* linux-low.c (O_LARGEFILE): Define.

	(linux_read_memory): Use /proc/PID/mem.
	* configure.ac: Use AC_GNU_SOURCE.  Check for pread64.
	* configure, config.in: Regenerated.

5 files changed, 160 insertions, 0 deletions

diff --git a/gdb/gdbserver/ChangeLog b/gdb/gdbserver/ChangeLog
index 13bb16c..c56f22f 100644
--- a/gdb/gdbserver/ChangeLog
+++ b/gdb/gdbserver/ChangeLog
@@ -1,3 +1,10 @@
+2007-09-19  Daniel Jacobowitz  <dan@codesourcery.com>
+
+	* linux-low.c (O_LARGEFILE): Define.
+	(linux_read_memory): Use /proc/PID/mem.
+	* configure.ac: Use AC_GNU_SOURCE.  Check for pread64.
+	* configure, config.in: Regenerated.
+
 2007-09-04  Daniel Jacobowitz  <dan@codesourcery.com>
 
 	* linux-low.c (linux_wait_for_event): Do not pass signals while
diff --git a/gdb/gdbserver/config.in b/gdb/gdbserver/config.in
index 675a50c..017a1ed 100644
--- a/gdb/gdbserver/config.in
+++ b/gdb/gdbserver/config.in
@@ -53,6 +53,9 @@
 /* Define to 1 if you have the <netinet/tcp.h> header file. */
 #undef HAVE_NETINET_TCP_H
 
+/* Define to 1 if you have the `pread64' function. */
+#undef HAVE_PREAD64
+
 /* Define if <sys/procfs.h> has prgregset_t. */
 #undef HAVE_PRGREGSET_T
 
@@ -160,3 +163,8 @@
 
 /* Define if an XML target description is available. */
 #undef USE_XML
+
+/* Enable GNU extensions on systems that have them.  */
+#ifndef _GNU_SOURCE
+# undef _GNU_SOURCE
+#endif
diff --git a/gdb/gdbserver/configure b/gdb/gdbserver/configure
index b6834c1..a283dcf 100755
--- a/gdb/gdbserver/configure
+++ b/gdb/gdbserver/configure
@@ -2228,6 +2228,12 @@ ac_link='$CC -o conftest$ac_exeext $CFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $
 ac_compiler_gnu=$ac_cv_c_compiler_gnu
 
 
+cat >>confdefs.h <<\_ACEOF
+#define _GNU_SOURCE 1
+_ACEOF
+
+
+
 ac_aux_dir=
 for ac_dir in $srcdir $srcdir/.. $srcdir/../..; do
   if test -f $ac_dir/install-sh; then
@@ -3093,6 +3099,108 @@ fi
 done
 
 
+for ac_func in pread64
+do
+as_ac_var=`echo "ac_cv_func_$ac_func" | $as_tr_sh`
+echo "$as_me:$LINENO: checking for $ac_func" >&5
+echo $ECHO_N "checking for $ac_func... $ECHO_C" >&6
+if eval "test \"\${$as_ac_var+set}\" = set"; then
+  echo $ECHO_N "(cached) $ECHO_C" >&6
+else
+  cat >conftest.$ac_ext <<_ACEOF
+/* confdefs.h.  */
+_ACEOF
+cat confdefs.h >>conftest.$ac_ext
+cat >>conftest.$ac_ext <<_ACEOF
+/* end confdefs.h.  */
+/* Define $ac_func to an innocuous variant, in case <limits.h> declares $ac_func.
+   For example, HP-UX 11i <limits.h> declares gettimeofday.  */
+#define $ac_func innocuous_$ac_func
+
+/* System header to define __stub macros and hopefully few prototypes,
+    which can conflict with char $ac_func (); below.
+    Prefer <limits.h> to <assert.h> if __STDC__ is defined, since
+    <limits.h> exists even on freestanding compilers.  */
+
+#ifdef __STDC__
+# include <limits.h>
+#else
+# include <assert.h>
+#endif
+
+#undef $ac_func
+
+/* Override any gcc2 internal prototype to avoid an error.  */
+#ifdef __cplusplus
+extern "C"
+{
+#endif
+/* We use char because int might match the return type of a gcc2
+   builtin and then its argument prototype would still apply.  */
+char $ac_func ();
+/* The GNU C library defines this for functions which it implements
+    to always fail with ENOSYS.  Some functions are actually named
+    something starting with __ and the normal name is an alias.  */
+#if defined (__stub_$ac_func) || defined (__stub___$ac_func)
+choke me
+#else
+char (*f) () = $ac_func;
+#endif
+#ifdef __cplusplus
+}
+#endif
+
+int
+main ()
+{
+return f != $ac_func;
+  ;
+  return 0;
+}
+_ACEOF
+rm -f conftest.$ac_objext conftest$ac_exeext
+if { (eval echo "$as_me:$LINENO: \"$ac_link\"") >&5
+  (eval $ac_link) 2>conftest.er1
+  ac_status=$?
+  grep -v '^ *+' conftest.er1 >conftest.err
+  rm -f conftest.er1
+  cat conftest.err >&5
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); } &&
+	 { ac_try='test -z "$ac_c_werror_flag"
+			 || test ! -s conftest.err'
+  { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
+  (eval $ac_try) 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); }; } &&
+	 { ac_try='test -s conftest$ac_exeext'
+  { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
+  (eval $ac_try) 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); }; }; then
+  eval "$as_ac_var=yes"
+else
+  echo "$as_me: failed program was:" >&5
+sed 's/^/| /' conftest.$ac_ext >&5
+
+eval "$as_ac_var=no"
+fi
+rm -f conftest.err conftest.$ac_objext \
+      conftest$ac_exeext conftest.$ac_ext
+fi
+echo "$as_me:$LINENO: result: `eval echo '${'$as_ac_var'}'`" >&5
+echo "${ECHO_T}`eval echo '${'$as_ac_var'}'`" >&6
+if test `eval echo '${'$as_ac_var'}'` = yes; then
+  cat >>confdefs.h <<_ACEOF
+#define `echo "HAVE_$ac_func" | $as_tr_cpp` 1
+_ACEOF
+
+fi
+done
+
+
 have_errno=no
 echo "$as_me:$LINENO: checking for errno" >&5
 echo $ECHO_N "checking for errno... $ECHO_C" >&6
diff --git a/gdb/gdbserver/configure.ac b/gdb/gdbserver/configure.ac
index 8007e14..de996ba8 100644
--- a/gdb/gdbserver/configure.ac
+++ b/gdb/gdbserver/configure.ac
@@ -25,6 +25,7 @@ AC_INIT(server.c)
 AC_CONFIG_HEADER(config.h:config.in)
 
