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-rw-r--r--arch/um/os-Linux/sigio.c164
1 files changed, 155 insertions, 9 deletions
diff --git a/arch/um/os-Linux/sigio.c b/arch/um/os-Linux/sigio.c
index 3fc43b33db66..8d4e0c6b8c92 100644
--- a/arch/um/os-Linux/sigio.c
+++ b/arch/um/os-Linux/sigio.c
@@ -8,6 +8,7 @@
8#include <termios.h> 8#include <termios.h>
9#include <pty.h> 9#include <pty.h>
10#include <signal.h> 10#include <signal.h>
11#include <fcntl.h>
11#include <errno.h> 12#include <errno.h>
12#include <string.h> 13#include <string.h>
13#include <sched.h> 14#include <sched.h>
@@ -16,10 +17,10 @@
16#include "init.h" 17#include "init.h"
17#include "user.h" 18#include "user.h"
18#include "kern_util.h" 19#include "kern_util.h"
19#include "user_util.h"
20#include "sigio.h" 20#include "sigio.h"
21#include "os.h" 21#include "os.h"
22#include "um_malloc.h" 22#include "um_malloc.h"
23#include "init.h"
23 24
24/* Protected by sigio_lock(), also used by sigio_cleanup, which is an 25/* Protected by sigio_lock(), also used by sigio_cleanup, which is an
25 * exitcall. 26 * exitcall.
@@ -68,11 +69,12 @@ static int write_sigio_thread(void *unused)
68 p = &fds->poll[i]; 69 p = &fds->poll[i];
69 if(p->revents == 0) continue; 70 if(p->revents == 0) continue;
70 if(p->fd == sigio_private[1]){ 71 if(p->fd == sigio_private[1]){
71 n = os_read_file(sigio_private[1], &c, sizeof(c)); 72 CATCH_EINTR(n = read(sigio_private[1], &c,
73 sizeof(c)));
72 if(n != sizeof(c)) 74 if(n != sizeof(c))
73 printk("write_sigio_thread : " 75 printk("write_sigio_thread : "
74 "read on socket failed, " 76 "read on socket failed, "
75 "err = %d\n", -n); 77 "err = %d\n", errno);
76 tmp = current_poll; 78 tmp = current_poll;
77 current_poll = next_poll; 79 current_poll = next_poll;
78 next_poll = tmp; 80 next_poll = tmp;
@@ -85,10 +87,10 @@ static int write_sigio_thread(void *unused)
85 (fds->used - i) * sizeof(*fds->poll)); 87 (fds->used - i) * sizeof(*fds->poll));
86 } 88 }
87 89
88 n = os_write_file(respond_fd, &c, sizeof(c)); 90 CATCH_EINTR(n = write(respond_fd, &c, sizeof(c)));
89 if(n != sizeof(c)) 91 if(n != sizeof(c))
90 printk("write_sigio_thread : write on socket " 92 printk("write_sigio_thread : write on socket "
91 "failed, err = %d\n", -n); 93 "failed, err = %d\n", errno);
92 } 94 }
93 } 95 }
94 96
@@ -126,15 +128,15 @@ static void update_thread(void)
126 char c; 128 char c;
127 129
128 flags = set_signals(0); 130 flags = set_signals(0);
129 n = os_write_file(sigio_private[0], &c, sizeof(c)); 131 n = write(sigio_private[0], &c, sizeof(c));
130 if(n != sizeof(c)){ 132 if(n != sizeof(c)){
131 printk("update_thread : write failed, err = %d\n", -n); 133 printk("update_thread : write failed, err = %d\n", errno);
132 goto fail; 134 goto fail;
133 } 135 }
134 136
135 n = os_read_file(sigio_private[0], &c, sizeof(c)); 137 CATCH_EINTR(n = read(sigio_private[0], &c, sizeof(c)));
136 if(n != sizeof(c)){ 138 if(n != sizeof(c)){
137 printk("update_thread : read failed, err = %d\n", -n); 139 printk("update_thread : read failed, err = %d\n", errno);
138 goto fail; 140 goto fail;
139 } 141 }
140 142
@@ -320,6 +322,10 @@ out_close1:
320 close(l_write_sigio_fds[1]); 322 close(l_write_sigio_fds[1]);
321} 323}
322 324
325/* Changed during early boot */
326static int pty_output_sigio = 0;
327static int pty_close_sigio = 0;
328
323void maybe_sigio_broken(int fd, int read) 329void maybe_sigio_broken(int fd, int read)
324{ 330{
325 int err; 331 int err;
@@ -357,3 +363,143 @@ static void sigio_cleanup(void)
