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Commit c65badbd authored by Jeff Dike's avatar Jeff Dike Committed by Linus Torvalds
Browse files

uml: move SIGIO testing to sigio.c 



This patch narrows the sigio interface.  The boot-time SIGIO testing used to
be in start_up.c, which meant that pty_output_sigio and pty_close_sigio needed
to be global.  By moving that code here, those can become static and the
declarations moved from user_util.h.

os_check_bugs is also here because it only does the SIGIO checking.  If it
does more, it'll probably move back to start_up.c.

Signed-off-by: default avatarJeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent c5e631cf

arch/um/include/user_util.h

+0 −3
Original line number Diff line number Diff line
@@ -51,9 +51,6 @@ extern unsigned long _stext, _etext, _sdata, _edata, __bss_start, _end; 
extern unsigned long _unprotected_end;

extern unsigned long brk_start;



extern int pty_output_sigio;

extern int pty_close_sigio;



extern void *add_signal_handler(int sig, void (*handler)(int));

extern int linux_main(int argc, char **argv);

extern void set_cmdline(char *cmd);

arch/um/os-Linux/sigio.c

+145 −0
Original line number Diff line number Diff line
@@ -8,6 +8,7 @@ 
#include <termios.h>

#include <pty.h>

#include <signal.h>

#include <fcntl.h>

#include <errno.h>

#include <string.h>

#include <sched.h>
@@ -20,6 +21,7 @@ 
#include "sigio.h"

#include "os.h"

#include "um_malloc.h"

#include "init.h"



/* Protected by sigio_lock(), also used by sigio_cleanup, which is an

 * exitcall.
@@ -320,6 +322,10 @@ static void write_sigio_workaround(void) 
	close(l_write_sigio_fds[1]);

}



/* Changed during early boot */

static int pty_output_sigio = 0;

static int pty_close_sigio = 0;



void maybe_sigio_broken(int fd, int read)

{

	int err;
@@ -357,3 +363,142 @@ static void sigio_cleanup(void) 
}



__uml_exitcall(sigio_cleanup);



/* Used as a flag during SIGIO testing early in boot */

static volatile int got_sigio = 0;



static void __init handler(int sig)

{

	got_sigio = 1;

}



struct openpty_arg {

	int master;

	int slave;

	int err;

};



static void openpty_cb(void *arg)

{

	struct openpty_arg *info = arg;



	info->err = 0;

	if(openpty(&info->master, &info->slave, NULL, NULL, NULL))

		info->err = -errno;

}



static int async_pty(int master, int slave)

{

	int flags;



	flags = fcntl(master, F_GETFL);

	if(flags < 0)

		return -errno;



	if((fcntl(master, F_SETFL, flags | O_NONBLOCK | O_ASYNC) < 0) ||

	   (fcntl(master, F_SETOWN, os_getpid()) < 0))

		return -errno;



	if((fcntl(slave, F_SETFL, flags | O_NONBLOCK) < 0))

		return -errno;



	return(0);

}



static void __init check_one_sigio(void (*proc)(int, int))

{

	struct sigaction old, new;

	struct openpty_arg pty = { .master = -1, .slave = -1 };

	int master, slave, err;



	initial_thread_cb(openpty_cb, &pty);

	if(pty.err){

		printk("openpty failed, errno = %d\n", -pty.err);

		return;

	}



	master = pty.master;

	slave = pty.slave;



	if((master == -1) || (slave == -1)){

		printk("openpty failed to allocate a pty\n");

		return;

	}



	/* Not now, but complain so we now where we failed. */

	err = raw(master);

	if (err < 0)

		panic("check_sigio : __raw failed, errno = %d\n", -err);



	err = async_pty(master, slave);

	if(err < 0)

		panic("tty_fds : sigio_async failed, err = %d\n", -err);



	if(sigaction(SIGIO, NULL, &old) < 0)

		panic("check_sigio : sigaction 1 failed, errno = %d\n", errno);

	new = old;

	new.sa_handler = handler;

	if(sigaction(SIGIO, &new, NULL) < 0)

		panic("check_sigio : sigaction 2 failed, errno = %d\n", errno);



	got_sigio = 0;

	(*proc)(master, slave);



	close(master);

	close(slave);



	if(sigaction(SIGIO, &old, NULL) < 0)

		panic("check_sigio : sigaction 3 failed, errno = %d\n", errno);

}



static void tty_output(int master, int slave)

{

	int n;

	char buf[512];



	printk("Checking that host ptys support output SIGIO...");



	memset(buf, 0, sizeof(buf));



	while(os_write_file(master, buf, sizeof(buf)) > 0) ;

	if(errno != EAGAIN)

		panic("check_sigio : write failed, errno = %d\n", errno);

	while(((n = os_read_file(slave, buf, sizeof(buf))) > 0) && !got_sigio) ;



	if(got_sigio){

		printk("Yes\n");

		pty_output_sigio = 1;

