Thank you!
I have another concern about this file: why do we use numerical constants like
1,2,3,... here instead of symbolic SIGHUP,SIGINT,SIGQUIT,...?
Linux signal(7) man page gives 3 different values for some signals on different
platforms. For example, SIGUSR1 could be 30, 10, or 16.
Standard signals
Linux supports the standard signals listed below. Several signal
numbers are architecture-dependent, as
indicated in the "Value" column. (Where three values are given, the
first one is usually valid for alpha
and sparc, the middle one for x86, arm, and most other architectures,
and the last one for mips. (Values
for parisc are not shown; see the Linux kernel source for signal
numbering on that architecture.) A -
denotes that a signal is absent on the corresponding architecture.)
First the signals described in the original POSIX.1-1990 standard.
Signal Value Action Comment
──────────────────────────────────────────────────────────────────────
SIGHUP 1 Term Hangup detected on controlling terminal
or death of controlling process
SIGINT 2 Term Interrupt from keyboard
SIGQUIT 3 Core Quit from keyboard
SIGILL 4 Core Illegal Instruction
SIGABRT 6 Core Abort signal from abort(3)
SIGFPE 8 Core Floating point exception
SIGKILL 9 Term Kill signal
SIGSEGV 11 Core Invalid memory reference
SIGPIPE 13 Term Broken pipe: write to pipe with no
readers
SIGALRM 14 Term Timer signal from alarm(2)
SIGTERM 15 Term Termination signal
SIGUSR1 30,10,16 Term User-defined signal 1
SIGUSR2 31,12,17 Term User-defined signal 2
SIGCHLD 20,17,18 Ign Child stopped or terminated
...
Eugene
> From: lab...@google.com
> Date: Wed, 20 May 2015 11:43:20 +0100
> Subject: Re: [lldb-dev] LLDB 3.7 swallows real-time signals
> To: eugen...@hotmail.com
> CC: lldb-dev@cs.uiuc.edu
>
> Hello Eugene,
>
> thanks for diagnosing this issue. I will commit something similar to
> LLDB shortly.
>
> cheers,
> pl
>
>
> On 19 May 2015 at 19:52, Eugene Birukov <eugen...@hotmail.com> wrote:
> > Hello,
> >
> > I debugged signal processing a bit, and I think that the right solution
> > would be just to add these signals to the list of known signals. I.e. in
> > LinuxSignals.cpp:
> >
> > void
> > LinuxSignals::Reset()
> > {
> > m_signals.clear();
> > AddSignal (1, "SIGHUP", "HUP", false, true , true ,
> > "hangup");
> > AddSignal (2, "SIGINT", "INT", true , true , true ,
> > "interrupt");
> > AddSignal (3, "SIGQUIT", "QUIT", false, true , true , "quit");
> > AddSignal (4, "SIGILL", "ILL", false, true , true , "illegal
> > instruction");
> > AddSignal (5, "SIGTRAP", "TRAP", true , true , true , "trace
> > trap (not reset when caught)");
> > AddSignal (6, "SIGABRT", "ABRT", false, true , true ,
> > "abort()");
> > AddSignal (6, "SIGIOT", "IOT", false, true , true , "IOT
> > trap");
> > AddSignal (7, "SIGBUS", "BUS", false, true , true , "bus
> > error");
> > AddSignal (8, "SIGFPE", "FPE", false, true , true ,
> > "floating point exception");
> > AddSignal (9, "SIGKILL", "KILL", false, true , true , "kill");
> > AddSignal (10, "SIGUSR1", "USR1", false, true , true , "user
> > defined signal 1");
> > AddSignal (11, "SIGSEGV", "SEGV", false, true , true ,
> > "segmentation violation");
> > AddSignal (12, "SIGUSR2", "USR2", false, true , true , "user
> > defined signal 2");
> > AddSignal (13, "SIGPIPE", "PIPE", false, true , true , "write
> > to pipe with reading end closed");
> > AddSignal (14, "SIGALRM", "ALRM", false, false, false,
> > "alarm");
> > AddSignal (15, "SIGTERM", "TERM", false, true , true ,
