-/* Intel 386 stuff.
- Copyright (C) 1988, 1989 Free Software Foundation, Inc.
+/* Intel 386 target-dependent stuff.
+ Copyright (C) 1988, 1989, 1991, 1994, 1995, 1996, 1998
+ Free Software Foundation, Inc.
-This file is part of GDB.
+ This file is part of GDB.
-GDB is free software; you can redistribute it and/or modify
-it under the terms of the GNU General Public License as published by
-the Free Software Foundation; either version 1, or (at your option)
-any later version.
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 2 of the License, or
+ (at your option) any later version.
-GDB is distributed in the hope that it will be useful,
-but WITHOUT ANY WARRANTY; without even the implied warranty of
-MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-GNU General Public License for more details.
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
-You should have received a copy of the GNU General Public License
-along with GDB; see the file COPYING. If not, write to
-the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
+ You should have received a copy of the GNU General Public License
+ along with this program; if not, write to the Free Software
+ Foundation, Inc., 59 Temple Place - Suite 330,
+ Boston, MA 02111-1307, USA. */
-#include <stdio.h>
#include "defs.h"
-#include "param.h"
+#include "gdb_string.h"
#include "frame.h"
#include "inferior.h"
#include "gdbcore.h"
+#include "target.h"
+#include "floatformat.h"
+#include "symtab.h"
+#include "gdbcmd.h"
+#include "command.h"
-#ifdef USG
-#include <sys/types.h>
-#endif
+static long i386_get_frame_setup PARAMS ((CORE_ADDR));
-#include <sys/param.h>
-#include <sys/dir.h>
-#include <signal.h>
-#include <sys/user.h>
-#include <sys/ioctl.h>
-#include <fcntl.h>
+static void i386_follow_jump PARAMS ((void));
-#ifndef N_SET_MAGIC
-#ifdef COFF_FORMAT
-#define N_SET_MAGIC(exec, val) ((exec).magic = (val))
-#else
-#define N_SET_MAGIC(exec, val) ((exec).a_magic = (val))
-#endif
-#endif
+static void codestream_read PARAMS ((unsigned char *, int));
-#include <sys/file.h>
-#include <sys/stat.h>
+static void codestream_seek PARAMS ((CORE_ADDR));
-/* I don't know whether this is right for cross-debugging even if you
- do somehow manage to get the right include file. */
-#if defined (USE_MACHINE_REG_H)
-#include <machine/reg.h>
-#else
-#include <sys/reg.h>
-#endif
+static unsigned char codestream_fill PARAMS ((int));
+
+CORE_ADDR skip_trampoline_code PARAMS ((CORE_ADDR, char *));
-/* helper functions for m-i386.h */
+static int gdb_print_insn_i386 (bfd_vma, disassemble_info *);
-/* stdio style buffering to minimize calls to ptrace */
+void _initialize_i386_tdep PARAMS ((void));
+
+/* This is the variable the is set with "set disassembly-flavor",
+ and its legitimate values. */
+static char att_flavor[] = "att";
+static char intel_flavor[] = "intel";
+static char *valid_flavors[] =
+{
+ att_flavor,
+ intel_flavor,
+ NULL
+};
+static char *disassembly_flavor = att_flavor;
+
+/* This is used to keep the bfd arch_info in sync with the disassembly flavor. */
+static void set_disassembly_flavor_sfunc PARAMS ((char *, int, struct cmd_list_element *));
+static void set_disassembly_flavor ();
+
+/* Stdio style buffering was used to minimize calls to ptrace, but this
+ buffering did not take into account that the code section being accessed
+ may not be an even number of buffers long (even if the buffer is only
+ sizeof(int) long). In cases where the code section size happened to
+ be a non-integral number of buffers long, attempting to read the last
+ buffer would fail. Simply using target_read_memory and ignoring errors,
+ rather than read_memory, is not the correct solution, since legitimate
+ access errors would then be totally ignored. To properly handle this
+ situation and continue to use buffering would require that this code
+ be able to determine the minimum code section size granularity (not the
+ alignment of the section itself, since the actual failing case that
+ pointed out this problem had a section alignment of 4 but was not a
+ multiple of 4 bytes long), on a target by target basis, and then
