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2006-09-29[PATCH] uml: don't roll my own random MAC generatorJeff Dike
Use the existing random_ether_addr() instead of cooking up my own version. Pointed out by Dave Hollis and Jason Lunz. Signed-off-by: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-29[PATCH] uml: stack consumption reductionJeff Dike
Fix some stack abuse in the sysrq t path. Signed-off-by: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-29[PATCH] uml: close file descriptor leaksJeff Dike
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>
2006-09-29[PATCH] uml: locking documentationJeff Dike
Some locking documentation and a cleanup. uml_exitcode is copied into a local before sprintf sees it, in case sprintf does anything non-atomic with it. The rest are comments about why certain globals don't need any kind of locking. Signed-off-by: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-29[PATCH] uml: mechanical tidying after random MACs changeJeff Dike
Mechanical, hopefully non-functional changes stemming from setup_etheraddr always succeeding now that it always assigns a MAC, either from the command line or generated randomly: the test of the return of setup_etheraddr is removed, and code dependent on it succeeding is now unconditional setup_etheraddr can now be made void struct uml_net.have_mac is now always 1, so tests of it can be similarly removed, and uses of it can be replaced with 1 struct uml_net.have_mac is no longer used, so it can be removed struct uml_net_private.have_mac is copied from struct uml_net, so it is always 1 tests of uml_net_private.have_mac can be removed uml_net_private.have_mac can now be removed the only call to dev_ip_addr was removed, so it can be deleted It also turns out that setup_etheraddr is called only once, from the same file, so it can be static and its declaration removed from net_kern.h. Similarly, set_ether_mac is defined and called only from one file. Finally, setup_etheraddr and set_ether_mac were moved to avoid needing forward declarations. Signed-off-by: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-29[PATCH] uml: assign random MACs to interfaces if necessaryJeff Dike
Assign a random MAC to an ethernet interface if one was not provided on the command line. This became pressing when distros started bringing interfaces up before assigning IPs to them. The previous pattern of assigning an IP then bringing it up allowed the MAC to be generated from the first IP assigned. However, once the thing is up, it's probably a bad idea to change the MAC, so the MAC stayed initialized to fe:fd:0:0:0:0. Now, if there is no MAC from the command line, one is generated. We use the microseconds from gettimeofday (20 bits), plus the low 12 bits of the pid to seed the random number generator. random() is called twice, with 16 bits of each result used. I didn't want to have to try to fill in 32 bits optimally given an arbitrary RAND_MAX, so I just assume that it is greater than 65536 and use 16 bits of each random() return. There is also a bit of reformatting and whitespace cleanup here. Signed-off-by: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-28[IPV4]: annotate struct in_ifaddrAl Viro
ifa_local, ifa_address, ifa_mask, ifa_broadcast and ifa_anycast are net-endian. Annotated them and variables that are inferred to be net-endian. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-09-27[PATCH] uml: fix allocation sizeJeff Dike
Fix an instance of ptr=alloc(sizeof(ptr)). Grepping showed no more instances of this pattern. Also fixed the formatting in the area. Signed-off-by: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-27[PATCH] uml: const more dataJeff Dike
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>
2006-09-27[PATCH] uml: fix proc-vs-interrupt context spinlock deadlockPaolo 'Blaisorblade' Giarrusso
This spinlock can be taken on interrupt too, so spin_lock_irq[save] must be used. However, Documentation/networking/netdevices.txt explains we are called with rtnl_lock() held - so we don't need to care about other concurrent opens. Verified also in LDD3 and by direct checking. Also verified that the network layer (through a state machine) guarantees us that nobody will close the interface while it's being used. Please correct me if I'm wrong. Also, we must check we don't sleep with irqs disabled!!! But anyway, this is not news - we already can't sleep while holding a spinlock. Who says this is guaranted really by the present code? Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Cc: Jeff Dike <jdike@addtoit.com> Cc: Jeff Garzik <jeff@garzik.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-26[PATCH] uml: clean our set_ether_macPaolo 'Blaisorblade' Giarrusso
