sim: ppc: track closed state of file descriptors 0, 1, and 2.

This change tracks the "closed" state of file descriptors 0, 1, and 2,
introducing the function fdbad() to emul_netbsd.c and emul_unix.c.
Note that a function of the same name and purpose exists in
sim/common/callback.c.

This patch eliminates all of the "unresolved testcases" when testing
GDB against the powerpc simulator.

This occurs because the powerpc simulator closes, on behalf of the
testcase, the file descriptors associated with stdin, stdout, and
stderr.  GDB still needs these descriptors to communicate with the
user or, in this case, with the testing framework.

diff --git a/sim/ppc/ChangeLog b/sim/ppc/ChangeLog
index 413a99d7a6bbd62929629a6ace0279c3a66777dd..7ce9a47be4432e3eabae0178a35470df22d7a5fd 100644 (file)
--- a/sim/ppc/ChangeLog
+++ b/sim/ppc/ChangeLog
@@ -1,3 +1,17 @@
+2015-12-29  Kevin Buettner  <kevinb@redhat.com>
+
+       * emul_netbsd.c (fd_closed): New static array.
+       (fdbad): New function.
+       (do_read, do_write, do_close, do_dup, do_ioctl, do_dup2, do_fcntl)
+       (do_fstatfs, do_fstat, do_lseek): Call `fdbad'.
+       (emul_netbsd_init): Initialize `fd_closed'.
+       * emul_unix.c (fd_closed): New static array.
+       (fdbad): New function.
+       (do_unix_read, do_unix_write, do_unix_close, do_unix_dup)
+       (do_unix_dup2, do_unix_lseek, do_solaris_fstat, do_solaris_ioctl)
+       (do_linux_fstat, do_linux_ioctl): Call `fdbad'.
+       (emul_solaris_init, emul_linux_init): Initialize `fd_closed'.
+
 2015-12-26  Mike Frysinger  <vapier@gentoo.org>
 
        * Makefile.in (TCONFIG_H): Delete.

diff --git a/sim/ppc/emul_netbsd.c b/sim/ppc/emul_netbsd.c
index 6bef3707a3e7c154c0670385f414e247acf5cd25..12dfb21b3b0697b63c0a0661f7f287c7ec79db70 100644 (file)
--- a/sim/ppc/emul_netbsd.c
+++ b/sim/ppc/emul_netbsd.c
@@ -292,6 +292,31 @@ write_rusage(unsigned_word addr,
 }
 #endif
 
+
+/* File descriptors 0, 1, and 2 should not be closed.  fd_closed[]
+   tracks whether these descriptors have been closed in do_close()
+   below.  */
+
+static int fd_closed[3];
+
+/* Check for some occurrences of bad file descriptors.  We only check
+   whether fd 0, 1, or 2 are "closed".  By "closed" we mean that these
+   descriptors aren't actually closed, but are considered to be closed
+   by this layer.
+
+   Other checks are performed by the underlying OS call.  */
+
+static int
+fdbad (int fd)
+{
+  if (fd >=0 && fd <= 2 && fd_closed[fd])
+    {
+      errno = EBADF;
+      return -1;
+    }
+  return 0;
+}
+
 static void
 do_exit(os_emul_data *emul,
        unsigned call,
@@ -339,7 +364,9 @@ do_read(os_emul_data *emul,
       status = -1;
   }
 #endif
-  status = read (d, scratch_buffer, nbytes);
+  status = fdbad (d);
+  if (status == 0)
+    status = read (d, scratch_buffer, nbytes);
 
   emul_write_status(processor, status, errno);
   if (status > 0)
@@ -374,7 +401,10 @@ do_write(os_emul_data *emul,
                   processor, cia);
 
   /* write */
-  status = write(d, scratch_buffer, nbytes);
+  status = fdbad (d);
+  if (status == 0)
+    status = write(d, scratch_buffer, nbytes);
+
   emul_write_status(processor, status, errno);
   free(scratch_buffer);
 
@@ -440,8 +470,20 @@ do_close(os_emul_data *emul,
 
   SYS(close);
 
-  /* Can't combine these statements, cuz close sets errno. */
-  status = close(d);
+  status = fdbad (d);
+  if (status == 0)
+    {
+      /* Do not close stdin, stdout, or stderr. GDB may still need access to
+        these descriptors.  */
+      if (d == 0 || d == 1 || d == 2)
+       {
+         fd_closed[d] = 1;
+         status = 0;
+       }
+      else
+       status = close(d);
+    }
+
   emul_write_status(processor, status, errno);
 }
 
