Cherry-pick local changes to 9.2

Cherry-picked commits:
    b711aa8: Add Unix domain socket support to gdbserver 7.9.1.
    4c58332: Go back to snprintf rather than strlcpy.
    c64829b: Fallback to open if multifs_open fails.
    2177073: Fix gdbserver process interruption.
    35ee683: Remove gdb hack.
    78af0f6: Handle cross compile for locale configuration
    dfc5ca4: Set the default gdb osabi to GNU/Linux.
    5cbd102: Specify osabi in arm/aarch64 tdescs. (updated)
    d378e66: Explicit link -ldl for gdbserver

Test: build
Change-Id: Iea7f0159ad5d4f5edba0db215a96bc85b3f332cd

10 files changed, 77 insertions, 24 deletions

diff --git a/gdb-9.2/gdb/arch/aarch32.c b/gdb-9.2/gdb/arch/aarch32.c
index 5bc24a301..7d0208779 100644
--- a/gdb-9.2/gdb/arch/aarch32.c
+++ b/gdb-9.2/gdb/arch/aarch32.c
@@ -39,5 +39,7 @@ aarch32_create_target_description ()
   regnum = create_feature_arm_arm_vfpv3 (tdesc, regnum);
   tdesc_create_feature (tdesc, "org.gnu.gdb.arm.neon");
 
+  set_tdesc_osabi (tdesc, "GNU/Linux");
+
   return tdesc;
 }
diff --git a/gdb-9.2/gdb/arch/aarch64.c b/gdb-9.2/gdb/arch/aarch64.c
index f61154349..4a23c13fe 100644
--- a/gdb-9.2/gdb/arch/aarch64.c
+++ b/gdb-9.2/gdb/arch/aarch64.c
@@ -47,5 +47,7 @@ aarch64_create_target_description (uint64_t vq, bool pauth_p)
   if (pauth_p)
     regnum = create_feature_aarch64_pauth (tdesc, regnum);
 
+  set_tdesc_osabi (tdesc, "GNU/Linux");
+
   return tdesc;
 }
diff --git a/gdb-9.2/gdb/arch/arm.c b/gdb-9.2/gdb/arch/arm.c
index 60d9f8588..ccb686dd9 100644
--- a/gdb-9.2/gdb/arch/arm.c
+++ b/gdb-9.2/gdb/arch/arm.c
@@ -419,6 +419,8 @@ arm_create_target_description (arm_fp_type fp_type)
       error (_("Invalid Arm FP type: %d"), fp_type);
     }
 
+  set_tdesc_osabi (tdesc, "GNU/Linux");
+
   return tdesc;
 }
 
diff --git a/gdb-9.2/gdb/configure b/gdb-9.2/gdb/configure
index b572d414c..d06110a2e 100755
--- a/gdb-9.2/gdb/configure
+++ b/gdb-9.2/gdb/configure
@@ -6737,7 +6737,7 @@ fi
 
 # For other settings, only the main target counts.
 gdb_sim=
-gdb_osabi=
+gdb_osabi=GDB_OSABI_LINUX
 build_gdbserver=
 targ=$target; . ${srcdir}/configure.tgt
 
diff --git a/gdb-9.2/gdb/gdbserver/Makefile.in b/gdb-9.2/gdb/gdbserver/Makefile.in
index 16a9f2fd3..782430936 100644
--- a/gdb-9.2/gdb/gdbserver/Makefile.in
+++ b/gdb-9.2/gdb/gdbserver/Makefile.in
@@ -410,7 +410,7 @@ gdbserver$(EXEEXT): $(sort $(OBS)) ${CDEPS} $(LIBGNU) $(LIBIBERTY)
 	$(SILENCE) rm -f gdbserver$(EXEEXT)
 	$(ECHO_CXXLD) $(CC_LD) $(INTERNAL_CFLAGS) $(INTERNAL_LDFLAGS) \
 		-o gdbserver$(EXEEXT) $(OBS) $(LIBGNU) $(LIBIBERTY) \
-		$(GDBSERVER_LIBS) $(XM_CLIBS)
+		$(GDBSERVER_LIBS) $(XM_CLIBS) -ldl
 
