Skip to content

L
linux

openthos / linux

通知 1
Star 0
Fork 0
L
linux

体验新版 GitCode，发现更多精彩内容 >>

切换分支/标签
  1. 12 2月, 2007 14 次提交
  3. 14 12月, 2006 1 次提交
  5. 09 12月, 2006 1 次提交
    • A
      [PATCH] tty: switch to ktermios · 606d099c
      由 Alan Cox 提交于 
      This is the grungy swap all the occurrences in the right places patch that
goes with the updates.  At this point we have the same functionality as
before (except that sgttyb() returns speeds not zero) and are ready to
begin turning new stuff on providing nobody reports lots of bugs

If you are a tty driver author converting an out of tree driver the only
impact should be termios->ktermios name changes for the speed/property
setting functions from your upper layers.

If you are implementing your own TCGETS function before then your driver
was broken already and its about to get a whole lot more painful for you so
please fix it 8)

Also fill in c_ispeed/ospeed on init for most devices, although the current
code will do this for you anyway but I'd like eventually to lose that extra
paranoia

[akpm@osdl.org: bluetooth fix]
[mp3@de.ibm.com: sclp fix]
[mp3@de.ibm.com: warning fix for tty3270]
[hugh@veritas.com: fix tty_ioctl powerpc build]
[jdike@addtoit.com: uml: fix ->set_termios declaration]
Signed-off-by: NAlan Cox <alan@redhat.com>
Signed-off-by: NMartin Peschke <mp3@de.ibm.com>
Acked-by: NPeter Oberparleiter <oberpar@de.ibm.com>
Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: NHugh Dickins <hugh@veritas.com>
Signed-off-by: NJeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      606d099c
  7. 08 12月, 2006 3 次提交
  9. 03 12月, 2006 1 次提交
  11. 26 11月, 2006 1 次提交
    • P
      [PATCH] uml: make execvp safe for our usage · 5d48545e
      由 Paolo 'Blaisorblade' Giarrusso 提交于 
      Reimplement execvp for our purposes - after we call fork() it is fundamentally
unsafe to use the kernel allocator - current is not valid there.  So we simply
pass to our modified execvp() a preallocated buffer.  This fixes a real bug
and works very well in testing (I've seen indirectly warning messages from the
forked thread - they went on the pipe connected to its stdout and where read
as a number by UML, when calling read_output().  I verified the obtained
number corresponded to "BUG:").

The added use of __cant_sleep() is not a new bug since __cant_sleep() is
already used in the same function - passing an atomicity parameter would be
better but it would require huge change, stating that this function must not
be called in atomic context and can sleep is a better idea (will make sure of
this gradually).
Signed-off-by: NPaolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Acked-by: NJeff Dike <jdike@addtoit.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      5d48545e
  13. 04 11月, 2006 1 次提交
    • J
      [PATCH] uml: fix I/O hang · 53b17332
      由 Jeff Dike 提交于 
      Fix a UML hang in which everything would just stop until some I/O happened
- a ping, someone whacking the keyboard - at which point everything would
start up again as though nothing had happened.

The cause was gcc reordering some code which absolutely needed to be
executed in the order in the source.  When unblock_signals switches signals
from off to on, it needs to see if any interrupts had happened in the
critical section.  The interrupt handlers check signals_enabled - if it is
zero, then the handler adds a bit to the "pending" bitmask and returns.
unblock_signals checks this mask to see if any signals need to be
delivered.

The crucial part is this:
	signals_enabled = 1;
	save_pending = pending;
	if(save_pending == 0)
		return;
	pending = 0;

In order to avoid an interrupt arriving between reading pending and setting
it to zero, in which case, the record of the interrupt would be erased,
signals are enabled.

What happened was that gcc reordered this so that 'save_pending = pending'
came before 'signals_enabled = 1', creating a one-instruction window within
which an interrupt could arrive, set its bit in pending, and have it be
immediately erased.

When the I/O workload is purely disk-based, the loss of a block device
interrupt stops the entire I/O system because the next block request will
wait for the current one to finish.  Thus the system hangs until something
else causes some I/O to arrive, such as a network packet or console input.

The fix to this particular problem is a memory barrier between enabling
signals and reading the pending signal mask.  An xchg would also probably
work.

Looking over this code for similar problems led me to do a few more
things:

- make signals_enabled and pending volatile so that they don't get cached
  in registers

- add an mb() to the return paths of block_signals and unblock_signals so
  that the modification of signals_enabled doesn't get shuffled into the
  caller in the event that these are inlined in the future.
Signed-off-by: NJeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      53b17332
  15. 01 11月, 2006 1 次提交
  17. 25 10月, 2006 1 次提交
    • A
      [PATCH] uml: mconsole fixes · 3a51237d
      由 Al Viro 提交于 
       * when we have stop/sysrq/go, we get pt_regs of whatever executes
   mc_work_proc().  Would be better to see what we had at the time of
   interrupt that got us stop.

 * stop/stop/stop.....  will give stack overflow.  Shouldn't allow stop
   from mconsole_stop().

 * stop/stop/go leaves us inside mconsole_stop() with
	os_set_fd_block(req->originating_fd, 0);
	reactivate_fd(req->originating_fd, MCONSOLE_IRQ);
   just done by nested mconsole_stop().  Ditto.

 * once we'd seen stop, there's a period when INTR commands are executed
   out of order (as they should; we might have the things stuck badly
   enough to never reach mconsole_stop(), but still not badly enough to
   block mconsole_interrupt(); in that situation we _want_ things like
   "cad" to be executed immediately).  Once we enter monsole_stop(), all
   INTR commands will be executed in order, mixed with PROC ones.  We'd
   better let user see that such change of behaviour has happened.
   (Suggested by lennert).

