commit bash-20210209 snapshot

CWRU/CWRU.chlog

@@ -9555,3 +9555,24 @@ lib/malloc/malloc.c
 	  old size and new size are both bigger than the mmap threshold
 	- internal_realloc: call internal_remap if the old size and new size
 	  are both above the threshold where we use mmap for allocation
+
+				   2/10
+				   ----
+include/timer.h
+	- new file, declaration for a timer struct to be used by a set of
+	  functions to implement timers using SIGALRM or select/pselect
+
+lib/sh/timers.c
+	- new file, set of functions to manipulate timer objects and timeouts
+	  using SIGALRM or select/pselect. Inspired by a patch from
+	  Koichi Murase <myoga.murase@gmail.com>. Not used yet
+
+				   2/11
+				   ----
+builtins/read.def
+	- read_builtin: if there is a timeout set, block SIGCHLD around calls
+	  to zread and its siblings, or calls to readline for `read -e', so
+	  SIGCHLD (and the consequent waitpid) doesn't interrupt the read.
+	  Fixes bug reported by Koichi Murase <myoga.murase@gmail.com>, but
+	  there may be a different fix coming
+

MANIFEST

@@ -230,6 +230,7 @@ include/shtty.h		f
 include/stat-time.h	f
 include/stdc.h		f
 include/systimes.h	f
+include/timer.h		f
 include/typemax.h	f
 include/unionwait.h	f
 lib/glob/Makefile.in	f
@@ -449,6 +450,7 @@ lib/sh/strtoul.c	f
 lib/sh/strtoull.c	f
 lib/sh/strtoumax.c	f
 lib/sh/strtrans.c	f
+lib/sh/timers.c		f
 lib/sh/times.c		f
 lib/sh/timeval.c	f
 lib/sh/tmpfile.c	f

Makefile.in

@@ -232,7 +232,8 @@ SHLIB_SOURCE =	${SH_LIBSRC}/clktck.c ${SH_LIBSRC}/getcwd.c \
 		${SH_LIBSRC}/fnxform.c ${SH_LIBSRC}/unicode.c \
 		${SH_LIBSRC}/wcswidth.c ${SH_LIBSRC}/wcsnwidth.c \
 		${SH_LIBSRC}/shmbchar.c ${SH_LIBSRC}/utf8.c \
-		${SH_LIBSRC}/random.c ${SH_LIBSRC}/gettimeofday.c
+		${SH_LIBSRC}/random.c ${SH_LIBSRC}/gettimeofday.c \
+		${SH_LIBSRC}/timers.c
 
 SHLIB_LIB = -lsh
 SHLIB_LIBNAME = libsh.a

bashline.c

@@ -4639,7 +4639,7 @@ bash_event_hook ()
   bashline_reset_event_hook ();
 
   /* posix mode SIGINT during read -e. We only get here if SIGINT is trapped. */
-  if (posixly_correct && this_shell_builtin == read_builtin && sig == 2)
+  if (posixly_correct && this_shell_builtin == read_builtin && sig == SIGINT)
     {
       last_command_exit_value = 128|SIGINT;
       throw_to_top_level ();

builtins/read.def

@@ -192,6 +192,7 @@ read_builtin (list)
   struct stat tsb;
   SHELL_VAR *var;
   TTYSTRUCT ttattrs, ttset;
+  sigset_t chldset, prevset;
 #if defined (ARRAY_VARS)
   WORD_LIST *alist;
   int vflags;
@@ -388,6 +389,12 @@ read_builtin (list)
 	}
     }
 
+#if defined (SIGCHLD)
+  sigemptyset (&chldset);
+  sigprocmask (SIG_BLOCK, (sigset_t *)0, &chldset);
+  sigaddset (&chldset, SIGCHLD); 
+#endif
+
   begin_unwind_frame ("read_builtin");
 
