Dmitry V. Levin [Sun, 25 Mar 2012 21:49:48 +0000 (21:49 +0000)]
Robustify parsing of numbers from strings
* defs.h (string_to_uint): New prototype.
* util.c (string_to_uint): New function.
* strace.c (error_opt_arg): New function.
(process_opt_p_list): Use string_to_uint instead of atoi.
Terminate in case of invalid process id.
(init): Use string_to_uint instead of atoi.
Use error_opt_arg in case of invalid option argument.
* syscall.c (qual_syscall, qual_signal, qual_desc): Use string_to_uint
instead of atoi.
After: movzbl (%eax),%edx
sub $0x30,%edx
cmp $0x9,%dl
ja lbl
text data bss dec hex filename
236869 704 18944 256517 3ea05 strace.before
236719 700 18944 256363 3e96b strace
* defs.h: Alias sigemptyset to __sigemptyset on glibc.
* syscall.c (qual_syscall): Open-code isdigit.
(qual_desc): Likewise.
(qual_signal): Open-code isdigit. Remove string copying
which was done for no apparent reason.
Denys Vlasenko [Thu, 22 Mar 2012 08:56:20 +0000 (09:56 +0100)]
Simplify current tcp switching and current column handling
Instead of using "static FILE *outf and static unsigned int curcol"
to cache current outfile and its position, we can simply
remember current tcb and use its ->outf and ->curcol.
This allows to drop numerous "tcp->curcol = curcol" ops in trace().
Turns out we can't drop "static FILE *outf", but now its role is
a bit clearer: it newer changes after init, stays == stderr or
opened to shared log (which may be the same thing if neither -o
nor -ff was specified). Let's rename it then.
text data bss dec hex filename
236953 704 18944 256601 3ea59 strace.before.prev.commit
236905 704 18944 256553 3ea29 strace.before
236869 704 18944 256517 3ea05 strace
* strace.c: Replace curcol static variable by struct tcb *current_tcp.
Rename static FILE *outf to shared_log (since it no longer caches tcp->outf).
(ptrace_restart): Use current_tcp->curcol instead of curcol.
(tprintf): Check current_tcp != NULL instead of outf != NULL.
Use current_tcp->outf instead of outf, current_tcp->curcol instead of curcol.
(tprints): Likewise.
(line_ended): Likewise.
(printleader): Switch current tcb by "current_tcp = tcp" istead of
assignments to outf and curcol.
(droptcb): Set current_tcp to NULL if we dropped it.
(startup_child): Rename outf to shared_log.
(init): Likewise.
(cleanup): Likewise.
(trace): Simplify current tcp switching and current column handling.
Denys Vlasenko [Thu, 22 Mar 2012 08:35:51 +0000 (09:35 +0100)]
Make threaded execve handling code more reabable and somewhat simpler
* strace.c (droptcb): Remove outfname check in "outfname && followfork >= 2" -
with recent changes, followfork >= 2 check guarantees that outfile
was specified, and _is already opened_.
(trace): Move tcb existence check before threaded execve handling.
This allows to remove tcp != NULL checks in threaded execve handling.
Rewrite threaded execve handling code to be less indented,
keeping the same logic.
Denys Vlasenko [Wed, 21 Mar 2012 10:06:20 +0000 (11:06 +0100)]
Replace reprinting decision logic
After this change, we no longer need to decide when we need
to set TCB_REPRINT, and when we don't: it's never needed :)
Well, almost. That pesky pid-changing execve needs special treatment.
If not it, it'd be possible to nuke TCB_REPRINT...
While at it, fix a case of mishandled -C.
* strace.c (printleader): Do not set TCB_REPRINT.
(trace): Set TCB_REPRINT only for execve with changing pid.
Fix mishandling of -C.
* syscall.c (trace_syscall_entering): Do not clear TCB_REPRINT.
(trace_syscall_exiting): Replace reprinting decision logic.
Remove call to printargs(): it is known to just return 0 here.
This tells user that strace failed to let sendto syscall
to be entered - process was dead at that point of time.
It is (marginally) better than to always say "<unfinished ...>"
While at it, patch removes tcp->ptrace_errno.
I added it many months ago, and it looks that after all
it is not needed for ptrace error detection: I failed to execute
a single existing code path which is accessible
through that variable only.