@@ -549,7 +591,7 @@ do_dup(os_emul_data *emul,
        unsigned_word cia)
 {
   int oldd = cpu_registers(processor)->gpr[arg0];
-  int status = dup(oldd);
+  int status = (fdbad (oldd) < 0) ? -1 : dup(oldd);
   int err = errno;
 
   if (WITH_TRACE && ppc_trace[trace_os_emul])
@@ -640,7 +682,9 @@ do_ioctl(os_emul_data *emul,
       || dir & IOC_OUT
       || !(dir & IOC_VOID))
     error("do_ioctl() read or write of parameter not implemented\n");
-  status = ioctl(d, request, NULL);
+  status = fdbad (d);
+  if (status == 0)
+    status = ioctl(d, request, NULL);
   emul_write_status(processor, status, errno);
 #endif
 
@@ -681,7 +725,7 @@ do_dup2(os_emul_data *emul,
 {
   int oldd = cpu_registers(processor)->gpr[arg0];
   int newd = cpu_registers(processor)->gpr[arg0+1];
-  int status = dup2(oldd, newd);
+  int status = (fdbad (oldd) < 0) ? -1 : dup2(oldd, newd);
   int err = errno;
 
   if (WITH_TRACE && ppc_trace[trace_os_emul])
@@ -711,7 +755,9 @@ do_fcntl(os_emul_data *emul,
     printf_filtered ("%d, %d, %d", fd, cmd, arg);
 
   SYS(fcntl);
-  status = fcntl(fd, cmd, arg);
+  status = fdbad (fd);
+  if (status == 0)
+    status = fcntl(fd, cmd, arg);
   emul_write_status(processor, status, errno);
 }
 #endif
@@ -796,7 +842,9 @@ do_fstatfs(os_emul_data *emul,
     printf_filtered ("%d, 0x%lx", fd, (long)buf_addr);
 
   SYS(fstatfs);
-  status = fstatfs(fd, (buf_addr == 0 ? NULL : &buf));
+  status = fdbad (fd);
+  if (status == 0)
+    status = fstatfs(fd, (buf_addr == 0 ? NULL : &buf));
   emul_write_status(processor, status, errno);
   if (status == 0) {
     if (buf_addr != 0)
@@ -849,7 +897,9 @@ do_fstat(os_emul_data *emul,
   SYS(fstat);
 #endif
   /* Can't combine these statements, cuz fstat sets errno. */
-  status = fstat(fd, &buf);
+  status = fdbad (fd);
+  if (status == 0)
+    status = fstat(fd, &buf);
   emul_write_status(processor, status, errno);
   write_stat(stat_buf_addr, buf, processor, cia);
 }
@@ -951,7 +1001,9 @@ do_lseek(os_emul_data *emul,
   int whence = cpu_registers(processor)->gpr[arg0+4];
   off_t status;
   SYS(lseek);
-  status = lseek(fildes, offset, whence);
+  status = fdbad (fildes);
+  if (status == 0)
+    status = lseek(fildes, offset, whence);
   if (status == -1)
     emul_write_status(processor, -1, errno);
   else {
@@ -1450,7 +1502,9 @@ static void
 emul_netbsd_init(os_emul_data *emul_data,
                 int nr_cpus)
 {
-  /* nothing yet */
+  fd_closed[0] = 0;
+  fd_closed[1] = 0;
+  fd_closed[2] = 0;
 }
 
 static void

diff --git a/sim/ppc/emul_unix.c b/sim/ppc/emul_unix.c
index d72525d8b01de0ed5d21db1e85158d5263cd355e..1475474727eaa452b706f53bf8644b6943c78d6f 100644 (file)
--- a/sim/ppc/emul_unix.c
+++ b/sim/ppc/emul_unix.c
@@ -195,6 +195,30 @@ struct     unix_rusage {
 };
 
 
+/* File descriptors 0, 1, and 2 should not be closed.  fd_closed[]
+   tracks whether these descriptors have been closed in do_close()
+   below.  */
+
+static int fd_closed[3];
+
+/* Check for some occurrences of bad file descriptors.  We only check
+   whether fd 0, 1, or 2 are "closed".  By "closed" we mean that these
+   descriptors aren't actually closed, but are considered to be closed
+   by this layer.
+
+   Other checks are performed by the underlying OS call.  */
+
+static int
+fdbad (int fd)
+{
+  if (fd >=0 && fd <= 2 && fd_closed[fd])
+    {
+      errno = EBADF;
+      return -1;
+    }
+  return 0;
+}
+
 static void
 do_unix_exit(os_emul_data *emul,
             unsigned call,
@@ -232,8 +256,10 @@ do_unix_read(os_emul_data *emul,
   /* check if buffer exists by reading it */
   emul_read_buffer(scratch_buffer, buf, nbytes, processor, cia);
 
+  status = fdbad (d);
   /* read */
-  status = read (d, scratch_buffer, nbytes);
+  if (status == 0)
+    status = read (d, scratch_buffer, nbytes);
 
   emul_write_status(processor, status, errno);
   if (status > 0)
@@ -266,8 +292,10 @@ do_unix_write(os_emul_data *emul,
   emul_read_buffer(scratch_buffer, buf, nbytes,
                   processor, cia);
 