+ adjust it's buffer size accordingly. This is messy, but potentially
+ feasible. It probably needs the bfd library's help and support. For
+ now, the buffer size is set to 1. (FIXME -fnf) */
+
+#define CODESTREAM_BUFSIZ 1 /* Was sizeof(int), see note above. */
static CORE_ADDR codestream_next_addr;
static CORE_ADDR codestream_addr;
-static unsigned char codestream_buf[sizeof (int)];
+static unsigned char codestream_buf[CODESTREAM_BUFSIZ];
static int codestream_off;
static int codestream_cnt;
#define codestream_get() (codestream_cnt-- == 0 ? \
codestream_fill(0) : codestream_buf[codestream_off++])
-static unsigned char
+static unsigned char
codestream_fill (peek_flag)
+ int peek_flag;
{
codestream_addr = codestream_next_addr;
- codestream_next_addr += sizeof (int);
+ codestream_next_addr += CODESTREAM_BUFSIZ;
codestream_off = 0;
- codestream_cnt = sizeof (int);
- read_memory (codestream_addr,
- (unsigned char *)codestream_buf,
- sizeof (int));
-
+ codestream_cnt = CODESTREAM_BUFSIZ;
+ read_memory (codestream_addr, (char *) codestream_buf, CODESTREAM_BUFSIZ);
+
if (peek_flag)
- return (codestream_peek());
+ return (codestream_peek ());
else
- return (codestream_get());
+ return (codestream_get ());
}
static void
codestream_seek (place)
+ CORE_ADDR place;
{
- codestream_next_addr = place & -sizeof (int);
+ codestream_next_addr = place / CODESTREAM_BUFSIZ;
+ codestream_next_addr *= CODESTREAM_BUFSIZ;
codestream_cnt = 0;
codestream_fill (1);
- while (codestream_tell() != place)
+ while (codestream_tell () != place)
codestream_get ();
}
static void
codestream_read (buf, count)
unsigned char *buf;
+ int count;
{
unsigned char *p;
int i;
}
/* next instruction is a jump, move to target */
-static
+
+static void
i386_follow_jump ()
{
- int long_delta;
- short short_delta;
- char byte_delta;
+ unsigned char buf[4];
+ long delta;
+
int data16;
- int pos;
-
+ CORE_ADDR pos;
+
pos = codestream_tell ();
-
+
data16 = 0;
if (codestream_peek () == 0x66)
{
codestream_get ();
data16 = 1;
}
-
+
switch (codestream_get ())
{
case 0xe9:
/* relative jump: if data16 == 0, disp32, else disp16 */
if (data16)
{
- codestream_read ((unsigned char *)&short_delta, 2);
- pos += short_delta + 3; /* include size of jmp inst */
+ codestream_read (buf, 2);
+ delta = extract_signed_integer (buf, 2);
+
+ /* include size of jmp inst (including the 0x66 prefix). */
+ pos += delta + 4;
}
else
{
- codestream_read ((unsigned char *)&long_delta, 4);
- pos += long_delta + 5;
+ codestream_read (buf, 4);
+ delta = extract_signed_integer (buf, 4);
+
+ pos += delta + 5;
}
break;
case 0xeb:
/* relative jump, disp8 (ignore data16) */
- codestream_read ((unsigned char *)&byte_delta, 1);
- pos += byte_delta + 2;
+ codestream_read (buf, 1);
+ /* Sign-extend it. */
+ delta = extract_signed_integer (buf, 1);
+
+ pos += delta + 2;
break;
}
- codestream_seek (pos + data16);
+ codestream_seek (pos);
}
/*
* if entry sequence doesn't make sense, return -1, and leave
* codestream pointer random
*/
+
static long
i386_get_frame_setup (pc)
+ CORE_ADDR pc;
{
unsigned char op;
-
+
codestream_seek (pc);
-
+
i386_follow_jump ();
-
+
op = codestream_get ();
-
+
if (op == 0x58) /* popl %eax */
{
/*
* this function must start with
*
- * popl %eax 0x58
+ * popl %eax 0x58
* xchgl %eax, (%esp) 0x87 0x04 0x24
* or xchgl %eax, 0(%esp) 0x87 0x44 0x24 0x00
*
*/
int pos;
unsigned char buf[4];
- static unsigned char proto1[3] = { 0x87,0x04,0x24 };
- static unsigned char proto2[4] = { 0x87,0x44,0x24,0x00 };
+ static unsigned char proto1[3] =
+ {0x87, 0x04, 0x24};
+ static unsigned char proto2[4] =
+ {0x87, 0x44, 0x24, 0x00};
pos = codestream_tell ();
codestream_read (buf, 4);
- if (bcmp (buf, proto1, 3) == 0)
+ if (memcmp (buf, proto1, 3) == 0)
pos += 3;
- else if (bcmp (buf, proto2, 4) == 0)
+ else if (memcmp (buf, proto2, 4) == 0)
+ pos += 4;
+
+ codestream_seek (pos);
+ op = codestream_get (); /* update next opcode */
+ }
+
+ if (op == 0x68 || op == 0x6a)
+ {
+ /*
+ * this function may start with
+ *
+ * pushl constant
+ * call _probe
+ * addl $4, %esp
+ * followed by
+ * pushl %ebp
+ * etc.
