[RFA] Re: Analyzing AMD64 corefiles on i386

[Michal Ludvig <mludvig@suse.cz>]

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Mark Kettenis told me that:
>    Date: Tue, 08 Jul 2003 14:43:49 +0200
>    From: Michal Ludvig <mludvig@suse.cz>
> 
>    Hi,
>    what must be done to enable reading of AMD64 corefiles in a gdb running 
>    on i386 with --target=amd64?
> 
> The necessary support for corefiles needs to be added to
> x86-64-linux-tdep.c.  Take a look at i386nbsd-tdep.c for an example.
> You'll need to create a `struct core_fns' together with the necessary
> support functions, and register it with add_core_fns.  Note that for
> the support functions you can't rely on definitions in header files
> and such since this is target code.  You'll also need to drop
> core-regset.o from NATDEPFILES in x86-64-linux.mh.

How about the attached one? Works for me on cross-gdb i386->amd64 as 
well as in native amd64 gdb. Can I apply it?

Michal Ludvig
-- 
* SuSE CR, s.r.o     * mludvig@suse.cz
* (+420) 296.545.373 * http://www.suse.cz

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2003-07-09  Michal Ludvig  <mludvig@suse.cz>

	* x86-64-linux-nat.c (regmap, supply_gregset, fill_gregset):
	Moved to x86-64-linux-tdep.c.
	* x86-64-linux-tdep.c (regmap, supply_gregset, fill_gregset):
	Moved from x86-64-linux-nat.c.
	(REGNR_*): New defines from <sys/reg.h>
	(fetch_core_registers, x86_64_core_fns): New.
	(_initialize_x86_64_linux_tdep): Call add_core_fns().
	* config/i386/x86-64linux.mh (NATDEPFILES): Remove corelow.o
	and core-regset.o.
	* config/i386/x86-64linux.mt (TDEPFILES): Add corelow.o.
	
Index: x86-64-linux-nat.c
===================================================================
RCS file: /cvs/src/src/gdb/x86-64-linux-nat.c,v
retrieving revision 1.23
diff -u -p -r1.23 x86-64-linux-nat.c
--- x86-64-linux-nat.c	31 May 2003 18:00:04 -0000	1.23
+++ x86-64-linux-nat.c	9 Jul 2003 10:56:13 -0000
@@ -39,24 +39,6 @@
 
 #include "x86-64-tdep.h"
 
-/* The register sets used in GNU/Linux ELF core-dumps are identical to
-   the register sets used by `ptrace'.  The corresponding types are
-   `elf_gregset_t' for the general-purpose registers (with
-   `elf_greg_t' the type of a single GP register) and `elf_fpregset_t'
-   for the floating-point registers.  */
-
-/* Mapping between the general-purpose registers in `struct user'
-   format and GDB's register array layout.  */
-static int regmap[] =
-{
-  RAX, RBX, RCX, RDX,
-  RSI, RDI, RBP, RSP,
-  R8, R9, R10, R11,
-  R12, R13, R14, R15,
-  RIP, EFLAGS, CS, SS, 
-  DS, ES, FS, GS
-};
-
 /* Which ptrace request retrieves which registers?
    These apply to the corresponding SET requests as well.  */
 
@@ -69,34 +51,6 @@ static int regmap[] =
 
 /* Transfering the general-purpose registers between GDB, inferiors
    and core files.  */
-
-/* Fill GDB's register array with the general-purpose register values
-   in *GREGSETP.  */
-
-void
-supply_gregset (elf_gregset_t *gregsetp)
-{
-  elf_greg_t *regp = (elf_greg_t *) gregsetp;
-  int i;
-
-  for (i = 0; i < X86_64_NUM_GREGS; i++)
-    supply_register (i, regp + regmap[i]);
-}
-
-/* Fill register REGNO (if it is a general-purpose register) in
-   *GREGSETPS with the value in GDB's register array.  If REGNO is -1,
-   do this for all registers.  */
-
-void
-fill_gregset (elf_gregset_t *gregsetp, int regno)
-{
-  elf_greg_t *regp = (elf_greg_t *) gregsetp;
-  int i;
-
-  for (i = 0; i < X86_64_NUM_GREGS; i++)
-    if (regno == -1 || regno == i)
-      regcache_collect (i, regp + regmap[i]);
-}
 
 /* Fetch all general-purpose registers from process/thread TID and
    store their values in GDB's register array.  */
Index: x86-64-linux-tdep.c
===================================================================
RCS file: /cvs/src/src/gdb/x86-64-linux-tdep.c,v
retrieving revision 1.19
diff -u -p -r1.19 x86-64-linux-tdep.c
--- x86-64-linux-tdep.c	31 May 2003 16:11:47 -0000	1.19
+++ x86-64-linux-tdep.c	9 Jul 2003 10:56:13 -0000
@@ -31,6 +31,113 @@
 
 #include "x86-64-tdep.h"
 
