This adds an option to remove vm86 support under CONFIG_EMBEDDED. Saves
about 5k.
This version eliminates most of the #ifdefs of the previous version and
instead uses function stubs in vm86.h. Also, release_vm86_irqs is moved
from asm-i386/irq.h to a more appropriate home in vm86.h so that the stubs
can live together.
$ size vmlinux-baseline vmlinux-novm86
text data bss dec hex filename
2920821 523232 190652 3634705 377611 vmlinux-baseline
2916268 523100 190492 3629860 376324 vmlinux-novm86
Signed-off-by: Matt Mackall <mpm@selenic.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Configurable 16-bit UID and friends support
This allows turning off the legacy 16 bit UID interfaces on embedded platforms.
text data bss dec hex filename
3330172 529036 190556 4049764 3dcb64 vmlinux-baseline
3328268 529040 190556 4047864 3dc3f8 vmlinux
From: Adrian Bunk <bunk@stusta.de>
UID16 was accidentially disabled for !EMBEDDED.
Signed-off-by: Matt Mackall <mpm@selenic.com>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Factor out common code for different RUSAGE_xxx cases.
Don't take ->sighand->siglock in RUSAGE_SELF case, suggested by Ravikiran G
Thirumalai <kiran@scalex86.org>.
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Use first_cpu(cpu_possible_map) for the single-thread workqueue case. We
used to hardcode 0, but that broke on systems where !cpu_possible(0) when
workqueue_struct->cpu_workqueue_struct was changed from a static array to
alloc_percpu.
Commit id bce61dd49d ("Fix hardcoded cpu=0 in
workqueue for per_cpu_ptr() calls") fixed that for Ben's funky sparc64
system, but it regressed my Power5. Offlining cpu 0 oopses upon the next
call to queue_work for a single-thread workqueue, because now we try to
manipulate per_cpu_ptr(wq->cpu_wq, 1), which is uninitialized.
So we need to establish an unchanging "slot" for single-thread workqueues
which will have a valid percpu allocation. Since alloc_percpu keys off of
cpu_possible_map, which must not change after initialization, make this
slot == first_cpu(cpu_possible_map).
Signed-off-by: Nathan Lynch <ntl@pobox.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Remove the redundant spinlock in the function resolve_symbol() as we are
not altering the module list, and we already hold the semaphore.
Signed-off-by: Ashutosh Naik <ashutosh.naik@gmail.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Currently TAINT_FORCED_RMMOD is totally unused. Because it is marked as
TAINT_FORCED_MODULE instead when user forced a module unload. This patch
marks it correctly
Signed-off-by: Akinobu Mita <mita@miraclelinux.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Dave Jones <davej@codemonkey.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Ensure that an exported symbol does not already exist in the kernel or in
some other module's exported symbol table. This is done by checking the
symbol tables for the exported symbol at the time of loading the module.
Currently this is done after the relocation of the symbol.
Signed-off-by: Ashutosh Naik <ashutosh.naik@gmail.com>
Signed-off-by: Anand Krishnan <anandhkrishnan@yahoo.co.in>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
sys_setpgid() allows to change ->pgrp of ptraced childs.
'man setpgid' does not tell anything about that, so I consider
this behaviour is a bug.
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Oren Laadan <orenl@cs.columbia.edu>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
setsid() does not work unless the calling process is a
thread_group_leader().
'man setpgid' does not tell anything about that, so I consider this
behaviour is a bug.
Signed-off-by: Oren Laadan <orenl@cs.columbia.edu>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
setpgid(0, pgid) or setpgid(forked_child_pid, pgid) does not work unless
the calling process is a thread_group_leader().
'man setpgid' does not tell anything about that, so I consider this
behaviour is a bug.
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Oren Laadan <orenl@cs.columbia.edu>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
In fork, child should recopy parent's pgrp/tty after it has tasklist_lock.
Otherwise following a setpgid() on the parent, *after* copy_signal(), the
child will own a stale pgrp (which may be reused); (eg. if copy_mm()
sleeps a long while due to memory pressure). Similar issue for the tty.
Signed-off-by: Oren Laadan <orenl@cs.columbia.edu>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The problem. It is expected that /sbin/halt -p works exactly like
/sbin/halt, when the kernel does not implement power off functionality.
The kernel can do a lot of work in the reboot notifiers and in
device_shutdown before we even get to machine_power_off. Some of that
shutdown is not safe if you are leaving the power on, and it definitely
gets in the way of using sysrq or pressing ctrl-alt-del. Since the
shutdown happens in generic code there is no way to fix this in
architecture specific code :(
Some machines are kernel oopsing today because of this.
The simple solution is to turn LINUX_REBOOT_CMD_POWER_OFF into
LINUX_REBOOT_CMD_HALT if power_off functionality is not implemented.
This has the unfortunate side effect of disabling the power off
functionality on architectures that leave pm_power_off to null and still
implement something in machine_power_off. And it will break the build on
some architectures that don't have a pm_power_off variable at all.
On both counts I say tough.
For architectures like alpha that don't implement the pm_power_off variable
pm_power_off is declared in linux/pm.h and it is a generic part of our
power management code, and all architectures should implement it.
For architectures like parisc that have a default power off method in
machine_power_off if pm_power_off is not implemented or fails. It is easy
enough to set the pm_power_off variable. And nothing bad happens there,
the machines just stop powering off.