	}

	else if(n == -EAGAIN) printk("No, enabling workaround\n");

	else panic("check_sigio : read failed, err = %d\n", n);

}



static void tty_close(int master, int slave)

{

	printk("Checking that host ptys support SIGIO on close...");



	close(slave);

	if(got_sigio){

		printk("Yes\n");

		pty_close_sigio = 1;

	}

	else printk("No, enabling workaround\n");

}



void __init check_sigio(void)

{

	if((os_access("/dev/ptmx", OS_ACC_R_OK) < 0) &&

	   (os_access("/dev/ptyp0", OS_ACC_R_OK) < 0)){

		printk("No pseudo-terminals available - skipping pty SIGIO "

		       "check\n");

		return;

	}

	check_one_sigio(tty_output);

	check_one_sigio(tty_close);

}



/* Here because it only does the SIGIO testing for now */

void __init os_check_bugs(void)

{

	check_sigio();

}

arch/um/os-Linux/start_up.c

+0 −145
Original line number Diff line number Diff line
@@ -553,148 +553,3 @@ int __init parse_iomem(char *str, int *add) 
 out:

	return 1;

}
 




/* Changed during early boot */

int pty_output_sigio = 0;

int pty_close_sigio = 0;



/* Used as a flag during SIGIO testing early in boot */

static volatile int got_sigio = 0;



static void __init handler(int sig)

{

	got_sigio = 1;

}



struct openpty_arg {

	int master;

	int slave;

	int err;

};



static void openpty_cb(void *arg)

{

	struct openpty_arg *info = arg;



	info->err = 0;

	if(openpty(&info->master, &info->slave, NULL, NULL, NULL))

		info->err = -errno;

}



static int async_pty(int master, int slave)

{

	int flags;



	flags = fcntl(master, F_GETFL);

	if(flags < 0)

		return -errno;



	if((fcntl(master, F_SETFL, flags | O_NONBLOCK | O_ASYNC) < 0) ||

	   (fcntl(master, F_SETOWN, os_getpid()) < 0))

		return -errno;



	if((fcntl(slave, F_SETFL, flags | O_NONBLOCK) < 0))

		return -errno;



	return(0);

}



static void __init check_one_sigio(void (*proc)(int, int))

{

	struct sigaction old, new;

	struct openpty_arg pty = { .master = -1, .slave = -1 };

	int master, slave, err;



	initial_thread_cb(openpty_cb, &pty);

	if(pty.err){

		printk("openpty failed, errno = %d\n", -pty.err);

		return;

	}



	master = pty.master;

	slave = pty.slave;



	if((master == -1) || (slave == -1)){

		printk("openpty failed to allocate a pty\n");

		return;

	}



	/* Not now, but complain so we now where we failed. */

	err = raw(master);

	if (err < 0)

		panic("check_sigio : __raw failed, errno = %d\n", -err);



	err = async_pty(master, slave);

	if(err < 0)

		panic("tty_fds : sigio_async failed, err = %d\n", -err);



	if(sigaction(SIGIO, NULL, &old) < 0)

		panic("check_sigio : sigaction 1 failed, errno = %d\n", errno);

	new = old;

	new.sa_handler = handler;

	if(sigaction(SIGIO, &new, NULL) < 0)

		panic("check_sigio : sigaction 2 failed, errno = %d\n", errno);



	got_sigio = 0;

	(*proc)(master, slave);



	close(master);

	close(slave);



	if(sigaction(SIGIO, &old, NULL) < 0)

		panic("check_sigio : sigaction 3 failed, errno = %d\n", errno);

}



static void tty_output(int master, int slave)

{

	int n;

	char buf[512];



	printk("Checking that host ptys support output SIGIO...");



	memset(buf, 0, sizeof(buf));



	while(os_write_file(master, buf, sizeof(buf)) > 0) ;

	if(errno != EAGAIN)

		panic("check_sigio : write failed, errno = %d\n", errno);

	while(((n = os_read_file(slave, buf, sizeof(buf))) > 0) && !got_sigio) ;



	if(got_sigio){

		printk("Yes\n");

		pty_output_sigio = 1;

	}

	else if(n == -EAGAIN) printk("No, enabling workaround\n");

	else panic("check_sigio : read failed, err = %d\n", n);

}



static void tty_close(int master, int slave)

{

	printk("Checking that host ptys support SIGIO on close...");



	close(slave);

	if(got_sigio){

		printk("Yes\n");

		pty_close_sigio = 1;

	}

	else printk("No, enabling workaround\n");

}



void __init check_sigio(void)

{

	if((os_access("/dev/ptmx", OS_ACC_R_OK) < 0) &&

	   (os_access("/dev/ptyp0", OS_ACC_R_OK) < 0)){

		printk("No pseudo-terminals available - skipping pty SIGIO "

		       "check\n");

		return;

	}

	check_one_sigio(tty_output);

	check_one_sigio(tty_close);

}



void os_check_bugs(void)

{

	check_ptrace();

	check_sigio();

}