Denys Vlasenko [Tue, 20 Mar 2012 16:10:35 +0000 (17:10 +0100)]
Remove redundant checks in syscall entry/exit, rename badly named function
* syscall.c (syscall_enter): Rename to get_syscall_args.
Document its return values.
(trace_syscall_entering): Don't check get_syscall_args() return
value for 0, it never returns that.
(syscall_fixup_on_sysexit): Make it return void.
(trace_syscall_exiting): Fix up syscall_fixup_on_sysexit()
call site accordingly.
Denys Vlasenko [Tue, 20 Mar 2012 09:57:41 +0000 (10:57 +0100)]
Simplify search in ioctl table
text data bss dec hex filename
236973 704 18944 256621 3ea6d strace.before
236929 704 18944 256577 3ea41 strace
* ioctl.c (compare): Simplify generation of compare result.
(ioctl_lookup): Pass key directly, not as part of dummy struct.
(ioctl_next_match): More readable code. No logic changes.
Denys Vlasenko [Mon, 19 Mar 2012 08:51:42 +0000 (09:51 +0100)]
Shrink space needed by undefined syscalls in syscall tables.
Undefined syscall looked like this before this change:
{ 5, 0, printargs, "SYS_53" },
That is, "SYS_53" string had to be allocated and stored in strace binary.
Since now SCNO_IN_RANGE() macro requires sysent[scno].sys_func != NULL
for valid syscalls, we can replace printargs with NULL in such lines
and make them "invalid", thus not requiring syscall name string.
Savings on i386:
text data bss dec hex filename
237389 704 18944 257037 3ec0d strace.before
236973 704 18944 256621 3ea6d strace
Savings on mips:
336551 153692 38320 528563 810b3 strace.before
275543 153688 38320 467551 7225f strace
Tested to still decode undefined syscalls correctly (syscall no. 222 on i386).
* linux/*/syscallent.h: Replace 'printargs, "SYS_nnn"' with
'NULL, NULL'.
Denys Vlasenko [Sun, 18 Mar 2012 21:10:48 +0000 (22:10 +0100)]
Make internal_fork and internal_exec static
text data bss dec hex filename
237917 672 18980 257569 3ee21 strace
237845 672 18980 257497 3edd9 strace_new
* defs.h: Remove declarations of internal_fork and internal_exec.
* process.c: Remove definitions of internal_fork and internal_exec.
* syscall.c: Move them here.
(internal_syscall): Return void instead of int. We were always
returning zero, and callers weren't checking it anyway.
Denys Vlasenko [Sun, 18 Mar 2012 03:16:59 +0000 (04:16 +0100)]
Remove code which is not used on Linux
Compile tested in qemu on armv4l,armv4tl,armv5l,armv6l,i686,
mipsel,mips,x86_64
* syscall.c: Remove code which handles RVAL_Lfoo constants.
* defs.h: Remove struct tcb::u_lrval member - it is never set.
Remove RVAL_Lfoo constants which signify return of "long" result -
they are never used.
Denys Vlasenko [Sun, 18 Mar 2012 03:13:14 +0000 (04:13 +0100)]
Remove unused version of sys_lseek
It is buggy: it returns RVAL_LUDECIMAL, which means the return value
is in tcp->u_lrval. But tcp->u_lrval is never set
(on Linux - it used to be set on other OSes).
* file.c (sys_lseek): Remove a version of this function which is
supposed to be used if off_t is long long. It appears to be buggy
and unused.
Denys Vlasenko [Sat, 17 Mar 2012 15:26:47 +0000 (16:26 +0100)]
Simplify sys_lseek64 conditional compilation.
It looks like sys_lseek64() is never used.
For one, it is buggy (always shows 0 return value), and no one complains.
From code inspection: sys_lseek64 name is not used anywhere.
It is defined to sys_lseek if HAVE_LONG_LONG_OFF_T is true.
Thus, if !HAVE_LONG_LONG_OFF_T, it is never used.
Therefore "if _LFS64_LARGEFILE || HAVE_LONG_LONG_OFF_T"
conditional it sits in can be simplified to
"if HAVE_LONG_LONG_OFF_T".
