This patch starts the removal of a very old, very broken piece of code. This
stems from the problem of passing a userspace buffer into read() or write() on
the host. If that buffer had not yet been faulted in, read and write will
return -EFAULT.
To avoid this problem, the solution was to fault the buffer in before the
system call by touching the pages that hold the buffer by doing a copy-user of
a byte to each page. This is obviously bogus, but it does usually work, in tt
mode, since the kernel and process are in the same address space and userspace
addresses can be accessed directly in the kernel.
In skas mode, where the kernel and process are in separate address spaces, it
is completely bogus because the userspace address, which is invalid in the
kernel, is passed into the system call instead of the corresponding physical
address, which would be valid. Here, it appears that this code, on every host
read() or write(), tries to fault in a random process page. This doesn't seem
to cause any correctness problems, but there is a performance impact. This
patch, and the ones following, result in a 10-15% performance gain on a kernel
build.
This code can't be immediately tossed out because when it is, you can't log
in. Apparently, there is some code in the console driver which depends on
this somehow.
However, we can start removing it by switching the code which does I/O using
kernel addresses to using plain read() and write(). This patch introduces
os_read_file_k and os_write_file_k for use with kernel buffers and converts
all call locations which use obvious kernel buffers to use them. These
include I/O using buffers which are local variables which are on the stack or
kmalloc-ed. Later patches will handle the less obvious cases, followed by a
mass conversion back to the original interface.
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>
Provide a register dump if handle_trap fails. Abstract out ptrace_dump_regs
since it now has two callers.
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>
If there's a segfault inside the kernel, we want a dump of the registers at
the point of the segfault, not the registers at the point of calling panic or
the last userspace registers.
sig_handler_common_skas now uses a static register set in the case of a
SIGSEGV to avoid messing up the process registers if the segfault turns out to
be non-fatal.
The architecture sigcontext-to-pt_regs copying code was repurposed to copy
data out of the SEGV stack frame.
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>
Tidying in preparation for the segfault register dumping patch which follows.
void * pointers are changed to union uml_pt_regs *. This makes the types
match reality, except in arch_fixup, which is changed to operate on a union
uml_pt_regs. This fixes a bug in the call from segv_handler, which passes a
union uml_pt_regs, to segv, which expects to pass a struct sigcontext to
arch_fixup.
Whitespace and other style fixes.
There's also a errno printk 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>
userspace code used to have to call the kernelspace function page_size() in
order to determine the value of the kernel's PAGE_SIZE. Since this is now
available directly from kern_constants.h as UM_KERN_PAGE_SIZE, page_size() can
be deleted and calls changed to use the constant.
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>
The build started finding calls from non-init to init functions. These are
just cases of init functions not being properly marked, so this patch fixes
that.
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>
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>
Rescue the useful contents of the soon-to-be-gone user-util.h.
pty.c now gets ptsname from stdlib.h like it should have always done.
CATCH_EINTR is now in os.h, although perhaps all usage should be under
os-Linux at some point.
get_pty is also in os.h.
This patch restores the old definition of ARRAY_SIZE in user.h. This file is
included only in userspace files, so there will be no conflict with the
kernel's new ARRAY_SIZE. The copy of the kernel's ARRAY_SIZE and associated
infrastructure 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>
This patch moves all the the symbols defined in um_arch.c, which are mostly
boundaries between different parts of the UML kernel address space, to a new
header, as-layout.h. There are also a few things here which aren't really
related to address space layout, but which don't really have a better place to
go.
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>
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>
This fixes a number of problems associated with network interface hotplug.
The userspace initialization function can fail in some cases, but the
failure was never passed back to eth_configure, which proceeded with the
configuration. This results in a zombie device that is present, but can't
work. This is fixed by allowing the initialization routines to return an
error, which is checked, and the configuration aborted on failure.
eth_configure failed to check for many failures. Even when it did check,
it didn't undo whatever initializations has already happened, so a present,
but partially initialized and non-working device could result. It now
checks everything that can fail, and bails out, undoing whatever had been
done.
The return value of eth_configure was always ignored, so it is now just
void.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Jeff Garzik <jeff@garzik.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix a bunch of formatting violations in the drivers:
return(n) -> return n
whitespace fixes
emacs formatting comment removal
breaking if(foo) return(n) into two lines
There are also a couple of errno use bugs:
using errno in a printk when the failure put errno into a local variable
saving errno after a printk, which can change 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>
Print out core dump limits at boot time. This is to allow core dumps
to be collected if something goes very wrong and to tell if a core
dump isn't going to happen because of a resource limit.
