Replaced the acpi_os_queue_for_execution() with a new
interface named acpi_os_execute(). The major difference is
that the new interface does not have a Priority parameter,
this appeared to be useless and has been replaced by
a Type parameter. The Type tells the OS what type of
execution is being requested, such as global lock handler,
notify handler, GPE handler, etc. This allows the host
to queue and execute the request as appropriate for the
request type, possibly using different work queues and
different priorities for the various request types. This
enables fixes for multithreading deadlock problems such as
http://bugzilla.kernel.org/show_bug.cgi?id=5534
(Alexey Starikovskiy and Bob Moore)
Fixed a possible memory leak associated with the
support for the so-called "implicit return" ACPI
extension. Reported by FreeBSD (Fiodor Suietov)
http://bugzilla.kernel.org/show_bug.cgi?id=6514
Fixed a problem with the Load() operator where a table
load from an operation region could overwrite an internal
table buffer by up to 7 bytes and cause alignment faults
on IPF systems. (With assistance from Luming Yu)
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Removed a device initialization optimization introduced in
20051216 where the _STA method was not run unless an _INI
was also present for the same device. This optimization
could cause problems because it could allow _INI methods
to be run within a not-present device subtree (If a
not-present device had no _INI, _STA would not be run,
the not-present status would not be discovered, and the
children of the device would be incorrectly traversed.)
Implemented a new _STA optimization where namespace
subtrees that do not contain _INI are identified and
ignored during device initialization. Selectively running
_STA can significantly improve boot time on large machines
(with assistance from Len Brown.)
Implemented support for the device initialization case
where the returned _STA flags indicate a device not-present
but functioning. In this case, _INI is not run, but the
device children are examined for presence, as per the
ACPI specification.
Implemented an additional change to the IndexField support
in order to conform to MS behavior. The value written to
the Index Register is not simply a byte offset, it is a
byte offset in units of the access width of the parent
Index Field. (Fiodor Suietov)
Defined and deployed a new OSL interface,
acpi_os_validate_address(). This interface is called during
the creation of all AML operation regions, and allows
the host OS to exert control over what addresses it will
allow the AML code to access. Operation Regions whose
addresses are disallowed will cause a runtime exception
when they are actually accessed (will not affect or abort
table loading.)
Defined and deployed a new OSL interface,
acpi_os_validate_interface(). This interface allows the host OS
to match the various "optional" interface/behavior strings
for the _OSI predefined control method as appropriate
(with assistance from Bjorn Helgaas.)
Restructured and corrected various problems in the
exception handling code paths within DsCallControlMethod
and DsTerminateControlMethod in dsmethod (with assistance
from Takayoshi Kochi.)
Modified the Linux source converter to ignore quoted string
literals while converting identifiers from mixed to lower
case. This will correct problems with the disassembler
and other areas where such strings must not be modified.
The ACPI_FUNCTION_* macros no longer require quotes around
the function name. This allows the Linux source converter
to convert the names, now that the converter ignores
quoted strings.
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Implemented header file support for the following
additional ACPI tables: ASF!, BOOT, CPEP, DBGP, MCFG, SPCR,
SPMI, TCPA, and WDRT. With this support, all current and
known ACPI tables are now defined in the ACPICA headers and
are available for use by device drivers and other software.
Implemented support to allow tables that contain ACPI
names with invalid characters to be loaded. Previously,
this would cause the table load to fail, but since
there are several known cases of such tables on
existing machines, this change was made to enable
ACPI support for them. Also, this matches the
behavior of the Microsoft ACPI implementation.
