brackets:
207 | void func(enum[short](RED,GREEN,BLUE)); |
211 "string" was also turned to lens. The argument can be either a
212 char*, or pointer to array of char, or array of char. The latter
213 is useful in cases like the following:
215 | void func_struct_2(struct(string(array(char, 6)))); |
217 *** Misspelling of "int" as "itn" temporarily accepted, but deprecated
219 Pre-0.7 ltrace shipped a buggy version of ltrace.conf that
220 contained the following prototype:
222 | itn acl_valid(addr); |
224 To support extant versions of ltrace.conf, that use is now
225 considered valid, and "itn" is a synonym of "int". It is however
226 deprecated, and will produce a warning in future.
228 *** Using void as top-level function argument now deprecated
230 Functions that take no arguments shouldn't pretend to take one
231 parameter of void type. For example the following:
235 ... should be declared like this:
239 To support extant versions of ltrace.conf, that use is now
240 considered valid. It is however deprecated, and will produce a
243 *** Using void to hide one argument is now obsolete
245 Ltrace needs to know the exact underlying type to decide what the
246 calling convention is. The use of void to mean "hide this
247 argument", such as the following example, is therefore obsolete:
249 | void func(void, array(int, arg1)); |
251 Instead, rewrite the prototype depending on the exact underlying
254 | void func(hide(int), array(int, arg1)); |
255 | void func(hide(long), array(int, arg1)); |
257 To support extant versions of ltrace.conf, this use is still
258 accepted, and "void" is taken to mean "hide(int)". It is however
259 obsolete, produces a warning, and will be removed in future.
263 *** New manual page ltrace.conf(5)
264 *** README, INSTALL brought up to date
265 *** New file CREDITS with a list of contributors
269 *** Fix detaching from a process
271 Earlier, a process that ltrace detached from would sometimes die
272 of SIGSEGV, SIGTRAP, or SIGILL. These were caused by ltrace
273 detaching from the process just after that process hit a
274 breakpoint. Program counter would thus be left pointing
275 mid-instruction, or signals would be left pending.
277 *** Argument to -n is now checked for validity
278 *** Fix tracing across exec in a stripped binary
279 *** [x86] ORIG_RAX/ORIG_EAX may not contain original syscall number
281 In cases where the system call shouldn't be restarted, these are
282 set to -1. In that case assume that the return is from the
283 topmost syscall. This gets rid of some "unexpected breakpoint"
284 messages on x86_64 and i386.
286 *** [ppc] Fix races in tracing -e events in 64-bit processes
288 On ppc, the contents of PLT table change after the first call.
289 Ltrace used to handle this by reinserting the (now overwritten)
290 breakpoint after the function returns. This introduced a window
291 where calls to the same function from the same binary (either a
292 recursive calls, or calls from another thread) weren't traced.
293 This is fixed as of 0.7.0.
295 As a side effect, events requested via -e now only hit when a PLT
296 call is made, which is consistent with other architectures.
298 *** [ppc] Allow stepping over lwarx instruction
302 *** [arm] Tracing is not supported at all on ARM
304 ltrace might work on older kernels, but no attempt was made to
305 fully support it. Newer kernels don't support PTRACE_SINGLESTEP,
306 which ltrace depends on. Before singlestepping is implemented in
307 software, ARM is considered unsupported.
309 * Version 0.6.0 [2011-01-06 Thu]
313 *** Use autotools for building
314 *** New option -b: disables output of signals received by the tracee
315 *** New option -w: print stack trace of events
317 Pass --with-libunwind to configure to enable the feature. This
320 *** Support tracing of symbols from libraries opened with dlopen
322 These symbols are selected by -x.
324 ** Architecture-specific Changes
326 *** Various fixes for MIPS and PowerPC
327 *** Support for ARM Thumb mode
328 *** Implement fetching of 5th and further function arguments on s390
329 *** Support fork/exec syscalls on 31-bit s390
330 *** Support for float and double arguments on x86_64
331 *** Fixes for return arguments (after '+') in nested calls on x86_64
334 -------------------------------------------------------------------------------
335 Copyright (C) 2012,2013 Petr Machata <pmachata@redhat.com>
336 This file is part of ltrace.
338 ltrace is free software; you can redistribute it and/or modify it
339 under the terms of the GNU General Public License as published by the
340 Free Software Foundation; either version 2 of the License, or (at your
341 option) any later version.
343 ltrace is distributed in the hope that it will be useful, but WITHOUT
344 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
345 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
348 You should have received a copy of the GNU General Public License
349 along with this program. If not, see <http://www.gnu.org/licenses/>.