+ */
+ int pos;
+ unsigned char buf[8];
+
+ /* Skip past the pushl instruction; it has either a one-byte
+ or a four-byte operand, depending on the opcode. */
+ pos = codestream_tell ();
+ if (op == 0x68)
pos += 4;
-
+ else
+ pos += 1;
+ codestream_seek (pos);
+
+ /* Read the following 8 bytes, which should be "call _probe" (6 bytes)
+ followed by "addl $4,%esp" (2 bytes). */
+ codestream_read (buf, sizeof (buf));
+ if (buf[0] == 0xe8 && buf[6] == 0xc4 && buf[7] == 0x4)
+ pos += sizeof (buf);
codestream_seek (pos);
- op = codestream_get (); /* update next opcode */
+ op = codestream_get (); /* update next opcode */
}
-
+
if (op == 0x55) /* pushl %ebp */
- {
+ {
/* check for movl %esp, %ebp - can be written two ways */
switch (codestream_get ())
{
return (-1);
}
/* check for stack adjustment
- *
+
* subl $XXX, %esp
*
* note: you can't subtract a 16 bit immediate
/* subl with signed byte immediate
* (though it wouldn't make sense to be negative)
*/
- return (codestream_get());
+ return (codestream_get ());
}
else if (op == 0x81)
{
- /* subl with 32 bit immed */
- int locals;
- codestream_get();
+ char buf[4];
+ /* Maybe it is subl with 32 bit immedediate. */
+ codestream_get ();
if (codestream_get () != 0xec)
/* Some instruction starting with 0x81 other than subl. */
{
codestream_seek (codestream_tell () - 2);
return 0;
}
- /* subl with 32 bit immediate */
- codestream_read ((unsigned char *)&locals, 4);
- return (locals);
+ /* It is subl with 32 bit immediate. */
+ codestream_read ((unsigned char *) buf, 4);
+ return extract_signed_integer (buf, 4);
}
else
{
}
else if (op == 0xc8)
{
+ char buf[2];
/* enter instruction: arg is 16 bit unsigned immed */
- unsigned short slocals;
- codestream_read ((unsigned char *)&slocals, 2);
- codestream_get (); /* flush final byte of enter instruction */
- return (slocals);
+ codestream_read ((unsigned char *) buf, 2);
+ codestream_get (); /* flush final byte of enter instruction */
+ return extract_unsigned_integer (buf, 2);
}
return (-1);
}
/* Return number of args passed to a frame.
