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2008-07-24UML: make several more things staticWANG Cong
- Make some variables and functions static, since they don't need to be global. - Remove an unused function - arch/um/kernel/time.c::sched_clock(). - Clean the style a bit as complained by checkpatch.pl. Cc: Jeff Dike <jdike@addtoit.com> Signed-off-by: WANG Cong <wangcong@zeuux.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-05-13uml: random driver fixesJeff Dike
The random driver would essentially hang if the host's /dev/random returned -EAGAIN. There was a test of need_resched followed by a schedule inside the loop, but that didn't help and it's the wrong way to work anyway. The right way is to ask for an interrupt when there is input available from the host and handle it then rather than polling. Now, when the host's /dev/random returns -EAGAIN, the driver asks for a wakeup when there's randomness available again and sleeps. The interrupt routine just wakes up whatever processes are sleeping on host_read_wait. There is an atomic_t, host_sleep_count, which counts the number of processes waiting for randomness. When this reaches zero, the interrupt is disabled. An added complication is that async I/O notification was only recently added to /dev/random (by me), so essentially all hosts will lack it. So, we use the sigio workaround here, which is to have a separate thread poll on the descriptor and send an interrupt when there is input on it. This mechanism is activated when a process gets -EAGAIN (activating this multiple times is harmless, if a bit wasteful) and deactivated by the last process still waiting. The module name was changed from "random" to "hw_random" in order for udev to recognize it. The sigio workaround needed some changes. sigio_broken was added for cases when we know that async notification doesn't work. This is now called from maybe_sigio_broken, which deals with pts devices. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-05-13uml: fix build when SLOB is enabledJeff Dike
Reintroduce uml_kmalloc for the benefit of UML libc code. The previous tactic of declaring __kmalloc so it could be called directly from the libc side of the house turned out to be getting too intimate with slab, and it doesn't work with slob. So, the uml_kmalloc wrapper is back. It calls kmalloc or whatever that translates into, and libc code calls it. kfree is left alone since that still works, leaving a somewhat inconsistent API. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: WANG Cong <xiyou.wangcong@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-05uml: syle fixes in arch/um/os-LinuxJeff Dike
Style fixes in arch/um/os-Linux/irq.c and arch/um/os-Linux/sigio.c: Updated copyrights trimmed includes added severity indicators to printks CodingStyle fixes turned an bunch of panics into printks call some libc functions directly instead of going through the os_* wrappers Signed-off-by: Jeff Dike <jdike@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-05arch/um: remove duplicate includesLucas Woods
Signed-off-by: Lucas Woods <woodzy@gmail.com> Cc: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-05uml: const and other tidyingWANG Cong
This patch also does some improvements for uml code. Improvements include dropping unnecessary cast, killing some unnecessary code and still some constifying for pointers etc.. Signed-off-by: WANG Cong <xiyou.wangcong@gmail.com> Signed-off-by: Jeff Dike <jdike@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-16uml: Eliminate kernel allocator wrappersJeff Dike
UML had two wrapper procedures for kmalloc, um_kmalloc and um_kmalloc_atomic because the flag constants weren't available in userspace code. kern_constants.h had made kernel constants available for a long time, so there is no need for these wrappers any more. Rather, userspace code calls kmalloc directly with the userspace versions of the gfp flags. kmalloc isn't a real procedure, so I had to essentially copy the inline wrapper around __kmalloc. vmalloc also had its own wrapper for no good reason. This is now gone. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-16uml: simplify helper stack handlingJeff Dike
run_helper and run_helper_thread had arguments which were the same in all callers. run_helper's stack_out was always NULL and run_helper_thread's stack_order was always 0. These are now gone, and the constants folded into the code. Also fixed leaks of the helper stack in the AIO and SIGIO code. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-07uml: convert libc layer to call read and writeJeff Dike
This patch converts calls in the os layer to os_{read,write}_file to calls directly to libc read() and write() where it is clear that the I/O buffer is in the kernel. We can do that here instead of calling os_{read,write}_file_k since we are in libc code and can call libc directly. With the change in the calls, error handling needs to be changed to refer to errno directly rather than the return value of the call. CATCH_EINTR wrappers were also added where needed. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-07uml: tidy libc codeJeff Dike
This patch lays some groundwork for the next one, which converts calls to os_{read,write}_file into {read,write}, by doing some tidying in the affected areas. do_not_aio gets restructured to make the final result a bit cleaner. There are also whitespace and other formatting fixes, fixes in error messages, and a typo fix. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-07uml: remove user_util.hJeff Dike