https://bugzilla.novell.com/show_bug.cgi?id=147621
Fixed a couple regressions introduced during the memory
optimization in the 20060317 release. The namespace
node definition required additional reorganization and
an internal datatype that had been changed to 8-bit was
restored to 32-bit. (Valery Podrezov)
Fixed a problem where a null pointer passed to
acpi_ut_delete_generic_state() could be passed through
to acpi_os_release_object which is unexpected. Such
null pointers are now trapped and ignored, matching
the behavior of the previous implementation before the
deployment of acpi_os_release_object(). (Valery Podrezov,
Fiodor Suietov)
Fixed a memory mapping leak during the deletion of
a SystemMemory operation region where a cached memory
mapping was not deleted. This became a noticeable problem
for operation regions that are defined within frequently
used control methods. (Dana Meyers)
Reorganized the ACPI table header files into two main
files: one for the ACPI tables consumed by the ACPICA core,
and another for the miscellaneous ACPI tables that are
consumed by the drivers and other software. The various
FADT definitions were merged into one common section and
three different tables (ACPI 1.0, 1.0+, and 2.0)
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Implemented the use of a cache object for all internal
namespace nodes. Since there are about 1000 static nodes
in a typical system, this will decrease memory use for
cache implementations that minimize per-allocation overhead
(such as a slab allocator.)
Removed the reference count mechanism for internal
namespace nodes, since it was deemed unnecessary. This
reduces the size of each namespace node by about 5%-10%
on all platforms. Nodes are now 20 bytes for the 32-bit
case, and 32 bytes for the 64-bit case.
Optimized several internal data structures to reduce
object size on 64-bit platforms by packing data within
the 64-bit alignment. This includes the frequently used
ACPI_OPERAND_OBJECT, of which there can be ~1000 static
instances corresponding to the namespace objects.
Added two new strings for the predefined _OSI method:
"Windows 2001.1 SP1" and "Windows 2006".
Split the allocation tracking mechanism out to a separate
file, from utalloc.c to uttrack.c. This mechanism appears
to be only useful for application-level code. Kernels may
wish to not include uttrack.c in distributions.
Removed all remnants of the obsolete ACPI_REPORT_* macros
and the associated code. (These macros have been replaced
by the ACPI_ERROR and ACPI_WARNING macros.)
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Tagged all external interfaces to the subsystem with the
new ACPI_EXPORT_SYMBOL macro. This macro can be defined
as necessary to assist kernel integration. For Linux,
the macro resolves to the EXPORT_SYMBOL macro. The default
definition is NULL.
Added the ACPI_THREAD_ID type for the return value from
acpi_os_get_thread_id(). This allows the host to define this
as necessary to simplify kernel integration. The default
definition is ACPI_NATIVE_UINT.
Valery Podrezov fixed two interpreter problems related
to error processing, the deletion of objects, and placing
invalid pointers onto the internal operator result stack.
http://bugzilla.kernel.org/show_bug.cgi?id=6028http://bugzilla.kernel.org/show_bug.cgi?id=6151
Increased the reference count threshold where a warning is
emitted for large reference counts in order to eliminate
unnecessary warnings on systems with large namespaces
(especially 64-bit.) Increased the value from 0x400
to 0x800.
Due to universal disagreement as to the meaning of the
'c' in the calloc() function, the ACPI_MEM_CALLOCATE
macro has been renamed to ACPI_ALLOCATE_ZEROED so that the
purpose of the interface is 'clear'. ACPI_MEM_ALLOCATE and
ACPI_MEM_FREE are renamed to ACPI_ALLOCATE and ACPI_FREE.
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Implemented a change to the IndexField support to match
the behavior of the Microsoft AML interpreter. The value
written to the Index register is now a byte offset,
no longer an index based upon the width of the Data
register. This should fix IndexField problems seen on
some machines where the Data register is not exactly one
byte wide. The ACPI specification will be clarified on
this point.
Fixed a problem where several resource descriptor
types could overrun the internal descriptor buffer due
to size miscalculation: VendorShort, VendorLong, and
Interrupt. This was noticed on IA64 machines, but could
affect all platforms.
Fixed a problem where individual resource descriptors were
misaligned within the internal buffer, causing alignment
faults on IA64 platforms.
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Removed a couple of extraneous ACPI_ERROR messages that
appeared during normal execution. These became apparent
after the conversion from ACPI_DEBUG_PRINT.
Fixed a problem where the CreateField operator could hang
if the BitIndex or NumBits parameter referred to a named
object. From Valery Podrezov.
http://bugzilla.kernel.org/show_bug.cgi?id=5359
Fixed a problem where a DeRefOf operation on a buffer
object incorrectly failed with an exception. This also
fixes a couple of related RefOf and DeRefOf issues.
