2 * Copryight 1997 Sean Eric Fagan
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5 * modification, are permitted provided that the following conditions
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11 * documentation and/or other materials provided with the distribution.
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13 * must display the following acknowledgement:
14 * This product includes software developed by Sean Eric Fagan
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16 * products derived from this software without specific prior written
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31 * $FreeBSD: src/usr.bin/truss/i386-fbsd.c,v 1.7.2.2 2001/10/29 20:12:56 des Exp $
32 * $DragonFly: src/usr.bin/truss/i386-fbsd.c,v 1.5 2008/10/16 01:52:33 swildner Exp $
36 * FreeBSD/386-specific system call handling. This is probably the most
37 * complex part of the entire truss program, although I've got lots of
38 * it handled relatively cleanly now. The system call names are generated
39 * automatically, thanks to /usr/src/sys/kern/syscalls.master. The
40 * names used for the various structures are confusing, I sadly admit.
43 #include <sys/types.h>
44 #include <sys/ioctl.h>
45 #include <sys/pioctl.h>
46 #include <sys/syscall.h>
48 #include <machine/reg.h>
49 #include <machine/psl.h>
69 static int nsyscalls
= sizeof(syscallnames
) / sizeof(syscallnames
[0]);
72 * This is what this particular file uses to keep track of a system call.
73 * It is probably not quite sufficient -- I can probably use the same
74 * structure for the various syscall personalities, and I also probably
75 * need to nest system calls (for signal handlers).
77 * 'struct syscall' describes the system call; it may be NULL, however,
78 * if we don't know about this particular system call yet.
80 static struct freebsd_syscall
{
85 int nargs
; /* number of arguments -- *not* number of words! */
86 char **s_args
; /* the printable arguments */
89 /* Clear up and free parts of the fsc structure. */
97 for (i
= 0; i
< fsc
.nargs
; i
++)
102 memset(&fsc
, 0, sizeof(fsc
));
106 * Called when a process has entered a system call. nargs is the
107 * number of words, not number of arguments (a necessary distinction
108 * in some cases). Note that if the STOPEVENT() code in i386/i386/trap.c
109 * is ever changed these functions need to keep up.
113 i386_syscall_entry(int pid
, int nargs
) {
115 struct reg regs
= { .r_err
= 0 };
118 unsigned int parm_offset
;
121 if (fd
== -1 || pid
!= cpid
) {
122 asprintf(&buf
, "%s/%d/regs", procfs_path
, pid
);
124 err(1, "Out of memory");
125 fd
= open(buf
, O_RDWR
);
128 fprintf(outfile
, "-- CANNOT READ REGISTERS --\n");
136 i
= read(fd
, ®s
, sizeof(regs
));
137 parm_offset
= regs
.r_esp
+ sizeof(int);
140 * FreeBSD has two special kinds of system call redirctions --
141 * SYS_syscall, and SYS___syscall. The former is the old syscall()
142 * routine, basicly; the latter is for quad-aligned arguments.
144 syscall_num
= regs
.r_eax
;
145 switch (syscall_num
) {
147 lseek(Procfd
, parm_offset
, SEEK_SET
);
148 read(Procfd
, &syscall_num
, sizeof(int));
149 parm_offset
+= sizeof(int);
152 lseek(Procfd
, parm_offset
, SEEK_SET
);
153 read(Procfd
, &syscall_num
, sizeof(int));
154 parm_offset
+= sizeof(quad_t
);
158 fsc
.number
= syscall_num
;
160 (syscall_num
< 0 || syscall_num
>= nsyscalls
) ? NULL
: syscallnames
[syscall_num
];
162 fprintf(outfile
, "-- UNKNOWN SYSCALL %d --\n", syscall_num
);
168 fsc
.args
= malloc((1+nargs
) * sizeof(unsigned long));
169 lseek(Procfd
, parm_offset
, SEEK_SET
);
170 if (read(Procfd
, fsc
.args
, nargs
* sizeof(unsigned long)) == -1)
173 sc
= get_syscall(fsc
.name
);
175 fsc
.nargs
= sc
->nargs
;
178 fprintf(outfile
, "unknown syscall %s -- setting args to %d\n",
184 fsc
.s_args
= malloc((1+fsc
.nargs
) * sizeof(char*));
185 memset(fsc
.s_args
, 0, fsc
.nargs
* sizeof(char*));
189 * At this point, we set up the system call arguments.
190 * We ignore any OUT ones, however -- those are arguments that
191 * are set by the system call, and so are probably meaningless
192 * now. This doesn't currently support arguments that are
193 * passed in *and* out, however.
199 fprintf(stderr
, "syscall %s(", fsc
.name
);
201 for (i
= 0; i
< fsc
.nargs
; i
++) {
203 fprintf(stderr
, "0x%x%s",
205 ? fsc
.args
[sc
->args
[i
].offset
]
207 i
< (fsc
.nargs
-1) ? "," : "");
209 if (sc
&& !(sc
->args
[i
].type
& OUT
)) {
210 fsc
.s_args
[i
] = print_arg(Procfd
, &sc
->args
[i
], fsc
.args
);
214 fprintf(stderr
, ")\n");
219 fprintf(outfile
, "\n");
223 * Some system calls should be printed out before they are done --
224 * execve() and exit(), for example, never return. Possibly change
225 * this to work for any system call that doesn't have an OUT
229 if (!strcmp(fsc
.name
, "execve") || !strcmp(fsc
.name
, "exit")) {
230 print_syscall(outfile
, fsc
.name
, fsc
.nargs
, fsc
.s_args
);
237 * And when the system call is done, we handle it here.
238 * Currently, no attempt is made to ensure that the system calls
239 * match -- this needs to be fixed (and is, in fact, why S_SCX includes
240 * the sytem call number instead of, say, an error status).
244 i386_syscall_exit(int pid
, int syscall_num __unused
) {
252 if (fd
== -1 || pid
!= cpid
) {
253 asprintf(&buf
, "%s/%d/regs", procfs_path
, pid
);
255 err(1, "Out of memory");
256 fd
= open(buf
, O_RDONLY
);
259 fprintf(outfile
, "-- CANNOT READ REGISTERS --\n");
266 if (read(fd
, ®s
, sizeof(regs
)) != sizeof(regs
))
269 errorp
= !!(regs
.r_eflags
& PSL_C
);
272 * This code, while simpler than the initial versions I used, could
273 * stand some significant cleaning.
278 for (i
= 0; i
< fsc
.nargs
; i
++) {
279 fsc
.s_args
[i
] = malloc(12);
280 sprintf(fsc
.s_args
[i
], "0x%lx", fsc
.args
[i
]);
284 * Here, we only look for arguments that have OUT masked in --
285 * otherwise, they were handled in the syscall_entry function.
287 for (i
= 0; i
< sc
->nargs
; i
++) {
289 if (sc
->args
[i
].type
& OUT
) {
291 * If an error occurred, than don't bothe getting the data;
292 * it may not be valid.
296 sprintf(temp
, "0x%lx", fsc
.args
[sc
->args
[i
].offset
]);
298 temp
= print_arg(Procfd
, &sc
->args
[i
], fsc
.args
);
300 fsc
.s_args
[i
] = temp
;
306 * It would probably be a good idea to merge the error handling,
307 * but that complicates things considerably.
310 print_syscall_ret(outfile
, fsc
.name
, fsc
.nargs
, fsc
.s_args
, errorp
, retval
);