Therefore, we can move it a bit up and merge with
"if !HAVE_LONG_LONG_OFF_T, use this sys_lseek()" code block,
by addind an "else" clause to it.
To simplify it more, drop define and just rename sys_lseek64 ->
sys_lseek.
Since the function is buggy, I think it is unused and we can
just drop it. (I checked: at least I386 never uses it).
* file.c (sys_lseek64): Rename to sys_lseek; don't compile it
if _LFS64_LARGEFILE but !HAVE_LONG_LONG_OFF_T since in this case
it is never used.
Denys Vlasenko [Sat, 17 Mar 2012 12:23:00 +0000 (13:23 +0100)]
Remove underscores from a few syscall names which have them
Affected names are "_newselect", "_llseek", "_sysctl".
I see no apparent reason why they have leading underscores.
Moreover, some arches have underscored names and some have
non-underscored ones. This is not consistent.
I verified that every architectire I touched did not have
a similarly named syscall without underscore, thus this change
does not introduce new ambiquities.
I left "_exit" untouched for now, but the same points stand for it too:
some architectures use "exit" and no one complains. So why many
arches are using "_exit"?
* linux/*/syscallent.h: Remove underscores from displayed
syscall names for _newselect, _llseek, _sysctl.
* strace.c (newoutf): Set tcp->outf in non-ff mode too.
(alloctcb): This define is removed.
(alloc_tcb): Renamed to alloctcb. Does not set tcp->outf anymore.
Lost 'command_options_parsed' flag parameter.
(startup_attach): Do not say "interrupt to quit" in attach message -
^C does not work in all cases, we mislead users.
Call newoutf(tcp) after successful attach.
(startup_child): Call newoutf(tcp) after successful attach.
(trace): Call newoutf(tcp) when we picked up already attached child.
Denys Vlasenko [Fri, 16 Mar 2012 14:11:34 +0000 (15:11 +0100)]
Make alloc_tcb and droptcb static. No code changes.
The change is trivial. Diff is large because it is confused
by function definitions being moved around.
* defs.h: Remove declarations of alloc_tcb and droptcb.
* strace.c: Make alloc_tcb and droptcb static.
Shuffle functions around to make compiler happy.
Denys Vlasenko [Fri, 16 Mar 2012 11:02:22 +0000 (12:02 +0100)]
Tidy up includes and copyright notices, fix indentation
The files not mentioned in changelog below had only
copyright notices fixes and indentation fixes.
* defs.h: Include <stdint.h> and <inttypes.h>.
* file.c: Do not include <inttypes.h>.
Move struct kernel_dirent declaration below top include block.
* block.c: Do not include <stdint.h> and <inttypes.h>.
* quota.c: Likewise.
* desc.c: Likewise.
* signal.c: Likewise.
Dmitry V. Levin [Thu, 15 Mar 2012 22:08:55 +0000 (22:08 +0000)]
Remove unused code
* syscall.c (subcall_style, decode_subcall): Remove.
[SYS_socket_subcall] (decode_socket_subcall): New function, based on
decode_subcall in deref_style.
[SYS_ipc_subcall] (decode_ipc_subcall): New function, based on
decode_subcall in shift_style.
(trace_syscall_entering): Use decode_socket_subcall and
decode_ipc_subcall instead of decode_subcall.
Dmitry V. Levin [Thu, 15 Mar 2012 20:42:46 +0000 (20:42 +0000)]
arm: fix compilation warnings
* configure.ac: Define SIZEOF_LONG.
* signal.c (sys_rt_sigaction) [SUPPORTED_PERSONALITIES > 1]: Help
compiler to optimize out unreachable code that is not expected to work
on platforms where sizeof(long) <= 4.
Mike Frysinger [Thu, 15 Mar 2012 05:09:19 +0000 (01:09 -0400)]
improve ifdef check with decode_subcall
Use the same ifdef logic around the call sites of decode_subcall()
to protect the definition of the func itself. This fixes warnings
for targets like hppa which don't use this func.
* syscall.c (decode_subcall): Wrap in SYS_socket_subcall and
SYS_ipc_subcall define checks.
* linux/alpha/syscallent.h: Call sys_sigprocmask for osf_sigprocmask,
and change number of arguments to two.
* signal.c (sys_sigprocmask): Fix decoding of alpha osf sigprocmask.