Clean set_ether_mac usage. Maybe could also be removed, but surely it can't be a global function taking a void* argument. Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Acked-by: Jeff Dike <jdike@addtoit.com> Cc: Jeff Garzik <jeff@garzik.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-26[PATCH] uml: Use ARRAY_SIZE more assiduouslyJeff Dike
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>
2006-07-10[PATCH] uml: make mconsole version requests happen in a processJeff Dike
Handling a host mconsole version request must be done in a process context rather than interrupt context now that utsname information can be process-specific rather than global. 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>
2006-07-10[PATCH] uml: remove unused variableJeff Dike
The dedevfsification of UML left an unused variable behind. 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>
2006-07-10[PATCH] uml: add some EINTR protectionJeff Dike
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>
2006-07-10[PATCH] uml: formatting fixesJeff Dike
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>
2006-07-02[PATCH] irq-flags: UM: Use the new IRQF_ constantsThomas Gleixner
Use the new IRQF_ constants and remove the SA_INTERRUPT define Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@elte.hu> Cc: "David S. Miller" <davem@davemloft.net> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: 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>
2006-06-30Merge git://git.kernel.org/pub/scm/linux/kernel/git/bunk/trivialLinus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/bunk/trivial: Remove obsolete #include <linux/config.h> remove obsolete swsusp_encrypt arch/arm26/Kconfig typos Documentation/IPMI typos Kconfig: Typos in net/sched/Kconfig v9fs: do not include linux/version.h Documentation/DocBook/mtdnand.tmpl: typo fixes typo fixes: specfic -> specific typo fixes in Documentation/networking/pktgen.txt typo fixes: occuring -> occurring typo fixes: infomation -> information typo fixes: disadvantadge -> disadvantage typo fixes: aquire -> acquire typo fixes: mecanism -> mechanism typo fixes: bandwith -> bandwidth fix a typo in the RTC_CLASS help text smb is no longer maintained Manually merged trivial conflict in arch/um/kernel/vmlinux.lds.S
2006-06-30[PATCH] uml: unregister useless console when it's not neededJeff Dike
-mm in combination with an FC5 init started dying with 'stderr=1' because init didn't like the lack of /dev/console and exited. The problem was that the stderr console, which is intended to dump printk output to the terminal before the regular console is initialized, isn't a tty, and so can't make /dev/console operational. However, since it is registered first, the normal console, when it is registered, doesn't become the preferred console, and isn't attached to /dev/console. Thus, /dev/console is never operational. This patch makes the stderr console unregister itself in an initcall, which is late enough that the normal console is registered. When that happens, the normal console will become the preferred console and will be able to run /dev/console. 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>
2006-06-30Remove obsolete #include <linux/config.h>Jörn Engel
Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de> Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-06-29Merge git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/devfs-2.6Linus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/devfs-2.6: (22 commits) [PATCH] devfs: Remove it from the feature_removal.txt file [PATCH] devfs: Last little devfs cleanups throughout the kernel tree. [PATCH] devfs: Rename TTY_DRIVER_NO_DEVFS to TTY_DRIVER_DYNAMIC_DEV [PATCH] devfs: Remove the tty_driver devfs_name field as it's no longer needed [PATCH] devfs: Remove the line_driver devfs_name field as it's no longer needed [PATCH] devfs: Remove the videodevice devfs_name field as it's no longer needed [PATCH] devfs: Remove the gendisk devfs_name field as it's no longer needed [PATCH] devfs: Remove the miscdevice devfs_name field as it's no longer needed [PATCH] devfs: Remove the devfs_fs_kernel.h file from the tree [PATCH] devfs: Remove devfs_remove() function from the kernel tree [PATCH] devfs: Remove devfs_mk_cdev() function from the kernel tree [PATCH] devfs: Remove devfs_mk_bdev() function from the kernel tree [PATCH] devfs: Remove devfs_mk_symlink() function from the kernel tree [PATCH] devfs: Remove devfs_mk_dir() function from the kernel tree [PATCH] devfs: Remove devfs_*_tape() functions from the kernel tree [PATCH] devfs: Remove devfs support from the sound subsystem [PATCH] devfs: Remove devfs support from the ide subsystem. [PATCH] devfs: Remove devfs support from the serial subsystem [PATCH] devfs: Remove devfs from the init code [PATCH] devfs: Remove devfs from the partition code ...