 $(LIBGNU) $(LIBIBERTY) $(GNULIB_H): all-lib
 all-lib: $(GNULIB_BUILDDIR)/Makefile $(LIBIBERTY_BUILDDIR)/Makefile
diff --git a/gdb-9.2/gdb/gdbserver/configure b/gdb-9.2/gdb/gdbserver/configure
index 4de751b44..37763d5af 100755
--- a/gdb-9.2/gdb/gdbserver/configure
+++ b/gdb-9.2/gdb/gdbserver/configure
@@ -8511,20 +8511,7 @@ _ACEOF
 fi
 
 
-case "${target}" in
-  *-android*)
-    # Starting with NDK version 9, <elf.h> actually includes definitions
-    # of Elf32_auxv_t and Elf64_auxv_t. But sadly, <elf.h> includes
-    # <sys/exec_elf.h> which defines some of the ELF types incorrectly,
-    # leading to conflicts with the defintions from <linux/elf.h>.
-    # This makes it impossible for us to include both <elf.h> and
-    # <linux/elf.h>, which means that, in practice, we do not have
-    # access to Elf32_auxv_t and Elf64_auxv_t on this platform.
-    # Therefore, do not try to auto-detect availability, as it would
-    # get it wrong on this platform.
-    ;;
-  *)
-    ac_fn_c_check_type "$LINENO" "Elf32_auxv_t" "ac_cv_type_Elf32_auxv_t" "#include <elf.h>
+ac_fn_c_check_type "$LINENO" "Elf32_auxv_t" "ac_cv_type_Elf32_auxv_t" "#include <elf.h>
 
 "
 if test "x$ac_cv_type_Elf32_auxv_t" = xyes; then :
@@ -8547,9 +8534,6 @@ _ACEOF
 
 fi
 
-esac
-
-
 
 # Check whether --with-pkgversion was given.
 if test "${with_pkgversion+set}" = set; then :
diff --git a/gdb-9.2/gdb/gdbserver/hostio.c b/gdb-9.2/gdb/gdbserver/hostio.c
index 8af4fbf40..edc75cba8 100644
--- a/gdb-9.2/gdb/gdbserver/hostio.c
+++ b/gdb-9.2/gdb/gdbserver/hostio.c
@@ -300,7 +300,7 @@ handle_open (char *own_buf)
 {
   char filename[HOSTIO_PATH_MAX];
   char *p;
-  int fileio_flags, fileio_mode, flags, fd;
+  int fileio_flags, fileio_mode, flags, fd = -1;
   mode_t mode;
   struct fd_list *new_fd;
 
@@ -324,7 +324,11 @@ handle_open (char *own_buf)
   if (hostio_fs_pid != 0 && the_target->multifs_open != NULL)
     fd = the_target->multifs_open (hostio_fs_pid, filename,
 				   flags, mode);
-  else
+
+  /* HACK: multifs_open will fail for android applications, because run-as does
+     not switch to the same mount namespace as the running application. Retry
+     with regular open if this happens.  */
+  if (fd == -1)
     fd = open (filename, flags, mode);
 
   if (fd == -1)
diff --git a/gdb-9.2/gdb/gdbserver/linux-low.c b/gdb-9.2/gdb/gdbserver/linux-low.c
index 4255795ea..762f8bafb 100644
--- a/gdb-9.2/gdb/gdbserver/linux-low.c
+++ b/gdb-9.2/gdb/gdbserver/linux-low.c
@@ -5904,9 +5904,7 @@ linux_look_up_symbols (void)
 static void
 linux_request_interrupt (void)
 {
-  /* Send a SIGINT to the process group.  This acts just like the user
-     typed a ^C on the controlling terminal.  */
-  kill (-signal_pid, SIGINT);
+  kill (signal_pid, SIGINT);
 }
 
 /* Copy LEN bytes from inferior's auxiliary vector starting at OFFSET
diff --git a/gdb-9.2/gdb/gdbserver/remote-utils.c b/gdb-9.2/gdb/gdbserver/remote-utils.c
index b757740ec..ee04b508a 100644
--- a/gdb-9.2/gdb/gdbserver/remote-utils.c
+++ b/gdb-9.2/gdb/gdbserver/remote-utils.c
@@ -321,11 +321,64 @@ remote_prepare (const char *name)
 /* Open a connection to a remote debugger.
    NAME is the filename used for communication.  */
 