Can return -1, meaning no way to tell. */
-/* on the 386, the instruction following the call could be:
- * popl %ecx - one arg
- * addl $imm, %esp - imm/4 args; imm may be 8 or 32 bits
- * anything else - zero args
- */
-
int
i386_frame_num_args (fi)
- struct frame_info fi;
+ struct frame_info *fi;
{
- int retpc;
- unsigned char op;
+#if 1
+ return -1;
+#else
+ /* This loses because not only might the compiler not be popping the
+ args right after the function call, it might be popping args from both
+ this call and a previous one, and we would say there are more args
+ than there really are. */
+
+ int retpc;
+ unsigned char op;
struct frame_info *pfi;
+ /* on the 386, the instruction following the call could be:
+ popl %ecx - one arg
+ addl $imm, %esp - imm/4 args; imm may be 8 or 32 bits
+ anything else - zero args */
+
int frameless;
- FRAMELESS_FUNCTION_INVOCATION (fi, frameless);
+ frameless = FRAMELESS_FUNCTION_INVOCATION (fi);
if (frameless)
/* In the absence of a frame pointer, GDB doesn't get correct values
for nameless arguments. Return -1, so it doesn't print any
nameless arguments. */
return -1;
- pfi = get_prev_frame_info ((fi));
+ pfi = get_prev_frame (fi);
if (pfi == 0)
{
/* Note: this can happen if we are looking at the frame for
- main, because FRAME_CHAIN_VALID won't let us go into
- start. If we have debugging symbols, that's not really
- a big deal; it just means it will only show as many arguments
- to main as are declared. */
+ main, because FRAME_CHAIN_VALID won't let us go into
+ start. If we have debugging symbols, that's not really
+ a big deal; it just means it will only show as many arguments
+ to main as are declared. */
return -1;
}
else
{
- retpc = pfi->pc;
- op = read_memory_integer (retpc, 1);
- if (op == 0x59)
- /* pop %ecx */
- return 1;
+ retpc = pfi->pc;
+ op = read_memory_integer (retpc, 1);
+ if (op == 0x59)
+ /* pop %ecx */
+ return 1;
else if (op == 0x83)
{
- op = read_memory_integer (retpc+1, 1);
- if (op == 0xc4)
- /* addl $<signed imm 8 bits>, %esp */
- return (read_memory_integer (retpc+2,1)&0xff)/4;
+ op = read_memory_integer (retpc + 1, 1);
+ if (op == 0xc4)
+ /* addl $<signed imm 8 bits>, %esp */
+ return (read_memory_integer (retpc + 2, 1) & 0xff) / 4;
else
return 0;
}
else if (op == 0x81)
- { /* add with 32 bit immediate */
- op = read_memory_integer (retpc+1, 1);
- if (op == 0xc4)
- /* addl $<imm 32>, %esp */
- return read_memory_integer (retpc+2, 4) / 4;
+ { /* add with 32 bit immediate */
+ op = read_memory_integer (retpc + 1, 1);
+ if (op == 0xc4)
+ /* addl $<imm 32>, %esp */
+ return read_memory_integer (retpc + 2, 4) / 4;
else
return 0;
}
return 0;
}
}
+#endif
}
/*
* next instruction will be a branch back to the start.
*/
+void
i386_frame_find_saved_regs (fip, fsrp)
struct frame_info *fip;
struct frame_saved_regs *fsrp;
{
- long locals;
- unsigned char *p;
+ long locals = -1;
unsigned char op;
CORE_ADDR dummy_bottom;
CORE_ADDR adr;
+ CORE_ADDR pc;
int i;
-
- bzero (fsrp, sizeof *fsrp);
-
+
+ memset (fsrp, 0, sizeof *fsrp);
+
/* if frame is the end of a dummy, compute where the
* beginning would be
*/
dummy_bottom = fip->frame - 4 - REGISTER_BYTES - CALL_DUMMY_LENGTH;
-
+
/* check if the PC is in the stack, in a dummy frame */
- if (dummy_bottom <= fip->pc && fip->pc <= fip->frame)
+ if (dummy_bottom <= fip->pc && fip->pc <= fip->frame)
{
/* all regs were saved by push_call_dummy () */
adr = fip->frame;
- for (i = 0; i < NUM_REGS; i++)
+ for (i = 0; i < NUM_REGS; i++)
{
adr -= REGISTER_RAW_SIZE (i);
