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  1. 01 4月, 2006 1 次提交
    • E
      [PATCH] Make setsid() more robust · 390e2ff0
      由 Eric W. Biederman 提交于 
      The core problem: setsid fails if it is called by init.  The effect in 2.6.16
and the earlier kernels that have this problem is that if you do a "ps -j 1 or
ps -ej 1" you will see that init and several of it's children have process
group and session == 0.  Instead of process group == session == 1.  Despite
init calling setsid.

The reason it fails is that daemonize calls set_special_pids(1,1) on kernel
threads that are launched before /sbin/init is called.

The only remaining effect in that current->signal->leader == 0 for init
instead of 1.  And the setsid call fails.  No one has noticed because
/sbin/init does not check the return value of setsid.

In 2.4 where we don't have the pidhash table, and daemonize doesn't exist
setsid actually works for init.

I care a lot about pid == 1 not being a special case that we leave broken,
because of the container/jail work that I am doing.

- Carefully allow init (pid == 1) to call setsid despite the kernel using
  its session.

- Use find_task_by_pid instead of find_pid because find_pid taking a
  pidtype is going away.
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      390e2ff0
  3. 29 3月, 2006 2 次提交
  5. 28 3月, 2006 1 次提交
    • A
      [PATCH] Notifier chain update: API changes · e041c683
      由 Alan Stern 提交于 
      The kernel's implementation of notifier chains is unsafe.  There is no
protection against entries being added to or removed from a chain while the
chain is in use.  The issues were discussed in this thread:

    http://marc.theaimsgroup.com/?l=linux-kernel&m=113018709002036&w=2

We noticed that notifier chains in the kernel fall into two basic usage
classes:

	"Blocking" chains are always called from a process context
	and the callout routines are allowed to sleep;

	"Atomic" chains can be called from an atomic context and
	the callout routines are not allowed to sleep.

We decided to codify this distinction and make it part of the API.  Therefore
this set of patches introduces three new, parallel APIs: one for blocking
notifiers, one for atomic notifiers, and one for "raw" notifiers (which is
really just the old API under a new name).  New kinds of data structures are
used for the heads of the chains, and new routines are defined for
registration, unregistration, and calling a chain.  The three APIs are
explained in include/linux/notifier.h and their implementation is in
kernel/sys.c.

With atomic and blocking chains, the implementation guarantees that the chain
links will not be corrupted and that chain callers will not get messed up by
entries being added or removed.  For raw chains the implementation provides no
guarantees at all; users of this API must provide their own protections.  (The
idea was that situations may come up where the assumptions of the atomic and
blocking APIs are not appropriate, so it should be possible for users to
handle these things in their own way.)

There are some limitations, which should not be too hard to live with.  For
atomic/blocking chains, registration and unregistration must always be done in
a process context since the chain is protected by a mutex/rwsem.  Also, a
callout routine for a non-raw chain must not try to register or unregister
entries on its own chain.  (This did happen in a couple of places and the code
had to be changed to avoid it.)

Since atomic chains may be called from within an NMI handler, they cannot use
spinlocks for synchronization.  Instead we use RCU.  The overhead falls almost
entirely in the unregister routine, which is okay since unregistration is much
less frequent that calling a chain.

Here is the list of chains that we adjusted and their classifications.  None
of them use the raw API, so for the moment it is only a placeholder.

  ATOMIC CHAINS
  -------------
arch/i386/kernel/traps.c:		i386die_chain
arch/ia64/kernel/traps.c:		ia64die_chain
arch/powerpc/kernel/traps.c:		powerpc_die_chain
arch/sparc64/kernel/traps.c:		sparc64die_chain
arch/x86_64/kernel/traps.c:		die_chain
drivers/char/ipmi/ipmi_si_intf.c:	xaction_notifier_list
kernel/panic.c:				panic_notifier_list
kernel/profile.c:			task_free_notifier
net/bluetooth/hci_core.c:		hci_notifier
net/ipv4/netfilter/ip_conntrack_core.c:	ip_conntrack_chain
net/ipv4/netfilter/ip_conntrack_core.c:	ip_conntrack_expect_chain
net/ipv6/addrconf.c:			inet6addr_chain
net/netfilter/nf_conntrack_core.c:	nf_conntrack_chain
net/netfilter/nf_conntrack_core.c:	nf_conntrack_expect_chain
net/netlink/af_netlink.c:		netlink_chain