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>
Move the host_info string from util.c to um_arch.c, where it is
actually initialized and used. Also document its lack of locking.
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>
Get rid of a bunch of unused stuff -
cpu_feature had no users
linux_prog is little-used, so its declaration is moved to the
user for easy deletion when the whole file goes away
a long-unused debugging aid in helper.c is gone
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>
For the places where we need a pointer to the mac header, it is still legal to
touch skb->mac.raw directly if just adding to, subtracting from or setting it
to another layer header.
This one also converts some more cases to skb_reset_mac_header() that my
regex missed as it had no spaces before nor after '=', ugh.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch uses MAX_REG_NR consistently to refer to the register file size.
FRAME_SIZE isn't sufficient because on x86_64, it is smaller than the
ptrace register file size. MAX_REG_NR was introduced as a consistent way
to get the number of registers, but wasn't used everywhere it should be.
When this causes a problem, it makes PTRACE_SETREGS fail on x86_64 because
of a corrupted segment register value in the known-good register file. The
patch also adds a register dump at that point in case there are any future
problems here.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
os_usr1_signal() is totally unused, os_usr1_process() is used only by TT mode.
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Acked-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Comment the fact that sig_info is initialized early in boot, and thus doesn't
need any locking.
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>
Add a debugging message in the case that mapping a stub fails.
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>
This fixes a problem seen by a number of people running UML on newer host
kernels. init would hang with an infinite segfault loop.
It turns out that the host kernel was providing a AT_SYSINFO_EHDR of
0xffffe000, which faked UML into believing that the host VDSO page could be
reused. However, AT_SYSINFO pointed into the middle of the address space, and
was unmapped as a result. Because UML was providing AT_SYSINFO_EHDR and
AT_SYSINFO to its own processes, these would branch to nowhere when trying to
use the VDSO.
The fix is to also check the location of AT_SYSINFO when deciding whether to
use the host's VDSO.
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>
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>
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>
x86_64 needs some TLS fixes. What was missing was remembering the child
thread id during clone and stuffing it into the child during each context
switch.
The %fs value is stored separately in the thread structure since the host
controls what effect it has on the actual register file. The host also needs
to store it in its own thread struct, so we need the value kept outside the
register file.
arch_prctl_skas was fixed to call PTRACE_ARCH_PRCTL appropriately. There is
some saving and restoring of registers in the ARCH_SET_* cases so that the
correct set of registers are changed on the host and restored to the process
when it runs again.
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>
The startup code panics a lot if anything goes wrong early on. This is wrong
for several reasons, like the kernel isn't running, so you can't really be
calling into it yet, but the harm comes from useful error messages being
trapped in the printk ring where no one will ever see them.
This patch changes these panics to perror and printf in wrappers which also
exit. Normal, informational, prints are also wrapped so that fflush(stdout)
is called after each one. This is so the output appears in the correct
sequence in the event of an error.
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>
Comment the lack of locking of data that's set up once at boot time.
Also fixed a couple of bogus printks.
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>
Formatting fixes in the register handling code.
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>
Comment the lack of locking of the elf data extracted from the ELF headers
passed to UML.
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>
Add an error message when two umids are put on the command line.
umid.h is kind of pointless since it only declares one thing, and that
is already declared in os.h.
Commented the lack of locking of some data in os-Linux/umid.h.
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>
Tidying the irq code -
make a variable static
activate_fd can call kmalloc directly since it's now kernel code
added a no-locking comment
fixed a style violation
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>
Fix a bunch of style violations in mem.c.
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>
We shouldn't be using the os wrappers from os code - we can use libc directly.
This patch replaces wrapper calls with libc calls.
It turns out that os_sigio_async had only one caller, which was in startup.c,
so that function is moved there and its name changed.
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>
Some style fixes in startup.c.
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>
Add a couple of comments about some non-locked data.
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>
Locking comments and emacs comment removal in the low-level memory and
temp file code.
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>
When the UML network driver generates random MACs for its devices, it was
possible for a number of UMLs to get the same MACs because the ethernet
initialization was done before the random pool was properly seeded.
This patch moves the initialization later so that it gets better randomness.
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>
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: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Acked-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
In order to get the __NR_* constants, we need sys/syscall.h.
linux/unistd.h works as well since it includes syscall.h, however syscall.h
is more parsimonious. We were inconsistent in this, and this patch adds
syscall.h includes where necessary and removes linux/unistd.h includes
where they are not needed.
asm/unistd.h also includes the __NR_* constants, but these are not the
glibc-sanctioned ones, so this also removes one such inclusion.
