Bug Summary

File:obj-scan-build/../xen/console.c
Location:line 53, column 8
Description:Branch condition evaluates to a garbage value

Annotated Source Code

1/*
2 * Copyright (C) 2006-2011 Free Software Foundation
3 *
4 * This program is free software ; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation ; either version 2 of the License, or
7 * (at your option) any later version.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY ; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with the program ; if not, write to the Free Software
16 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
17 */
18
19#include <sys/types.h>
20#include <device/tty.h>
21#include <device/cons.h>
22#include <machine/pmap.h>
23#include <machine/machspl.h>
24#include <xen/public/io/console.h>
25#include "console.h"
26#include "ring.h"
27#include "evt.h"
28
29/* Hypervisor part */
30
31decl_simple_lock_data(static, outlock)static struct simple_lock_data_empty outlock;;
32decl_simple_lock_data(static, inlock)static struct simple_lock_data_empty inlock;;
33static struct xencons_interface *console;
34static int kd_pollc;
35int kb_mode; /* XXX: actually don't care. */
36
37#undef hyp_console_write
38void hyp_console_write(const char *str, int len)
39{
40 hyp_console_io (CONSOLEIO_write0, len, kvtolin(str)((vm_offset_t)(str) - 0xC0000000UL + ((0xc0000000UL))));
41}
42
43int hypputc(int c)
44{
45 if (!console) {
2
←
Assuming 'console' is non-null
→
3
←
Taking false branch
→
46 char d = c;
47 hyp_console_io(CONSOLEIO_write0, 1, kvtolin(&d)((vm_offset_t)(&d) - 0xC0000000UL + ((0xc0000000UL))));
48 } else {
49 spl_t spl = splhigh();
50 int complain;
4
←
Variable 'complain' declared without an initial value
→
51 simple_lock(&outlock);
52 while (hyp_ring_smash(console->out, console->out_prod, console->out_cons)((((unsigned)((console->out_prod) + 1)) & (sizeof((console
->out))-1)) == (((unsigned)((console->out_cons))) &
(sizeof((console->out))-1)))) {
5
←
Loop condition is true. Entering loop body
→
53 if (!complain) {
6
←
Branch condition evaluates to a garbage value
54 complain = 1;
55 hyp_console_put("ring smash\n")({ const char *__str = (void*) ("ring smash\n"); hyp_console_write
(__str, strlen (__str)); });
56 }
57 /* TODO: are we allowed to sleep in putc? */
58 hyp_yield()hyp_sched_op(0, 0);
59 }
60 hyp_ring_cell(console->out, console->out_prod)(console->out)[(((unsigned)((console->out_prod))) &
(sizeof((console->out))-1))] = c;
61 wmb()__asm__ __volatile__("lock; addl $0,0(%esp)");
62 console->out_prod++;
63 hyp_event_channel_send(boot_info.console_evtchnconsole.domU.evtchn);
64 simple_unlock(&outlock)((void)(&outlock));
65 splx(spl);
66 }
67 return 0;
68}
69
70int hypcnputc(dev_t dev, int c)
71{
72 return hypputc(c);
1
Calling 'hypputc'
→
73}
74
75/* get char by polling, used by debugger */
76int hypcngetc(dev_t dev, int wait)
77{
78 int ret;
79 if (wait)
80 while (console->in_prod == console->in_cons)
81 hyp_yield()hyp_sched_op(0, 0);
82 else
83 if (console->in_prod == console->in_cons)
84 return -1;
85 ret = hyp_ring_cell(console->in, console->in_cons)(console->in)[(((unsigned)((console->in_cons))) & (
sizeof((console->in))-1))];
86 mb()__asm__ __volatile__("lock; addl $0,0(%esp)");
87 console->in_cons++;
88 hyp_event_channel_send(boot_info.console_evtchnconsole.domU.evtchn);
89 return ret;
90}
91
92void cnpollc(boolean_t on) {
93 if (on) {
94 kd_pollc++;
95 } else {
96 --kd_pollc;
97 }
98}
99
100void kd_setleds1(u_char val)
101{
102 /* Can't do this. */
103}
104
105/* Mach part */
106
107struct tty hypcn_tty;
108
109static void hypcnintr(int unit, spl_t spl, void *ret_addr, void *regs) {
110 struct tty *tp = &hypcn_tty;
