Add a new gdbarch method to fetch signal information from core files.

Previously the core_xfer_partial method used core_get_siginfo to handle
TARGET_OBJECT_SIGNAL_INFO requests.  However, core_get_siginfo looked for
Linux-specific sections in the core file.  To support fetching siginfo
from cores on other systems, add a new gdbarch method (`core_xfer_siginfo`)
and move the body of the existing core_get_siginfo into a
linux_core_xfer_siginfo implementation of this method in linux-tdep.c.

gdb/ChangeLog:

	* corelow.c (get_core_siginfo): Remove.
	(core_xfer_partial): Use the gdbarch "core_xfer_siginfo" method
	instead of get_core_siginfo.
	* gdbarch.sh (core_xfer_siginfo): New gdbarch callback.
	* gdbarch.h: Re-generate.
	* gdbarch.c: Re-generate.
	* linux-tdep.c (linux_core_xfer_siginfo): New.
	(linux_init_abi): Install gdbarch "core_xfer_siginfo" method.

1 files changed, 21 insertions, 0 deletions

diff --git a/gdb/linux-tdep.c b/gdb/linux-tdep.c
index 2792cbd..5c7f8a0 100644
--- a/gdb/linux-tdep.c
+++ b/gdb/linux-tdep.c
@@ -1127,6 +1127,26 @@ linux_core_info_proc (struct gdbarch *gdbarch, const char *args,
     error (_("unable to handle request"));
 }
 
+/* Read siginfo data from the core, if possible.  Returns -1 on
+   failure.  Otherwise, returns the number of bytes read.  READBUF,
+   OFFSET, and LEN are all as specified by the to_xfer_partial
+   interface.  */
+
+static LONGEST
+linux_core_xfer_siginfo (struct gdbarch *gdbarch, gdb_byte *readbuf,
+			 ULONGEST offset, ULONGEST len)
+{
+  thread_section_name section_name (".note.linuxcore.siginfo", inferior_ptid);
+  asection *section = bfd_get_section_by_name (core_bfd, section_name.c_str ());
+  if (section == NULL)
+    return -1;
+
+  if (!bfd_get_section_contents (core_bfd, section, readbuf, offset, len))
+    return -1;
+
+  return len;
+}
+
 typedef int linux_find_memory_region_ftype (ULONGEST vaddr, ULONGEST size,
 					    ULONGEST offset, ULONGEST inode,
 					    int read, int write,
@@ -2516,6 +2536,7 @@ linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
   set_gdbarch_core_pid_to_str (gdbarch, linux_core_pid_to_str);
   set_gdbarch_info_proc (gdbarch, linux_info_proc);
   set_gdbarch_core_info_proc (gdbarch, linux_core_info_proc);
+  set_gdbarch_core_xfer_siginfo (gdbarch, linux_core_xfer_siginfo);
   set_gdbarch_find_memory_regions (gdbarch, linux_find_memory_regions);
   set_gdbarch_make_corefile_notes (gdbarch, linux_make_corefile_notes);
   set_gdbarch_has_shared_address_space (gdbarch,