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2007-07-17kallsyms: make KSYM_NAME_LEN include space for trailing '\0'Tejun Heo
KSYM_NAME_LEN is peculiar in that it does not include the space for the trailing '\0', forcing all users to use KSYM_NAME_LEN + 1 when allocating buffer. This is nonsense and error-prone. Moreover, when the caller forgets that it's very likely to subtly bite back by corrupting the stack because the last position of the buffer is always cleared to zero. This patch increments KSYM_NAME_LEN by one and updates code accordingly. * off-by-one bug in asm-powerpc/kprobes.h::kprobe_lookup_name() macro is fixed. * Where MODULE_NAME_LEN and KSYM_NAME_LEN were used together, MODULE_NAME_LEN was treated as if it didn't include space for the trailing '\0'. Fix it. Signed-off-by: Tejun Heo <htejun@gmail.com> Acked-by: Paulo Marques <pmarques@grupopie.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-16modules: remove modlist_lockRusty Russell
Now we always use stop_machine for module insertion or deletion, we no longer need the modlist_lock: merely disabling preemption is sufficient to block against list manipulation. This avoids deadlock on OOPSen where we can potentially grab the lock twice. Bug: 8695 Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Ingo Molnar <mingo@elte.hu> Cc: Tobias Oed <tobiasoed@hotmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-16Make /proc/modules use seq_list_xxx helpersPavel Emelianov
Here there is not need even in .show callback altering. The original code passes list_head in *v. Signed-off-by: Pavel Emelianov <xemul@openvz.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-11sysfs: kill unnecessary attribute->ownerTejun Heo
sysfs is now completely out of driver/module lifetime game. After deletion, a sysfs node doesn't access anything outside sysfs proper, so there's no reason to hold onto the attribute owners. Note that often the wrong modules were accounted for as owners leading to accessing removed modules. This patch kills now unnecessary attribute->owner. Note that with this change, userland holding a sysfs node does not prevent the backing module from being unloaded. For more info regarding lifetime rule cleanup, please read the following message. http://article.gmane.org/gmane.linux.kernel/510293 (tweaked by Greg to not delete the field just yet, to make it easier to merge things properly.) Signed-off-by: Tejun Heo <htejun@gmail.com> Cc: Cornelia Huck <cornelia.huck@de.ibm.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-05-09Fix minor typoes in kernel/module.cRobert P. J. Day
Fix minor (comment) typoes in kernel/module.c. Signed-off-by: Robert P. J. Day <rpjday@mindspring.com> Signed-off-by: Adrian Bunk <bunk@stusta.de>
2007-05-08Fix race between cat /proc/slab_allocators and rmmodAlexey Dobriyan
Same story as with cat /proc/*/wchan race vs rmmod race, only /proc/slab_allocators want more info than just symbol name. Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru> Acked-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-08Fix race between cat /proc/*/wchan and rmmod et alAlexey Dobriyan
kallsyms_lookup() can go iterating over modules list unprotected which is OK for emergency situations (oops), but not OK for regular stuff like /proc/*/wchan. Introduce lookup_symbol_name()/lookup_module_symbol_name() which copy symbol name into caller-supplied buffer or return -ERANGE. All copying is done with module_mutex held, so... Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru> Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-08Simplify kallsyms_lookup()Alexey Dobriyan
Several kallsyms_lookup() pass dummy arguments but only need, say, module's name. Make kallsyms_lookup() accept NULLs where possible. Also, makes picture clearer about what interfaces are needed for all symbol resolving business. Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru> Cc: Rusty Russell <rusty@rustcorp.com.au> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-08Fix race between rmmod and cat /proc/kallsymsAlexey Dobriyan
module_get_kallsym() leaks "struct module *" outside of module_mutex which is no-no, because module can dissapear right after mutex unlock. Copy all needed information from inside module_mutex into caller-supplied space. [bunk@stusta.de: is_exported() can now become static] Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru> Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-08Simplify module_get_kallsym() by dropping length argAlexey Dobriyan
module_get_kallsym() could in theory truncate module symbol name to fit in buffer, but nobody does this. Always use KSYM_NAME_LEN + 1 bytes for name. Suggested by lg^WRusty. Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru> Acked-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-08module: use kreallocPekka Enberg
This converts an open-coded krealloc() to use the shiny new API. Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi> Acked-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-05Merge branch 'for-linus' of git://one.firstfloor.org/home/andi/git/linux-2.6Linus Torvalds
* 'for-linus' of git://one.firstfloor.org/home/andi/git/linux-2.6: (231 commits) [PATCH] i386: Don't delete cpu_devs data to identify different x86 types in late_initcall [PATCH] i386: type may be unused [PATCH] i386: Some additional chipset register values validation. [PATCH] i386: Add missing !X86_PAE dependincy to the 2G/2G split. [PATCH] x86-64: Don't exclude asm-offsets.c in Documentation/dontdiff [PATCH] i386: avoid redundant preempt_disable in __unlazy_fpu [PATCH] i386: white space fixes in i387.h [PATCH] i386: Drop noisy e820 debugging printks [PATCH] x86-64: Fix allnoconfig error in genapic_flat.c [PATCH] x86-64: Shut up warnings for vfat compat ioctls on other file systems [PATCH] x86-64: Share identical video.S between i386 and x86-64 [PATCH] x86-64: Remove CONFIG_REORDER [PATCH] x86-64: Print type and size correctly for unknown compat ioctls [PATCH] i386: Remove copy_*_user BUG_ONs for (size < 0) [PATCH] i386: Little cleanups in smpboot.c [PATCH] x86-64: Don't enable NUMA for a single node in K8 NUMA scanning [PATCH] x86: Use RDTSCP for synchronous get_cycles if possible [PATCH] i386: Add X86_FEATURE_RDTSCP [PATCH] i386: Implement X86_FEATURE_SYNC_RDTSC on i386 [PATCH] i386: Implement alternative_io for i386 ... Fix up trivial conflict in include/linux/highmem.h manually. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-03remove "struct subsystem" as it is no longer neededGreg Kroah-Hartman