  BLOCKING CHAINS
  ---------------
arch/powerpc/platforms/pseries/reconfig.c:	pSeries_reconfig_chain
arch/s390/kernel/process.c:		idle_chain
arch/x86_64/kernel/process.c		idle_notifier
drivers/base/memory.c:			memory_chain
drivers/cpufreq/cpufreq.c		cpufreq_policy_notifier_list
drivers/cpufreq/cpufreq.c		cpufreq_transition_notifier_list
drivers/macintosh/adb.c:		adb_client_list
drivers/macintosh/via-pmu.c		sleep_notifier_list
drivers/macintosh/via-pmu68k.c		sleep_notifier_list
drivers/macintosh/windfarm_core.c	wf_client_list
drivers/usb/core/notify.c		usb_notifier_list
drivers/video/fbmem.c			fb_notifier_list
kernel/cpu.c				cpu_chain
kernel/module.c				module_notify_list
kernel/profile.c			munmap_notifier
kernel/profile.c			task_exit_notifier
kernel/sys.c				reboot_notifier_list
net/core/dev.c				netdev_chain
net/decnet/dn_dev.c:			dnaddr_chain
net/ipv4/devinet.c:			inetaddr_chain

It's possible that some of these classifications are wrong.  If they are,
please let us know or submit a patch to fix them.  Note that any chain that
gets called very frequently should be atomic, because the rwsem read-locking
used for blocking chains is very likely to incur cache misses on SMP systems.
(However, if the chain's callout routines may sleep then the chain cannot be
atomic.)

The patch set was written by Alan Stern and Chandra Seetharaman, incorporating
material written by Keith Owens and suggestions from Paul McKenney and Andrew
Morton.

[jes@sgi.com: restructure the notifier chain initialization macros]
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NChandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: NJes Sorensen <jes@sgi.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      e041c683
  7. 26 3月, 2006 3 次提交
  9. 24 3月, 2006 3 次提交
    • A
      [PATCH] RLIMIT_CPU: document wrong return value · d3561f78
      由 Andrew Morton 提交于 
      Document the fact that setrlimit(RLIMIT_CPU) doesn't return error codes when
it should.  I don't think we can fix this without a 2.7.x..

Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Ulrich Weigand <uweigand@de.ibm.com>
Cc: Cliff Wickman <cpw@sgi.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      d3561f78
    • A
      [PATCH] RLIMIT_CPU: fix handling of a zero limit · e0661111
      由 Andrew Morton 提交于 
      At present the kernel doesn't honour an attempt to set RLIMIT_CPU to zero
seconds.  But the spec says it should, and that's what 2.4.x does.

Fixing this for real would involve some complexity (such as adding a new
it-has-been-set flag to the task_struct, and testing that everwhere, instead
of overloading the value of it_prof_expires).

Given that a 2.4 kernel won't actually send the signal until one second has
expired anyway, let's just handle this case by treating the caller's
zero-seconds as one second.

Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Ulrich Weigand <uweigand@de.ibm.com>
Cc: Cliff Wickman <cpw@sgi.com>
Acked-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      e0661111
    • A
      [PATCH] sys_setrlimit() cleanup · ec9e16ba
      由 Andrew Morton 提交于 
      - Whitespace cleanups

- Make that expression comprehensible.

There's a potential logic change here: we do the "is it_prof_expires equal to
zero" test after converting it to seconds, rather than doing the comparison
between raw cputime_t's.

But given that it's in units of seconds anyway, that shouldn't change
anything.

Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Ulrich Weigand <uweigand@de.ibm.com>
Cc: Cliff Wickman <cpw@sgi.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      ec9e16ba
  11. 23 3月, 2006 2 次提交
  13. 08 2月, 2006 1 次提交
  15. 12 1月, 2006 2 次提交
  17. 09 1月, 2006 5 次提交
    • O
      [PATCH] simplify k_getrusage() · 0f59cc4a
      由 Oleg Nesterov 提交于 
      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: NOleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      0f59cc4a
    • O
      [PATCH] setpgid: should not accept ptraced childs · f7dd795e
      由 Oleg Nesterov 提交于 
      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: NOleg Nesterov <oleg@tv-sign.ru>
Cc: Oren Laadan <orenl@cs.columbia.edu>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      f7dd795e
    • O
      [PATCH] setpgid: should work for sub-threads · e19f247a
      由 Oren Laadan 提交于 
      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: NOren Laadan <orenl@cs.columbia.edu>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      e19f247a
    • O
      [PATCH] setpgid: should work for sub-threads · ee0acf90
      由 Oleg Nesterov 提交于 
      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: NOleg Nesterov <oleg@tv-sign.ru>
Cc: Oren Laadan <orenl@cs.columbia.edu>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      ee0acf90
    • E
      [PATCH] Don't attempt to power off if power off is not implemented · 5e38291d
      由 Eric W. Biederman 提交于 
      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: NEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NHayato Fujiwara <fujiwara@linux-m32r.org>
Signed-off-by: NHirokazu Takata <takata@linux-m32r.org>
Signed-off-by: NMiklos Szeredi <miklos@szeredi.hu>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      5e38291d
  19. 16 12月, 2005 1 次提交
  21. 13 12月, 2005 1 次提交
  23. 11 11月, 2005 1 次提交
  25. 07 11月, 2005 4 次提交
  27. 23 9月, 2005 1 次提交
  29. 18 9月, 2005 1 次提交
  31. 08 9月, 2005 1 次提交
    • J
      [PATCH] remove a redundant variable in sys_prctl() · 0730ded5
      由 Jesper Juhl 提交于 
      The patch removes a redundant variable `sig' from sys_prctl().

