[PATCH 07/10] Add a common utility function to read and write siginfo_t in inferior

[Kamil Rytarowski <n54@gmx.com>]

gdb/ChangeLog:

        * netbsd-nat.h (netbsd_nat::qxfer_siginfo): Add.
        * netbsd-nat.c (netbsd_nat::qxfer_siginfo): Likewise.
---
 gdb/ChangeLog        |  5 +++++
 gdb/nat/netbsd-nat.c | 30 ++++++++++++++++++++++++++++++
 gdb/nat/netbsd-nat.h |  4 ++++
 3 files changed, 39 insertions(+)

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 06d3476c137..1dcf5d0ca81 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,8 @@
+2020-08-13  Kamil Rytarowski  <n54@gmx.com>
+
+	* netbsd-nat.h (netbsd_nat::qxfer_siginfo): Add.
+	* netbsd-nat.c (netbsd_nat::qxfer_siginfo): Likewise.
+
 2020-08-13  Kamil Rytarowski  <n54@gmx.com>

 	* netbsd-nat.h (netbsd_nat::enable_proc_events): Add.
diff --git a/gdb/nat/netbsd-nat.c b/gdb/nat/netbsd-nat.c
index 88c70ebe1bb..fef273a125a 100644
--- a/gdb/nat/netbsd-nat.c
+++ b/gdb/nat/netbsd-nat.c
@@ -180,4 +180,34 @@ enable_proc_events (pid_t pid)
     perror_with_name (("ptrace"));
 }

+/* Implement reading and writing of inferior's siginfo_t specified by PID.
+   Returns -1 on failure and the number of bytes on a successful transfer.  */
+
+int
+qxfer_siginfo (pid_t pid, const char *annex, unsigned char *readbuf,
+	       unsigned const char *writebuf, CORE_ADDR offset, int len)
+{
+  ptrace_siginfo_t psi;
+
+  if (offset > sizeof (siginfo_t))
+    return -1;
+
+  if (ptrace (PT_GET_SIGINFO, pid, &psi, sizeof (psi)) == -1)
+    return -1;
+
+  if (offset + len > sizeof (siginfo_t))
+    len = sizeof (siginfo_t) - offset;
+
+  if (readbuf != NULL)
+    memcpy (readbuf, ((gdb_byte *) &psi.psi_siginfo) + offset, len);
+  else
+    {
+      memcpy (((gdb_byte *) &psi.psi_siginfo) + offset, writebuf, len);
+
+      if (ptrace (PT_SET_SIGINFO, pid, &psi, sizeof (psi)) == -1)
+	return -1;
+    }
+  return len;
+}
+
 }
diff --git a/gdb/nat/netbsd-nat.h b/gdb/nat/netbsd-nat.h
index c93e5d4822d..9bd4e19697e 100644
--- a/gdb/nat/netbsd-nat.h
+++ b/gdb/nat/netbsd-nat.h
@@ -37,6 +37,10 @@ extern void list_threads (pid_t pid,
 			  gdb::function_view<void (ptid_t)> callback);

 extern void enable_proc_events (pid_t pid);
+
+extern int qxfer_siginfo (pid_t pid, const char *annex, unsigned char *readbuf,
+			  unsigned const char *writebuf, CORE_ADDR offset,
+			  int len);
 }

 #endif
--
2.28.0