- truss can now log the system call invoked by a thread during a
voluntary process exit. No return value is logged, but the value passed
to exit() is included in the trace output. Arguments passed to thread
exit system calls such as thr_exit() are not logged as voluntary thread
exits cannot be distinguished from involuntary thread exits during a
system call.
- New events are now reported for thread births and exits similar to the
recently added events for new child processes when following forks.
Reviewed by: kib
Differential Revision: https://reviews.freebsd.org/D5561
- Consolidate duplicate code for printing the metadata at the start of
each line into a shared function.
- Add an -H option which will log the thread ID of the relevant thread
for each event.
While here, remove some extraneous calls to clock_gettime() in
print_syscall() and print_syscall_ret(). The caller of print_syscall_ret()
always updates the current thread's "after" time before it is called.
Reviewed by: kib
MFC after: 1 month
Differential Revision: https://reviews.freebsd.org/D5363
instead of passing some of that state as arguments to print_syscall() and
print_syscallret(). This just makes the calls of these functions shorter
and easier to read.
A new sysdecode_syscallname() function accepts a system call code and
returns a string of the corresponding name (or NULL if the code is
unknown). To support different process ABIs, the new function accepts a
value from a new sysdecode_abi enum as its first argument to select the
ABI in use. Current ABIs supported include FREEBSD (native binaries),
FREEBSD32, LINUX, LINUX32, and CLOUDABI64. Note that not all ABIs are
supported by all platforms. In general, a given ABI is only supported
if a platform can execute binaries for that ABI.
To simplify the implementation, libsysdecode's build reuses the
existing pre-generated files from the kernel source tree rather than
duplicating new copies of said files during the build.
kdump(1) and truss(1) now use these functions to map system call
identifiers to names. For kdump(1), a new 'syscallname()' function
consolidates duplicated code from ktrsyscall() and ktrsyscallret().
The Linux ABI no longer requires custom handling for ktrsyscall() and
linux_ktrsyscall() has been removed as a result.
Reviewed by: bdrewery
Differential Revision: https://reviews.freebsd.org/D4823
This is done by changing get_syscall() to either lookup the known syscall
or add it into the list with the default handlers for printing.
This also simplifies some code to not have to check if the syscall variable
is set or NULL.
Reviewed by: jhb
Relnotes: yes
Differential Revision: https://reviews.freebsd.org/D3792
- Refactor the interface between the ABI-independent code and the
ABI-specific backends. The backends now provide smaller hooks to
fetch system call arguments and return values. The rest of the
system call entry and exit handling that was previously duplicated
among all the backends has been moved to one place.
- Merge the loop when waiting for an event with the loop for handling stops.
This also means not emulating a procfs-like interface on top of ptrace().
Instead, use a single event loop that fetches process events via waitid().
Among other things this allows us to report the full 32-bit exit value.
- Use PT_FOLLOW_FORK to follow new child processes instead of forking a new
truss process for each new child. This allows one truss process to monitor
a tree of processes and truss -c should now display one total for the
entire tree instead of separate summaries per process.
- Use the recently added fields to ptrace_lwpinfo to determine the current
system call number and argument count. The latter is especially useful
and fixes a regression since the conversion from procfs. truss now
generally prints the correct number of arguments for most system calls
rather than printing extra arguments for any call not listed in the
table in syscalls.c.
- Actually check the new ABI when processes call exec. The comments claimed
that this happened but it was not being done (perhaps this was another
regression in the conversion to ptrace()). If the new ABI after exec
is not supported, truss detaches from the process. If truss does not
support the ABI for a newly executed process the process is killed
before it returns from exec.
- Along with the refactor, teach the various ABI-specific backends to
fetch both return values, not just the first. Use this to properly
report the full 64-bit return value from lseek(). In addition, the
handler for "pipe" now pulls the pair of descriptors out of the
return values (which is the true kernel system call interface) but
displays them as an argument (which matches the interface exported by
libc).
- Each ABI handler adds entries to a linker set rather than requiring
a statically defined table of handlers in main.c.
