usr.bin/truss/aarch64-freebsd.c

   1 /*
   2  * Copyright (c) 2015 The FreeBSD Foundation
   3  *
   4  * Portions of this software were developed by Konstantin Belousov
   5  * under sponsorship from the FreeBSD Foundation.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  26  * SUCH DAMAGE.
  27  */
  28
  29 #include <sys/cdefs.h>
  30 __FBSDID("$FreeBSD$");
  31
  32 /* FreeBSD/arm64-specific system call handling. */
  33
  34 #include <sys/ptrace.h>
  35 #include <sys/syscall.h>
  36
  37 #include <machine/reg.h>
  38 #include <machine/armreg.h>
  39 #include <machine/ucontext.h>
  40
  41 #include <stdio.h>
  42 #include <sysdecode.h>
  43
  44 #include "truss.h"
  45
  46 static int
  47 aarch64_fetch_args(struct trussinfo *trussinfo, u_int narg)
  48 {
  49         struct reg regs;
  50         struct current_syscall *cs;
  51         lwpid_t tid;
  52         u_int i, reg, syscall_num;
  53
  54         tid = trussinfo->curthread->tid;
  55         cs = &trussinfo->curthread->cs;
  56         if (ptrace(PT_GETREGS, tid, (caddr_t)&regs, 0) < 0) {
  57                 fprintf(trussinfo->outfile, "-- CANNOT READ REGISTERS --\n");
  58                 return (-1);
  59         }
  60
  61         /*
  62          * FreeBSD has two special kinds of system call redirections --
  63          * SYS_syscall, and SYS___syscall.  The former is the old syscall()
  64          * routine, basically; the latter is for quad-aligned arguments.
  65          *
  66          * The system call argument count and code from ptrace() already
  67          * account for these, but we need to skip over the first argument.
  68          */
  69         syscall_num = regs.x[8];
  70         if (syscall_num == SYS_syscall || syscall_num == SYS___syscall) {
  71                 reg = 1;
  72                 syscall_num = regs.x[0];
  73         } else {
  74                 reg = 0;
  75         }
  76
  77         for (i = 0; i < narg && reg < 8; i++, reg++)
  78                 cs->args[i] = regs.x[reg];
  79         return (0);
  80 }
  81
  82 static int
  83 aarch64_fetch_retval(struct trussinfo *trussinfo, long *retval, int *errorp)
  84 {
  85         struct reg regs;
  86         lwpid_t tid;
  87
  88         tid = trussinfo->curthread->tid;
  89         if (ptrace(PT_GETREGS, tid, (caddr_t)&regs, 0) < 0) {
  90                 fprintf(trussinfo->outfile, "-- CANNOT READ REGISTERS --\n");
  91                 return (-1);
  92         }
  93
  94         retval[0] = regs.x[0];
  95         retval[1] = regs.x[1];
  96         *errorp = !!(regs.spsr & PSR_C);
  97         return (0);
  98 }
  99
 100 static struct procabi aarch64_freebsd = {
 101         "FreeBSD ELF64",
 102         SYSDECODE_ABI_FREEBSD,
 103         aarch64_fetch_args,
 104         aarch64_fetch_retval
 105 };
 106
 107 PROCABI(aarch64_freebsd);