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>
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: 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>
Fix commit 5f4c6bc1f3: it spits out warnings
about missing syscall prototype (it is in <unistd.h>) and it does not
recognize that two uses of _syscallX are to be resolved against kernel
headers in the source tree, not against _syscallX; they in fact do not
compile and would not work anyway.
If _syscallX macros will be removed from the kernel tree altogether, the
only reasonable solution for that piece of code is switching to open-coded
inline assembly (it's remapping the whole executable from memory, except
the page containing this code).
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>
Freeing the stack is left uselessly to the caller of run_helper in some cases
- this is taken from run_helper_thread, but here it is useless, so no caller
needs it and the only place where this happens has a potential leak - in case
of error neither run_helper() nor xterm_open() call free_stack(). At this
point passing a pointer is not needed - the stack pointer should be passed
directly, but this change is not done here.
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>
CONFIG_MODE_TT does not work there, the UML_ prefixed version must be used -
this causes a link-time failure when CONFIG_MODE_TT is enabled (i.e. always
here, never by Jeff).
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>
Fix coding conventions violations is arch/um/os-Linux/helper.c.
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>
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>
On a 64bit Uml, if run under "setarch i386" (which a user did), uname()
currently returns the obtained i686 as machine - fix that. Btw, I'm quite
surprised that under setarch i386 a 64-bit binary can run.
Cc: Andi Kleen <ak@suse.de>
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>
Make TT mode compile after the introduction of klibc's implementation of
setjmp.
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>
User mode linux uses _syscallX() to call into the host kernel. The
recommended way to do this is to use the syscall() function from libc.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Andi Kleen <ak@muc.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Ian Molton <spyro@f2s.com>
Cc: Mikael Starvik <starvik@axis.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Hirokazu Takata <takata.hirokazu@renesas.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Kazumoto Kojima <kkojima@rr.iij4u.or.jp>
Cc: Richard Curnow <rc@rc0.org.uk>
Cc: William Lee Irwin III <wli@holomorphy.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Miles Bader <uclinux-v850@lsi.nec.co.jp>
Cc: Chris Zankel <chris@zankel.net>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Close two file descriptor leaks, one in the ubd driver and one to
/proc/mounts. The ubd driver bug also leaked some vmalloc space. The
/proc/mounts leak was a descriptor that was just never closed.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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: 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>
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: 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>
Make lots of structures const in order to make it obvious that they need no
locking.
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>
The KSTK_* macros used an inordinate amount of stack. In order to overcome
an impedance mismatch between their interface, which just returns a single
register value, and the interface of get_thread_regs, which took a full
pt_regs, the implementation created an on-stack pt_regs, filled it in, and
returned one field. do_task_stat calls KSTK_* twice, resulting in two
local pt_regs, blowing out the stack.
This patch changes the interface (and name) of get_thread_regs to just
return a single register from a jmp_buf.
The include of archsetjmp.h" in registers.h to get the definition of
jmp_buf exposed a bogus include of <setjmp.h> in start_up.c. <setjmp.h>
shouldn't be used anywhere any more since UML uses the klibc
setjmp/longjmp.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
timer_irq_inited was useless, so it is removed.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
set_interval returns an error instead of panicing if setitimer fails. Some of
its callers now check the return.
enable_timer is largely tt-mode-specific, so it is marked as such, and the
only skas-mode caller is made to call set-interval instead.
user_time_init was a no-value-added wrapper around set_interval, so it is
gone.
Since set_interval is now called from kernel code, callers no longer pass
ITIMER_* to it. Instead, they pass a flag which is converted into ITIMER_REAL
or ITIMER_VIRTUAL.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Have most signals go through an arch-provided handler which recovers the
sigcontext and then calls a generic handler. This replaces the
ARCH_GET_SIGCONTEXT macro, which was somewhat fragile. On x86_64, recovering
%rdx (which holds the sigcontext pointer) must be the first thing that
happens. sig_handler duly invokes that first, but there is no guarantee that
I can see that instructions won't be reordered such that %rdx is used before
that. Having the arch provide the handler seems much more robust.
Some signals in some parts of UML require their own handlers - these places
don't call set_handler any more. They call sigaction or signal themselves.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
- 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>
There were some bugs in handling failures to exec helper programs. errno was
passed back from the child with the wrong sign. It was also ignored. In the
case where it mattered, the errno from the (successful) read in the parent was
used instead.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
There were a bunch of missed ARRAY_SIZE opportunities.
