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-*-org-*-
* Version 0.7.0
** Tracing
*** Full support for tracing multi-threaded processes
Ltrace now understands thread groups, and it stops all threads
before manipulating breakpoints. The downside is that performance
of multi-threaded processes is rather bad, because handling any
event implies stopping the whole job. The upside is that
individual threads don't get random SIGILL's and SIGSEGV's and
events are not missed.
*** Support for tracing inter-library calls
-e and -x were extended to allow library selectors. See the man
page for details.
*** Better support for parameter passing ("fetch backend")
This version brings a more complete support for parameter passing,
including passing structures in registers, passing double on i386,
and other edge cases that were unsupported before. The following
architectures now have implementation of fetch backend: x86, ppc,
ia64, s390, m68k.
*** Awareness of deny_ptrace SELinux boolean
The deny_ptrace boolean denies all processes from being able to
use ptrace to manipulate other processes. Ltrace now understands
that this boolean exists, and recommends turning it off, if it is
on and ltrace fails to attach to a process.
*** Limited support for tracing returns from tail call functions
*** -e, -x and -l selectors now allow using globs and regular expressions
See the man page for details of the selector syntax.
*** Test suite can now be run under valgrind
Use --enable-valgrind to turn this on.
*** [ppc] Support both BSS and secure PLTs for 32-bit processes
*** [mips] Implement software singlestepping
*** [mips] Add support for CPIC main programs
*** Support tracing PIE binaries
** Configuration Files
*** New abstraction: parameter pack
Parameter packs make it much simpler to add specialized decoding
logic. The only parameter pack currently implemented is "format"
for decoding printf-style format strings. It should be relatively
straightforward to add more parameter packs for functions like
execl, strftime, and others.
*** New expression: zero
When used in array length expressions, it means "this array ends
at the first element with zero value". C strigs are essentially
array(char, zero)*.
*** Lenses: change the way that underlying type is rendered
Lenses are used similarly to parametrized types, e.g.:
| void func(lens(int)); |
**** octal
"octal", which used to be a separate type, is now lens, which can
be used to render any underlying type in base 8. Plain "octal"
is still valid and means the same as "octal(int)".
**** hex, hide, bool
Similarly, "hex" lens was introduced to format as base 16.
"hide" was introduced to conceal given argument. "bool" lens was
added to format objects as either true, or false.
**** enum
"enum" became lens as well. Because enum already uses
parentheses to denote the list of enumeration values, the
underlying type is selected by square brackets:
| void func(enum[short](RED,GREEN,BLUE)); |
**** string
"string" was also turned to lens. The argument can be either a
char*, or pointer to array of char, or array of char. The latter
is useful in cases like the following:
| void func_struct_2(struct(string(array(char, 6)))); |
*** Using void as sole argument to a function now obsolete
Functions that take no arguments shouldn't pretend to take one
parameter of void type. That use is now obsolete (but still
accepted):
| void func(void); |
Instead, such functions should be declared like this:
| void func(); |
*** Using void to hide one argument is no longer supported
Instead use "hide" lens (see above). ltrace needs to know the
exact underlying type to decide what the calling convention is.
In the following two declarations, how the second argument is
passed may depend on the exact type of the hidden argument:
| void func(hide(int), int); |
| void func(hide(struct(float,float)), int); |
** Documentation
*** New manual page ltrace.conf(5)
*** README, INSTALL brought up to date
*** New file CREDITS with a list of contributors
** Bugfixes
*** Fix detaching from a process
Earlier, a process that ltrace detached from would sometimes die
of SIGSEGV, SIGTRAP, or SIGILL. These were caused by ltrace
detaching from the process just after that process hit a
breakpoint. Program counter would thus be left pointing
mid-instruction, or signals would be left pending.
*** Argument to -n is now checked for validity
*** Fix tracing across exec in a stripped binary
*** [x86] ORIG_RAX/ORIG_EAX may not contain original syscall number
In cases where the system call shouldn't be restarted, these are
set to -1. In that case assume that the return is from the
topmost syscall. This gets rid of some "unexpected breakpoint"
messages on x86_64 and i386.
*** [ppc] Fix races in tracing -e events in 64-bit processes
As a side effect, events requested via -e now only hit when a PLT
call is made, which is consistent with other architectures.
*** [ppc] Allow stepping over lwarx instruction
** Known bugs
*** [arm] Tracing is not supported at all on ARM
ltrace might work on older kernels, but no attempt was made to
fully support it. Newer kernels don't support PTRACE_SINGLESTEP,
which ltrace depends on. Before singlestepping is implemented in
software, ARM is considered unsupported.
* Version 0.6.0
** General Features
*** Use autotools for building
*** New option -b: disables output of signals received by the tracee
*** New option -w: print stack trace of events
Pass --with-libunwind to configure to enable the feature. This
requires libunwind.
*** Support tracing of symbols from libraries opened with dlopen
These symbols are selected by -x.
** Architecture-specific Changes
*** Various fixes for MIPS and PowerPC
*** Support for ARM Thumb mode
*** Implement fetching of 5th and further function arguments on s390
*** Support fork/exec syscalls on 31-bit s390
*** Support for float and double arguments on x86_64
*** Fixes for return arguments (after '+') in nested calls on x86_64
* License
-------------------------------------------------------------------------------
Copyright (C) 2012 Petr Machata <pmachata@redhat.com>
This file is part of ltrace.
ltrace is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by the
Free Software Foundation; either version 2 of the License, or (at your
option) any later version.
ltrace is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
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