fsrp->regs[i] = adr;
}
return;
}
-
- locals = i386_get_frame_setup (get_pc_function_start (fip->pc));
-
- if (locals >= 0)
+
+ pc = get_pc_function_start (fip->pc);
+ if (pc != 0)
+ locals = i386_get_frame_setup (pc);
+
+ if (locals >= 0)
{
adr = fip->frame - 4 - locals;
- for (i = 0; i < 8; i++)
+ for (i = 0; i < 8; i++)
{
op = codestream_get ();
if (op < 0x50 || op > 0x57)
break;
+#ifdef I386_REGNO_TO_SYMMETRY
+ /* Dynix uses different internal numbering. Ick. */
+ fsrp->regs[I386_REGNO_TO_SYMMETRY (op - 0x50)] = adr;
+#else
fsrp->regs[op - 0x50] = adr;
+#endif
adr -= 4;
}
}
-
+
fsrp->regs[PC_REGNUM] = fip->frame + 4;
fsrp->regs[FP_REGNUM] = fip->frame;
}
/* return pc of first real instruction */
+
+int
i386_skip_prologue (pc)
+ int pc;
{
unsigned char op;
int i;
-
+ static unsigned char pic_pat[6] =
+ {0xe8, 0, 0, 0, 0, /* call 0x0 */
+ 0x5b, /* popl %ebx */
+ };
+ CORE_ADDR pos;
+
if (i386_get_frame_setup (pc) < 0)
return (pc);
-
+
/* found valid frame setup - codestream now points to
* start of push instructions for saving registers
*/
-
+
/* skip over register saves */
for (i = 0; i < 8; i++)
{
op = codestream_peek ();
/* break if not pushl inst */
- if (op < 0x50 || op > 0x57)
+ if (op < 0x50 || op > 0x57)
break;
codestream_get ();
}
-
+
+ /* The native cc on SVR4 in -K PIC mode inserts the following code to get
+ the address of the global offset table (GOT) into register %ebx.
+ call 0x0
+ popl %ebx
+ movl %ebx,x(%ebp) (optional)
+ addl y,%ebx
+ This code is with the rest of the prologue (at the end of the
+ function), so we have to skip it to get to the first real
+ instruction at the start of the function. */
+
+ pos = codestream_tell ();
+ for (i = 0; i < 6; i++)
+ {
+ op = codestream_get ();
+ if (pic_pat[i] != op)
+ break;
+ }
+ if (i == 6)
+ {
+ unsigned char buf[4];
+ long delta = 6;
+
+ op = codestream_get ();
+ if (op == 0x89) /* movl %ebx, x(%ebp) */
+ {
+ op = codestream_get ();
+ if (op == 0x5d) /* one byte offset from %ebp */
+ {
+ delta += 3;
+ codestream_read (buf, 1);
+ }
+ else if (op == 0x9d) /* four byte offset from %ebp */
+ {
+ delta += 6;
+ codestream_read (buf, 4);
+ }
+ else /* unexpected instruction */
+ delta = -1;
+ op = codestream_get ();
+ }
+ /* addl y,%ebx */
+ if (delta > 0 && op == 0x81 && codestream_get () == 0xc3)
+ {
+ pos += delta + 6;
+ }
+ }
+ codestream_seek (pos);
+
i386_follow_jump ();
-
+
return (codestream_tell ());
}
+void
i386_push_dummy_frame ()
{
CORE_ADDR sp = read_register (SP_REGNUM);
int regnum;
char regbuf[MAX_REGISTER_RAW_SIZE];
-
+
sp = push_word (sp, read_register (PC_REGNUM));
sp = push_word (sp, read_register (FP_REGNUM));
write_register (FP_REGNUM, sp);
write_register (SP_REGNUM, sp);
}
+void
i386_pop_frame ()
{
- FRAME frame = get_current_frame ();
+ struct frame_info *frame = get_current_frame ();
CORE_ADDR fp;
int regnum;
struct frame_saved_regs fsr;
- struct frame_info *fi;
char regbuf[MAX_REGISTER_RAW_SIZE];
-
- fi = get_frame_info (frame);
- fp = fi->frame;
- get_frame_saved_regs (fi, &fsr);
- for (regnum = 0; regnum < NUM_REGS; regnum++)
+
+ fp = FRAME_FP (frame);
+ get_frame_saved_regs (frame, &fsr);
+ for (regnum = 0; regnum < NUM_REGS; regnum++)
{
CORE_ADDR adr;
adr = fsr.regs[regnum];
write_register (PC_REGNUM, read_memory_integer (fp + 4, 4));
write_register (SP_REGNUM, fp + 8);
flush_cached_frames ();
- set_current_frame ( create_new_frame (read_register (FP_REGNUM),
- read_pc ()));
+}
+
+#ifdef GET_LONGJMP_TARGET
+
+/* Figure out where the longjmp will land. Slurp the args out of the stack.