 * stack footprint of monsole_interrupt() is an atrocity; AFAICS we can
   safely make struct mc_request req; static in function there.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Acked-by: NJeff Dike <jdike@addtoit.com>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      3a51237d
  19. 21 10月, 2006 1 次提交
  21. 16 10月, 2006 1 次提交
  23. 12 10月, 2006 4 次提交
  25. 09 10月, 2006 2 次提交
  27. 04 10月, 2006 2 次提交
  29. 02 10月, 2006 1 次提交
    • J
      [PATCH] const struct tty_operations · b68e31d0
      由 Jeff Dike 提交于 
      As part of an SMP cleanliness pass over UML, I consted a bunch of
structures in order to not have to document their locking.  One of these
structures was a struct tty_operations.  In order to const it in UML
without introducing compiler complaints, the declaration of
tty_set_operations needs to be changed, and then all of its callers need to
be fixed.

This patch declares all struct tty_operations in the tree as const.  In all
cases, they are static and used only as input to tty_set_operations.  As an
extra check, I ran an i386 allyesconfig build which produced no extra
warnings.

53 drivers are affected.  I checked the history of a bunch of them, and in
most cases, there have been only a handful of maintenance changes in the
last six months.  serial_core.c was the busiest one that I looked at.
Signed-off-by: NJeff Dike <jdike@addtoit.com>
Acked-by: NAlan Cox <alan@redhat.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      b68e31d0
  31. 30 9月, 2006 3 次提交
    • J
      [PATCH] uml: don't roll my own random MAC generator · fade5d54
      由 Jeff Dike 提交于 
      Use the existing random_ether_addr() instead of cooking up my own
version.  Pointed out by Dave Hollis and Jason Lunz.
Signed-off-by: NJeff Dike <jdike@addtoit.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      fade5d54
    • J
      [PATCH] uml: mechanical tidying after random MACs change · b10aeeef
      由 Jeff Dike 提交于 
      Mechanical, hopefully non-functional changes stemming from
setup_etheraddr always succeeding now that it always assigns a MAC,
either from the command line or generated randomly:
   the test of the return of setup_etheraddr is removed, and code
dependent on it succeeding is now unconditional
   setup_etheraddr can now be made void
   struct uml_net.have_mac is now always 1, so tests of it can be
similarly removed, and uses of it can be replaced with 1
   struct uml_net.have_mac is no longer used, so it can be removed
   struct uml_net_private.have_mac is copied from struct uml_net, so
it is always 1
   tests of uml_net_private.have_mac can be removed
   uml_net_private.have_mac can now be removed
   the only call to dev_ip_addr was removed, so it can be deleted

It also turns out that setup_etheraddr is called only once, from the same
file, so it can be static and its declaration removed from net_kern.h.

Similarly, set_ether_mac is defined and called only from one file.

Finally, setup_etheraddr and set_ether_mac were moved to avoid needing forward
declarations.
Signed-off-by: NJeff Dike <jdike@addtoit.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      b10aeeef
    • J
      [PATCH] uml: assign random MACs to interfaces if necessary · f3e7ed2b
      由 Jeff Dike 提交于 
      Assign a random MAC to an ethernet interface if one was not provided on the
command line.  This became pressing when distros started bringing interfaces
up before assigning IPs to them.  The previous pattern of assigning an IP then
bringing it up allowed the MAC to be generated from the first IP assigned.
However, once the thing is up, it's probably a bad idea to change the MAC, so
the MAC stayed initialized to fe:fd:0:0:0:0.

Now, if there is no MAC from the command line, one is generated.  We use the
microseconds from gettimeofday (20 bits), plus the low 12 bits of the pid to
seed the random number generator.  random() is called twice, with 16 bits of
each result used.  I didn't want to have to try to fill in 32 bits optimally
given an arbitrary RAND_MAX, so I just assume that it is greater than 65536
and use 16 bits of each random() return.

There is also a bit of reformatting and whitespace cleanup here.
Signed-off-by: NJeff Dike <jdike@addtoit.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      f3e7ed2b
  33. 27 9月, 2006 2 次提交
    • J
      [PATCH] uml: thread creation tidying · 3c917350
      由 Jeff Dike 提交于 
      fork on UML has always somewhat subtle.  The underlying cause has been the
need to initialize a stack for the new process.  The only portable way to
initialize a new stack is to set it as the alternate signal stack and take a
signal.  The signal handler does whatever initialization is needed and jumps
back to the original stack, where the fork processing is finished.  The basic
context switching mechanism is a jmp_buf for each process.  You switch to a
new process by longjmping to its jmp_buf.

Now that UML has its own implementation of setjmp and longjmp, and I can poke
around inside a jmp_buf without fear that libc will change the structure, a
much simpler mechanism is possible.  The jmpbuf can simply be initialized by
hand.

This eliminates -
	the need to set up and remove the alternate signal stack
	sending and handling a signal
	the signal blocking needed around the stack switching, since
there is no stack switching
	setting up the jmp_buf needed to jump back to the original
stack after the new one is set up

In addition, since jmp_buf is now defined by UML, and not by libc, it can be
embedded in the thread struct.  This makes it unnecessary to have it exist on
the stack, where it used to be.  It also simplifies interfaces, since the
switch jmp_buf used to be a void * inside the thread struct, and functions
which took it as an argument needed to define a jmp_buf variable and assign it
from the void *.
Signed-off-by: NJeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      3c917350
    • J
      [PATCH] uml: mark some tt-mode code · 0915ee38
      由 Jeff Dike 提交于 
      Mark a symbol and file as being tt-mode only.  This shrinks the binary
slightly when tt mode support is compiled out and makes it easier to identity
stuff when tt mode is removed.
Signed-off-by: NJeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      0915ee38