The current semantics are impossible without a flag at the top level so we
can avoid the problem code if a power off is not implemented. pm_power_off
is as good a flag as any with the bonus that it works without modification
on at least x86, x86_64, powerpc, and ppc today.
Andrew can you pick this up and put this in the mm tree. Kernels that
don't compile or don't power off seem saner than kernels that oops or
panic. Until we get the arch specific patches for the problem
architectures this probably isn't smart to push into the stable kernel.
Unfortunately I don't have the time at the moment to walk through every
architecture and make them work. And even if I did I couldn't test it :(
From: Hirokazu Takata <takata@linux-m32r.org>
Add pm_power_off() for build fix of arch/m32r/kernel/process.c.
From: Miklos Szeredi <miklos@szeredi.hu>
UML build fix
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Hayato Fujiwara <fujiwara@linux-m32r.org>
Signed-off-by: Hirokazu Takata <takata@linux-m32r.org>
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch forces RCU torture threads off various CPUs in the system
allowing them to become idle and go tickless. Meant to test support for
such tickless idle CPU in RCU.
Signed-off-by: Srivatsa Vaddagiri <vatsa@in.ibm.com>
Cc: Dipankar Sarma <dipankar@in.ibm.com>
Cc: "Paul E. McKenney" <paulmck@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Kernels that have had Windows drivers loaded into them are undebuggable.
I've wasted a number of hours chasing bugs filed in Fedora bugzilla only to
find out much later that the user had used such 'helpers', and their
problems were unreproducable without them loaded.
Acked-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Dave Jones <davej@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Some long time ago, dentry struct was carefully tuned so that on 32 bits
UP, sizeof(struct dentry) was exactly 128, ie a power of 2, and a multiple
of memory cache lines.
Then RCU was added and dentry struct enlarged by two pointers, with nice
results for SMP, but not so good on UP, because breaking the above tuning
(128 + 8 = 136 bytes)
This patch reverts this unwanted side effect, by using an union (d_u),
where d_rcu and d_child are placed so that these two fields can share their
memory needs.
At the time d_free() is called (and d_rcu is really used), d_child is known
to be empty and not touched by the dentry freeing.
Lockless lookups only access d_name, d_parent, d_lock, d_op, d_flags (so
the previous content of d_child is not needed if said dentry was unhashed
but still accessed by a CPU because of RCU constraints)
As dentry cache easily contains millions of entries, a size reduction is
worth the extra complexity of the ugly C union.
Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Cc: Dipankar Sarma <dipankar@in.ibm.com>
Cc: Maneesh Soni <maneesh@in.ibm.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: "Paul E. McKenney" <paulmck@us.ibm.com>
Cc: Ian Kent <raven@themaw.net>
Cc: Paul Jackson <pj@sgi.com>
Cc: Al Viro <viro@ftp.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: Neil Brown <neilb@cse.unsw.edu.au>
Cc: James Morris <jmorris@namei.org>
Cc: Stephen Smalley <sds@epoch.ncsc.mil>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch removes unneeded sig->curr_target recalculation under 'if
(atomic_dec_and_test(&sig->count))' in __exit_signal().
When sig->count == 0 the signal can't be sent to this task and
next_thread(tsk) == tsk anyway.
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
zap_other_threads() sets SIGNAL_GROUP_EXIT at the very start,
do_group_exit() doesn't need to do it.
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
__create_workqueue() not checking return of alloc_percpu()
NULL dereference was possible.
Signed-off-by: Ben Collins <bcollins@ubuntu.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
While rooting aroung in the signal code trying to understand how to fix the
SIG_IGN ploy (set sig handler to SIG_IGN and flood system with high speed
repeating timers) I came across what, I think, is a problem in sigaction()
in that when processing a SIG_IGN request it flushes signals from 1 to
SIGRTMIN and leaves the rest. Attempt to fix this.
Signed-off-by: George Anzinger <george@mvista.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
What's the true meaning of the printk return value? Should it include the
priority prefix length of 3? and what about the timing information? In
both cases it was broken:
strace -e write echo 1 > /dev/kmsg
=> write(1, "1\n", 2) = 5
strace -e write echo "<1>1" > /dev/kmsg
=> write(1, "<1>1\n", 5) = 8
The returned length was "length of input string + 3", I made it "length
of string output to the log buffer".
Note that I couldn't find any printk caller in the kernel interested by its
return value besides kmsg_write.
Signed-off-by: Guillaume Chazarain <guichaz@yahoo.fr>
Acked-By: Tim Bird <tim.bird@am.sony.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The ptrace_get_task_struct() helper that I added as part of the ptrace
consolidation is useful in variety of places that currently opencode it.
Switch them to the common helpers.
Add a ptrace_traceme() helper that needs to be explicitly called, and simplify
the ptrace_get_task_struct() interface. We don't need the request argument
now, and we return the task_struct directly, using ERR_PTR() for error
returns. It's a bit more code in the callers, but we have two sane routines
that do one thing well now.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Use atomic_inc_not_zero for rcu files instead of special case rcuref.
Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: "Paul E. McKenney" <paulmck@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch contains the following cleanups:
- make needlessly global functions static
- every file should include the headers containing the prototypes for
it's global functions
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Acked-by: "Paul E. McKenney" <paulmck@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