111 if (kd_pollc)
112 return;
113 simple_lock(&inlock);
114 while (console->in_prod != console->in_cons) {
115 int c = hyp_ring_cell(console->in, console->in_cons)(console->in)[(((unsigned)((console->in_cons))) & (
sizeof((console->in))-1))];
116 mb()__asm__ __volatile__("lock; addl $0,0(%esp)");
117 console->in_cons++;
118#if MACH_KDB1
119 if (c == (char)'£') {
120 printf("£ pressed\n");
121 kdb_kintr();
122 continue;
123 }
124#endif /* MACH_KDB */
125 if ((tp->t_state & (TS_ISOPEN0x00000008|TS_WOPEN0x00000004)))
126 (*linesw[tp->t_line].l_rint)(c, tp);
127 }
128 hyp_event_channel_send(boot_info.console_evtchnconsole.domU.evtchn);
129 simple_unlock(&inlock)((void)(&inlock));
130}
131
132int hypcnread(int dev, io_req_t ior)
133{
134 struct tty *tp = &hypcn_tty;
135 tp->t_state |= TS_CARR_ON0x00000020;
136 return char_read(tp, ior);
137}
138
139int hypcnwrite(int dev, io_req_t ior)
140{
141 return char_write(&hypcn_tty, ior);
142}
143
144void hypcnstart(struct tty *tp)
145{
146 spl_t o_pri;
147 int ch;
148 unsigned char c;
149
150 if (tp->t_state & TS_TTSTOP0x00000100)
151 return;
152 while (1) {
153 tp->t_state &= ~TS_BUSY0x00000040;
154 if (tp->t_state & TS_TTSTOP0x00000100)
155 break;
156 if ((tp->t_outq.c_cc <= 0) || (ch = getc(&tp->t_outq)) == -1)
157 break;
158 c = ch;
159 o_pri = splsoftclock();
160 hypputc(c);
161 splx(o_pri);
162 }
163 if (tp->t_outq.c_cc <= TTLOWAT(tp)ttlowat[(tp)->t_ospeed]) {
164 tt_write_wakeup(tp)(tty_queue_completion(&(tp)->t_delayed_write));
165 }
166}
167
168void hypcnstop()
169{
170}
171
172io_return_t hypcngetstat(dev_t dev, int flavor, int *data, unsigned int *count)
173{
174 return tty_get_status(&hypcn_tty, flavor, data, count);
175}
176
177io_return_t hypcnsetstat(dev_t dev, int flavor, int *data, unsigned int count)
178{
179 return tty_set_status(&hypcn_tty, flavor, data, count);
180}
181
182int hypcnportdeath(dev_t dev, mach_port_t port)
183{
184 return tty_portdeath(&hypcn_tty, (ipc_port_t) port);
185}
186
187int hypcnopen(dev_t dev, int flag, io_req_t ior)
188{
189 struct tty *tp = &hypcn_tty;
190 spl_t o_pri;
191
192 o_pri = spltty();
193 simple_lock(&tp->t_lock);
194 if (!(tp->t_state & (TS_ISOPEN0x00000008|TS_WOPEN0x00000004))) {
195 /* XXX ttychars allocates memory */
196 simple_unlock(&tp->t_lock)((void)(&tp->t_lock));
197 ttychars(tp);
198 simple_lock(&tp->t_lock);
199 tp->t_oproct_start = hypcnstart;
200 tp->t_stop = hypcnstop;
201 tp->t_ospeed = tp->t_ispeed = B960013;
202 tp->t_flags = ODDP0x00000002|EVENP0x00000004|ECHO0x00000080|CRMOD0x00000100|XTABS0x00000200;
203 }
204 tp->t_state |= TS_CARR_ON0x00000020;
205 simple_unlock(&tp->t_lock)((void)(&tp->t_lock));
206 splx(o_pri);
207 return (char_open(dev, tp, flag, ior));
208}
209
210int hypcnclose(int dev, int flag)
211{
212 struct tty *tp = &hypcn_tty;
213 spl_t s = spltty();
214 simple_lock(&tp->t_lock);
215 ttyclose(tp);
216 simple_unlock(&tp->t_lock)((void)(&tp->t_lock));
217 splx(s);
218 return 0;
219}
220
221int hypcnprobe(struct consdev *cp)
222{
223 cp->cn_dev = makedev(0, 0)((((0) & 0xFF) << 8) | ((0) & 0xFF));
224 cp->cn_pri = CN_INTERNAL2;
225 return 0;
226}
227
228int hypcninit(struct consdev *cp)
229{
230 if (console)
231 return 0;
232 simple_lock_init(&outlock);
233 simple_lock_init(&inlock);
234 console = (void*) mfn_to_kv(boot_info.console_mfn)((vm_offset_t)(((vm_offset_t)(((((unsigned long *) 0xF5800000UL
)[boot_info.console.domU.mfn])) << 12))) + 0xC0000000UL
);
235#ifdef MACH_PV_PAGETABLES
236 pmap_set_page_readwrite(console);
237#endif /* MACH_PV_PAGETABLES */
238 hyp_evt_handler(boot_info.console_evtchnconsole.domU.evtchn, hypcnintr, 0, SPL66);
239 return 0;
240}