Denys Vlasenko [Thu, 15 Mar 2012 17:03:56 +0000 (18:03 +0100)]
pathtrace_select() is never called with NULL, remove dead code
pathtrace_select() is only called for -P FILE options,
and FILE is never a NULL pointer.
text data bss dec hex filename
239453 672 19012 259137 3f441 strace.before
239329 672 19012 259013 3f3c5 strace
* pathtrace.c (pathtrace_select): Remove "if (path == NULL)...".
(pathtrace_select): Remove code which only executes if path == NULL.
The code was also buggy, it can free non-malloced pointer.
(getfdpath): Simplify snprintf to sprintf.
(pathmatch): Use strcmp() == 0 idiom for string equality test.
(pathtrace_match): Likewise.
Denys Vlasenko [Thu, 15 Mar 2012 16:32:56 +0000 (17:32 +0100)]
manpage: remove bugs which are fixed
"A traced process ignores SIGSTOP" - fixed, expected to be in linux-3.4.x.
"A traced process which tries to block SIGTRAP will be sent a SIGSTOP
in an attempt to force continuation of tracing." - not needed
and no longer done.
"On Linux, exciting as it would be, tracing the init process is forbidden"
- not true anymore.
"When a traced process receives a SIGTRAP signal not
associated with tracing, strace will not report that signal correctly."
- not true anymore.
Denys Vlasenko [Thu, 15 Mar 2012 16:24:49 +0000 (17:24 +0100)]
When reporting signals, use short signal names (SIGfoo) instead of strerror
* defs.h: Remove strsignal declaration.
* signal.c: Better check for SI_FROMUSER define.
* strace.c (strerror): Remove this function.
(trace): Use short signal names (SIGfoo) instead of strerror.
Denys Vlasenko [Thu, 15 Mar 2012 13:36:28 +0000 (14:36 +0100)]
Fix lame kernel version checking code
The code "os_release[0] >= '3'" is not good for any
finer-grained checks such as "kernel >= 3.2.1".
Let's proactively fix it.
* strace.c: Change os_release from string to integer.
(get_os_release): Parse uname.release to KERNEL_VERSION
representation.
(init): Convert kernel version check to KERNEL_VERSION.
Denys Vlasenko [Thu, 15 Mar 2012 12:44:17 +0000 (13:44 +0100)]
Experimental support for "detach on execve" feature
* strace.c: Define new detach_on_execve, skip_startup_execve bool variables.
(init): Set detach_on_execve on -b, set skip_startup_execve if
"strace PROG" form is used.
(trace): Detach from process if -b and we see PTRACE_EVENT_EXEC event.
Denys Vlasenko [Thu, 15 Mar 2012 11:56:25 +0000 (12:56 +0100)]
Remove extra include directives. No code changes.
* defs.h: Include <signal.h> unconditionally.
Other files were doing it unconditionally, so no harm done.
* bjm.c: Remove system includes which are already included by defs.h.
* pathtrace.c: Likewise.
* process.c: Likewise.
* signal.c: Likewise.
* strace.c: Likewise.
* stream.c: Likewise.
* syscall.c: Likewise.
* system.c: Likewise.
* util.c: Likewise.
Denys Vlasenko [Thu, 15 Mar 2012 11:49:52 +0000 (12:49 +0100)]
Tidy up order of includes; make bool variables explicit.
Bool variables are more compact in data and (on x86) on code too:
text data bss dec hex filename
237950 676 19044 257670 3ee86 strace.before
237838 676 19012 257526 3edf6 strace
* defs.h: Group library includes at the top of the file.
Rename dtime to Tflag, debug to debug_flag.
Change debug_flag,Tflag,qflag,not_failing_only,show_fd_path,tracing_paths
variable declarations from int to bool.
* strace.c: Change corresponding definitions. Do the same for static
variables iflag,rflag,print_pid_pfx.
Rename dtime to Tflag, debug to debug_flag.
* syscall.c: Rename dtime to Tflag, debug to debug_flag.
Dmitry V. Levin [Thu, 15 Mar 2012 02:03:36 +0000 (02:03 +0000)]
Fix compiler warnings about breaking strict-aliasing rules
* system.c (sys_capget, sys_capset): Use proxy unions to cast long*
pointers to cap_user_header_t and cap_user_data_t pointers without
breaking strict-aliasing rules.