From Valery Podrezov.
http://bugzilla.kernel.org/show_bug.cgi?id=5360http://bugzilla.kernel.org/show_bug.cgi?id=5387http://bugzilla.kernel.org/show_bug.cgi?id=5392
Fixed a problem where the AE_BUFFER_LIMIT exception was
returned instead of AE_STRING_LIMIT on an out-of-bounds
Index() operation. From Valery Podrezov.
http://bugzilla.kernel.org/show_bug.cgi?id=5480
Implemented a memory cleanup at the end of the execution
of each iteration of an AML While() loop, preventing the
accumulation of outstanding objects. From Valery Podrezov.
http://bugzilla.kernel.org/show_bug.cgi?id=5427
Eliminated a chunk of duplicate code in the object
resolution code. From Valery Podrezov.
http://bugzilla.kernel.org/show_bug.cgi?id=5336
Fixed several warnings during the 64-bit code generation.
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
* git://git.kernel.org/pub/scm/linux/kernel/git/kyle/parisc-2.6: (24 commits)
[PARISC] Fix double free when removing HIL drivers
[PARISC] Add atomic_sub_and_test
[PARISC] Enabled some NLS modules in a500, b180 and c3000 defconfigs
[PARISC] Kill duplicated EXPORT_SYMBOL warnings
[PARISC] Move ioremap EXPORT_SYMBOL from parisc_ksyms.c
[PARISC] Make local_t use atomic_long_t
[PARISC] Update defconfigs
[PARISC] Add PREEMPT support
[PARISC] More useful readwrite lock helpers
[PARISC] Convert HIL drivers to use input_allocate_device
[PARISC] Fixup CONFIG_EISA a bit
[PARISC] getsockopt should be ENTRY_COMP
[PARISC] Remove obsolete CONFIG_DEBUG_IOREMAP
[PARISC] Temporary FIXME for ioremapping EISA regions
[PARISC] Enable ioremap functionality unconditionally
[PARISC] Fix stifb with IOREMAP and a 64-bit kernel
[PARISC] Add CONFIG_HPPA_IOREMAP to conditionally enable ioremap
[PARISC] Add STRICT_MM_TYPECHECKS
[PARISC] Fix IOREMAP with a 64-bit kernel
[PARISC] Add parisc implementation of flush_kernel_dcache_page()
...
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/roland/infiniband:
IB/mad: RMPP support for additional classes
IB/mad: include GID/class when matching receives
IB/mthca: Fix section mismatch problems
IPoIB: Fix oops with raw sockets
IB/mthca: Fix check of size in SRQ creation
IB/srp: Fix unmapping of fake scatterlist
* 'upstream-linus' of master.kernel.org:/pub/scm/linux/kernel/git/jgarzik/libata-dev:
[PATCH] sata_mv: three bug fixes
[PATCH] libata: ata_dev_init_params() fixes
[PATCH] libata: Fix interesting use of "extern" and also some bracketing
[PATCH] libata: Simplex and other mode filtering logic
[PATCH] libata - ATA is both ATA and CFA
[PATCH] libata: Add ->set_mode hook for odd drivers
[PATCH] libata: BMDMA handling updates
[PATCH] libata: kill trailing whitespace
[PATCH] libata: add FIXME above ata_dev_xfermask()
[PATCH] libata: cosmetic changes in ata_bus_softreset()
[PATCH] libata: kill E.D.D.
* 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux-2.6:
[IA64] ioremap() should prefer WB over UC
[IA64] Add __mca_table to the DISCARD list in gate.lds
[IA64] Move __mca_table out of the __init section
[IA64] simplify some condition checks in iosapic_check_gsi_range
[IA64] correct some messages and fixes some minor things
[IA64-SGI] fix for-loop in sn_hwperf_geoid_to_cnode()
[IA64-SGI] sn_hwperf use of num_online_cpus()
[IA64] optimize flush_tlb_range on large numa box
[IA64] lazy_mmu_prot_update needs to be aware of huge pages
This enables the caller to migrate pages from one address space page
cache to another. In buzz word marketing, you can do zero-copy file
copies!