2006-06-26[PATCH] devfs: Remove the line_driver devfs_name field as it's no longer neededGreg Kroah-Hartman
Also fixes all drivers that set this field. Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-06-26[PATCH] devfs: Remove the gendisk devfs_name field as it's no longer neededGreg Kroah-Hartman
And remove the now unneeded number field. Also fixes all drivers that set these fields. Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-06-26[PATCH] devfs: Remove the devfs_fs_kernel.h file from the treeGreg Kroah-Hartman
Also fixes up all files that #include it. Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-06-26[PATCH] devfs: Remove devfs_mk_symlink() function from the kernel treeGreg Kroah-Hartman
Removes the devfs_mk_symlink() function and all callers of it. Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-06-26[PATCH] devfs: Remove devfs_mk_dir() function from the kernel treeGreg Kroah-Hartman
Removes the devfs_mk_dir() function and all callers of it. Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-06-26spelling fixesAndreas Mohr
acquired (aquired) contiguous (contigious) successful (succesful, succesfull) surprise (suprise) whether (weather) some other misspellings Signed-off-by: Andreas Mohr <andi@lisas.de> Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-06-25[PATCH] kernel/sys.c: cleanupsAdrian Bunk
- proper prototypes for the following functions: - ctrl_alt_del() (in include/linux/reboot.h) - getrusage() (in include/linux/resource.h) - make the following needlessly global functions static: - kernel_restart_prepare() - kernel_kexec() [akpm@osdl.org: compile fix] Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-05-01[PATCH] uml: fix patch mismergePaolo 'Blaisorblade' Giarrusso
I sent a patch, it was applied as cda402b283c34a24b091f78eee116963e9494762, then it was applied again as 181ae4005d0a4010802be534d929b38c42b9ac06 by mistake. But while the 1st time it modified (correctly) cow_header_v3, the 2nd it modified cow_header_v3_broken. 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>
2006-04-19[PATCH] uml: make 64-bit COW files compatible with 32-bit onesPaolo 'Blaisorblade' Giarrusso
This is the minimal fix to make 64-bit UML binaries create 32-bit compatible COW files and read them. I've indeed tested that current code doesn't do this - the code gets SIGFPE for a division by a value read at the wrong place, where 0 is found. 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>
2006-04-11[PATCH] uml: avoid warnings for diffent names for an unsigned quadwordPaolo 'Blaisorblade' Giarrusso
Since on some 64-bit systems __u64 is rightfully defined to unsigned long and GCC recognizes anyway unsigned long and unsigned long long as different, fix some types back to being unsigned long long to avoid warnings and errors (for prototype mismatch) on those systems. Thanks to the report by Wesley Emeneker wesleyemeneker (at) google (dot) com 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>
2006-04-11[PATCH] uml: local_irq_save, not local_save_flagsPaolo 'Blaisorblade' Giarrusso
The call to local_save_flags seems bogus since it is followed by local_irq_restore, and it's intended to lock the list from concurrent mconsole_interrupt invocations. 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>
2006-04-11[PATCH] uml: fix hang on run_helper() failure on uml_netPaolo 'Blaisorblade' Giarrusso
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>
2006-04-11[PATCH] uml: fix format errorsPaolo 'Blaisorblade' Giarrusso
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>
2006-04-11[PATCH] uml: fix 2 harmless cast warnings for 64-bitPaolo 'Blaisorblade' Giarrusso
Fix two harmless warnings in 64-bit compilation (the 2nd doesn't trigger for now because of a missing __attribute((format)) for cow_printf, but next patches fix that). 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>
2006-04-11[PATCH] uml: safe migration path to the correct V3 COW formatPaolo 'Blaisorblade' Giarrusso
- Correct the layout of all header versions - make all them well-specified for any external event. As we don't have 1-byte or 2-byte wide fields, the 32-bit layout (historical one) has no extra padding, so we can safely add __attribute__((packed)). - Add detection and reading of the broken 64-bit COW format which has been around for a while - to allow safe migration to the correct 32-bit format. Safe detection is possible, thanks to some luck with the existing format, and it works in practice. 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>