 #if defined (BUFFERED_INPUT)
@@ -576,6 +583,10 @@ read_builtin (list)
 	      free (rlbuf);
 	      rlbuf = (char *)0;
 	    }
+#if defined (SIGCHLD)
+	  if (tmsec > 0 || tmusec > 0)
+	    sigprocmask (SIG_SETMASK, &chldset, &prevset);
+#endif
 	  if (rlbuf == 0)
 	    {
 	      reading = 1;
@@ -583,6 +594,10 @@ read_builtin (list)
 	      reading = 0;
 	      rlind = 0;
 	    }
+#if defined (SIGCHLD)
+	  if (tmsec > 0 || tmusec > 0)
+	    sigprocmask (SIG_SETMASK, &prevset, (sigset_t *)0);
+#endif
 	  if (rlbuf == 0)
 	    {
 	      eof = 1;
@@ -606,12 +621,22 @@ read_builtin (list)
       reading = 1;
       CHECK_ALRM;
       errno = 0;
+
+#if defined (SIGCHLD)
+      if (tmsec > 0 || tmusec > 0)
+	sigprocmask (SIG_SETMASK, &chldset, &prevset);
+#endif
       if (unbuffered_read == 2)
 	retval = posixly_correct ? zreadintr (fd, &c, 1) : zreadn (fd, &c, nchars - nr);
       else if (unbuffered_read)
 	retval = posixly_correct ? zreadintr (fd, &c, 1) : zread (fd, &c, 1);
       else
 	retval = posixly_correct ? zreadcintr (fd, &c) : zreadc (fd, &c);
+#if defined (SIGCHLD)
+      if (tmsec > 0 || tmusec > 0)
+	sigprocmask (SIG_SETMASK, &prevset, (sigset_t *)0);
+#endif
+
       reading = 0;
 
       if (retval <= 0)

include/timer.h

@@ -0,0 +1,63 @@
+/* timer.h -- data structures used by the shell timers in lib/sh/timers.c */
+
+/* Copyright (C) 2021 Free Software Foundation, Inc.
+
+   This file is part of GNU Bash, the Bourne Again SHell.
+
+   Bash 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 3 of the License, or
+   (at your option) any later version.
+
+   Bash 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 Bash.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include "bashjmp.h"
+typedef struct _shtimer
+{
+  struct timeval tmout;
+
+  int fd;
+  int flags;
+
+  int alrmflag;					/* should be set by alrm_handler */
+
+  SigHandler *alrm_handler;
+  SigHandler *old_handler;
+
+  procenv_t jmpenv;
+
+  void (*handler) (struct _shtimer *);		/* XXX - unused right now */
+  PTR_T	*data;					/* reserved */
+} sh_timer;
+
+#define SHTIMER_ALARM	0x01			/* mutually exclusive */
+#define SHTIMER_SELECT	0x02
+#define SHTIMER_LONGJMP	0x04
+
+#define SHTIMER_SIGSET	0x100
+
+extern sh_timer *shtimer_alloc (void);
+extern void shtimer_flush (sh_timer *);
+extern void shtimer_dispose (sh_timer *);
+
+extern void shtimer_set (sh_timer *, time_t, long);
+extern void shtimer_unset (sh_timer *);
+
+extern void shtimer_cleanup (sh_timer *);
+extern void shtimer_clear (sh_timer *);
+
+extern int shtimer_chktimeout (sh_timer *);
+
+extern int shtimer_select (sh_timer *);
+extern int shtimer_alrm (sh_timer *);

lib/sh/Makefile.in

@@ -93,7 +93,7 @@ CSOURCES = clktck.c clock.c getcwd.c getenv.c oslib.c setlinebuf.c \
 	   wcsdup.c fpurge.c zgetline.c mbscmp.c uconvert.c ufuncs.c \
 	   casemod.c dprintf.c input_avail.c mbscasecmp.c fnxform.c \
 	   strchrnul.c unicode.c wcswidth.c wcsnwidth.c shmbchar.c strdup.c \
-	   utf8.c random.c gettimeofday.c
+	   utf8.c random.c gettimeofday.c timers.c
 
 # The header files for this library.
 HSOURCES = 
@@ -108,7 +108,7 @@ OBJECTS = clktck.o clock.o getenv.o oslib.o setlinebuf.o strnlen.o \
 	  fmtullong.o fmtumax.o zcatfd.o zmapfd.o winsize.o wcsdup.o \
 	  fpurge.o zgetline.o mbscmp.o uconvert.o ufuncs.o casemod.o \
 	  input_avail.o mbscasecmp.o fnxform.o unicode.o shmbchar.o \
-	  utf8.o random.o gettimeofday.o wcsnwidth.o ${LIBOBJS}
+	  utf8.o random.o gettimeofday.o timers.o wcsnwidth.o ${LIBOBJS}
 
