23 Mar, 2006
1 commit
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Implement SMP alternatives, i.e. switching at runtime between different
code versions for UP and SMP. The code can patch both SMP->UP and UP->SMP.
The UP->SMP case is useful for CPU hotplug.With CONFIG_CPU_HOTPLUG enabled the code switches to UP at boot time and
when the number of CPUs goes down to 1, and switches to SMP when the number
of CPUs goes up to 2.Without CONFIG_CPU_HOTPLUG or on non-SMP-capable systems the code is
patched once at boot time (if needed) and the tables are released
afterwards.The changes in detail:
* The current alternatives bits are moved to a separate file,
the SMP alternatives code is added there.* The patch adds some new elf sections to the kernel:
.smp_altinstructions
like .altinstructions, also contains a list
of alt_instr structs.
.smp_altinstr_replacement
like .altinstr_replacement, but also has some space to
save original instruction before replaving it.
.smp_locks
list of pointers to lock prefixes which can be nop'ed
out on UP.
The first two are used to replace more complex instruction
sequences such as spinlocks and semaphores. It would be possible
to deal with the lock prefixes with that as well, but by handling
them as special case the table sizes become much smaller.* The sections are page-aligned and padded up to page size, so they
can be free if they are not needed.* Splitted the code to release init pages to a separate function and
use it to release the elf sections if they are unused.Signed-off-by: Gerd Hoffmann
Signed-off-by: Chuck Ebbert
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
22 Mar, 2006
2 commits
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set_page_count usage outside mm/ is limited to setting the refcount to 1.
Remove set_page_count from outside mm/, and replace those users with
init_page_count() and set_page_refcounted().This allows more debug checking, and tighter control on how code is allowed
to play around with page->_count.Signed-off-by: Nick Piggin
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
A couple of places set_page_count(page, 1) that don't need to.
Signed-off-by: Nick Piggin
Cc: Paul Mackerras
Cc: Jeff Dike
Cc: Paolo 'Blaisorblade' Giarrusso
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
25 Feb, 2006
6 commits
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Improve (especially for coherence) some prototypes, and return code of
init_cow_file in error case - for a short write return -EINVAL, otherwise
return the error we got!Signed-off-by: Paolo 'Blaisorblade' Giarrusso
Acked-by: Jeff Dike
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Do precise error handling: print precise error messages, distinguishing short
reads and read errors. This functions fails frequently enough for me so I
bothered doing this fix.Signed-off-by: Paolo 'Blaisorblade' Giarrusso
Acked-by: Jeff Dike
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Fix an fd leak and a return of -1 instead of -errno in the error path - this
showed up in intensive testing of HPPFS, the os_connect_socket user.Signed-off-by: Paolo 'Blaisorblade' Giarrusso
Acked-by: Jeff Dike
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Use __attribute_used__ instead of __attribute__ ((unused)). This will help
with GCC > 3.2.Signed-off-by: Paolo 'Blaisorblade' Giarrusso
Acked-by: Jeff Dike
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
To avoid conflicts, in kernel files errno is expanded to kernel_errno, to
distinguish it from glibc errno. In this case, the code wants to use the libc
errno but the kernel one is used; in the other usage, we return errno in place
of -errno in case of an error.Signed-off-by: Paolo 'Blaisorblade' Giarrusso
Acked-by: Jeff Dike
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Improve some error messages in the COW driver, and say V3, not V2, when
talking about V3 format. Also resync with our userspace code utility a bit
more.Signed-off-by: Paolo 'Blaisorblade' Giarrusso
Acked-by: Jeff Dike
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
08 Feb, 2006
6 commits
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A previous patch removed a file from the build without removing it from the
tree.Signed-off-by: Jeff Dike
Cc: Paolo 'Blaisorblade' Giarrusso
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
We weren't making sure that we initialized the FP registers of new processes
to sane values.This patch also moves some defines in the affected area closer to where they
are used.Signed-off-by: Jeff Dike
Cc: Paolo 'Blaisorblade' Giarrusso
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
The process that UML uses to probe the host's ptrace capabilities can (rarely)
receive a SIGWINCH, confusing the parent. This fixes that by blocking
SIGWINCH.Signed-off-by: Jeff Dike
Cc: Paolo 'Blaisorblade' Giarrusso
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
The network driver added an interface to the "opened" list when it was
configured, not when it was brought up, and removed it when it was taken down.
A sequence of ifconfig up, ifconfig down, ... caused it to be removed
multiple times from the list without being added in between, resulting in a
crash. This patch moves the add to when the interface is brought up.Signed-off-by: Jeff Dike
Cc: Paolo 'Blaisorblade' Giarrusso
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
When UML opens a TUN/TAP device, the file descriptor could be copied into
later, long-lived threads, holding the device open even after the interface is
taken down, preventing it from being brought up again. This patch makes these
descriptors close-on-exec so that they disappear from helper processes, and
adds CLONE_FILES to a UML helper thread so that the descriptors are closed in
the thread when they are closed elsewhere in UML.Signed-off-by: Jeff Dike
Cc: Paolo 'Blaisorblade' Giarrusso
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
It doesn't do anything but emit a warning, but there's a user population
that's used to adding 'debug' to the UML command line in order to gdb it.