Dmitry V. Levin [Tue, 13 Mar 2012 23:26:01 +0000 (23:26 +0000)]
Fix *at syscalls flags decoding
Several *at decoders were defining own incomplete *atflags xlat
structures. That was error prone, and fchownat decoder actually
failed to recognize AT_EMPTY_PATH. Merging these incomplete
structures into the single at_flags xlat structure will fix
flags handling in all these decoders altogether.
* file.c: Define all AT_* constants used by *at decoders.
(at_flags): New xlat structure, with records for all AT_* constants.
(fstatatflags, linkat_flags, unlinkatflags): Remove.
(sys_newfstatat, sys_linkat, sys_unlinkat, sys_fchownat,
sys_utimensat): Use at_flags.
Dmitry V. Levin [Tue, 13 Mar 2012 15:51:13 +0000 (15:51 +0000)]
Implement sys_rt_tgsigqueueinfo syscall decoder
* linux/dummy.h (sys_rt_tgsigqueueinfo): Remove.
* linux/syscall.h (sys_rt_tgsigqueueinfo): New prototype.
* signal.c (print_sigqueueinfo): New function, based on
sys_rt_sigqueueinfo.
(sys_rt_sigqueueinfo): Use print_sigqueueinfo.
(sys_rt_tgsigqueueinfo): New function.
Denys Vlasenko [Tue, 13 Mar 2012 10:44:31 +0000 (11:44 +0100)]
Fix logging for "strace -o FILE -ff test/threaded_execve" test case
Our logic which was deciding whether to print "<unfinished ...>"
thingy wasn't working properly for -ff case.
* defs.h: Group log generation-related declarations together.
Add a large comment which explains how it works.
Add declaration of line_ended() function.
* strace.c (line_ended): New function which sets up internal data
to indicate that previous line was finished.
(printleader): Change logic to fix log generation in -ff mode.
(newoutf): Make check for -ff mode consistent with other places.
(droptcb): Print "<detached ...>" if last line for this tcp wasn't finished.
(cleanup): Remove code to print "<unfinished ...>", printleader()
or detach() will do it instead.
(trace): Remove code to print "<unfinished ...>".
Add code which finishes threaded execve's incomplete line
with " <pid changed to PID ...>" message. Replace printing_tcp = NULL
followed by fflush() by line_ended() call.
* process.c (sys_exit): Call line_ended() to indicate that we finished priting.
* syscall.c (trace_syscall_exiting): Set printing_tcp to current tcp.
Call line_ended() to indicate that we finished priting.
Remove call to fflush(), it is done by line_ended() now.
Denys Vlasenko [Mon, 12 Mar 2012 22:05:25 +0000 (23:05 +0100)]
Reduce stack usage by ~0.5k
main() uses ~0.5k of stack for local variables and such. When we enter
main tracing loop, most of these variables are no longer used.
But they still take up stack for the entire life of strace.
We can avoid this wastage if we move init code into a separate function.
(Need to be careful and not allow automatic inlining).
* strace.c (init): New function. Most of pre-existing code of
main is now living here.
(main): Call init() to do initialization.
Dmitry V. Levin [Sun, 11 Mar 2012 23:59:29 +0000 (23:59 +0000)]
Implement sendmmsg syscall decoder
* linux/dummy.h (sys_sendmmsg): Remove.
* linux/syscall.h (sys_sendmmsg): New prototype.
* net.c (printmmsghdr): Add index argument specifying the element in
mmsghdr array to print.
(decode_mmsg): New function, prints the whole mmsghdr array, its length
and message flags.
(sys_sendmmsg): New function.
(sys_recvmmsg): Use decode_mmsg to fix mmsghdr array decoding.
Dmitry V. Levin [Sun, 11 Mar 2012 21:25:51 +0000 (21:25 +0000)]
Implement clock_adjtime syscall decoder
* linux/dummy.h (sys_clock_adjtime): Remove.
* linux/syscall.h (sys_clock_adjtime): New prototype.
* time.c (do_adjtimex): New function, based on sys_adjtimex.
(sys_adjtimex): Use it.
(sys_clock_adjtime): New function.