2006-04-11[PATCH] uml: make 64-bit COW files compatible with 32-bit onesPaolo 'Blaisorblade' Giarrusso
This is the minimal fix to make 64-bit UML binaries create 32-bit compatible COW files and read them. I've indeed tested that current code doesn't do this - the code gets SIGFPE for a division by a value read at the wrong place, where 0 is found. 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>
2006-04-11[PATCH] uml: memory hotplug cleanupsJeff Dike
Change memory hotplug to use GFP_NOWAIT instead of GFP_ATOMIC, so that it will grab memory without sleeping, but doesn't try to use the emergency pools. A small list initialization suggested by Daniel Phillips - don't initialize lists which are just about to be list_add-ed. Signed-off-by: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-31[PATCH] uml: fix min usageAl Viro
type-safe min() in arch/um/drivers/mconsole_kern.c 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>
2006-03-31[PATCH] uml: sparse cleanupsAl Viro
misc sparse annotations 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>
2006-03-31[PATCH] uml: fix initcall return valuesJeff Dike
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>
2006-03-31[PATCH] UML: Hotplug memory, take 2Jeff Dike
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>
2006-03-27[PATCH] Notifier chain update: API changesAlan Stern
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: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com> Signed-off-by: Jes Sorensen <jes@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-27[PATCH] uml: allow ubd devices to be shared in a clusterJeff Dike
This adds a 'c' option to the ubd switch which turns off host file locking so that the device can be shared, as with a cluster. There's also some whitespace cleanup while I was in this file. 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>
2006-02-24[PATCH] uml: tidying COW codePaolo 'Blaisorblade' Giarrusso
Improve (especially for coherence) some prototypes, and return code of init_cow_file in error case - for a short write return -EINVAL, otherwise return the error we got! Signed-off-by: Paolo 'Blaisorblade' Giarrusso <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>
2006-02-24[PATCH] uml: better error reporting for read_outputPaolo 'Blaisorblade' Giarrusso
Do precise error handling: print precise error messages, distinguishing short reads and read errors. This functions fails frequently enough for me so I bothered doing this fix. Signed-off-by: Paolo 'Blaisorblade' Giarrusso <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>
2006-02-24[PATCH] uml: correct error messages in COW driverPaolo 'Blaisorblade' Giarrusso
Improve some error messages in the COW driver, and say V3, not V2, when talking about V3 format. Also resync with our userspace code utility a bit more. Signed-off-by: Paolo 'Blaisorblade' Giarrusso <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>
2006-02-07[PATCH] uml: balance list_add and list_del in the network driverJeff Dike
The network driver added an interface to the "opened" list when it was configured, not when it was brought up, and removed it when it was taken down. A sequence of ifconfig up, ifconfig down, ... caused it to be removed multiple times from the list without being added in between, resulting in a crash. This patch moves the add to when the interface is brought up. Signed-off-by: Jeff Dike <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>
2006-02-07[PATCH] uml: close TUN/TAP file descriptorsJeff Dike
When UML opens a TUN/TAP device, the file descriptor could be copied into later, long-lived threads, holding the device open even after the interface is taken down, preventing it from being brought up again. This patch makes these descriptors close-on-exec so that they disappear from helper processes, and adds CLONE_FILES to a UML helper thread so that the descriptors are closed in the thread when they are closed elsewhere in UML. Signed-off-by: Jeff Dike <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>
2006-02-01[PATCH] uml: some harmless sparse warning fixesPaolo 'Blaisorblade' Giarrusso
Fix some simple sparse warnings - a lot more staticness and a misplaced __user. 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>