+/* The register sets used in GNU/Linux ELF core-dumps are identical to
+   the register sets used by `ptrace'.  The corresponding types are
+   `elf_gregset_t' for the general-purpose registers (with
+   `elf_greg_t' the type of a single GP register) and `elf_fpregset_t'
+   for the floating-point registers.  */
+
+/* Register indexes from <sys/reg.h>.  */
+#define REGNR_R15    0
+#define REGNR_R14    1
+#define REGNR_R13    2
+#define REGNR_R12    3
+#define REGNR_RBP    4
+#define REGNR_RBX    5
+#define REGNR_R11    6
+#define REGNR_R10    7
+#define REGNR_R9     8
+#define REGNR_R8     9
+#define REGNR_RAX    10
+#define REGNR_RCX    11
+#define REGNR_RDX    12
+#define REGNR_RSI    13
+#define REGNR_RDI    14
+#define REGNR_RIP    16
+#define REGNR_CS     17
+#define REGNR_EFLAGS 18
+#define REGNR_RSP    19
+#define REGNR_SS     20
+#define REGNR_DS     23
+#define REGNR_ES     24
+#define REGNR_FS     25
+#define REGNR_GS     26
+
+/* Mapping between the general-purpose registers in `struct user'
+   format and GDB's register array layout.  */
+static int regmap[] =
+{
+  REGNR_RAX, REGNR_RBX, REGNR_RCX, REGNR_RDX,
+  REGNR_RSI, REGNR_RDI, REGNR_RBP, REGNR_RSP,
+  REGNR_R8, REGNR_R9, REGNR_R10, REGNR_R11,
+  REGNR_R12, REGNR_R13, REGNR_R14, REGNR_R15,
+  REGNR_RIP, REGNR_EFLAGS, REGNR_CS, REGNR_SS,
+  REGNR_DS, REGNR_ES, REGNR_FS, REGNR_GS
+};
+
+/* Fill GDB's register array with the general-purpose register values
+   in *GREGSETP.  */
+
+void
+supply_gregset (char *regp)
+{
+  int i;
+
+  for (i = 0; i < X86_64_NUM_GREGS; i++)
+    supply_register (i, regp + (regmap[i] * 8));
+}
+
+/* Fill register REGNO (if it is a general-purpose register) in
+   *GREGSETPS with the value in GDB's register array.  If REGNO is -1,
+   do this for all registers.  */
+
+void
+fill_gregset (char *regp, int regno)
+{
+  int i;
+
+  for (i = 0; i < X86_64_NUM_GREGS; i++)
+    if (regno == -1 || regno == i)
+      regcache_collect (i, regp + (regmap[i] * 8));
+}
+
+static void
+fetch_core_registers (char *core_reg_sect, unsigned core_reg_size,
+			 int which, CORE_ADDR ignore)
+{
+  switch (which)
+    {
+    case 0:  /* Integer registers.  */
+      if (core_reg_size != 216)
+	warning ("Wrong size register set in core file.");
+      else
+	supply_gregset (core_reg_sect);
+      break;
+
+    case 2:  /* Floating point registers.  */
+    case 3:  /* "Extended" floating point registers.  This is gdb-speak
+		for SSE/SSE2. */
+      if (core_reg_size != 512)
+	warning ("Wrong size XMM register set in core file.");
+      else
+	x86_64_supply_fxsave (core_reg_sect);
+      break;
+
+    default:
+      /* Don't know what kind of register request this is; just ignore it.  */
+      break;
+    }
+}
+
+static struct core_fns x86_64_core_fns = 
+{
+  bfd_target_elf_flavour,		/* core_flavour */
+  default_check_format,			/* check_format */
+  default_core_sniffer,			/* core_sniffer */
+  fetch_core_registers,			/* core_read_registers */
+  NULL					/* next */
+};
+
 #define LINUX_SIGTRAMP_INSN0	0x48	/* mov $NNNNNNNN, %rax */
 #define LINUX_SIGTRAMP_OFFSET0	0
 #define LINUX_SIGTRAMP_INSN1	0x0f	/* syscall */
@@ -175,6 +282,8 @@ extern void _initialize_x86_64_linux_tde
 void
 _initialize_x86_64_linux_tdep (void)
 {
+  add_core_fns (&x86_64_core_fns);
+
   gdbarch_register_osabi (bfd_arch_i386, bfd_mach_x86_64, GDB_OSABI_LINUX,
 			  x86_64_linux_init_abi);
 }
Index: config/i386/x86-64linux.mh
===================================================================
RCS file: /cvs/src/src/gdb/config/i386/x86-64linux.mh,v
retrieving revision 1.9
diff -u -p -r1.9 x86-64linux.mh
--- config/i386/x86-64linux.mh	15 Jun 2003 20:56:47 -0000	1.9
+++ config/i386/x86-64linux.mh	9 Jul 2003 10:56:13 -0000
@@ -3,8 +3,8 @@
 XM_FILE= xm-i386.h
 
 NAT_FILE= nm-x86-64linux.h
-NATDEPFILES= infptrace.o inftarg.o fork-child.o corelow.o \
-	core-regset.o i386-nat.o x86-64-linux-nat.o \
+NATDEPFILES= infptrace.o inftarg.o fork-child.o \
+	i386-nat.o x86-64-linux-nat.o \
 	linux-nat.o \
 	proc-service.o thread-db.o lin-lwp.o linux-proc.o gcore.o 
 
Index: config/i386/x86-64linux.mt
===================================================================
RCS file: /cvs/src/src/gdb/config/i386/x86-64linux.mt,v
retrieving revision 1.7
diff -u -p -r1.7 x86-64linux.mt
--- config/i386/x86-64linux.mt	31 May 2003 08:15:38 -0000	1.7
+++ config/i386/x86-64linux.mt	9 Jul 2003 10:56:13 -0000
@@ -1,7 +1,7 @@
 # Target: AMD x86-64 running GNU/Linux
 TDEPFILES= x86-64-tdep.o x86-64-linux-tdep.o \
 	i386-tdep.o i387-tdep.o i386-linux-tdep.o \
-	solib.o solib-svr4.o solib-legacy.o
+	solib.o solib-svr4.o solib-legacy.o corelow.o
 
 GDB_MULTI_ARCH=GDB_MULTI_ARCH_TM