From 0fd864ff792d7bcbbcbed5ee0ae9f429f1fd2353 Mon Sep 17 00:00:00 2001
From: Mahesh Bodapati <mbodapat@xilinx.com>
Date: Tue, 24 Jan 2017 14:55:56 +0530
Subject: [PATCH 33/43] Initial port of core reading support Added support for
 reading notes in linux core dumps Support for reading of PRSTATUS and PSINFO
 information for rebuilding ".reg" sections of core dumps at run time.

Signed-off-by: David Holsgrove <david.holsgrove@petalogix.com>
Signed-off-by: Nathan Rossi <nathan.rossi@petalogix.com>
---
 bfd/elf32-microblaze.c      | 84 ++++++++++++++++++++++++++++++++++
 gdb/configure.tgt           |  2 +-
 gdb/microblaze-linux-tdep.c | 57 +++++++++++++++++++++++
 gdb/microblaze-tdep.c       | 90 +++++++++++++++++++++++++++++++++++++
 gdb/microblaze-tdep.h       | 27 +++++++++++
 5 files changed, 259 insertions(+), 1 deletion(-)

diff --git a/bfd/elf32-microblaze.c b/bfd/elf32-microblaze.c
index 6a795c5069..c280431df6 100644
--- a/bfd/elf32-microblaze.c
+++ b/bfd/elf32-microblaze.c
@@ -767,6 +767,87 @@ microblaze_elf_is_local_label_name (bfd *abfd, const char *name)
   return _bfd_elf_is_local_label_name (abfd, name);
 }
 
+/* Support for core dump NOTE sections.  */
+static bfd_boolean
+microblaze_elf_grok_prstatus (bfd *abfd, Elf_Internal_Note *note)
+{
+  int offset;
+  unsigned int size;
+
+  switch (note->descsz)
+    {
+      default:
+        return FALSE;
+
+      case 228:         /* Linux/MicroBlaze */
+        /* pr_cursig */
+        elf_tdata (abfd)->core->signal = bfd_get_16 (abfd, note->descdata + 12);
+
+        /* pr_pid */
+        elf_tdata (abfd)->core->pid = bfd_get_32 (abfd, note->descdata + 24);
+
+        /* pr_reg */
+        offset = 72;
+        size = 50 * 4;
+
+        break;
+    }
+
+  /* Make a ".reg/999" section.  */
+  return _bfd_elfcore_make_pseudosection (abfd, ".reg",
+                                          size, note->descpos + offset);
+}
+
+static bfd_boolean
+microblaze_elf_grok_psinfo (bfd *abfd, Elf_Internal_Note *note)
+{
+  switch (note->descsz)
+    {
+      default:
+        return FALSE;
+
+      case 128:         /* Linux/MicroBlaze elf_prpsinfo */
+        elf_tdata (abfd)->core->program
+         = _bfd_elfcore_strndup (abfd, note->descdata + 32, 16);
+        elf_tdata (abfd)->core->command
+         = _bfd_elfcore_strndup (abfd, note->descdata + 48, 80);
+    }
+
+  /* Note that for some reason, a spurious space is tacked
+     onto the end of the args in some (at least one anyway)
+     implementations, so strip it off if it exists.  */
+
+  {
+    char *command = elf_tdata (abfd)->core->command;
+    int n = strlen (command);
+
+    if (0 < n && command[n - 1] == ' ')
+      command[n - 1] = '\0';
+  }
+
+  return TRUE;
+}
+
+/* The microblaze linker (like many others) needs to keep track of
+   the number of relocs that it decides to copy as dynamic relocs in
+   check_relocs for each symbol. This is so that it can later discard
+   them if they are found to be unnecessary.  We store the information
+   in a field extending the regular ELF linker hash table.  */
+
+struct elf32_mb_dyn_relocs
+{
+  struct elf32_mb_dyn_relocs *next;
+
+  /* The input section of the reloc.  */
+  asection *sec;
+
+  /* Total number of relocs copied for the input section.  */
+  bfd_size_type count;
+
+  /* Number of pc-relative relocs copied for the input section.  */
+  bfd_size_type pc_count;
+};
+
 /* ELF linker hash entry.  */
 
 struct elf32_mb_link_hash_entry
@@ -3672,4 +3753,7 @@ microblaze_elf_add_symbol_hook (bfd *abfd,
 #define elf_backend_size_dynamic_sections	microblaze_elf_size_dynamic_sections
 #define elf_backend_add_symbol_hook		microblaze_elf_add_symbol_hook
 
