[ARC] Parse NOTE section in core dump files

This patch adds function elf32_arc_grok_parse to parse NOTE section of core
dump files. GDB requires this to work properly with core dumps.

bfd/
2016-08-24  Anton Kolesov  <Anton.Kolesov@synopsys.com>

	* elf32-arc.c (elf32_arc_grok_prstatus): New function.

Signed-off-by: Claudiu Zissulescu <claziss@synopsys.com>

diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index 84fceea..529a3b5 100644 (file)
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,3 +1,7 @@
+2016-08-24  Anton Kolesov  <Anton.Kolesov@synopsys.com>
+
+       * elf32-arc.c (elf32_arc_grok_prstatus): New function.
+
 2016-08-23  Nick Clifton  <nickc@redhat.com>
 
        * elf32-arm.c (elf32_arm_count_additional_relocs): Return zero if

diff --git a/bfd/elf32-arc.c b/bfd/elf32-arc.c
index 00828be..89a2b52 100644 (file)
--- a/bfd/elf32-arc.c
+++ b/bfd/elf32-arc.c
@@ -2439,6 +2439,39 @@ elf_arc_add_symbol_hook (bfd * abfd,
   return TRUE;
 }
 
+/* GDB expects general purpose registers to be in section .reg.  However Linux
+   kernel doesn't create this section and instead writes registers to NOTE
+   section.  It is up to the binutils to create a pseudo-section .reg from the
+   contents of NOTE.  Also BFD will read pid and signal number from NOTE.  This
+   function relies on offsets inside elf_prstatus structure in Linux to be
+   stable.  */
+
+static bfd_boolean
+elf32_arc_grok_prstatus (bfd *abfd, Elf_Internal_Note *note)
+{
+  int offset;
+  size_t size;
+
+  switch (note->descsz)
+    {
+    default:
+      return FALSE;
+
+    case 236: /* sizeof (struct elf_prstatus) on Linux/arc.  */
+      /* pr_cursig */
+      elf_tdata (abfd)->core->signal = bfd_get_16 (abfd, note->descdata + 12);
+      /* pr_pid */
+      elf_tdata (abfd)->core->lwpid = bfd_get_32 (abfd, note->descdata + 24);
+      /* pr_regs */
+      offset = 72;
+      size = (40 * 4); /* There are 40 registers in user_regs_struct.  */
+      break;
+    }
+  /* Make a ".reg/999" section.  */
+  return _bfd_elfcore_make_pseudosection (abfd, ".reg", size,
+                                         note->descpos + offset);
+}
+
 #define TARGET_LITTLE_SYM   arc_elf32_le_vec
 #define TARGET_LITTLE_NAME  "elf32-littlearc"
 #define TARGET_BIG_SYM     arc_elf32_be_vec
@@ -2484,6 +2517,8 @@ elf_arc_add_symbol_hook (bfd * abfd,
 #define elf_backend_may_use_rela_p     1
 #define elf_backend_default_use_rela_p 1
 
+#define elf_backend_grok_prstatus elf32_arc_grok_prstatus
+
 #define elf_backend_default_execstack  0
 
 #include "elf32-target.h"