Signed-off-by: Jens Axboe <axboe@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This adds support for the sys_splice system call. Using a pipe as a
transport, it can connect to files or sockets (latter as output only).
From the splice.c comments:
"splice": joining two ropes together by interweaving their strands.
This is the "extended pipe" functionality, where a pipe is used as
an arbitrary in-memory buffer. Think of a pipe as a small kernel
buffer that you can use to transfer data from one end to the other.
The traditional unix read/write is extended with a "splice()" operation
that transfers data buffers to or from a pipe buffer.
Named by Larry McVoy, original implementation from Linus, extended by
Jens to support splicing to files and fixing the initial implementation
bugs.
Signed-off-by: Jens Axboe <axboe@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Fix up some ISA/EISA stuff.
(Note: isa_ accessors have been removed from asm/io.h)
Signed-off-by: Helge Deller <deller@parisc-linux.org>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
Remove CONFIG_DEBUG_IOREMAP, it's now obsolete and won't work anyway.
Remove it from lib/KConfig since it was only available on parisc.
Signed-off-by: Helge Deller <deller@parisc-linux.org>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
Enable CONFIG_HPPA_IOREMAP by default and remove all now unnecessary code.
Signed-off-by: Helge Deller <deller@parisc-linux.org>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
Instead of making it a #define in asm/io.h, allow user to select
to turn on IOREMAP from the config menu.
Signed-off-by: Helge Deller <deller@parisc-linux.org>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
We need to do a little renaming of our original syntax because
of the difference in arguments.
Signed-off-by: James Bottomley <jejb@parisc-linux.org>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
This should now allow SG_IO and fuse to function correctly on our
platform.
Signed-off-by: James Bottomley <jejb@parisc-linux.org>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
Add __mca_table to the DISCARD list for the gate.lds linker script to
avoid broken linker references when linking the final vmlinux file.
Also add comment to include/asm-ia64/asmmacros.h to avoid anyone else
hitting this problem in the future.
Credits to James Bottomley <James.Bottomley@SteelEye.com> for spotting
the DISCARD list in gate.lds.S
Signed-off-by: Jes Sorensen <jes@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Add RMPP support for additional management classes that support it.
Also, validate RMPP is consistent with management class specified.
Signed-off-by: Hal Rosenstock <halr@voltaire.com>
Signed-off-by: Sean Hefty <sean.hefty@intel.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Add a field to the host_set called 'flags' (was host_set_flags changed
to suit Jeff)
Add a simplex_claimed field so we can remember who owns the DMA channel
Add a ->mode_filter() hook to allow drivers to filter modes
Add docs for mode_filter and set_mode
Filter according to simplex state
Filter cable in core
This provides the needed framework to support all the mode rules found
in the PATA world. The simplex filter deals with 'to spec' simplex DMA
systems found in older chips. The cable filter avoids duplicating the
same rules in each chip driver with PATA. Finally the mode filter is
neccessary because drive/chip combinations have errata that forbid
certain modes with some drives or types of ATA object.
Drive speed setup remains per channel for now and the filters now use
the framework Tejun put into place which cleans them up a lot from the
older libata-pata patches.
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Some hardware doesn't want the usual mode setup logic running. This
allows the hardware driver to replace it for special cases in the least
invasive way possible.
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
This is the minimal patch set to enable the current code to be used with
a controller following SFF (ie any PATA and early SATA controllers)
safely without crashes if there is no BMDMA area or if BMDMA is not
assigned by the BIOS for some reason.
Simplex status is recorded but not acted upon in this change, this isn't
a problem with the current drivers as none of them are for simplex
hardware. A following diff will deal with that.
The flags in the probe structure remain ->host_set_flags although Jeff
asked me to rename them, simply because the rename would break the usual
Linux rules that old code should break when there are changes. not
compile and run and then blow up/eat your computer/etc. Renaming this
later is a trivial exercise once a better name is chosen.