+ We expect the first arg to be a pointer to the jmp_buf structure from which
+ we extract the pc (JB_PC) that we will land at. The pc is copied into PC.
+ This routine returns true on success. */
+
+int
+get_longjmp_target (pc)
+ CORE_ADDR *pc;
+{
+ char buf[TARGET_PTR_BIT / TARGET_CHAR_BIT];
+ CORE_ADDR sp, jb_addr;
+
+ sp = read_register (SP_REGNUM);
+
+ if (target_read_memory (sp + SP_ARG0, /* Offset of first arg on stack */
+ buf,
+ TARGET_PTR_BIT / TARGET_CHAR_BIT))
+ return 0;
+
+ jb_addr = extract_address (buf, TARGET_PTR_BIT / TARGET_CHAR_BIT);
+
+ if (target_read_memory (jb_addr + JB_PC * JB_ELEMENT_SIZE, buf,
+ TARGET_PTR_BIT / TARGET_CHAR_BIT))
+ return 0;
+
+ *pc = extract_address (buf, TARGET_PTR_BIT / TARGET_CHAR_BIT);
+
+ return 1;
+}
+
+#endif /* GET_LONGJMP_TARGET */
+
+void
+i386_extract_return_value (type, regbuf, valbuf)
+ struct type *type;
+ char regbuf[REGISTER_BYTES];
+ char *valbuf;
+{
+/* On AIX, floating point values are returned in floating point registers. */
+#ifdef I386_AIX_TARGET
+ if (TYPE_CODE_FLT == TYPE_CODE (type))
+ {
+ double d;
+ /* 387 %st(0), gcc uses this */
+ floatformat_to_double (&floatformat_i387_ext,
+ ®buf[REGISTER_BYTE (FP0_REGNUM)],
+ &d);
+ store_floating (valbuf, TYPE_LENGTH (type), d);
+ }
+ else
+#endif /* I386_AIX_TARGET */
+ {
+ memcpy (valbuf, regbuf, TYPE_LENGTH (type));
+ }
+}
+
+#ifdef I386V4_SIGTRAMP_SAVED_PC
+/* Get saved user PC for sigtramp from the pushed ucontext on the stack
+ for all three variants of SVR4 sigtramps. */
+
+CORE_ADDR
+i386v4_sigtramp_saved_pc (frame)
+ struct frame_info *frame;
+{
+ CORE_ADDR saved_pc_offset = 4;
+ char *name = NULL;
+
+ find_pc_partial_function (frame->pc, &name, NULL, NULL);
+ if (name)
+ {
+ if (STREQ (name, "_sigreturn"))
+ saved_pc_offset = 132 + 14 * 4;
+ else if (STREQ (name, "_sigacthandler"))
+ saved_pc_offset = 80 + 14 * 4;
+ else if (STREQ (name, "sigvechandler"))
+ saved_pc_offset = 120 + 14 * 4;
+ }
+
+ if (frame->next)
+ return read_memory_integer (frame->next->frame + saved_pc_offset, 4);
+ return read_memory_integer (read_register (SP_REGNUM) + saved_pc_offset, 4);
+}
+#endif /* I386V4_SIGTRAMP_SAVED_PC */
+
+#ifdef I386_LINUX_SIGTRAMP
+
+/* When the i386 Linux kernel calls a signal handler, the return
+ address points to a bit of code on the stack. This function
+ returns whether the PC appears to be within this bit of code.
+
+ The instruction sequence is
+ pop %eax
+ mov $0x77,%eax
+ int $0x80
+ or 0x58 0xb8 0x77 0x00 0x00 0x00 0xcd 0x80.
+
+ Checking for the code sequence should be somewhat reliable, because
+ the effect is to call the system call sigreturn. This is unlikely
+ to occur anywhere other than a signal trampoline.
