On Sat, 6 Feb 2021 00:26:54 +0900 Takashi Yano wrote: > On Fri, 5 Feb 2021 19:34:57 +0900 > Takashi Yano wrote: > > On Tue, 26 Jan 2021 12:14:02 +0900 > > Takashi Yano wrote: > > > Hi GDB maintainer, > > > > > > In GDB, debugged process cannot continue execution after break > > > if it reads stdin. > > > > > > With the following steps, cat is terminated with error. > > > > > > 1) Install coreutils-debuginfo package. > > > 2) Run "gdb cat" in console (command prompt), not in mintty. > > > 3) Enter "start" in gdb. > > > 4) Enter "cont" in gdb. > > > > > > This results in: > > > /usr/bin/cat: -: Input/output error > > > > > > Both gdb-9.2-1 and gdb-10.1-1(TEST) have this problem. > > > > > > I looked into this problem and found the cause is that the pgid > > > setting for /usr/bin/cat is lost after break. The following patch > > > for GDB source resolves the issue. In the following section, > > > winpid is passed to getpgid() rather than cygwin pid. Also, winpid > > > is passed to other POSIX system calls such as kill() elsewhere. > > > > > > --- inflow.c.orig 2020-05-24 06:10:29.000000000 +0900 > > > +++ inflow.c 2021-01-23 17:48:27.963609500 +0900 > > > @@ -364,11 +364,11 @@ > > > #ifdef HAVE_TERMIOS_H > > > /* If we can't tell the inferior's actual process group, > > > then restore whatever was the foreground pgrp the last > > > time the inferior was running. See also comments > > > describing terminal_state::process_group. */ > > > -#ifdef HAVE_GETPGID > > > +#if defined (HAVE_GETPGID) && !defined (__CYGWIN__) > > > result = tcsetpgrp (0, getpgid (inf->pid)); > > > #else > > > result = tcsetpgrp (0, tinfo->process_group); > > > #endif > > > if (result == -1) > > > > > > > > > I hope the GDB maintainer will check it out. > > > > > > Addresses: https://cygwin.com/pipermail/cygwin-patches/2021q1/011018.html > > > > I have noticed that cygwin gdb essentially has the problem > > regarding terminal process group. > > > > Cygwin gdb uses CreateProcessW() to execute debugging process > > rather than exec(). If the debugging process is a cygwin process, > > cygwin pid is assigned, however, if the debugging process is a > > non cygwin process, cygwin pid is not assigned. Therefore, there > > is no appropriate process group ID to set. > > > > I wonder what is the right thing under that situation. Any idea? > > The patch below seems to be better than the previous one a bit. > > diff --git a/inflow.c.orig b/inflow.c > index 00b2235..fa7b408 100644 > --- a/inflow.c.orig > +++ b/inflow.c > @@ -40,6 +40,10 @@ > #include <sys/ioctl.h> > #endif > > +#ifdef __CYGWIN__ > +#include <sys/cygwin.h> > +#endif > + > #ifndef O_NOCTTY > #define O_NOCTTY 0 > #endif > @@ -367,7 +371,13 @@ child_terminal_inferior (struct target_ops *self) > time the inferior was running. See also comments > describing terminal_state::process_group. */ > #ifdef HAVE_GETPGID > +#ifdef __CYGWIN__ > + pid_t cygpid = cygwin_internal (CW_WINPID_TO_CYGWIN_PID, inf->pid); > + if (cygpid <= cygwin_internal (CW_MAX_CYGWIN_PID)) > + result = tcsetpgrp (0, getpgid (cygpid)); > +#else > result = tcsetpgrp (0, getpgid (inf->pid)); > +#endif > #else > result = tcsetpgrp (0, tinfo->process_group); > #endif
I confirmed that gdb-10.2-1 (TEST) still has this problem. -- Takashi Yano <takashi.y...@nifty.ne.jp> -- Problem reports: https://cygwin.com/problems.html FAQ: https://cygwin.com/faq/ Documentation: https://cygwin.com/docs.html Unsubscribe info: https://cygwin.com/ml/#unsubscribe-simple
