1/* 2 * Copyright 1997 Sean Eric Fagan 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 1. Redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer. 9 * 2. Redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution. 12 * 3. All advertising materials mentioning features or use of this software 13 * must display the following acknowledgement: 14 * This product includes software developed by Sean Eric Fagan 15 * 4. Neither the name of the author may be used to endorse or promote 16 * products derived from this software without specific prior written 17 * permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 */ 31 32#include <sys/cdefs.h> 33__FBSDID("$FreeBSD: stable/11/usr.bin/truss/i386-linux.c 312084 2017-01-13 21:30:18Z jhb $"); 34 35/* Linux/i386-specific system call handling. */ 36 37#include <sys/ptrace.h> 38 39#include <machine/reg.h> 40#include <machine/psl.h> 41 42#include <stdbool.h> 43#include <stdio.h> 44#include <sysdecode.h> 45 46#include "truss.h" 47 48static int 49i386_linux_fetch_args(struct trussinfo *trussinfo, u_int narg) 50{ 51 struct reg regs; 52 struct current_syscall *cs; 53 lwpid_t tid; 54 55 tid = trussinfo->curthread->tid; 56 cs = &trussinfo->curthread->cs; 57 if (ptrace(PT_GETREGS, tid, (caddr_t)®s, 0) < 0) { 58 fprintf(trussinfo->outfile, "-- CANNOT READ REGISTERS --\n"); 59 return (-1); 60 } 61 62 /* 63 * Linux passes syscall arguments in registers, not 64 * on the stack. Fortunately, we've got access to the 65 * register set. Note that we don't bother checking the 66 * number of arguments. And what does linux do for syscalls 67 * that have more than five arguments? 68 */ 69 switch (narg) { 70 default: 71 cs->args[5] = regs.r_ebp; /* Unconfirmed */ 72 case 5: 73 cs->args[4] = regs.r_edi; 74 case 4: 75 cs->args[3] = regs.r_esi; 76 case 3: 77 cs->args[2] = regs.r_edx; 78 case 2: 79 cs->args[1] = regs.r_ecx; 80 case 1: 81 cs->args[0] = regs.r_ebx; 82 } 83 84 return (0); 85} 86 87static int 88i386_linux_fetch_retval(struct trussinfo *trussinfo, long *retval, int *errorp) 89{ 90 struct reg regs; 91 lwpid_t tid; 92 93 tid = trussinfo->curthread->tid; 94 if (ptrace(PT_GETREGS, tid, (caddr_t)®s, 0) < 0) { 95 fprintf(trussinfo->outfile, "-- CANNOT READ REGISTERS --\n"); 96 return (-1); 97 } 98 99 retval[0] = regs.r_eax; 100 retval[1] = regs.r_edx; 101 *errorp = !!(regs.r_eflags & PSL_C); 102 return (0); 103} 104 105static struct procabi i386_linux = { 106 "Linux ELF", 107 SYSDECODE_ABI_LINUX, 108 i386_linux_fetch_args, 109 i386_linux_fetch_retval, 110 STAILQ_HEAD_INITIALIZER(i386_linux.extra_syscalls), 111 { NULL } 112}; 113 114PROCABI(i386_linux); 115