+#define elf_backend_grok_prstatus               microblaze_elf_grok_prstatus
+#define elf_backend_grok_psinfo                 microblaze_elf_grok_psinfo
+
 #include "elf32-target.h"
diff --git a/gdb/configure.tgt b/gdb/configure.tgt
index 27f122ad04..622bd486b3 100644
--- a/gdb/configure.tgt
+++ b/gdb/configure.tgt
@@ -397,7 +397,7 @@ mep-*-*)
 
 microblaze*-linux-*|microblaze*-*-linux*)
 	# Target: Xilinx MicroBlaze running Linux
-	gdb_target_obs="microblaze-tdep.o microblaze-linux-tdep.o solib-svr4.o \
+	gdb_target_obs="microblaze-tdep.o microblaze-linux-tdep.o solib-svr4.o glibc-tdep.o \
 			symfile-mem.o linux-tdep.o"
 	gdb_sim=../sim/microblaze/libsim.a
 	;;
diff --git a/gdb/microblaze-linux-tdep.c b/gdb/microblaze-linux-tdep.c
index 7ab650a1cc..e2225d778a 100644
--- a/gdb/microblaze-linux-tdep.c
+++ b/gdb/microblaze-linux-tdep.c
@@ -135,11 +135,54 @@ static struct tramp_frame microblaze_linux_sighandler_tramp_frame =
   microblaze_linux_sighandler_cache_init
 };
 
+const struct microblaze_gregset microblaze_linux_core_gregset;
+
+static void
+microblaze_linux_supply_core_gregset (const struct regset *regset,
+                                   struct regcache *regcache,
+                                   int regnum, const void *gregs, size_t len)
+{
+  microblaze_supply_gregset (&microblaze_linux_core_gregset, regcache,
+                             regnum, gregs);
+}
+
+static void
+microblaze_linux_collect_core_gregset (const struct regset *regset,
+                                    const struct regcache *regcache,
+                                    int regnum, void *gregs, size_t len)
+{
+  microblaze_collect_gregset (&microblaze_linux_core_gregset, regcache,
+                              regnum, gregs);
+}
+
+static void
+microblaze_linux_supply_core_fpregset (const struct regset *regset,
+                                    struct regcache *regcache,
+                                    int regnum, const void *fpregs, size_t len)
+{
+  /* FIXME.  */
+  microblaze_supply_fpregset (regcache, regnum, fpregs);
+}
+
+static void
+microblaze_linux_collect_core_fpregset (const struct regset *regset,
+                                     const struct regcache *regcache,
+                                     int regnum, void *fpregs, size_t len)
+{
+  /* FIXME.  */
+  microblaze_collect_fpregset (regcache, regnum, fpregs);
+}
 
 static void
 microblaze_linux_init_abi (struct gdbarch_info info,
 			   struct gdbarch *gdbarch)
 {
+  struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
+
+  tdep->gregset = regset_alloc (gdbarch, microblaze_linux_supply_core_gregset,
+                                microblaze_linux_collect_core_gregset);
+  tdep->sizeof_gregset = 200;
+
   linux_init_abi (info, gdbarch);
 
   set_gdbarch_memory_remove_breakpoint (gdbarch,
@@ -153,6 +196,20 @@ microblaze_linux_init_abi (struct gdbarch_info info,
   tramp_frame_prepend_unwinder (gdbarch,
 				&microblaze_linux_sighandler_tramp_frame);
 
+  /* BFD target for core files.  */
+  if (gdbarch_byte_order (gdbarch) == BFD_ENDIAN_BIG)
+    set_gdbarch_gcore_bfd_target (gdbarch, "elf32-microblaze");
+  else
+    set_gdbarch_gcore_bfd_target (gdbarch, "elf32-microblazeel");
+
+
+  /* Shared library handling.  */
+  set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target);
+  set_gdbarch_skip_solib_resolver (gdbarch, glibc_skip_solib_resolver);
+
+  set_gdbarch_regset_from_core_section (gdbarch,
+					microblaze_regset_from_core_section);
+
   /* Enable TLS support.  */
   set_gdbarch_fetch_tls_load_module_address (gdbarch,
                                              svr4_fetch_objfile_link_map);
diff --git a/gdb/microblaze-tdep.c b/gdb/microblaze-tdep.c
index 730a2b281f..49713ea9b1 100644
--- a/gdb/microblaze-tdep.c
+++ b/gdb/microblaze-tdep.c
@@ -137,6 +137,14 @@ microblaze_fetch_instruction (CORE_ADDR pc)
 constexpr gdb_byte microblaze_break_insn[] = MICROBLAZE_BREAKPOINT;
 
 typedef BP_MANIPULATION (microblaze_break_insn) microblaze_breakpoint;
+static CORE_ADDR
+microblaze_store_arguments (struct regcache *regcache, int nargs,
+			    struct value **args, CORE_ADDR sp,
+			    int struct_return, CORE_ADDR struct_addr)
+{
+  error (_("store_arguments not implemented"));
+  return sp;
+}
 static int
 microblaze_linux_memory_remove_breakpoint (struct gdbarch *gdbarch,
 				    struct bp_target_info *bp_tgt)
@@ -541,6 +549,12 @@ microblaze_frame_base_address (struct frame_info *next_frame,
   return cache->base;
 }
 
+static const struct frame_unwind *
+microblaze_frame_sniffer (struct frame_info *next_frame)
+{
+  return &microblaze_frame_unwind;
+}
+
 static const struct frame_base microblaze_frame_base =
 {
   &microblaze_frame_unwind,
@@ -677,6 +691,71 @@ microblaze_register_g_packet_guesses (struct gdbarch *gdbarch)
                                   tdesc_microblaze_with_stack_protect);
 }
 