+
+ It kind of sucks that we have to read memory from the process in
+ order to identify a signal trampoline, but there doesn't seem to be
+ any other way. The IN_SIGTRAMP macro in tm-linux.h arranges to
+ only call us if no function name could be identified, which should
+ be the case since the code is on the stack. */
+
+#define LINUX_SIGTRAMP_INSN0 (0x58) /* pop %eax */
+#define LINUX_SIGTRAMP_OFFSET0 (0)
+#define LINUX_SIGTRAMP_INSN1 (0xb8) /* mov $NNNN,%eax */
+#define LINUX_SIGTRAMP_OFFSET1 (1)
+#define LINUX_SIGTRAMP_INSN2 (0xcd) /* int */
+#define LINUX_SIGTRAMP_OFFSET2 (6)
+
+static const unsigned char linux_sigtramp_code[] =
+{
+ LINUX_SIGTRAMP_INSN0, /* pop %eax */
+ LINUX_SIGTRAMP_INSN1, 0x77, 0x00, 0x00, 0x00, /* mov $0x77,%eax */
+ LINUX_SIGTRAMP_INSN2, 0x80 /* int $0x80 */
+};
+
+#define LINUX_SIGTRAMP_LEN (sizeof linux_sigtramp_code)
+
+/* If PC is in a sigtramp routine, return the address of the start of
+ the routine. Otherwise, return 0. */
+
+static CORE_ADDR
+i386_linux_sigtramp_start (pc)
+ CORE_ADDR pc;
+{
+ unsigned char buf[LINUX_SIGTRAMP_LEN];
+
+ /* We only recognize a signal trampoline if PC is at the start of
+ one of the three instructions. We optimize for finding the PC at
+ the start, as will be the case when the trampoline is not the
+ first frame on the stack. We assume that in the case where the
+ PC is not at the start of the instruction sequence, there will be
+ a few trailing readable bytes on the stack. */
+
+ if (read_memory_nobpt (pc, (char *) buf, LINUX_SIGTRAMP_LEN) != 0)
+ return 0;
+
+ if (buf[0] != LINUX_SIGTRAMP_INSN0)
+ {
+ int adjust;
+
+ switch (buf[0])
+ {
+ case LINUX_SIGTRAMP_INSN1:
+ adjust = LINUX_SIGTRAMP_OFFSET1;
+ break;
+ case LINUX_SIGTRAMP_INSN2:
+ adjust = LINUX_SIGTRAMP_OFFSET2;
+ break;
+ default:
+ return 0;
+ }
+
+ pc -= adjust;
+
+ if (read_memory_nobpt (pc, (char *) buf, LINUX_SIGTRAMP_LEN) != 0)
+ return 0;
+ }
+
+ if (memcmp (buf, linux_sigtramp_code, LINUX_SIGTRAMP_LEN) != 0)
+ return 0;
+
+ return pc;
+}
+
+/* Return whether PC is in a Linux sigtramp routine. */
+
+int
+i386_linux_sigtramp (pc)
+ CORE_ADDR pc;
+{
+ return i386_linux_sigtramp_start (pc) != 0;
+}
+
+/* Assuming FRAME is for a Linux sigtramp routine, return the saved
+ program counter. The Linux kernel will set up a sigcontext
+ structure immediately before the sigtramp routine on the stack. */
+
+CORE_ADDR
+i386_linux_sigtramp_saved_pc (frame)
+ struct frame_info *frame;
+{
+ CORE_ADDR pc;
+
+ pc = i386_linux_sigtramp_start (frame->pc);
+ if (pc == 0)
+ error ("i386_linux_sigtramp_saved_pc called when no sigtramp");
+ return read_memory_integer ((pc
+ - LINUX_SIGCONTEXT_SIZE
+ + LINUX_SIGCONTEXT_PC_OFFSET),
+ 4);
+}
+
+/* Assuming FRAME is for a Linux sigtramp routine, return the saved
+ stack pointer. The Linux kernel will set up a sigcontext structure
+ immediately before the sigtramp routine on the stack. */
+
+CORE_ADDR
+i386_linux_sigtramp_saved_sp (frame)
+ struct frame_info *frame;
+{
+ CORE_ADDR pc;
+
+ pc = i386_linux_sigtramp_start (frame->pc);
+ if (pc == 0)
+ error ("i386_linux_sigtramp_saved_sp called when no sigtramp");
+ return read_memory_integer ((pc
+ - LINUX_SIGCONTEXT_SIZE
+ + LINUX_SIGCONTEXT_SP_OFFSET),
+ 4);
+}
+
