freebsd-dev/gnu/usr.bin/binutils/gdb/i386/freebsd-nat.c
1995-05-30 05:05:38 +00:00

620 lines
15 KiB
C

/* Native-dependent code for BSD Unix running on i386's, for GDB.
Copyright 1988, 1989, 1991, 1992 Free Software Foundation, Inc.
This file is part of GDB.
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.
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 this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
$Id: freebsd-nat.c,v 1.6 1995/05/09 13:59:22 rgrimes Exp $
*/
#include <sys/types.h>
#include <sys/param.h>
#include <signal.h>
#include <sys/user.h>
#include <machine/reg.h>
#include <machine/frame.h>
#include <sys/ptrace.h>
#include "defs.h"
/* this table must line up with REGISTER_NAMES in tm-i386v.h */
/* symbols like 'tEAX' come from <machine/reg.h> */
static int tregmap[] =
{
tEAX, tECX, tEDX, tEBX,
tESP, tEBP, tESI, tEDI,
tEIP, tEFLAGS, tCS, tSS,
tDS, tES, tSS, tSS, /* lies: no fs or gs */
};
/* blockend is the value of u.u_ar0, and points to the
place where ES is stored. */
int
i386_register_u_addr (blockend, regnum)
int blockend;
int regnum;
{
return (blockend + 4 * tregmap[regnum]);
}
#define fpstate save87
#define U_FPSTATE(u) u.u_pcb.pcb_savefpu
static void
i387_to_double (from, to)
char *from;
char *to;
{
long *lp;
/* push extended mode on 387 stack, then pop in double mode
*
* first, set exception masks so no error is generated -
* number will be rounded to inf or 0, if necessary
*/
asm ("pushl %eax"); /* grab a stack slot */
asm ("fstcw (%esp)"); /* get 387 control word */
asm ("movl (%esp),%eax"); /* save old value */
asm ("orl $0x3f,%eax"); /* mask all exceptions */
asm ("pushl %eax");
asm ("fldcw (%esp)"); /* load new value into 387 */
asm ("movl 8(%ebp),%eax");
asm ("fldt (%eax)"); /* push extended number on 387 stack */
asm ("fwait");
asm ("movl 12(%ebp),%eax");
asm ("fstpl (%eax)"); /* pop double */
asm ("fwait");
asm ("popl %eax"); /* flush modified control word */
asm ("fnclex"); /* clear exceptions */
asm ("fldcw (%esp)"); /* restore original control word */
asm ("popl %eax"); /* flush saved copy */
}
#if 0
static void
double_to_i387 (from, to)
char *from;
char *to;
{
/* push double mode on 387 stack, then pop in extended mode
* no errors are possible because every 64-bit pattern
* can be converted to an extended
*/
asm ("movl 8(%ebp),%eax");
asm ("fldl (%eax)");
asm ("fwait");
asm ("movl 12(%ebp),%eax");
asm ("fstpt (%eax)");
asm ("fwait");
}
#endif
struct env387
{
unsigned short control;
unsigned short r0;
unsigned short status;
unsigned short r1;
unsigned short tag;
unsigned short r2;
unsigned long eip;
unsigned short code_seg;
unsigned short opcode;
unsigned long operand;
unsigned short operand_seg;
unsigned short r3;
unsigned char regs[8][10];
};
/* static */ void
print_387_control_word (control)
unsigned int control;
{
printf ("control 0x%04x: ", control);
printf ("compute to ");
switch ((control >> 8) & 3)
{
case 0: printf ("24 bits; "); break;
case 1: printf ("(bad); "); break;
case 2: printf ("53 bits; "); break;
case 3: printf ("64 bits; "); break;
}
printf ("round ");
switch ((control >> 10) & 3)
{
case 0: printf ("NEAREST; "); break;
case 1: printf ("DOWN; "); break;
case 2: printf ("UP; "); break;
case 3: printf ("CHOP; "); break;
}
if (control & 0x3f)
{
printf ("mask:");
if (control & 0x0001) printf (" INVALID");
if (control & 0x0002) printf (" DENORM");
if (control & 0x0004) printf (" DIVZ");
if (control & 0x0008) printf (" OVERF");
if (control & 0x0010) printf (" UNDERF");
