minix/commands/mdb/syscalls.c
2010-06-10 14:04:46 +00:00

85 lines
1.4 KiB
C

/*
* syscall.c for mdb
*/
#include "mdb.h"
#ifdef SYSCALLS_SUPPORT
#include <stdio.h>
#include <stdlib.h>
#include <sys/ptrace.h>
#include "proto.h"
#define SYSCALL_NAME "__sendrec"
#ifdef __i386
#define SYSCALL_OFFSET 0xF
#define SYSCALL_OLD 0x21CD
#else
#define SYSCALL_OFFSET 0xE
#define SYSCALL_OLD 0x20CD
#endif
PRIVATE long intaddr;
PUBLIC void start_syscall(addr)
long addr;
{
long old;
syscalls = FALSE;
if ( addr == 0 ) {
intaddr = symbolvalue( SYSCALL_NAME, TRUE );
if ( intaddr == 0 )
return;
intaddr += SYSCALL_OFFSET;
}
else {
intaddr = addr;
Printf("Using %lx as syscall address\n",addr);
}
old = breakpt(intaddr,"\n");
/* Check instruction */
if ( (old & 0xFFFF) == SYSCALL_OLD)
syscalls = TRUE;
}
PUBLIC void do_syscall(addr)
long addr;
{
unsigned reg_ax,reg_bx;
if ( addr != intaddr ) return;
Printf("syscall to ");
reg_ax = get_reg(curpid,reg_addr("AX"));
switch (reg_ax) {
case 0: Printf(" PM ");
break;
case 1: Printf(" VFS ");
break;
case 2: Printf(" INET ");
break;
default: Printf("Invalid dest = %d", reg_ax);
exit(0);
}
reg_bx = get_reg(curpid,reg_addr("BX"));
decode_message(reg_bx);
/* Single step */
tstart(T_STEP, 0, 0, 1);
/* Check return code */
reg_ax = get_reg(curpid,reg_addr("AX"));
if ( reg_ax != 0 )
Printf("syscall failed AX=%d\n",reg_ax);
else
decode_result();
}
#endif /* SYSCALLS_SUPPORT */