 SUPPORT = Makefile
 
@@ -197,6 +197,7 @@ strtoul.o: strtoul.c
 strtoull.o: strtoull.c
 strtoumax.o: strtoumax.c
 strtrans.o: strtrans.c
+timers.o: timers.c
 times.o: times.c
 timeval.o: timeval.c
 tmpfile.o: tmpfile.c
@@ -277,6 +278,7 @@ strtoul.o: ${BUILD_DIR}/config.h
 strtoull.o: ${BUILD_DIR}/config.h
 strtoumax.o: ${BUILD_DIR}/config.h
 strtrans.o: ${BUILD_DIR}/config.h
+timers.o: ${BUILD_DIR}/config.h
 times.o: ${BUILD_DIR}/config.h
 timeval.o: ${BUILD_DIR}/config.h
 tmpfile.o: ${BUILD_DIR}/config.h ${topdir}/config-top.h 
@@ -620,6 +622,14 @@ fnxform.o: ${topdir}/bashintl.h ${LIBINTL_H} ${BASHINCDIR}/gettext.h
 shmbchar.o: ${BASHINCDIR}/shmbchar.h
 shmbchar.o: ${BASHINCDIR}/shmbutil.h
 
+timers.o: ${topdir}/bashansi.h ${BASHINCDIR}/ansi_stdlib.h
+timers.o: ${BASHINCDIR}/stdc.h
+timers.o: ${topdir}/xmalloc.h ${topdir}/sig.h
+timers.o: ${BASHINCDIR}/posixtime.h ${BASHINCDIR}/stat-time.h
+timers.o: ${BASHINCDIR}/posixselect.h
+timers.o: ${topdir}/bashjmp.h ${BASHINCDIR}/posixjmp.h
+timers.o: ${BASHINCDIR}/timer.h
+
 unicode.o: ${topdir}/bashansi.h ${BASHINCDIR}/ansi_stdlib.h
 unicode.o: ${BASHINCDIR}/stdc.h
 unicode.o: ${topdir}/xmalloc.h