if (control & 0x0020) printf (" LOS");
printf (";");
}
printf ("\n");
if (control & 0xe080) printf ("warning: reserved bits on 0x%x\n",
control & 0xe080);
}
/* static */ void
print_387_status_word (status)
unsigned int status;
{
printf ("status 0x%04x: ", status);
if (status & 0xff)
{
printf ("exceptions:");
if (status & 0x0001) printf (" INVALID");
if (status & 0x0002) printf (" DENORM");
if (status & 0x0004) printf (" DIVZ");
if (status & 0x0008) printf (" OVERF");
if (status & 0x0010) printf (" UNDERF");
if (status & 0x0020) printf (" LOS");
if (status & 0x0040) printf (" FPSTACK");
printf ("; ");
}
printf ("flags: %d%d%d%d; ",
(status & 0x4000) != 0,
(status & 0x0400) != 0,
(status & 0x0200) != 0,
(status & 0x0100) != 0);
printf ("top %d\n", (status >> 11) & 7);
}
static void
print_387_status (status, ep)
unsigned short status;
struct env387 *ep;
{
int i;
int bothstatus;
int top;
int fpreg;
unsigned char *p;
bothstatus = ((status != 0) && (ep->status != 0));
if (status != 0)
{
if (bothstatus)
printf ("u: ");
print_387_status_word ((unsigned int)status);
}
if (ep->status != 0)
{
if (bothstatus)
printf ("e: ");
print_387_status_word ((unsigned int)ep->status);
}
print_387_control_word ((unsigned int)ep->control);
printf ("opcode 0x%x; ", ep->opcode);
printf ("pc 0x%x:0x%x; ", ep->code_seg, ep->eip);
printf ("operand 0x%x:0x%x\n", ep->operand_seg, ep->operand);
top = (ep->status >> 11) & 7;
printf (" regno tag msb lsb value\n");
for (fpreg = 7; fpreg >= 0; fpreg--)
{
int st_regno;
double val;
/* The physical regno `fpreg' is only relevant as an index into the
* tag word. Logical `%st' numbers are required for indexing ep->regs.
*/
st_regno = (fpreg + 8 - top) & 7;
printf ("%%st(%d) %s ", st_regno, fpreg == top ? "=>" : " ");
switch ((ep->tag >> (fpreg * 2)) & 3)
{
case 0: printf ("valid "); break;
case 1: printf ("zero "); break;
case 2: printf ("trap "); break;
case 3: printf ("empty "); break;
}
for (i = 9; i >= 0; i--)
printf ("%02x", ep->regs[st_regno][i]);
i387_to_double (ep->regs[st_regno], (char *)&val);
printf (" %g\n", val);
}
}
void
i386_float_info ()
{
struct user u; /* just for address computations */
int i;
/* fpstate defined in <sys/user.h> */
struct fpstate *fpstatep;
char buf[sizeof (struct fpstate) + 2 * sizeof (int)];
unsigned int uaddr;
char fpvalid;
unsigned int rounded_addr;
unsigned int rounded_size;
/*extern int corechan;*/
int skip;
extern int inferior_pid;
uaddr = (char *)&U_FPSTATE(u) - (char *)&u;
if (inferior_pid)
{
int *ip;
rounded_addr = uaddr & -sizeof (int);
rounded_size = (((uaddr + sizeof (struct fpstate)) - uaddr) +
sizeof (int) - 1) / sizeof (int);
skip = uaddr - rounded_addr;
ip = (int *)buf;
for (i = 0; i < rounded_size; i++)
{
*ip++ = ptrace (PT_READ_U, inferior_pid, (caddr_t)rounded_addr, 0);
rounded_addr += sizeof (int);
}
}
else
{
#if 1
printf("float info: can't do a core file (yet)\n");
return;
#else
if (lseek (corechan, uaddr, 0) < 0)
perror_with_name ("seek on core file");
if (myread (corechan, buf, sizeof (struct fpstate)) < 0)
perror_with_name ("read from core file");
skip = 0;
#endif
}
fpstatep = (struct fpstate *)(buf + skip);
print_387_status (fpstatep->sv_ex_sw, (struct env387 *)fpstatep);
}
#ifdef SETUP_ARBITRARY_FRAME
FRAME
setup_arbitrary_frame (numargs, args)
int numargs;
unsigned int *args;
{
if (numargs > 2)
error ("Too many args in frame specification");
return create_new_frame ((CORE_ADDR)args[0], (CORE_ADDR)args[1]);
}
#endif
#ifdef KERNEL_DEBUG
#include <sys/proc.h>
#include <sys/stat.h>