+// ANDROID BEGIN.
+#ifndef USE_WIN32API
+#include <sys/un.h>
+#endif
+// ANDROID END.
+
 void
 remote_open (const char *name)
 {
+  client_state &cs = get_client_state ();
   const char *port_str;
 
+  // ANDROID BEGIN.
+  // The Android NDK uses Unix domain sockets because applications
+  // aren't allowed to bind to localhost TCP sockets, and developers
+  // debugging on production devices can't get root.
+  // Typical ndk-gdb usage is "gdbserver +debug-socket --attach 123".
+  if (name[0] == '+')
+    {
+#ifdef USE_WIN32API
+      error ("Only <host>:<port> is supported on this platform.");
+#else
+      struct sockaddr_un sockaddr;
+      socklen_t sockaddrlen;
+
+      listen_desc = socket (AF_UNIX, SOCK_STREAM, 0);
+      if (listen_desc == -1)
+        perror_with_name ("Can't create Unix domain socket");
+
+      /* Skip the initial '+'. */
+      name++;
+
+      memset (&sockaddr, 0, sizeof sockaddr);
+      sockaddr.sun_family = AF_UNIX;
+      snprintf (sockaddr.sun_path, sizeof (sockaddr.sun_path), "%s", name);
+      sockaddrlen = sizeof (sockaddr.sun_family) +
+          strlen (sockaddr.sun_path) + 1;
+
+      unlink (sockaddr.sun_path);
+
+      if (bind (listen_desc, (struct sockaddr *) &sockaddr, sockaddrlen)
+          || listen (listen_desc, 1))
+        perror_with_name ("Can't bind Unix domain socket");
+
+      fprintf (stderr, "Listening on Unix domain socket '%s'\n",
+               sockaddr.sun_path);
+      fflush (stderr);
+
+      /* Register the event loop handler.  */
+      add_file_handler (listen_desc, handle_accept_event, NULL);
+
+      cs.transport_is_reliable = 1;
+#endif
+
+      return;
+    }
+  // ANDROID END.
+
   port_str = strchr (name, ':');
 #ifdef USE_WIN32API
   if (port_str == NULL)
diff --git a/gdb-9.2/gnulib/configure b/gdb-9.2/gnulib/configure
index 7c74371e8..c0c2e37a3 100644
--- a/gdb-9.2/gnulib/configure
+++ b/gdb-9.2/gnulib/configure
@@ -10128,6 +10128,8 @@ $as_echo "$gl_cv_header_sys_socket_h_shut" >&6; }
 $as_echo_n "checking absolute name of <sys/socket.h>... " >&6; }
 if ${gl_cv_next_sys_socket_h+:} false; then :
   $as_echo_n "(cached) " >&6
+elif test "$cross_compiling" = yes; then :
+  gt_cv_locale_ja=none
 else
 
              if test $ac_cv_header_sys_socket_h = yes; then
@@ -10320,6 +10322,8 @@ done
 $as_echo_n "checking whether $gl_func is declared without a macro... " >&6; }
 if eval \${$as_gl_Symbol+:} false; then :
   $as_echo_n "(cached) " >&6
+elif test "$cross_compiling" = yes; then :
+  gt_cv_locale_zh_CN=none
 else
   cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
@@ -10418,6 +10422,8 @@ $as_echo "#define HAVE_IPV4 1" >>confdefs.h
 $as_echo_n "checking for IPv6 sockets... " >&6; }
   if ${gl_cv_socket_ipv6+:} false; then :
   $as_echo_n "(cached) " >&6
+elif test "$cross_compiling" = yes; then :
+  gt_cv_locale_fr_utf8=none
 else
   cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
@@ -10554,6 +10560,8 @@ $as_echo "$gl_cv_next_limits_h" >&6; }
 $as_echo_n "checking whether limits.h has ULLONG_WIDTH etc.... " >&6; }
 if ${gl_cv_header_limits_width+:} false; then :
   $as_echo_n "(cached) " >&6
+elif test "$cross_compiling" = yes; then :
+  gt_cv_locale_fr=none
 else
   cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */