[PATCH 6/7] Implement qXfer:exec-file:read in gdbserver

Gary Benson
2015-04-01T11:30:48Z

This commit implements the "qXfer:exec-file:read" packet in gdbserver.

gdb/gdbserver/ChangeLog:

* target.h (struct target_ops) <pid_to_exec_file>: New field.
* linux-low.c (linux_target_ops): Initialize pid_to_exec_file.
* server.c (handle_qxfer_exec_file): New function.
(qxfer_packets): Add exec-file entry.
(handle_query): Report qXfer:exec-file:read as supported packet.
---
gdb/gdbserver/ChangeLog | 8 ++++++++
gdb/gdbserver/linux-low.c | 1 +
gdb/gdbserver/server.c | 40 ++++++++++++++++++++++++++++++++++++++++
gdb/gdbserver/target.h | 8 ++++++++
4 files changed, 57 insertions(+), 0 deletions(-)

diff --git a/gdb/gdbserver/linux-low.c b/gdb/gdbserver/linux-low.c
index e4c5420..5ce39fb 100644
--- a/gdb/gdbserver/linux-low.c
+++ b/gdb/gdbserver/linux-low.c
@@ -6429,6 +6429,7 @@ static struct target_ops linux_target_ops = {
NULL,
#endif
linux_supports_range_stepping,
+ linux_pid_to_exec_file,
};

static void
diff --git a/gdb/gdbserver/server.c b/gdb/gdbserver/server.c
index 96b31b8..31a2c04 100644
--- a/gdb/gdbserver/server.c
+++ b/gdb/gdbserver/server.c
@@ -1137,6 +1137,42 @@ handle_qxfer_auxv (const char *annex,
return (*the_target->read_auxv) (offset, readbuf, len);
}

+/* Handle qXfer:exec-file:read. */
+
+static int
+handle_qxfer_exec_file (const char *const_annex,
+ gdb_byte *readbuf, const gdb_byte *writebuf,
+ ULONGEST offset, LONGEST len)
+{
+ char *annex, *file;
+ ULONGEST pid;
+ int total_len;
+
+ if (the_target->pid_to_exec_file == NULL || writebuf != NULL)
+ return -2;
+
+ annex = alloca (strlen (const_annex) + 1);
+ strcpy (annex, const_annex);
+ annex = unpack_varlen_hex (annex, &pid);
+ if (annex[0] != '\0' || pid == 0)
+ return -1;
+
+ file = (*the_target->pid_to_exec_file) (pid);
+ if (file == NULL)
+ return -1;
+
+ total_len = strlen (file);
+
+ if (offset > total_len)
+ return -1;
+
+ if (offset + len > total_len)
+ len = total_len - offset;
+
+ memcpy (readbuf, file + offset, len);
+ return len;
+}
+
/* Handle qXfer:features:read. */

static int
@@ -1638,6 +1674,7 @@ static const struct qxfer qxfer_packets[] =
{ "auxv", handle_qxfer_auxv },
{ "btrace", handle_qxfer_btrace },
{ "btrace-conf", handle_qxfer_btrace_conf },
+ { "exec-file", handle_qxfer_exec_file},
{ "fdpic", handle_qxfer_fdpic},
{ "features", handle_qxfer_features },
{ "libraries", handle_qxfer_libraries },
@@ -2082,6 +2119,9 @@ handle_query (char *own_buf, int packet_len, int *new_packet_len_p)
if (target_supports_stopped_by_hw_breakpoint ())
strcat (own_buf, ";hwbreak+");

+ if (the_target->pid_to_exec_file != NULL)
+ strcat (own_buf, ";qXfer:exec-file:read+");
+
return;
}

diff --git a/gdb/gdbserver/target.h b/gdb/gdbserver/target.h
index 126c861..dc7802d 100644
--- a/gdb/gdbserver/target.h
+++ b/gdb/gdbserver/target.h
@@ -394,6 +394,14 @@ struct target_ops

/* Return true if target supports range stepping. */
int (*supports_range_stepping) (void);
+
+ /* Return the pathname of the executable file that was run to
+ create the process PID. If the executable file cannot be
+ determined, NULL is returned. Otherwise, a pointer to a
+ character string containing the pathname is returned. This
+ string should be copied into a buffer by the client if the
+ string will not be immediately used, or if it must persist. */
+ char *(*pid_to_exec_file) (int pid);
};

extern struct target_ops *the_target;
--
1.7.1