Also, some formatting fixes in the affected areas of code.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch adds an implementation of setjmp and longjmp to UML, allowing
access to the inside of a jmpbuf without needing the access macros formerly
provided by libc.
The implementation is stolen from klibc. I copy the relevant files into
arch/um. I have another patch which avoids the copying, but requires klibc be
in the tree.
setjmp and longjmp users required some tweaking. Includes of <setjmp.h> were
removed and includes of the UML longjmp.h were added where necessary. There
are also replacements of siglongjmp with UML_LONGJMP which I somehow missed
earlier.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The UML_SETJMP macro was requiring its users to pass in a argument which it
could supply itself, since it wasn't used outside that invocation of the
macro.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Add some more uses of the CATCH_EINTR wrapper.
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>
Fix a bunch of formatting problems.
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>
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>
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>
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>
uml_idle_timer is tt-mode only, so ifdef it as such to make it easier to spot
when tt mode is killed.
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>
It turns out that init_new_thread_signals is always called with altstack == 1,
so we can eliminate the parameter.
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>
wall_to_monotonic isn't used in this file, so we can remove the declaration.
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>
This cleans up the mess that is the timer initialization. There used to be
two timer handlers - one that basically ran during delay loop calibration and
one that handled the timer afterwards. There were also two sets of timer
initialization code - one that starts in user code and calls into the kernel
side of the house, and one that starts in kernel code and calls user code.
This eliminates one timer handler and consolidates the two sets of
initialization code.
[akpm@osdl.org: use new INTF_ flags]
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>
Rename actually_do_remove() to remove_files_and_dir(), make it call
closedir(), make it ignore ENOENT (I see it frequently enough).
ENOENT is probably due to multiple threads calling the exitcall functions
together*, but fixing that is non-trivial; and ignoring it is perfectly ok
in any case.
* it can surely happen: last_ditch_exit() is installed as SIGTERM handler
at boot, and it's not removed on thread creation. So killall vmlinux
(which I do) surely causes that. I've seen also a crash which seems to
do the same.
Installing the handler on only the main thread would make UML do no cleanup
when another thread exits, and we're not sure we want that. And mutual
exclusion in that context is tricky - we can't use spinlock in code not on
a kernel stack (spinlock debugging uses "current" a lot).
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>
The bug occurred to me when a UML left an empty ~/.uml/Sarge-norm folder -
when trying to reuse not_dead_yet() failed one of its check. The comment
says that's ok and means that we can take the directory, but while normally
not_dead_yet() removes it and returns 0 (i.e. go on, use this), on failure
it returns 0 but forgets to remove it. The fix is to remove it anytime
we're going to return 0.
But since "not_dead_yet" didn't make the interface so clear, causing this
bug, and I couldn't find a convenient name for the mix of things it did, I
split it into two parts:
is_umdir_used() - returns a boolean, contains all checks of not_dead_yet()
umdir_take_if_dead - tries to remove the dir unless it's used - returns
whether it removed it, that is we now own it.
With this changes the control flow is IMHO a bit clearer and needs less
comment for control flow.
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>
Fix an off-by-one bug in temp file creation. Seeking to the desired length
and writing a byte resulted in the file being one byte longer than expected.
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>
When parsing /proc/mounts looking for a tmpfs mount on /dev/shm, if a string
that we are looking for if split across reads, then it won't be recognized.
Fix this by refilling the buffer whenever we advance the cursor.
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>
From: Jeff Dike <jdike@addtoit.com>
We had a spurious semicolon somehow.
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>
From: Jeff Dike <jdike@addtoit.com>
Initialize wall_to_monotonic correctly. This fixes a problem where sleeps
lasted about one secone less than they should. This also called for a bit of
code restructuring, following a patch which Blaisorblade had been keeping.
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>
GCC hardened introduces additional symbol refererences (for the canary and
friends), also in modules - add weak export_symbols for them. We already
tested that the weak declaration creates no problem on both GCC's providing
the function definition and on GCC's which don't provide it.
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Acked-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Append /usr/lib/uml to the existing PATH environment variable to let execvp()
search uml_net in FHS compliant locations.
Signed-off-by: Mattia Dongili <malattia@linux.it>
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Acked-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Blairsorblade noticed some confusion between our use of a system
call's return value and errno. This patch fixes a number of related
bugs -
using errno instead of a return value
using a return value instead of errno
forgetting to negate a error return to get a positive error code
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>
The MADVISE_REMOVE-checking code didn't clean up after itself.