With skas0 mode, that's not necessary, but these users need some indication
that 'debug' doesn't do what they want.Signed-off-by: Jeff Dike
Cc: Paolo 'Blaisorblade' Giarrusso
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
02 Feb, 2006
9 commits
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Olaf Hering
Olaf reported UML doesn't build for him with a clear analisys of what happened
- we're using NR_CPUS in files linked against glibc headers. Seems like it
defines CONFIG_SMP but not CONFIG_NR_CPUS, so we get CONFIG_NR_CPUS
undeclared.The fix is to move the declaration away from that header file and move it in
asm-um headers, and to add that header where needed.Signed-off-by: Paolo 'Blaisorblade' Giarrusso
Cc: Jeff Dike
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Fix some simple sparse warnings - a lot more staticness and a misplaced
__user.Signed-off-by: Paolo 'Blaisorblade' Giarrusso
Cc: Jeff Dike
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Fixes a bug introduced in commit e32dacb9f481fd6decb41adb28e720c923d34f54 -
index is initialized based on syscall before syscall is calculated.I'm bothering with this mainly because it gives a correct warning when the
config option is enabled, even if the code is for a almost unused debugging
option.Signed-off-by: Paolo 'Blaisorblade' Giarrusso
Cc: Jeff Dike
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Fix stupid typo.
Signed-off-by: Paolo 'Blaisorblade' Giarrusso
Cc: Jeff Dike
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
The C99 initialization, with GCC's bad handling, for 6K wide structs (which
_aren't_ on the stack), is causing GCC to use 12K for these silly procs with 3
vars. Workaround this.Note that .name = { '\0' } translates to memset(->name, 0, '->name' size) - I verified
this with GCC's docs and a testprogram.Signed-off-by: Paolo 'Blaisorblade' Giarrusso
Cc: Jeff Dike
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
While fixing myself the mktime conflict (which someone already merged), I also
improved a few comments. Merge them up.Signed-off-by: Paolo 'Blaisorblade' Giarrusso
Cc: Jeff Dike
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Fix a couple of typos.
Signed-off-by: Jeff Dike
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
kern_constants.h now depends on arch/um/include to make sure it exists
before we try to create symlinks in it.Signed-off-by: Jeff Dike
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
CC arch/um/sys-i386/ldt.o
arch/um/sys-i386/ldt.c:19:21: proc_mm.h: No such file or directory
make[1]: *** [arch/um/sys-i386/ldt.o] Error 1Signed-off-by: Pekka Enberg
Signed-off-by: Jeff Dike
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
19 Jan, 2006
16 commits
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Use the generic sys_rt_sigsuspend.
Signed-off-by: Jeff Dike
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Add support for TIF_RESTORE_SIGMASK. I copy the i386 handling of the flag.
sys_sigsuspend is also changed to follow i386.
Also a bit of cleanup -
turn an if into a switch
get rid of a couple more emacs formatting commentsSigned-off-by: Jeff Dike
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Correct a bit of whitespace problems while working here.
Signed-off-by: Paolo 'Blaisorblade' Giarrusso
Cc: Jeff Dike
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
When the user specifies both a COW file and its backing file, if the previous
backing file is not found, currently UML tries again to use it and fails.This can be corrected by changing same_backing_files() return value in that
case, so that the caller will try to change the COW file to point to the new
location, as already done in other cases.Additionally, given the change in the meaning of the func, change its name,
invert its return value, so all values are inverted except when
stat(from_cow,&buf2) fails. And add some comments and two minor bugfixes -
remove a fd leak (return err rather than goto out) and a repeated check.Tested well.
Signed-off-by: Paolo 'Blaisorblade' Giarrusso
Cc: Jeff Dike
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
*) mark as "EXPERIMENTAL" various items that either aren't very stable or
that are actively crashing the setup of users which don't really need them
(i.e. HIGHMEM and 3-level pagetables on x86 - nobody needs either,
everybody reports "I'm using it and getting trouble").*) move net/Kconfig near to the rest of network configurations, and
drivers/block/Kconfig near "Block layer" submenu.*) it's useless and doesn't work well to force NETDEVICES on and to disable
the prompt like it's done. Better remove the attempt, and change that to a
simple "default y if UML".*) drop the warning about "report problems about HPPFS" - it's redundant
anyway, as that's the usual procedure, and HPPFS users are especially
technical (i.e. they know reporting bugs is _good_).Signed-off-by: Paolo 'Blaisorblade' Giarrusso
Cc: Jeff Dike
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Ugly trick to help make malloc not sleeping - we can't do anything else. But
this is not yet optimal, since spinlock don't trigger in_atomic() when
preemption is disabled.Also, even if ugly, this was already used in one place, and was even more
bogus. Fix it.Signed-off-by: Paolo 'Blaisorblade' Giarrusso
Cc: Jeff Dike
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
In a previous patch I shifted an allocation to being atomic.