+#endif /* I386_LINUX_SIGTRAMP */
+
+#ifdef STATIC_TRANSFORM_NAME
+/* SunPRO encodes the static variables. This is not related to C++ mangling,
+ it is done for C too. */
+
+char *
+sunpro_static_transform_name (name)
+ char *name;
+{
+ char *p;
+ if (IS_STATIC_TRANSFORM_NAME (name))
+ {
+ /* For file-local statics there will be a period, a bunch
+ of junk (the contents of which match a string given in the
+ N_OPT), a period and the name. For function-local statics
+ there will be a bunch of junk (which seems to change the
+ second character from 'A' to 'B'), a period, the name of the
+ function, and the name. So just skip everything before the
+ last period. */
+ p = strrchr (name, '.');
+ if (p != NULL)
+ name = p + 1;
+ }
+ return name;
+}
+#endif /* STATIC_TRANSFORM_NAME */
+
+
+
+/* Stuff for WIN32 PE style DLL's but is pretty generic really. */
+
+CORE_ADDR
+skip_trampoline_code (pc, name)
+ CORE_ADDR pc;
+ char *name;
+{
+ if (pc && read_memory_unsigned_integer (pc, 2) == 0x25ff) /* jmp *(dest) */
+ {
+ unsigned long indirect = read_memory_unsigned_integer (pc + 2, 4);
+ struct minimal_symbol *indsym =
+ indirect ? lookup_minimal_symbol_by_pc (indirect) : 0;
+ char *symname = indsym ? SYMBOL_NAME (indsym) : 0;
+
+ if (symname)
+ {
+ if (strncmp (symname, "__imp_", 6) == 0
+ || strncmp (symname, "_imp_", 5) == 0)
+ return name ? 1 : read_memory_unsigned_integer (indirect, 4);
+ }
+ }
+ return 0; /* not a trampoline */
+}
+
+static int
+gdb_print_insn_i386 (memaddr, info)
+ bfd_vma memaddr;
+ disassemble_info *info;
+{
+ if (disassembly_flavor == att_flavor)
+ return print_insn_i386_att (memaddr, info);
+ else if (disassembly_flavor == intel_flavor)
+ return print_insn_i386_intel (memaddr, info);
+ /* Never reached - disassembly_flavour is always either att_flavor
+ or intel_flavor */
+ abort ();
+}
+
+/* If the disassembly mode is intel, we have to also switch the
+ bfd mach_type. This function is run in the set disassembly_flavor
+ command, and does that. */
+
+static void
+set_disassembly_flavor_sfunc (args, from_tty, c)
+ char *args;
+ int from_tty;
+ struct cmd_list_element *c;
+{
+ set_disassembly_flavor ();
+}
+
+static void
+set_disassembly_flavor ()
+{
+ if (disassembly_flavor == att_flavor)
+ set_architecture_from_arch_mach (bfd_arch_i386, bfd_mach_i386_i386);
+ else if (disassembly_flavor == intel_flavor)
+ set_architecture_from_arch_mach (bfd_arch_i386, bfd_mach_i386_i386_intel_syntax);
+}
+
+void
+_initialize_i386_tdep ()
+{
+ struct cmd_list_element *new_cmd;
+
+ tm_print_insn = gdb_print_insn_i386;
+ tm_print_insn_info.mach = bfd_lookup_arch (bfd_arch_i386, 0)->mach;
+
+ /* Add the variable that controls the disassembly flavor */
+
+ new_cmd = add_set_enum_cmd ("disassembly-flavor", no_class,
+ valid_flavors,
+ (char *) &disassembly_flavor,
+ "Set the disassembly flavor, the valid values are \"att\" and \"intel\", \
+and the default value is \"att\".",
+ &setlist);
+ new_cmd->function.sfunc = set_disassembly_flavor_sfunc;
+ add_show_from_set (new_cmd, &showlist);
+
+ /* Finally, initialize the disassembly flavor to the default given
+ in the disassembly_flavor variable */
+
+ set_disassembly_flavor ();
+
}
projects / deliverable / binutils-gdb.git / blobdiff