#include <sys/fcntl.h>
#include <unistd.h>
#include <vm/vm.h>
#include <vm/vm_param.h>
#include <machine/vmparam.h>
#include <machine/pcb.h>
#define KERNOFF ((unsigned)KERNBASE)
#define INKERNEL(x) ((x) >= KERNOFF)
static CORE_ADDR sbr;
static CORE_ADDR curpcb;
static CORE_ADDR kstack;
static int found_pcb;
static int devmem;
static int kfd;
static struct pcb pcb;
int read_pcb (int, CORE_ADDR);
static CORE_ADDR kvtophys (int, CORE_ADDR);
static physrd(int, u_int, char*, int);
extern CORE_ADDR ksym_lookup(const char *);
/* substitutes for the stuff in libkvm which doesn't work */
/* most of this was taken from the old kgdb */
/* we don't need all this stuff, but the call should look the same */
kvm_open (efile, cfile, sfile, perm, errout)
char *efile;
char *cfile;
char *sfile; /* makes this kvm_open more compatible to the one in libkvm */
int perm;
char *errout; /* makes this kvm_open more compatible to the one in libkvm */
{
struct stat stb;
CORE_ADDR addr;
int cfd;
if ((cfd = open(cfile, perm, 0)) < 0)
return (cfd);
fstat(cfd, &stb);
if ((stb.st_mode & S_IFMT) == S_IFCHR && stb.st_rdev == makedev(2, 0)) {
devmem = 1;
kfd = open ("/dev/kmem", perm, 0);
}
physrd(cfd, ksym_lookup("IdlePTD") - KERNOFF, (char*)&sbr, sizeof sbr);
printf("IdlePTD %x\n", sbr);
curpcb = ksym_lookup("curpcb") - KERNOFF;
physrd(cfd, curpcb, (char*)&curpcb, sizeof curpcb);
kstack = ksym_lookup("kstack");
found_pcb = 1; /* for vtophys */
if (!devmem)
read_pcb(cfd, ksym_lookup("dumppcb") - KERNOFF);
else
read_pcb(cfd, kvtophys(cfd, kstack));
return (cfd);
}
kvm_close (fd)
{
return (close (fd));
}
kvm_write(core_kd, memaddr, myaddr, len)
CORE_ADDR memaddr;
char *myaddr;
{
int cc;
if (devmem) {
if (kfd > 0) {
/*
* Just like kvm_read, only we write.
*/
errno = 0;
if (lseek(kfd, (off_t)memaddr, 0) < 0 && errno != 0) {
error("kvm_write:invalid address (%x)", memaddr);
return (0);
}
cc = write(kfd, myaddr, len);
if (cc < 0) {
error("kvm_write:write failed");
return (0);
} else if (cc < len)
error("kvm_write:short write");
return (cc);
} else
return (0);
} else {
printf("kvm_write not implemented for dead kernels\n");
return (0);
}
/* NOTREACHED */
}
kvm_read(core_kd, memaddr, myaddr, len)
CORE_ADDR memaddr;
char *myaddr;
{
return (kernel_core_file_hook (core_kd, memaddr, myaddr, len));
}
kvm_uread(core_kd, p, memaddr, myaddr, len)
register struct proc *p;
CORE_ADDR memaddr;
char *myaddr;
{
register char *cp;
char procfile[MAXPATHLEN];
ssize_t amount;
int fd;
if (devmem) {
cp = myaddr;
sprintf(procfile, "/proc/%d/mem", p->p_pid);
fd = open(procfile, O_RDONLY, 0);
if (fd < 0) {
error("cannot open %s", procfile);
close(fd);
return (0);
}
while (len > 0) {
if (lseek(fd, memaddr, 0) == -1 && errno != 0) {
error("invalid address (%x) in %s",
memaddr, procfile);
break;
}
amount = read(fd, cp, len);
if (amount < 0) {
error("error reading %s", procfile);
break;
}
cp += amount;
memaddr += amount;
len -= amount;
}
close(fd);
return (ssize_t)(cp - myaddr);
} else {
return (kernel_core_file_hook (core_kd, memaddr, myaddr, len));
}
}
static
physrd(cfd, addr, dat, len)
u_int addr;
char *dat;
{
if (lseek(cfd, (off_t)addr, L_SET) == -1)
return (-1);
return (read(cfd, dat, len));
}
static CORE_ADDR
kvtophys (fd, addr)
CORE_ADDR addr;
{
CORE_ADDR v;
struct pte pte;
static CORE_ADDR PTD = -1;
CORE_ADDR current_ptd;
/*
* If we're looking at the kernel stack,
* munge the address to refer to the user space mapping instead;
* that way we get the requested process's kstack, not the running one.