For some reason, when sys_prctl is called with option == PR_SET_PDEATHSIG
then the value of arg2 is assigned to an int variable named sig.  Then sig
is tested with valid_signal() and later used to set the value of
current->pdeath_signal .

There is no reason to use this intermediate variable since valid_signal()
takes a unsigned long argument, so it can handle being passed arg2
directly, and if the call to valid_signal is OK, then we know the value of
arg2 is in the range zero to _NSIG and thus it'll easily fit in a plain int
and thus there's no problem assigning it later to current->pdeath_signal
(which is an int).

The patch gets rid of the pointless variable `sig'.
This reduces the size of kernel/sys.o in 2.6.13-rc6-mm1 by 32 bytes on my
system.

Patch has been compile tested, boot tested, and just to make damn sure I
didn't break anything I wrote a quick test app that calls
prctl(PR_SET_PDEATHSIG ...) with the entire range of values for a
unsigned long, and it behaves as expected with and without the patch.
Signed-off-by: NJesper Juhl <jesper.juhl@gmail.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      0730ded5
  33. 04 8月, 2005 1 次提交
    • B
      [PATCH] Remove suspend() calls from shutdown path · c36f19e0
      由 Benjamin Herrenschmidt 提交于 
      This removes the calls to device_suspend() from the shutdown path that
were added sometime during 2.6.13-rc*.  They aren't working properly on
a number of configs (I got reports from both ppc powerbook users and x86
users) causing the system to not shutdown anymore.

I think it isn't the right approach at the moment anyway.  We have
already a shutdown() callback for the drivers that actually care about
shutdown and the suspend() code isn't yet in a good enough shape to be
so much generalized.  Also, the semantics of suspend and shutdown are
slightly different on a number of setups and the way this was patched in
provides little way for drivers to cleanly differenciate.  It should
have been at least a different message.

For 2.6.13, I think we should revert to 2.6.12 behaviour and have a
working suspend back.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      c36f19e0
  35. 30 7月, 2005 1 次提交
  37. 28 7月, 2005 1 次提交
  39. 27 7月, 2005 4 次提交
  41. 26 6月, 2005 2 次提交
  43. 24 6月, 2005 1 次提交
    • D
      [PATCH] Keys: Make request-key create an authorisation key · 3e30148c
      由 David Howells 提交于 
      The attached patch makes the following changes:

 (1) There's a new special key type called ".request_key_auth".

     This is an authorisation key for when one process requests a key and
     another process is started to construct it. This type of key cannot be
     created by the user; nor can it be requested by kernel services.

     Authorisation keys hold two references:

     (a) Each refers to a key being constructed. When the key being
     	 constructed is instantiated the authorisation key is revoked,
     	 rendering it of no further use.

     (b) The "authorising process". This is either:

     	 (i) the process that called request_key(), or:

     	 (ii) if the process that called request_key() itself had an
     	      authorisation key in its session keyring, then the authorising
     	      process referred to by that authorisation key will also be
     	      referred to by the new authorisation key.

	 This means that the process that initiated a chain of key requests
	 will authorise the lot of them, and will, by default, wind up with
	 the keys obtained from them in its keyrings.

 (2) request_key() creates an authorisation key which is then passed to
     /sbin/request-key in as part of a new session keyring.

 (3) When request_key() is searching for a key to hand back to the caller, if
     it comes across an authorisation key in the session keyring of the
     calling process, it will also search the keyrings of the process
     specified therein and it will use the specified process's credentials
     (fsuid, fsgid, groups) to do that rather than the calling process's
     credentials.

     This allows a process started by /sbin/request-key to find keys belonging
     to the authorising process.

 (4) A key can be read, even if the process executing KEYCTL_READ doesn't have
     direct read or search permission if that key is contained within the
     keyrings of a process specified by an authorisation key found within the
     calling process's session keyring, and is searchable using the
     credentials of the authorising process.

     This allows a process started by /sbin/request-key to read keys belonging
     to the authorising process.

 (5) The magic KEY_SPEC_*_KEYRING key IDs when passed to KEYCTL_INSTANTIATE or
     KEYCTL_NEGATE will specify a keyring of the authorising process, rather
     than the process doing the instantiation.

 (6) One of the process keyrings can be nominated as the default to which
     request_key() should attach new keys if not otherwise specified. This is
     done with KEYCTL_SET_REQKEY_KEYRING and one of the KEY_REQKEY_DEFL_*
     constants. The current setting can also be read using this call.

 (7) request_key() is partially interruptible. If it is waiting for another
     process to finish constructing a key, it can be interrupted. This permits
     a request-key cycle to be broken without recourse to rebooting.
Signed-Off-By: NDavid Howells <dhowells@redhat.com>
Signed-Off-By: NBenoit Boissinot <benoit.boissinot@ens-lyon.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      3e30148c