+void
+microblaze_supply_gregset (const struct microblaze_gregset *gregset,
+                        struct regcache *regcache,
+                        int regnum, const void *gregs)
+{
+  unsigned int *regs = gregs;
+  if (regnum >= 0)
+    regcache_raw_supply (regcache, regnum, regs + regnum);
+
+  if (regnum == -1) {
+    int i;
+
+    for (i = 0; i < 50; i++) {
+      regcache_raw_supply (regcache, i, regs + i);
+    }
+  }
+}
+
+
+void
+microblaze_collect_gregset (const struct microblaze_gregset *gregset,
+                         const struct regcache *regcache,
+                         int regnum, void *gregs)
+{
+   /* FIXME.  */
+}
+
+void
+microblaze_supply_fpregset (struct regcache *regcache,
+                         int regnum, const void *fpregs)
+{
+   /* FIXME.  */
+}
+
+void
+microblaze_collect_fpregset (const struct regcache *regcache,
+                          int regnum, void *fpregs)
+{
+   /* FIXME.  */
+}
+
+
+/* Return the appropriate register set for the core section identified
+   by SECT_NAME and SECT_SIZE.  */
+
+const struct regset *
+microblaze_regset_from_core_section (struct gdbarch *gdbarch,
+                                     const char *sect_name, size_t sect_size)
+{
+  struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
+
+  microblaze_debug ("microblaze_regset_from_core_section, sect_name = %s\n", sect_name);
+
+  if (strcmp (sect_name, ".reg") == 0 && sect_size >= tdep->sizeof_gregset)
+    return tdep->gregset;
+
+  if (strcmp (sect_name, ".reg2") == 0 && sect_size >= tdep->sizeof_fpregset)
+    return tdep->fpregset;
+
+  microblaze_debug ("microblaze_regset_from_core_section returning null :-( \n");
+  return NULL;
+}
+
+
+
 static struct gdbarch *
 microblaze_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
 {
@@ -733,6 +812,10 @@ microblaze_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
   tdep = XCNEW (struct gdbarch_tdep);
   gdbarch = gdbarch_alloc (&info, tdep);
 
+  tdep->gregset = NULL;
+  tdep->sizeof_gregset = 0;
+  tdep->fpregset = NULL;
+  tdep->sizeof_fpregset = 0;
   set_gdbarch_long_double_bit (gdbarch, 128);
 
   set_gdbarch_num_regs (gdbarch, MICROBLAZE_NUM_REGS);
@@ -781,6 +864,13 @@ microblaze_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
   frame_base_append_sniffer (gdbarch, dwarf2_frame_base_sniffer);
   if (tdesc_data != NULL)
     tdesc_use_registers (gdbarch, tdesc, tdesc_data);
+  //frame_base_append_sniffer (gdbarch, microblaze_frame_sniffer);
+
+  /* If we have register sets, enable the generic core file support.  */
+  if (tdep->gregset) {
+      set_gdbarch_regset_from_core_section (gdbarch,
+                                          microblaze_regset_from_core_section);
+  }
 
   return gdbarch;
 }
diff --git a/gdb/microblaze-tdep.h b/gdb/microblaze-tdep.h
index 63aab84ef6..02650f61d9 100644
--- a/gdb/microblaze-tdep.h
+++ b/gdb/microblaze-tdep.h
@@ -22,8 +22,22 @@
 
 
 /* Microblaze architecture-specific information.  */
+struct microblaze_gregset
+{
+   unsigned int gregs[32];
+   unsigned int fpregs[32];
+   unsigned int pregs[16];
+};
+
 struct gdbarch_tdep
 {
+  int dummy;		// declare something.
+
+  /* Register sets.  */
+  struct regset *gregset;
+  size_t sizeof_gregset;
+  struct regset *fpregset;
+  size_t sizeof_fpregset;
 };
 
 /* Register numbers.  */
@@ -120,5 +134,18 @@ struct microblaze_frame_cache
 #define MICROBLAZE_BREAKPOINT {0xba, 0x0c, 0x00, 0x18}
 #define MICROBLAZE_BREAKPOINT_LE {0x18, 0x00, 0x0c, 0xba}
 
+extern void microblaze_supply_gregset (const struct microblaze_gregset *gregset,
+                                    struct regcache *regcache,
+                                    int regnum, const void *gregs);
+extern void microblaze_collect_gregset (const struct microblaze_gregset *gregset,
+                                     const struct regcache *regcache,
+                                     int regnum, void *gregs);
+extern void microblaze_supply_fpregset (struct regcache *regcache,
+                                     int regnum, const void *fpregs);
+extern void microblaze_collect_fpregset (const struct regcache *regcache,
+                                      int regnum, void *fpregs);
+
+extern const struct regset * microblaze_regset_from_core_section (struct gdbarch *gdbarch,
+                                     const char *sect_name, size_t sect_size);
 
 #endif /* microblaze-tdep.h */
-- 
2.17.1