+  status = fdbad (d);
   /* write */
-  status = write(d, scratch_buffer, nbytes);
+  if (status == 0)
+    status = write(d, scratch_buffer, nbytes);
   emul_write_status(processor, status, errno);
   free(scratch_buffer);
 
@@ -310,7 +338,20 @@ do_unix_close(os_emul_data *emul,
   if (WITH_TRACE && ppc_trace[trace_os_emul])
     printf_filtered ("%d", d);
 
-  status = close(d);
+  status = fdbad (d);
+  if (status == 0)
+    {
+      /* Do not close stdin, stdout, or stderr. GDB may still need access to
+        these descriptors.  */
+      if (d == 0 || d == 1 || d == 2)
+       {
+         fd_closed[d] = 1;
+         status = 0;
+       }
+      else
+       status = close(d);
+    }
+
   emul_write_status(processor, status, errno);
 }
 
@@ -490,7 +531,7 @@ do_unix_dup(os_emul_data *emul,
            unsigned_word cia)
 {
   int oldd = cpu_registers(processor)->gpr[arg0];
-  int status = dup(oldd);
+  int status = (fdbad (oldd) < 0) ? -1 : dup(oldd);
   int err = errno;
 
   if (WITH_TRACE && ppc_trace[trace_os_emul])
@@ -512,7 +553,7 @@ do_unix_dup2(os_emul_data *emul,
 {
   int oldd = cpu_registers(processor)->gpr[arg0];
   int newd = cpu_registers(processor)->gpr[arg0+1];
-  int status = dup2(oldd, newd);
+  int status = (fdbad (oldd) < 0) ? -1 : dup2(oldd, newd);
   int err = errno;
 
   if (WITH_TRACE && ppc_trace[trace_os_emul])
@@ -540,7 +581,9 @@ do_unix_lseek(os_emul_data *emul,
   if (WITH_TRACE && ppc_trace[trace_os_emul])
     printf_filtered ("%d %ld %d", fildes, (long)offset, whence);
 
-  status = lseek(fildes, offset, whence);
+  status = fdbad (fildes);
+  if (status == 0)
+    status = lseek(fildes, offset, whence);
   emul_write_status(processor, (int)status, errno);
 }
 #endif
@@ -1196,7 +1239,9 @@ do_solaris_fstat(os_emul_data *emul,
   if (WITH_TRACE && ppc_trace[trace_os_emul])
     printf_filtered ("%d, 0x%lx", fildes, (long)stat_pkt);
 
-  status = fstat (fildes, &buf);
+  status = fdbad (fildes);
+  if (status == 0)
+    status = fstat (fildes, &buf);
   if (status == 0)
     convert_to_solaris_stat (stat_pkt, &buf, processor, cia);
 
@@ -1433,6 +1478,10 @@ do_solaris_ioctl(os_emul_data *emul,
 #endif
 #endif
 
+  status = fdbad (fildes);
+  if (status != 0)
+    goto done;
+
   switch (request)
     {
     case 0:                                    /* make sure we have at least one case */
@@ -1474,6 +1523,7 @@ do_solaris_ioctl(os_emul_data *emul,
 #endif /* HAVE_TERMIOS_STRUCTURE */
     }
 
+done:
   emul_write_status(processor, status, errno);
 
   if (WITH_TRACE && ppc_trace[trace_os_emul])
@@ -1925,7 +1975,9 @@ static void
 emul_solaris_init(os_emul_data *emul_data,
                  int nr_cpus)
 {
-  /* nothing yet */
+  fd_closed[0] = 0;
+  fd_closed[1] = 0;
+  fd_closed[2] = 0;
 }
 
 static void
@@ -2124,7 +2176,9 @@ do_linux_fstat(os_emul_data *emul,
   if (WITH_TRACE && ppc_trace[trace_os_emul])
     printf_filtered ("%d, 0x%lx", fildes, (long)stat_pkt);
 
-  status = fstat (fildes, &buf);
+  status = fdbad (fildes);
+  if (status == 0)
+    status = fstat (fildes, &buf);
   if (status == 0)
     convert_to_linux_stat (stat_pkt, &buf, processor, cia);
 
@@ -2388,6 +2442,10 @@ do_linux_ioctl(os_emul_data *emul,
 #endif
 #endif
 
+  status = fdbad (fildes);
+  if (status != 0)
+    goto done;
+
   switch (request)
     {
     case 0:                                    /* make sure we have at least one case */
@@ -2429,6 +2487,7 @@ do_linux_ioctl(os_emul_data *emul,
 #endif /* HAVE_TERMIOS_STRUCTURE */
     }
 
+done:
   emul_write_status(processor, status, errno);
 
   if (WITH_TRACE && ppc_trace[trace_os_emul])
@@ -2795,7 +2854,9 @@ static void
 emul_linux_init(os_emul_data *emul_data,
                int nr_cpus)
 {
-  /* nothing yet */
+  fd_closed[0] = 0;
+  fd_closed[1] = 0;
+  fd_closed[2] = 0;
 }
 
 static void