 AC_PROG_CC
+AC_GNU_SOURCE
 
 AC_CANONICAL_SYSTEM
 
@@ -40,6 +41,7 @@ AC_CHECK_HEADERS(sgtty.h termio.h termios.h sys/reg.h string.h dnl
  		 errno.h fcntl.h signal.h sys/file.h malloc.h dnl
 		 sys/ioctl.h netinet/in.h sys/socket.h netdb.h dnl
 		 netinet/tcp.h arpa/inet.h sys/wait.h)
+AC_CHECK_FUNCS(pread64)
 
 have_errno=no
 AC_MSG_CHECKING(for errno)
diff --git a/gdb/gdbserver/linux-low.c b/gdb/gdbserver/linux-low.c
index aaa09ef..fa5c5b2 100644
--- a/gdb/gdbserver/linux-low.c
+++ b/gdb/gdbserver/linux-low.c
@@ -40,6 +40,10 @@
 # define PTRACE_SETSIGINFO 0x4203
 #endif
 
+#ifndef O_LARGEFILE
+#define O_LARGEFILE 0
+#endif
+
 #ifdef __UCLIBC__
 #if !(defined(__UCLIBC_HAS_MMU__) || defined(__ARCH_HAS_MMU__))
 #define HAS_NOMMU
@@ -1488,7 +1492,38 @@ linux_read_memory (CORE_ADDR memaddr, unsigned char *myaddr, int len)
   /* Allocate buffer of that many longwords.  */
   register PTRACE_XFER_TYPE *buffer
     = (PTRACE_XFER_TYPE *) alloca (count * sizeof (PTRACE_XFER_TYPE));
+  int fd;
+  char filename[64];
+
+  /* Try using /proc.  Don't bother for one word.  */
+  if (len >= 3 * sizeof (long))
+    {
+      /* We could keep this file open and cache it - possibly one per
+	 thread.  That requires some juggling, but is even faster.  */
+      sprintf (filename, "/proc/%ld/mem", inferior_pid);
+      fd = open (filename, O_RDONLY | O_LARGEFILE);
+      if (fd == -1)
+	goto no_proc;
+
+      /* If pread64 is available, use it.  It's faster if the kernel
+	 supports it (only one syscall), and it's 64-bit safe even on
+	 32-bit platforms (for instance, SPARC debugging a SPARC64
+	 application).  */
+#ifdef HAVE_PREAD64
+      if (pread64 (fd, myaddr, len, memaddr) != len)
+#else
+      if (lseek (fd, memaddr, SEEK_SET) == -1 || read (fd, memaddr, len) != len)
+#endif
+	{
+	  close (fd);
+	  goto no_proc;
+	}
+
+      close (fd);
+      return 0;
+    }
 
+ no_proc:
   /* Read all the longwords */
   for (i = 0; i < count; i++, addr += sizeof (PTRACE_XFER_TYPE))
     {