> > "termination requested");
> > AddSignal (16, "SIGSTKFLT", "STKFLT", false, true , true , "stack
> > fault");
> > AddSignal (16, "SIGCLD", "CLD", false, false, true , "same as
> > SIGCHLD");
> > AddSignal (17, "SIGCHLD", "CHLD", false, false, true , "child
> > status has changed");
> > AddSignal (18, "SIGCONT", "CONT", false, true , true , "process
> > continue");
> > AddSignal (19, "SIGSTOP", "STOP", true , true , true , "process
> > stop");
> > AddSignal (20, "SIGTSTP", "TSTP", false, true , true , "tty
> > stop");
> > AddSignal (21, "SIGTTIN", "TTIN", false, true , true ,
> > "background tty read");
> > AddSignal (22, "SIGTTOU", "TTOU", false, true , true ,
> > "background tty write");
> > AddSignal (23, "SIGURG", "URG", false, true , true , "urgent
> > data on socket");
> > AddSignal (24, "SIGXCPU", "XCPU", false, true , true , "CPU
> > resource exceeded");
> > AddSignal (25, "SIGXFSZ", "XFSZ", false, true , true , "file
> > size limit exceeded");
> > AddSignal (26, "SIGVTALRM", "VTALRM", false, true , true , "virtual
> > time alarm");
> > AddSignal (27, "SIGPROF", "PROF", false, false, false,
> > "profiling time alarm");
> > AddSignal (28, "SIGWINCH", "WINCH", false, true , true , "window
> > size changes");
> > AddSignal (29, "SIGPOLL", "POLL", false, true , true ,
> > "pollable event");
> > AddSignal (29, "SIGIO", "IO", false, true , true ,
> > "input/output ready");
> > AddSignal (30, "SIGPWR", "PWR", false, true , true , "power
> > failure");
> > AddSignal (31, "SIGSYS", "SYS", false, true , true , "invalid
> > system call");
> >
> > // Add real-time signals
> > for (int rtsig = SIGRTMIN + 1; rtsig < SIGRTMAX; ++rtsig)
> > {
> > char signame[16];
> > char sigdescr[64];
> > ::snprintf(signame, sizeof(signame), "SIG%d", rtsig);
> > ::snprintf(sigdescr, sizeof(sigdescr), "Real-time event %d", rtsig);
> > AddSignal (rtsig, signame, signame, false, true, true, sigdescr);
> > }
> > }
> >
> > Thanks,
> > Eugene
> > ________________________________
> > From: eugen...@hotmail.com
> > To: lldb-dev@cs.uiuc.edu
> > Date: Tue, 19 May 2015 10:22:14 -0700
> > Subject: [lldb-dev] LLDB 3.7 swallows real-time signals
> >
> >
> > Hi,
> >
> > I have a simple program that uses real-time signals on Linux Ubuntu 14.04:
> >
> >
> > $ cat rt.cpp
> > #include <iostream>
> > #include <sys/mman.h>
> > #include <signal.h>
> > #include <assert.h>
> > #include <sys/types.h>
> > #include <unistd.h>
> >
> > void handler(int sig, siginfo_t* info, void* context)
> > {
> > std::cout << "signal " << sig << " received with value " <<
> > info->si_value.sival_in << "\n";
> > }
> > int main()
> > {
> > int signo = SIGRTMIN + 1;
> > if (SIGRTMAX > SIGRTMIN)
> > {
> > struct sigaction action;
> > action.sa_sigaction = handler;
> > action.sa_flags = SA_SIGINFO;
> > sigaction(signo, &action, NULL);
> > for (int i = 0; i < 3; ++i)
> > {
> > sigval value;
> > value.sival_int = i + 10;
> > sigqueue(getpid(), signo, value);
> > }
> > }
> > else
> > {
> > std::cerr << "real-time signals not supported";
> > }
> > }
> >
> > This program works correctly standalone. GDB is capable of intercepting this
> > signal and continue. LLDB-3.6 that I installed using apt-get does not
> > intercept the signal but the program still receives it. But LLDB 3.7 that I
> > built from sources from http://llvm.org/svn/llvm-project/lldb/trunk simply
> > swallows the signals. I think GDB behavior is the best option, but I could
> > live with 3.6 behavior.