- The arm and mips system call fetching code was changed to follow the
same pattern as amd64 (and the in-kernel handler) of fetching register
arguments first and then reading any remaining arguments from the
stack. This should fix indirect system call arguments on at least
arm.
- The mipsn32 and n64 ABIs will now look for arguments in A4 through A7.
- Use register %ebp for the 6th system call argument for Linux/i386 ABIs
to match the in-kernel argument fetch code.
- For powerpc binaries on a powerpc64 system, fetch the extra arguments
on the stack as 32-bit values that are then copied into the 64-bit
argument array instead of reading the 32-bit values directly into the
64-bit array.
Reviewed by: kib (earlier version)
Tested on: amd64 (FreeBSD/amd64 & i386), i386, arm (earlier version)
Tested on: powerpc64 (FreeBSD/powerpc64 & powerpc)
MFC after: 1 month
Differential Revision: https://reviews.freebsd.org/D3575
When truss is detaching from very active process it is possible to
hang on waitpid(2) in restore_proc() forever, because
ptrace(PT_SYSCALL) must be called before detaching, to allow the
debugging process to continue execution. Also when truss called with
'-c' argument, it does not print anything after detach, because it
immediately exits from restore_proc().
To fix these two problems make detaching deferred, but then it is
impossible to detach from a process which does not do any system call.
To fix this issue use sigaction(2) instead of signal(3) to disable
SA_RESTART flag for waitpid(2) that makes it non-restartable. Remove
global variable child_pid, because now detaching is handled in context
where child's pid is known.
Reported by: mjg
Tested by: mjg, swills
Approved by: kib (mentor)
MFC after: 2 weeks
Using a separate process group here is bad, since (for example) job
control in the TTY layer prevents interaction with the TTY, causing the
child process to hang.
Mentioned on: current@
MFC after: 2 weeks
- Fix logic handling execve(). We will not be able to
obtain information otherwise.
- truss coredump [1].
- truss does not work against itself [2].
PR: bin/58970 [1], bin/45193 [2]
Submitted by: Howard Su
Approved by: re (kensmith)
rename, __getcwd, shutdown, getrlimit, setrlimit, _umtx_lock, _umtx_unlock,
pathconf, truncate, ftruncate, kill
- Decode more arguments of open, mprot, *stat, and fcntl.
- Convert all constant-macro and bitfield decoding to lookup tables; much
cleaner than previous code.
- Print the timestamp of process exit and signal reception when -d or -D are in
use
- Try six times with 1/2 second delay to debug the child
PR: bin/52190 (updated)
Submitted by: Dan Nelson <dnelson@allantgroup.com>
Approved by: alfred
depend on namespace pollution in <signal.h>. (truss shouldn't be
using timevals anyway, since it was implemented long after timevals
were obsoleted by timespecs.)
to wake up any processes waiting via PIOCWAIT on process exit, and truss
needs to be more aware that a process may actually disappear while it's
waiting.
Reviewed by: Paul Saab <ps@yahoo-inc.com>
execvp() in the child branch of a vfork(). Changed to use fork()
instead.
Some of these (mv, find, apply, xargs) might benefit greatly from
being rewritten to use vfork() properly.
PR: Loosely related to bin/8252
Approved by: jkh and bde
Correct usage: one of {-p pid, command} is required.
Open output file when command line is fully analyzed: incorrect `truss -o f'
command does not create an empty file anymore.
change from
ioctl(fd, PIOC<foo>, &i);
to
ioctl(fd, PIOC<foo>, i);
This is going from the _IOW to _IO ioctl macro. The kernel, procctl, and
truss must be in synch for it all to work (not doing so will get errors about
inappropriate ioctl's, fortunately). Hopefully I didn't forget anything :).
said process will not have its event mask cleared (and be restarted) on
the last close of a procfs/mem file for that pid. This reduces the chance
that a truss-monitored process will be left hanging with these bits set
and nobody looking for it.
This is the least-tested change of all of these, I'm afraid.
