From 1ccb2c170cea50671f7aa00eb6a2be2a33ea24a5 Mon Sep 17 00:00:00 2001
From: Kamil Rytarowski <n54@gmx.com>
Date: Wed, 2 Sep 2020 19:21:19 +0200
Subject: [PATCH] Add a common utility function to read and write siginfo_t in
 inferior

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 | 29 +++++++++++++++++++++++++++++
 gdb/nat/netbsd-nat.h | 10 ++++++++++
 3 files changed, 44 insertions(+)

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 41bd6998bb9..ecf8e37f58b 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,8 @@
+2020-09-10  Kamil Rytarowski  <n54@gmx.com>
+
+	* netbsd-nat.h (netbsd_nat::qxfer_siginfo): Add.
+	* netbsd-nat.c (netbsd_nat::qxfer_siginfo): Likewise.
+
 2020-09-10  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 d805b892404..41b67cb72fc 100644
--- a/gdb/nat/netbsd-nat.c
+++ b/gdb/nat/netbsd-nat.c
@@ -181,4 +181,33 @@ enable_proc_events (pid_t pid)
     perror_with_name (("ptrace"));
 }
 
+/* See netbsd-nat.h.  */
+
+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 6472cc56da4..d77119bb862 100644
--- a/gdb/nat/netbsd-nat.h
+++ b/gdb/nat/netbsd-nat.h
@@ -57,6 +57,16 @@ extern void for_each_thread (pid_t pid,
    traced.  */
 
 extern void enable_proc_events (pid_t pid);
+
+/* 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.
+
+   This function assumes internally that the queried process is stopped and
+   traced.  */
+
+extern int qxfer_siginfo (pid_t pid, const char *annex, unsigned char *readbuf,
+			  unsigned const char *writebuf, CORE_ADDR offset,
+			  int len);
 }
 
 #endif
-- 
2.30.2