Signed-off-by: Jeff Garzik <jeff@garzik.org>
* git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc: (67 commits)
[PATCH] powerpc: Remove oprofile spinlock backtrace code
[PATCH] powerpc: Add oprofile calltrace support to all powerpc cpus
[PATCH] powerpc: Add oprofile calltrace support
[PATCH] for_each_possible_cpu: ppc
[PATCH] for_each_possible_cpu: powerpc
[PATCH] lock PTE before updating it in 440/BookE page fault handler
[PATCH] powerpc: Kill _machine and hard-coded platform numbers
ppc: Fix compile error in arch/ppc/lib/strcase.c
[PATCH] git-powerpc: WARN was a dumb idea
[PATCH] powerpc: a couple of trivial compile warning fixes
powerpc: remove OCP references
powerpc: Make uImage default build output for MPC8540 ADS
powerpc: move math-emu over to arch/powerpc
powerpc: use memparse() for mem= command line parsing
ppc: fix strncasecmp prototype
[PATCH] powerpc: make ISA floppies work again
[PATCH] powerpc: Fix some initcall return values
[PATCH] powerpc: Workaround for pSeries RTAS bug
[PATCH] spufs: fix __init/__exit annotations
[PATCH] powerpc: add hvc backend for rtas
...
Remove oprofile spinlock backtrace code now we have proper calltrace
support. Also make MMCRA sihv and sipr bits a variable since they may
change in future cpus. Finally, MMCRA should be a 64bit quantity.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Add oprofile calltrace support to powerpc. Disable spinlock backtracing
now we can use calltrace info.
(Updated to work on both 32bit and 64bit by me).
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
for_each_cpu() actually iterates across all possible CPUs. We've had mistakes
in the past where people were using for_each_cpu() where they should have been
iterating across only online or present CPUs. This is inefficient and
possibly buggy.
We're renaming for_each_cpu() to for_each_possible_cpu() to avoid this in the
future.
This patch replaces for_each_cpu with for_each_possible_cpu.
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Fix 44x and BookE page fault handler to correctly lock PTE before
trying to pte_update() it, otherwise this PTE might be swapped out
after pte_present() check but before pte_uptdate() call, resulting in
corrupted PTE. This can happen with enabled preemption and low memory
condition.
Signed-off-by: Eugene Surovegin <ebs@ebshome.net>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Move 'tsk->sighand = NULL' from cleanup_sighand() to __exit_signal(). This
makes the exit path more understandable and allows us to do
cleanup_sighand() outside of ->siglock protected section.
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch kills PIDTYPE_TGID pid_type thus saving one hash table in
kernel/pid.c and speeding up subthreads create/destroy a bit. It is also a
preparation for the further tref/pids rework.
This patch adds 'struct list_head thread_group' to 'struct task_struct'
instead.
We don't detach group leader from PIDTYPE_PID namespace until another
thread inherits it's ->pid == ->tgid, so we are safe wrt premature
free_pidmap(->tgid) call.
Currently there are no users of find_task_by_pid_type(PIDTYPE_TGID).
Should the need arise, we can use find_task_by_pid()->group_leader.
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Acked-By: Eric Biederman <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
__exit_signal() is private to release_task() now. I think it is better to
make it static in kernel/exit.c and export flush_sigqueue() instead - this
function is much more simple and straightforward.
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>
Cosmetic, rename __exit_sighand to cleanup_sighand and move it close to
copy_sighand().
This matches copy_signal/cleanup_signal naming, and I think it is easier to
follow.
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
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>
__exit_signal() does important cleanups atomically under ->siglock. It is
also called from copy_process's error path. This is not good, for example we
can't move __unhash_process() under ->siglock for that reason.
We should not mix these 2 paths, just look at ugly 'if (p->sighand)' under
'bad_fork_cleanup_sighand:' label. For copy_process() case it is sufficient
to just backout copy_signal(), nothing more.
Again, nobody can see this task yet. For CLONE_THREAD case we just decrement
signal->count, otherwise nobody can see this ->signal and we can free it
lockless.
This patch assumes it is safe to do exit_thread_group_keys() without
tasklist_lock.
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: David Howells <dhowells@redhat.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>
The only caller of exit_sighand(tsk) is copy_process's error path. We can
call __exit_sighand() directly and kill exit_sighand().