*/
if (addr >= kstack && addr < kstack + ctob(UPAGES))
addr = (addr - kstack) + curpcb;
/*
* We may no longer have a linear system page table...
*
* Here's the scoop. IdlePTD contains the physical address
* of a page table directory that always maps the kernel.
* IdlePTD is in memory that is mapped 1-to-1, so we can
* find it easily given its 'virtual' address from ksym_lookup().
* For hysterical reasons, the value of IdlePTD is stored in sbr.
*
* To look up a kernel address, we first convert it to a 1st-level
* address and look it up in IdlePTD. This gives us the physical
* address of a page table page; we extract the 2nd-level part of
* VA and read the 2nd-level pte. Finally, we add the offset part
* of the VA into the physical address from the pte and return it.
*
* User addresses are a little more complicated. If we don't have
* a current PCB from read_pcb(), we use PTD, which is the (fixed)
* virtual address of the current ptd. Since it's NOT in 1-to-1
* kernel space, we must look it up using IdlePTD. If we do have
* a pcb, we get the ptd from pcb_ptd.
*/
if (INKERNEL(addr))
current_ptd = sbr;
else if (found_pcb == 0) {
if (PTD == -1)
PTD = kvtophys(fd, ksym_lookup("PTD"));
current_ptd = PTD;
} else
current_ptd = pcb.pcb_ptd;
/*
* Read the first-level page table (ptd).
*/
v = current_ptd + ((unsigned)addr >> PD_SHIFT) * sizeof pte;
if (physrd(fd, v, (char *)&pte, sizeof pte) < 0 || pte.pg_v == 0)
return (~0);
/*
* Read the second-level page table.
*/
v = i386_ptob(pte.pg_pfnum) + ((addr&PT_MASK) >> PG_SHIFT) * sizeof pte;
if (physrd(fd, v, (char *) &pte, sizeof(pte)) < 0 || pte.pg_v == 0)
return (~0);
addr = i386_ptob(pte.pg_pfnum) + (addr & PGOFSET);
#if 0
printf("vtophys(%x) -> %x\n", oldaddr, addr);
#endif
return (addr);
}
read_pcb (fd, uaddr)
CORE_ADDR uaddr;
{
int i;
int *pcb_regs = (int *)&pcb;
int eip;
if (physrd(fd, uaddr, (char *)&pcb, sizeof pcb) < 0) {
error("cannot read pcb at %x\n", uaddr);
return (-1);
}
printf("current pcb at %x\n", uaddr);
/*
* get the register values out of the sys pcb and
* store them where `read_register' will find them.
*/
for (i = 0; i < 8; ++i)
supply_register(i, &pcb_regs[i+10]);
supply_register(8, &pcb_regs[8]); /* eip */
supply_register(9, &pcb_regs[9]); /* eflags */
for (i = 10; i < 13; ++i) /* cs, ss, ds */
supply_register(i, &pcb_regs[i+9]);
supply_register(13, &pcb_regs[18]); /* es */
for (i = 14; i < 16; ++i) /* fs, gs */
supply_register(i, &pcb_regs[i+8]);
#if 0 /* doesn't work ??? */
/* Hmm... */
if (target_read_memory(pcb_regs[5+10]+4, &eip, sizeof eip, 0))
error("Cannot read PC.");
supply_register(8, &eip); /* eip */
#endif
/* XXX 80387 registers? */
}
/*
* read len bytes from kernel virtual address 'addr' into local
* buffer 'buf'. Return numbert of bytes if read ok, 0 otherwise. On read
* errors, portion of buffer not read is zeroed.
*/
kernel_core_file_hook(fd, addr, buf, len)
CORE_ADDR addr;
char *buf;
int len;
{
int i;
CORE_ADDR paddr;
register char *cp;
int cc;
cp = buf;
while (len > 0) {
paddr = kvtophys(fd, addr);
if (paddr == ~0) {
bzero(buf, len);
break;
}
/* we can't read across a page boundary */
i = min(len, NBPG - (addr & PGOFSET));
if ((cc = physrd(fd, paddr, cp, i)) <= 0) {
bzero(cp, len);
return (cp - buf);
}
cp += cc;
addr += cc;
len -= cc;
}
return (cp - buf);
}
#endif /* KERNEL_DEBUG */