Date: Thu, 30 Sep 1999 13:48:02 +0400 (MSD) From: isupov@moonhe.jinr.ru To: FreeBSD-gnats-submit@freebsd.org Subject: i386/14048: ``doscmd -r'' doesn't work Message-ID: <199909300948.NAA07887@moonhe.jinr.ru>
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>Number: 14048
>Category: i386
>Synopsis: ``doscmd -r'' doesn't work
>Confidential: no
>Severity: non-critical
>Priority: low
>Responsible: freebsd-bugs
>State: open
>Quarter:
>Keywords:
>Date-Required:
>Class: sw-bug
>Submitter-Id: current-users
>Arrival-Date: Thu Sep 30 02:50:01 PDT 1999
>Closed-Date:
>Last-Modified:
>Originator: Isupov A.Yu.
>Release: FreeBSD 3.2-RELEASE i386
>Organization:
LHE, JINR
>Environment:
- FreeBSD 3.2-RELEASE i386
- doscmd(1) recompiled with X support, as described in doscmd.1
manual pages, DIAGNOSTICS
- Processors: AMD K6-III-400 and Pentium P54C 90MHz
>Description:
1. doscmd/tty.c/console_init(): mmap() of /dev/vga:
Invalid argument
2. doscmd/tty.c/console_init(): doscmd/AsyncIO.c/_RegisterIO():
1060: Invalid FD
3. doscmd/trap.c/sigbus():
ax=0003 bx=0000 cx=ffff dx=0000
si=0000 di=ffff sp=7fe5 bp=0000
cs=6f00 ss=9800 ds=0000 es=0000
ip=0 eflags=b0286
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
addb %al,(%bx+%si)
doscmd: fatal error unsupported instruction
(Note, that ``doscmd -x'' works.)
>How-To-Repeat:
1. ``doscmd -r'' on console
2. ``doscmd -r'' on console after fix 1.
3. ``doscmd -r'' on console after fix 2.
>Fix:
1. device vga0 in kernel reports (and this reasonable!):
/kernel: vga0 at 0x3b0-0x3df maddr 0xa0000 msize 131072 on isa
but in the doscmd/tty.c/console_init() we have:
addr = mmap((caddr_t)0xA0000, 5 * 64 * 1024,
PROT_EXEC | PROT_READ | PROT_WRITE,
MAP_FILE | MAP_FIXED | MAP_INHERIT | MAP_SHARED,
fd, 0);
so 5*64*1024 = 327680 (from 0xA0000 to 0xEFFFF !) slightly huge...
I think, 2*64*1024 = 131072 (from 0xA0000 to 0xBFFFF) will be enough ?
Following fix proposed (diff -c):
-----------------fix 1----------------------------------------------
*** tty.c.orig Thu Sep 30 12:21:23 1999
--- tty.c Thu Sep 30 13:25:07 1999
***************
*** 286,292 ****
perror("/dev/vga");
quit(1);
}
! addr = mmap((caddr_t)0xA0000, 5 * 64 * 1024,
PROT_EXEC | PROT_READ | PROT_WRITE,
MAP_FILE | MAP_FIXED | MAP_INHERIT | MAP_SHARED,
fd, 0);
--- 286,292 ----
perror("/dev/vga");
quit(1);
}
! addr = mmap((caddr_t)0xA0000, 2 * 64 * 1024,
PROT_EXEC | PROT_READ | PROT_WRITE,
MAP_FILE | MAP_FIXED | MAP_INHERIT | MAP_SHARED,
fd, 0);
-----------------fix 1 end-------------------------------------------
2. In the doscmd/tty.c/console_init() we have:
if ((fd = open("/dev/console", 2)) < 0) {
perror("/dev/console");
quit(1);
}
fd = squirrel_fd(fd);
squirrel_fd() duplicates file descriptor at the top of the permitted
fd range. It's high limit obtained by sysconf(_SC_OPEN_MAX).
But this incompatible with doscmd/AsyncIO.c, where we have definition:
static Async handlers[OPEN_MAX];
and direct check in the doscmd/AsyncIO.c/_RegisterIO() :
if (fd < 0 || fd > OPEN_MAX) {
printf("%d: Invalid FD\n", fd);
return;
}
Following fix proposed (diff -c):
-----------------fix 2------------------------------------------
*** tty.c.orig Thu Sep 30 12:21:23 1999
--- tty.c Thu Sep 30 13:25:07 1999
***************
*** 311,317 ****
quit(1);
}
! fd = squirrel_fd(fd);
kbd_fd = fd;
#ifdef __FreeBSD__
--- 311,317 ----
quit(1);
}
! fd = squirrel1_fd(fd);
kbd_fd = fd;
#ifdef __FreeBSD__
*** doscmd.c.orig Thu Sep 30 12:21:23 1999
--- doscmd.c Thu Sep 30 13:25:41 1999
***************
*** 761,766 ****
--- 761,784 ----
return(fd);
}
+ int
+ squirrel1_fd(int fd)
+ {
+ int sfd = OPEN_MAX;
+ struct stat sb;
+
+ do {
+ errno = 0;
+ fstat(--sfd, &sb);
+ } while (sfd > 0 && errno != EBADF);
+
+ if (errno == EBADF && dup2(fd, sfd) >= 0) {
+ close(fd);
+ return(sfd);
+ }
+ return(fd);
+ }
+
/*
** Exit-time stuff
*/
-----------------fix 2 end----------------------------------
3. doscmd(1) obtain SIGBUS for unknown reasons. Fix unknown.
>Release-Note:
>Audit-Trail:
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