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1 /*
2  * Copyright (c) 1993, 1994, 1995, 1996 Rick Sladkey <jrs@world.std.com>
3  * Copyright (c) 1996-1999 Wichert Akkerman <wichert@cistron.nl>
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  * 3. The name of the author may not be used to endorse or promote products
15  *    derived from this software without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27  */
28 
29 #include "defs.h"
30 #include <poll.h>
31 
32 #include "xlat/pollflags.h"
33 
34 static bool
print_pollfd(struct tcb * tcp,void * elem_buf,size_t elem_size,void * data)35 print_pollfd(struct tcb *tcp, void *elem_buf, size_t elem_size, void *data)
36 {
37 	const struct pollfd *fds = elem_buf;
38 
39 	tprints("{fd=");
40 	printfd(tcp, fds->fd);
41 	if (fds->fd >= 0) {
42 		tprints(", events=");
43 		printflags(pollflags, (unsigned short) fds->events, "POLL???");
44 	}
45 	tprints("}");
46 
47 	return true;
48 }
49 
50 static void
decode_poll_entering(struct tcb * tcp)51 decode_poll_entering(struct tcb *tcp)
52 {
53 	const kernel_ulong_t addr = tcp->u_arg[0];
54 	const unsigned int nfds = tcp->u_arg[1];
55 	struct pollfd fds;
56 
57 	print_array(tcp, addr, nfds, &fds, sizeof(fds),
58 		    umoven_or_printaddr, print_pollfd, 0);
59 	tprintf(", %u, ", nfds);
60 }
61 
62 static int
decode_poll_exiting(struct tcb * const tcp,const kernel_ulong_t pts)63 decode_poll_exiting(struct tcb *const tcp, const kernel_ulong_t pts)
64 {
65 	struct pollfd fds;
66 	const unsigned int nfds = tcp->u_arg[1];
67 	const unsigned long size = sizeof(fds) * nfds;
68 	const kernel_ulong_t start = tcp->u_arg[0];
69 	const kernel_ulong_t end = start + size;
70 	kernel_ulong_t cur;
71 	const unsigned int max_printed =
72 		abbrev(tcp) ? max_strlen : -1U;
73 	unsigned int printed;
74 
75 	static char outstr[1024];
76 	char *outptr;
77 #define end_outstr (outstr + sizeof(outstr))
78 
79 	if (syserror(tcp))
80 		return 0;
81 	if (tcp->u_rval == 0) {
82 		tcp->auxstr = "Timeout";
83 		return RVAL_STR;
84 	}
85 
86 	if (!verbose(tcp) || !start || !nfds ||
87 	    size / sizeof(fds) != nfds || end < start)
88 		return 0;
89 
90 	outptr = outstr;
91 
92 	for (printed = 0, cur = start; cur < end; cur += sizeof(fds)) {
93 		if (umove(tcp, cur, &fds) < 0) {
94 			if (outptr == outstr)
95 				*outptr++ = '[';
96 			else
97 				outptr = stpcpy(outptr, ", ");
98 			outptr += sprintf(outptr, "%#" PRI_klx, cur);
99 			break;
100 		}
101 		if (!fds.revents)
102 			continue;
103 		if (outptr == outstr)
104 			*outptr++ = '[';
105 		else
106 			outptr = stpcpy(outptr, ", ");
107 		if (printed >= max_printed) {
108 			outptr = stpcpy(outptr, "...");
109 			break;
110 		}
111 
112 		static const char fmt[] = "{fd=%d, revents=";
113 		char fdstr[sizeof(fmt) + sizeof(int) * 3];
114 		sprintf(fdstr, fmt, fds.fd);
115 
116 		const char *flagstr = sprintflags("", pollflags,
117 						  (unsigned short) fds.revents);
118 
119 		if (outptr + strlen(fdstr) + strlen(flagstr) + 1 >=
120 		    end_outstr - (2 + 2 * sizeof(long) + sizeof(", ], ..."))) {
121 			outptr = stpcpy(outptr, "...");
122 			break;
123 		}
124 		outptr = stpcpy(outptr, fdstr);
125 		outptr = stpcpy(outptr, flagstr);
126 		*outptr++ = '}';
127 		++printed;
128 	}
129 
130 	if (outptr != outstr)
131 		*outptr++ = ']';
132 
133 	*outptr = '\0';
134 	if (pts) {
135 		const char *str = sprint_timespec(tcp, pts);
136 
137 		if (outptr + sizeof(", left ") + strlen(str) < end_outstr) {
138 			outptr = stpcpy(outptr, outptr == outstr ? "left " : ", left ");
139 			outptr = stpcpy(outptr, str);
140 		} else {
141 			outptr = stpcpy(outptr, ", ...");
142 		}
143 	}
144 
145 	if (outptr == outstr)
146 		return 0;
147 
148 	tcp->auxstr = outstr;
149 	return RVAL_STR;
150 #undef end_outstr
151 }
152 
SYS_FUNC(poll)153 SYS_FUNC(poll)
154 {
155 	if (entering(tcp)) {
156 		decode_poll_entering(tcp);
157 		int timeout = tcp->u_arg[2];
158 
159 #ifdef INFTIM
160 		if (INFTIM == timeout)
161 			tprints("INFTIM");
162 		else
163 #endif
164 			tprintf("%d", timeout);
165 
166 		return 0;
167 	} else {
168 		return decode_poll_exiting(tcp, 0);
169 	}
170 }
171 
SYS_FUNC(ppoll)172 SYS_FUNC(ppoll)
173 {
174 	if (entering(tcp)) {
175 		decode_poll_entering(tcp);
176 
177 		print_timespec(tcp, tcp->u_arg[2]);
178 		tprints(", ");
179 		/* NB: kernel requires arg[4] == NSIG_BYTES */
180 		print_sigset_addr_len(tcp, tcp->u_arg[3], tcp->u_arg[4]);
181 		tprintf(", %" PRI_klu, tcp->u_arg[4]);
182 
183 		return 0;
184 	} else {
185 		return decode_poll_exiting(tcp, tcp->u_arg[2]);
186 	}
187 }
188