In this patch, a better but more intrusive solution is implemented, i.e. hold
the lock only when really needing it, especially not over pipe operations, nor
over the culprit allocation.Additionally, while at it, add a missing kfree in the failure path, and make
sure that if we fail in forking, write_sigio_pid is -1 and not, say, -ENOMEM.And fix whitespace, at least for things I was touching anyway.
Signed-off-by: Paolo 'Blaisorblade' Giarrusso
Cc: Jeff Dike
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
In this error path, when the interface has had a problem, we call dev_close(),
which is disallowed for two reasons:*) takes again the UML internal spinlock, inside the ->stop method of this
device
*) can be called in process context only, while we're in interrupt context.I've also thought that calling dev_close() may be a wrong policy to follow,
but it's not up to me to decide that.However, we may end up with multiple dev_close() queued on the same device.
But the initial test for (dev->flags & IFF_UP) makes this harmless, though -
and dev_close() is supposed to care about races with itself. So there's no
harm in delaying the shutdown, IMHO.Something to mark the interface as "going to shutdown" would be appreciated,
but dev_deactivate has the same problems as dev_close(), so we can't use it
either.Signed-off-by: Paolo 'Blaisorblade' Giarrusso
Cc: Jeff Dike
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Pre-clear transport-specific private structure before passing it down.
In fact, I just got a slab corruption and kernel panic on exit because kfree()
was called on a pointer which probably was never allocated, BUT hadn't been
set to NULL by the driver.As the code is full of such errors, I've decided for now to go the safe way
(we're talking about drivers), and to do the simple thing. I'm also starting
to fix drivers, and already sent a patch for the daemon transport.Signed-off-by: Paolo 'Blaisorblade' Giarrusso
Cc: Jeff Dike
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Avoid uninitialized data in the daemon_data structure. I used this transport
before doing proper setup before-hand, and I got some very nice SLAB
corruption due to freeing crap pointers. So just make sure to clear
everything when appropriate.Signed-off-by: Paolo 'Blaisorblade' Giarrusso
Cc: Jeff Dike
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Some fixes to make softints work in tt mode.
Signed-off-by: Jeff Dike
Cc: Paolo 'Blaisorblade' Giarrusso
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Now that we are doing soft interrupts, there's no point in using sigsetjmp and
siglongjmp. Using setjmp and longjmp saves a sigprocmask on every jump.Signed-off-by: Jeff Dike
Cc: Paolo 'Blaisorblade' Giarrusso
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
This patch implements soft interrupts. Interrupt enabling and disabling no
longer map to sigprocmask. Rather, a flag is set indicating whether
interrupts may be handled. If a signal comes in and interrupts are marked as
OK, then it is handled normally. If interrupts are marked as off, then the
signal handler simply returns after noting that a signal needs handling. When
interrupts are enabled later on, this pending signals flag is checked, and the
IRQ handlers are called at that point.The point of this is to reduce the cost of local_irq_save et al, since they
are very much more common than the signals that they are enabling and
disabling. Soft interrupts produce a speed-up of ~25% on a kernel build.Subtleties -
UML uses sigsetjmp/siglongjmp to switch contexts. sigsetjmp has been
wrapped in a save_flags-like macro which remembers the interrupt state at
setjmp time, and restores it when it is longjmp-ed back to.The enable_signals function has to loop because the IRQ handler
disables interrupts before returning. enable_signals has to return with
signals enabled, and signals may come in between the disabling and the
return to enable_signals. So, it loops for as long as there are pending
signals, ensuring that signals are enabled when it finally returns, and
that there are no pending signals that need to be dealt with.Signed-off-by: Jeff Dike
Cc: Paolo 'Blaisorblade' Giarrusso
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Stop using global variables to hold the file descriptor and offset used to map
the skas0 stubs. Instead, calculate them using the page physical addresses.Signed-off-by: Jeff Dike
Cc: Paolo 'Blaisorblade' Giarrusso
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
The serial UML OS-abstraction layer patch (um/kernel/skas dir).
This moves all systemcalls from skas/process.c file under os-Linux dir and
join skas/process.c and skas/process_kern.c files.Signed-off-by: Gennady Sharapov
Signed-off-by: Jeff Dike
Cc: Paolo 'Blaisorblade' Giarrusso
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
The serial UML OS-abstraction layer patch (um/kernel/skas dir).
This moves all systemcalls from skas/mem_user.c file under os-Linux dir and
join skas/mem_user.c and skas/mem.c files.Signed-off-by: Gennady Sharapov
Signed-off-by: Jeff Dike
Cc: Paolo 'Blaisorblade' Giarrusso
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