user_util.h isn't needed any more, so delete it and remove all includes of it. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-07uml: move SIGIO testing to sigio.cJeff Dike
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: Jeff Dike <jdike@linux.intel.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-03-01[PATCH] uml: add back accidentally removed errorJeff Dike
In the 2.6.20 hang patch, I accidentally threw out an error message. This puts it back. Signed-off-by: Jeff Dike <jdike@addtoit.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-16[PATCH] uml: fix 2.6.20 hangJeff Dike
A previous cleanup misused need_poll, which had a fairly broken interface. It implemented a growable array, changing the used elements count itself, but leaving it up to the caller to fill in the actual elements, including the entire array if the array had to be reallocated. This worked because the previous users were switching between two such structures, and the elements were copied from the inactive array to the active array after making sure the active array had enough room. maybe_sigio_broken was made to use need_poll, but it was operating on a single array, so when the buffer was reallocated, the previous contents were lost. This patch makes need_poll implement more sane semantics. It merely assures that the array is of the proper size and that the contents are preserved. It is up to the caller to adjust the used elements count and to ensure that the proper elements are resent. This manifested itself as a hang in 2.6.20 as the uninitialized buffer convinced UML that one of its own file descriptors didn't support SIGIO and needed to be watched by poll in a separate thread. The result was an interrupt flood as control traffic over this descriptor sparked interrupts, which resulted in more control traffic, ad nauseum. Signed-off-by: Jeff Dike <jdike@addtoit.com> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2006-10-20[PATCH] uml: split memory allocation prototypes out of user.hPaolo 'Blaisorblade' Giarrusso
user.h is too generic a header name. I've split out allocation routines from it. Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Cc: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-26[PATCH] uml: SIGIO cleanupsJeff Dike
- Various cleanups in the sigio code. - Removed explicit zero-initializations of a few structures. - Improved some error messages. - An API change - there was an asymmetry between reactivate_fd calling maybe_sigio_broken, which goes through all the machinery of figuring out if a file descriptor supports SIGIO and applying the workaround to it if not, and deactivate_fd, which just turns off the descriptor. This is changed so that only activate_fd calls maybe_sigio_broken, when the descriptor is first seen. reactivate_fd now calls add_sigio_fd, which is symmetric with ignore_sigio_fd. This removes a recursion which makes a critical section look more critical than it really was, obsoleting a big comment to that effect. This requires keeping track of all descriptors which are getting the SIGIO treatment, not just the ones being polled at any given moment, so that reactivate_fd, through add_sigio_fd, doesn't try to tell the SIGIO thread about descriptors it doesn't care about. Signed-off-by: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-10[PATCH] uml: make some symbols staticJeff Dike
A few sigio-related things can be made static. Signed-off-by: Jeff Dike <jdike@addtoit.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-10[PATCH] uml: fix exitcall ordering bugJeff Dike
This fixes an exitcall ordering bug - calls to ignore_sigio_fd can come from exitcalls that come after the sigio thread has been killed. This would cause shutdown to hang or crash. Fixed by having ignore_sigio_fd check that the thread is present before trying to communicate with it. Signed-off-by: Jeff Dike <jdike@addtoit.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-10[PATCH] uml: remove os_isattyJeff Dike
os_isatty can be made to disappear by moving maybe_sigio_broken from kernel to user code. This also lets write_sigio_workaround become static. Signed-off-by: Jeff Dike <jdike@addtoit.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-04-11[PATCH] uml: move outside spinlock call not needing itPaolo 'Blaisorblade' Giarrusso
Move a call to kfree on a local variable out of a spinlock - there's no need to have it in. Done on a just merged patch. Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Cc: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-27[PATCH] uml: fix thread startup raceJeff Dike
This fixes a race in the starting of write_sigio_thread. Previously, some of the data needed by the thread was initialized after the clone. If the thread ran immediately, it would see the uninitialized data, including an empty pollfds, which would cause it to hang. We move the data initialization to before the clone, and adjust the error paths and cleanup accordingly. Signed-off-by: Jeff Dike <jdike@addtoit.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-27[PATCH] uml: move sigio_user.c to os-Linux/sigio.cJeff Dike
The serial UML OS-abstraction layer patch (um/kernel dir). This moves sigio_user.c to os-Linux dir Signed-off-by: Gennady Sharapov <Gennady.V.Sharapov@intel.com> Signed-off-by: Jeff Dike <jdike@addtoit.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>