1 files changed, 49 insertions, 3 deletions

diff --git a/gdb/ia64-hpux-nat.c b/gdb/ia64-hpux-nat.c
index 07a433e..741d3d8 100644
--- a/gdb/ia64-hpux-nat.c
+++ b/gdb/ia64-hpux-nat.c
@@ -485,6 +485,37 @@ ia64_hpux_xfer_memory_bs (struct target_ops *ops, const char *annex,
     return 0;
 }
 
+/* Get a register value as a unsigned value directly from the system,
+   instead of going through the regcache.
+
+   This function is meant to be used when inferior_ptid is not
+   a thread/process known to GDB.  */
+
+static ULONGEST
+ia64_hpux_get_register_from_save_state_t (int regnum, int reg_size)
+{
+  gdb_byte *buf = alloca (reg_size);
+  int offset = u_offsets[regnum];
+  int status;
+
+  /* The register is assumed to be available for fetching.  */
+  gdb_assert (offset != -1);
+
+  status = ia64_hpux_read_register_from_save_state_t (offset, buf, reg_size);
+  if (status < 0)
+    {
+      /* This really should not happen.  If it does, emit a warning
+	 and pretend the register value is zero.  Not exactly the best
+	 error recovery mechanism, but better than nothing.  We will
+	 try to do better if we can demonstrate that this can happen
+	 under normal circumstances.  */
+      warning (_("Failed to read value of register number %d."), regnum);
+      return 0;
+    }
+
+  return extract_unsigned_integer (buf, reg_size, BFD_ENDIAN_BIG);
+}
+
 /* The "xfer_partial" target_ops routine for ia64-hpux, in the case
    where the requested object is TARGET_OBJECT_MEMORY.  */
 
@@ -504,9 +535,24 @@ ia64_hpux_xfer_memory (struct target_ops *ops, const char *annex,
        (3) The region inside the backing-store, which needs to be
            read/written specially.  */
 
-  regcache_raw_read_unsigned (get_current_regcache (), IA64_BSP_REGNUM, &bsp);
-  regcache_raw_read_unsigned (get_current_regcache (), IA64_BSPSTORE_REGNUM,
-                              &bspstore);
+  if (in_inferior_list (ptid_get_pid (inferior_ptid)))
+    {
+      struct regcache *regcache = get_current_regcache ();
+
+      regcache_raw_read_unsigned (regcache, IA64_BSP_REGNUM, &bsp);
+      regcache_raw_read_unsigned (regcache, IA64_BSPSTORE_REGNUM, &bspstore);
+    }
+  else
+    {
+      /* This is probably a child of our inferior created by a fork.
+	 Because this process has not been added to our inferior list
+	 (we are probably in the process of handling that child
+	 process), we do not have a regcache to read the registers
+	 from.  So get those values directly from the kernel.  */
+      bsp = ia64_hpux_get_register_from_save_state_t (IA64_BSP_REGNUM, 8);
+      bspstore =
+	ia64_hpux_get_register_from_save_state_t (IA64_BSPSTORE_REGNUM, 8);
+    }
 
   /* 1. Memory region before BSPSTORE.  */