> >
> > Is this a known problem? Is there a workaround or fix I can apply locally?
> >
> > Thanks,
> > Eugene
> >
> > $ cat rt.cpp
> > #include <iostream>
> > #include <sys/mman.h>
> > #include <signal.h>
> > #include <assert.h>
> > #include <sys/types.h>
> > #include <unistd.h>
> >
> > void handler(int sig, siginfo_t* info, void* context)
> > {
> > std::cout << "signal " << sig << " received with value " <<
> > info->si_value.sival_in << "\n";
> > }
> >
> > int main()
> > {
> > int signo = SIGRTMIN + 1;
> > if (SIGRTMAX > SIGRTMIN)
> > {
> > struct sigaction action;
> > action.sa_sigaction = handler;
> > action.sa_flags = SA_SIGINFO;
> > sigaction(signo, &action, NULL);
> > for (int i = 0; i < 3; ++i)
> > {
> > sigval value;
> > value.sival_int = i + 10;
> > sigqueue(getpid(), signo, value);
> > }
> > }
> > else
> > {
> > std::cerr << "real-time signals are not supported";
> > }
> > }
> >
> > $ ./rt
> > signal 35 received with value 10
> > signal 35 received with value 11
> > signal 35 received with value 12
> >
> > $ ~/llvm/bin/lldb ./rt
> > (lldb) target create "./rt"
> > Current executable set to './rt' (x86_64).
> > (lldb) pr lau
> > Process 18697 launched: './rt' (x86_64)
> > Process 18697 exited with status = 0 (0x00000000)
> > (lldb) q
> >
> > $ lldb-3.6 ./rt
> > (lldb) target create "./rt"
> > Current executable set to './rt' (x86_64).
> > (lldb) pr lau
> > Process 18674 launching
> > Process 18674 launched: './rt' (x86_64)
> > signal 35 received with value 10
> > signal 35 received with value 11
> > signal 35 received with value 12
> > Process 18674 exited with status = 0 (0x00000000)
> > (lldb) q
> >
> > $ gdb --quiet ./rt
> > Reading symbols from ./rt...done.
> > (gdb) r
> > Starting program: /home/eugene/Z/tmp/rt
> > Program received signal SIG35, Real-time event 35.
> > 0x00007ffff722cfc4 in __sigqueue (pid=18662, sig=35, val=...) at
> > ../sysdeps/unix/sysv/linux/sigqueue.c:46
> > 46 ../sysdeps/unix/sysv/linux/sigqueue.c: No such file or directory.
> > (gdb) c
> > Continuing.
> > signal 35 received with value 10
> > Program received signal SIG35, Real-time event 35.
> > 0x00007ffff722cfc4 in __sigqueue (pid=18662, sig=35, val=...) at
> > ../sysdeps/unix/sysv/linux/sigqueue.c:46
> > 46 in ../sysdeps/unix/sysv/linux/sigqueue.c
> > (gdb) c
> > Continuing.
> > signal 35 received with value 11
> > Program received signal SIG35, Real-time event 35.
> > 0x00007ffff722cfc4 in __sigqueue (pid=18662, sig=35, val=...) at
> > ../sysdeps/unix/sysv/linux/sigqueue.c:46
> > 46 in ../sysdeps/unix/sysv/linux/sigqueue.c
> > (gdb) c
> > Continuing.
> > signal 35 received with value 12
> > [Inferior 1 (process 18662) exited normally]
> > (gdb) q
> >
> >
> > _______________________________________________ lldb-dev mailing list
> > lldb-dev@cs.uiuc.edu http://lists.cs.uiuc.edu/mailman/listinfo/lldb-dev
> >
> > _______________________________________________
> > lldb-dev mailing list
> > lldb-dev@cs.uiuc.edu
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> >
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