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>
Remove redundant NULL checks before [kv]free + small CodingStyle cleanup for
arch/
Signed-off-by: Jesper Juhl <jesper.juhl@gmail.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>
UML really wants shared memory semantics form its physical memory map file,
and the place for that is /dev/shm. So move the default, and fix the error
messages to recognize that this value can be overridden.
Signed-off-by: Rob Landley <rob@landley.net>
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Clean up the jmpbuf code. Since softints, we no longer use sig_setjmp, so
the UML_SIGSETJMP wrapper now has a misleading name. Also, I forgot to
change the buffers from sigjmp_buf to jmp_buf.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
MADV_REMOVE fixes - change the test mapping to be MAP_SHARED instead of
MAP_PRIVATE, as MADV_REMOVE on MAP_PRIVATE maps won't work. Also, use
the kernel's definition of MADV_REMOVE instead of hardcoding it if there
isn't a libc definition.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Switch this proc from storing 4k of data (a whole path) on the stack to
keeping it on the heap.
Maybe it's not called in process context but only in early boot context (where
in UML you have a normal process stack on the host) but just to be safe, fix
it.
While at it some little readability simplifications.
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>
Little fix for error paths in this code.
- Some bug come from conversion to os-Linux (open() doesn't follow the
kernel -errno return convention, while the old code called os_open_file()
which followed it). This caused the wrong return code to be printed.
- Then be more precise about what happened and do some whitespace fixes.
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>
Fix an hang on a pipe when run_helper() fails when called by change_tramp()
(i.e. when calling uml_net) - reproduced the bug and verified this fixes 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>
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>
Some functions are exported twice in current code - remove the excess export.
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>
Now that GCC warns about format errors, fix them. Nothing able to cause a
crash, however.
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>
Two small TLS fixes -
arch/um/os-Linux/sys-i386/tls.c uses errno and -E* so it should include
errno.h
__setup_host_supports_tls returns 1, but as an initcall, it should return 0
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
If running on a host not supporting TLS (for instance 2.4) we should report
that cleanly to the user, instead of printing not comprehensible "error 5" for
that.
Additionally, i386 and x86_64 support different ranges for
user_desc->entry_number, and we must account for that; we couldn't pass
ourselves -1 because we need to override previously existing TLS descriptors
which glibc has possibly set, so test at startup the range to use.
x86 and x86_64 existing ranges are hardcoded.
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Acked-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Copy the definition of struct user_desc (with another name) for use by
userspace sources (where we use the host headers, and we can't be sure about
their content) to make sure UML compiles.
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Acked-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Implement sys_[gs]et_thread_area and the corresponding ptrace operations for
UML. This is the main chunk, additional parts follow. This implementation is
now well tested and has run reliably for some time, and we've understood all
the previously existing problems.
Their implementation saves the new GDT content and then forwards the call to
the host when appropriate, i.e. immediately when the target process is
running or on context switch otherwise (i.e. on fork and on ptrace() calls).
In SKAS mode, we must switch registers on each context switch (because SKAS
does not switches tls_array together with current->mm).
Also, added get_cpu() locking; this has been done for SKAS mode, since TT does
not need it (it does not use smp_processor_id()).
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Acked-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Removed assignments to unused variables in arch/um/os-Linux/Makefile
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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>
A number of UML initcalls were improperly returning 1. Also removed any
nearby emacs formatting comments.
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>
Changes since first version
added check for MADV_REMOVE support on the host
fixed error return botch
shrunk sprintf array by one character
This adds hotplug memory support to UML. The mconsole syntax is
config mem=[+-]n[KMG]
In other words, add or subtract some number of kilobytes, megabytes, or
gigabytes.
Unplugged pages are allocated and then madvise(MADV_TRUNCATE), which is a
currently experimental madvise extension. These pages are tracked so they
can be plugged back in later if the admin decides to give them back. The
first page to be unplugged is used to keep track of about 4M of other
pages. A list_head is the first thing on this page. The rest is filled
with addresses of other unplugged pages. This first page is not madvised,
obviously.
When this page is filled, the next page is used in a similar way and linked
onto a list with the first page. Etc. This whole process reverses when
pages are plugged back in. When a tracking page no longer tracks any
unplugged pages, then it is next in line for plugging, which is done by
freeing pages back to the kernel.
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>
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>
Behavior when booting two UMLs with the same umid was broken. The second one
would steal the umid. This fixes that, making the second UML take a random
umid instead.
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>
The serial UML OS-abstraction layer patch (um/kernel dir).
This moves all systemcalls from tty_log.c file under os-Linux dir
Signed-off-by: Gennady Sharapov <Gennady.V.Sharapov@intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