This 'tsk' was not yet registered in pid_hash[] or init_task.tasks, it has no
external references, nobody can see it, and
IF (clone_flags & CLONE_SIGHAND)
At least 'current' has a reference to ->sighand, this
means atomic_dec_and_test(sighand->count) can't be true.
ELSE
Nobody can see this ->sighand, this means we can free it
without any locking.
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
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>
Add lock_task_sighand() helper and converts group_send_sig_info() to use
it. Hopefully we will have more users soon.
This patch also removes '!sighand->count' and '!p->usage' checks, I think
they both are bogus, racy and unneeded (but probably it makes sense to
restore them as BUG_ON()s).
->sighand is cleared and it's ->count is decremented in release_task() with
sighand->siglock held, so it is a bug to have '!p->usage || !->count' after
we already locked and verified it is the same. On the other hand, an
already dead task without ->sighand can have a non-zero ->usage due to
ptrace, for example.
If we read the stale value of ->sighand we must see the change after
spin_lock(), because that change was done while holding that same old
->sighand.siglock.
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch borrows a clever Hugh's 'struct anon_vma' trick.
Without tasklist_lock held we can't trust task->sighand until we locked it
and re-checked that it is still the same.
But this means we don't need to defer 'kmem_cache_free(sighand)'. We can
return the memory to slab immediately, all we need is to be sure that
sighand->siglock can't dissapear inside rcu protected section.
To do so we need to initialize ->siglock inside ctor function,
SLAB_DESTROY_BY_RCU does the rest.
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>
daemonize() calls set_special_pids(1,1), while init and kernel threads spawned
from init/main.c:init() run with 0,0 special pids. This patch changes
INIT_SIGNALS() so that that they run with ->pgrp == ->session == 1 also. This
patch relies on fact that swapper's pid == 1.
Now we have no hashed zero pids in pid_hash[].
User-space visibible change is that now /sbin/init runs with (1,1) special
pids and becomes a session leader.
Quoting Eric W. Biederman:
>
> daemonize consuming pids (1,1) then consumes pgrp 1. So that when
> /sbin/init calls setsid() it thinks /sbin/init is a process group
> leader and setsid() fails. So /sbin/init wants pgrp 1 session 1
> but doesn't get it. I am pretty certain daemonize did not exist so
> /sbin/init got pgrp 1 session 1 in 2.4.
>
> That is the bug that is being fixed.
>
> This patch takes things one step farther and essentially calls
> setsid() for pid == 1 before init is execed. That is new behavior
> but it cleans up the kernel as we now do not need to support the
> case of a process without a process group or a session.
>
> The only process that could have possibly cared was /sbin/init
> and it already calls setsid() because it doesn't want that.
>
> If this was going to break anything noticeable the change in behavior
> from 2.4 to 2.6 would have already done that.
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
fork_idle() does unhash_process() just after copy_process(). Contrary,
boot_cpu's idle thread explicitely registers itself for each pid_type with nr
= 0.
copy_process() already checks p->pid != 0 before process_counts++, I think we
can just skip attach_pid() calls and job control inits for idle threads and
kill unhash_process(). We don't need to cleanup ->proc_dentry in fork_idle()
because with this patch idle threads are never hashed in
kernel/pid.c:pid_hash[].
We don't need to hash pid == 0 in pidmap_init(). free_pidmap() is never
called with pid == 0 arg, so it will never be reused. So it is still possible
to use pid == 0 in any PIDTYPE_xxx namespace from kernel/pid.c's POV.
However with this patch we don't hash pid == 0 for PIDTYPE_PID case. We still
have have PIDTYPE_PGID/PIDTYPE_SID entries with pid == 0: /sbin/init and
kernel threads which don't call daemonize().
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Both SET_LINKS() and SET_LINKS/REMOVE_LINKS() have exactly one caller, and
these callers already check thread_group_leader().
This patch kills theese macros, they mix two different things: setting
process's parent and registering it in init_task.tasks list. Callers are
updated to do these actions by hand.
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
add_parent(p, parent) is always called with parent == p->parent, and it makes
no sense to do it differently. This patch removes this argument.
No changes in affected .o files.
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Bob Moore