357} 363}
358 364
359__uml_exitcall(sigio_cleanup); 365__uml_exitcall(sigio_cleanup);
366
367/* Used as a flag during SIGIO testing early in boot */
368static volatile int got_sigio = 0;
369
370static void __init handler(int sig)
371{
372 got_sigio = 1;
373}
374
375struct openpty_arg {
376 int master;
377 int slave;
378 int err;
379};
380
381static void openpty_cb(void *arg)
382{
383 struct openpty_arg *info = arg;
384
385 info->err = 0;
386 if(openpty(&info->master, &info->slave, NULL, NULL, NULL))
387 info->err = -errno;
388}
389
390static int async_pty(int master, int slave)
391{
392 int flags;
393
394 flags = fcntl(master, F_GETFL);
395 if(flags < 0)
396 return -errno;
397
398 if((fcntl(master, F_SETFL, flags | O_NONBLOCK | O_ASYNC) < 0) ||
399 (fcntl(master, F_SETOWN, os_getpid()) < 0))
400 return -errno;
401
402 if((fcntl(slave, F_SETFL, flags | O_NONBLOCK) < 0))
403 return -errno;
404
405 return(0);
406}
407
408static void __init check_one_sigio(void (*proc)(int, int))
409{
410 struct sigaction old, new;
411 struct openpty_arg pty = { .master = -1, .slave = -1 };
412 int master, slave, err;
413
414 initial_thread_cb(openpty_cb, &pty);
415 if(pty.err){
416 printk("openpty failed, errno = %d\n", -pty.err);
417 return;
418 }
419
420 master = pty.master;
421 slave = pty.slave;
422
423 if((master == -1) || (slave == -1)){
424 printk("openpty failed to allocate a pty\n");
425 return;
426 }
427
428 /* Not now, but complain so we now where we failed. */
429 err = raw(master);
430 if (err < 0)
431 panic("check_sigio : __raw failed, errno = %d\n", -err);
432
433 err = async_pty(master, slave);
434 if(err < 0)
435 panic("tty_fds : sigio_async failed, err = %d\n", -err);
436
437 if(sigaction(SIGIO, NULL, &old) < 0)
438 panic("check_sigio : sigaction 1 failed, errno = %d\n", errno);
439 new = old;
440 new.sa_handler = handler;
441 if(sigaction(SIGIO, &new, NULL) < 0)
442 panic("check_sigio : sigaction 2 failed, errno = %d\n", errno);
443
444 got_sigio = 0;
445 (*proc)(master, slave);
446
447 close(master);
448 close(slave);
449
450 if(sigaction(SIGIO, &old, NULL) < 0)
451 panic("check_sigio : sigaction 3 failed, errno = %d\n", errno);
452}
453
454static void tty_output(int master, int slave)
455{
456 int n;
457 char buf[512];
458
459 printk("Checking that host ptys support output SIGIO...");
460
461 memset(buf, 0, sizeof(buf));
462
463 while(write(master, buf, sizeof(buf)) > 0) ;
464 if(errno != EAGAIN)
465 panic("tty_output : write failed, errno = %d\n", errno);
466 while(((n = read(slave, buf, sizeof(buf))) > 0) && !got_sigio) ;
467
468 if(got_sigio){
469 printk("Yes\n");
470 pty_output_sigio = 1;
471 }
472 else if(n == -EAGAIN)
473 printk("No, enabling workaround\n");
474 else panic("tty_output : read failed, err = %d\n", n);
475}
476
477static void tty_close(int master, int slave)
478{
479 printk("Checking that host ptys support SIGIO on close...");
480
481 close(slave);
482 if(got_sigio){
483 printk("Yes\n");
484 pty_close_sigio = 1;
485 }
486 else printk("No, enabling workaround\n");
487}
488
489void __init check_sigio(void)
490{
491 if((os_access("/dev/ptmx", OS_ACC_R_OK) < 0) &&
492 (os_access("/dev/ptyp0", OS_ACC_R_OK) < 0)){
493 printk("No pseudo-terminals available - skipping pty SIGIO "
494 "check\n");
495 return;
496 }
497 check_one_sigio(tty_output);
498 check_one_sigio(tty_close);
499}
500
501/* Here because it only does the SIGIO testing for now */
502void __init os_check_bugs(void)
503{
504 check_sigio();
505}