lib/sh/timers.c

@@ -0,0 +1,238 @@
+/* timers - functions to manage shell timers */
+
+/* Copyright (C) 2021 Free Software Foundation, Inc.
+
+   This file is part of GNU Bash, the Bourne Again SHell.
+
+   Bash 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 3 of the License, or
+   (at your option) any later version.
+
+   Bash 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 Bash.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "config.h"
+
+#include "bashtypes.h"
+#include "posixtime.h"
+
+#if defined (HAVE_UNISTD_H)
+#include <unistd.h>
+#endif
+
+#if defined (HAVE_SELECT)
+#  include "posixselect.h"
+#  include "stat-time.h"
+#endif
+
+#include "sig.h"
+#include "bashjmp.h"
+#include "xmalloc.h"
+
+#include "timer.h"
+
+#include <errno.h>
+#if !defined (errno)
+extern int errno;
+#endif /* !errno */
+
+extern unsigned int falarm (unsigned int, unsigned int);
+
+sh_timer *
+shtimer_alloc (void)
+{
+  sh_timer *r;
+
+  r = (sh_timer *)xmalloc (sizeof (sh_timer));
+  shtimer_flush (r);
+  return r;
+}
+
+void
+shtimer_flush (sh_timer *t)
+{
+  t->tmout.tv_sec = 0;
+  t->tmout.tv_usec = 0;
+
+  t->fd = t->flags = t->alrmflag = 0;
+
+  t->alrm_handler = t->old_handler = 0;
+
+  memset (t->jmpenv, '\0', sizeof (t->jmpenv));
+
+  t->handler = 0;
+  t->data = 0;
+}
+
+void
+shtimer_dispose (sh_timer *t)
+{
+  free (t);
+}
+
+/* We keep the timer as an offset into the future from the time it's set. */
+void
+shtimer_set (sh_timer *t, time_t sec, long usec)
+{
+  struct timeval now;
+
+  if (t->flags & SHTIMER_ALARM)
+    {
+      t->alrmflag = 0;		/* just paranoia */
+      t->old_handler = set_signal_handler (SIGALRM, t->alrm_handler);
+      t->flags |= SHTIMER_SIGSET;
+      falarm (t->tmout.tv_sec = sec, t->tmout.tv_usec = usec);
+      return;
+    }
+
+  if (gettimeofday (&now, 0) < 0)
+    {
+      now.tv_sec = 0;
+      now.tv_usec = 0;
+    }
+  t->tmout.tv_sec = now.tv_sec + sec;
+  t->tmout.tv_usec = now.tv_usec + usec;
+  if (t->tmout.tv_usec > USEC_PER_SEC)
+    {
+      t->tmout.tv_sec++;
+      t->tmout.tv_usec -= USEC_PER_SEC;
+    }
+}
+
+void
+shtimer_unset (sh_timer *t)
+{
+  t->tmout.tv_sec = 0;
+  t->tmout.tv_usec = 0;
+
+  if (t->flags & SHTIMER_ALARM)
+    {
+      t->alrmflag = 0;
+      falarm (0, 0);
+      if (t->old_handler && (t->flags & SHTIMER_SIGSET))
+	{
+	  set_signal_handler (SIGALRM, t->old_handler);
+	  t->flags &= ~SHTIMER_SIGSET;
+	}
+    }
+}
+
+void
+shtimer_cleanup (sh_timer *t)
+{
+  shtimer_unset (t);
+}
+
+void
+shtimer_clear (sh_timer *t)
+{
+  shtimer_unset (t);
+  shtimer_dispose (t);
+}
+
+int
+shtimer_chktimeout (sh_timer *t)
+{
+  struct timeval now;
+  int r;
+
+  /* Use the flag to avoid returning sigalrm_seen here */
+  if (t->flags & SHTIMER_ALARM)
+    return t->alrmflag;
+
+  /* Could check a flag for this */
+  if (t->tmout.tv_sec == 0 && t->tmout.tv_usec == 0)
+    return 0;
+
+  if (gettimeofday (&now, 0) < 0)
+    return 0;
+  r = ((now.tv_sec > t->tmout.tv_sec) ||
+	(now.tv_sec == t->tmout.tv_sec && now.tv_usec >= t->tmout.tv_usec));
+
+  return r;
+}
+
+#if defined (HAVE_SELECT) || defined (HAVE_PSELECT)
+int
+shtimer_select (sh_timer *t)
+{
+  int r;
+  sigset_t blocked_sigs, prevmask;
+  struct timeval now, tv;
+  fd_set readfds;
+#if defined (HAVE_PSELECT)
+  struct timespec ts;
+#endif
+
+  /* We don't want a SIGCHLD to interrupt this */
+  sigemptyset (&blocked_sigs);
+#  if defined (SIGCHLD)
+  sigaddset (&blocked_sigs, SIGCHLD);
+#  endif
+
+  if (gettimeofday (&now, 0) < 0)
+    {
+      if (t->flags & SHTIMER_LONGJMP)
+	sh_longjmp (t->jmpenv, 1);
+      else
+	return -1;
+    }
+
+  /* If the timer has already expired, return immediately */    
+  if ((now.tv_sec > t->tmout.tv_sec) ||
+	(now.tv_sec == t->tmout.tv_sec && now.tv_usec >= t->tmout.tv_usec))
+    {
+      if (t->flags & SHTIMER_LONGJMP)
+	sh_longjmp (t->jmpenv, 1);
+      else
+	return 0;
+    }
+
+  /* compute timeout */
+  tv.tv_sec = t->tmout.tv_sec - now.tv_sec;
+  tv.tv_usec = t->tmout.tv_usec - now.tv_usec;
+  if (tv.tv_usec < 0)
+    {
+      tv.tv_sec--;
+      tv.tv_usec += USEC_PER_SEC;
+    }
+
+#if defined (HAVE_PSELECT)
+  ts.tv_sec = tv.tv_sec;
+  ts.tv_nsec = tv.tv_usec * 1000;
+#else
+  sigemptyset (&prevmask);
+#endif /* !HAVE_PSELECT */
+
+  FD_ZERO (&readfds);
+  FD_SET (t->fd, &readfds);
+
+#if defined (HAVE_PSELECT)
+  r = pselect(t->fd + 1, &readfds, (fd_set *)0, (fd_set *)0, &ts, &blocked_sigs);
+#else
+  sigprocmask (SIG_SETMASK, &blocked_sigs, &prevmask);
+  r = select(t->fd + 1, &readfds, (fd_set *)0, (fd_set *)0, &tv);
+  sigprocmask (SIG_SETMASK, &prevmask, NULL);
+#endif
+
+  if (r < 0)
+    return r;		/* caller will handle */
+  else if (r == 0 && (t->flags & SHTIMER_LONGJMP))
+    sh_longjmp (t->jmpenv, 1);
+  else
+    return r;
+}
+#endif /* !HAVE_TIMEVAL || !HAVE_SELECT */
+
+int
+shtimer_alrm (sh_timer *t)
+{
+  return 0;
+}

shell.h

@@ -165,7 +165,8 @@ extern struct user_info current_user;
 /* Structure in which to save partial parsing state when doing things like
    PROMPT_COMMAND and bash_execute_unix_command execution. */
 
-typedef struct _sh_parser_state_t {
+typedef struct _sh_parser_state_t
+{
 
   /* parsing state */
   int parser_state;
@@ -208,7 +209,8 @@ typedef struct _sh_parser_state_t {
   REDIRECT *redir_stack[HEREDOC_MAX];
 } sh_parser_state_t;
 
-typedef struct _sh_input_line_state_t {
+typedef struct _sh_input_line_state_t
+{
   char *input_line;
   size_t input_line_index;
   size_t input_line_size;