We need to work on cleaning up the relationship between kobjects, ksets and ktypes. The removal of 'struct subsystem' is the first step of this, especially as it is not really needed at all. Thanks to Kay for fixing the bugs in this patch. Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-05-02[PATCH] x86: Allow percpu variables to be page-alignedJeremy Fitzhardinge
Let's allow page-alignment in general for per-cpu data (wanted by Xen, and Ingo suggested KVM as well). Because larger alignments can use more room, we increase the max per-cpu memory to 64k rather than 32k: it's getting a little tight. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: Andi Kleen <ak@suse.de> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: Andi Kleen <ak@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2007-05-02[PATCH] x86-64: Account for module percpu space separately from kernel percpuJeremy Fitzhardinge
Rather than using a single constant PERCPU_ENOUGH_ROOM, compute it as the sum of kernel_percpu + PERCPU_MODULE_RESERVE. This is now common to all architectures; if an architecture wants to set PERCPU_ENOUGH_ROOM to something special, then it may do so (ia64 is the only one which does). Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: Andi Kleen <ak@suse.de> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Andi Kleen <ak@suse.de>
2007-04-27mod_sysfs_setup() doesn't return errno when kobject_add_dir() failure occursAkinobu Mita
mod_sysfs_setup() doesn't return an errno when kobject_add_dir() for module "holders" directory fails. So caller of mod_sysfs_setup() will keep going and get oops. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-04-02[PATCH] driver core: fix built-in drivers sysfs linksKay Sievers
built-in drivers had broken sysfs links that caused bootup hangs for certain driver unregistry sequences. Signed-off-by: Ingo Molnar <mingo@elte.hu> Acked-by: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Greg KH <greg@kroah.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-03-09Revert "driver core: refcounting fix"Greg Kroah-Hartman
This reverts commit 63ce18cfe685115ff8d341bae4c9204a79043cf0. It was the incorrect fix and causes a reference counting bug whenever any driver module is removed from the system. Mike Galbraith <efault@gmx.de> is looking for the real fix for his problem. Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-02-23Revert "Driver core: let request_module() send a /sys/modules/kmod/-uevent"Greg Kroah-Hartman
This reverts commit c353c3fb0700a3c17ea2b0237710a184232ccd7f. It turns out that we end up with a loop trying to load the unix module and calling netfilter to do that. Will redo the patch later to not have this loop. Acked-by: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-02-23driver core: refcounting fixMike Galbraith
Fix a reference counting bug exposed by commit 725522b5453dd680412f2b6463a988e4fd148757. If driver.mod_name exists, we take a reference in module_add_driver(), and never release it. Undo that reference in module_remove_driver(). Signed-off-by: Mike Galbraith <efault@gmx.de> Cc: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-02-16sysfs: fix build errors: uevent with CONFIG_SYSFS=nRandy Dunlap
Fix source files to build with CONFIG_SYSFS=n. module_subsys is not available. SYSFS=n, MODULES=y: T:y SYSFS=n, MODULES=n: T:y SYSFS=y, MODULES=y: T:y SYSFS=y, MODULES=n: T:y Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-02-16Driver: remove redundant kobject_unregister checksMariusz Kozlowski
Here is a patch that removes all redundant kobject_unregister argument checks. Signed-off-by: Mariusz Kozlowski <m.kozlowski@tuxland.pl> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-02-16Driver core: let request_module() send a /sys/modules/kmod/-ueventKay Sievers
On recent systems, calls to /sbin/modprobe are handled by udev depending on the kind of device the kernel has discovered. This patch creates an uevent for the kernels internal request_module(), to let udev take control over the request, instead of forking the binary directly by the kernel. The direct execution of /sbin/modprobe can be disabled by setting: /sys/module/kmod/mod_request_helper (/proc/sys/kernel/modprobe) to an empty string, the same way /proc/sys/kernel/hotplug is disabled on an udev system. Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-02-07/sys/modules/*/holdersKay Sievers
/sys/module/usbcore/ |-- drivers | |-- usb:hub -> ../../../subsystem/usb/drivers/hub | |-- usb:usb -> ../../../subsystem/usb/drivers/usb | `-- usb:usbfs -> ../../../subsystem/usb/drivers/usbfs |-- holders | |-- ehci_hcd -> ../../../module/ehci_hcd | |-- uhci_hcd -> ../../../module/uhci_hcd | |-- usb_storage -> ../../../module/usb_storage | `-- usbhid -> ../../../module/usbhid |-- initstate Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-02-07Modules: only add drivers/ direcory if neededGreg Kroah-Hartman
This changes the module core to only create the drivers/ directory if we are going to put something in it. Cc: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-02-07MODULES: add the module name for built in kernel driversKay Sievers
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-01-05[PATCH] Driver core: Fix prefix driver links in /sys/module by bus-nameKay Sievers
Modules may have drivers with the same name on different buses. This patch fixes this problem. Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-12-30[PATCH] module: fix mod_sysfs_setup() return valueAkinobu Mita
mod_sysfs_setup() doesn't return error when kobject_add_dir() failed. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: Greg KH <greg@kroah.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-13Driver core: show "initstate" of moduleKay Sievers
Show the initialization state(live, coming, going) of the module: $ cat /sys/module/usbcore/initstate live Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-12-07[PATCH] struct seq_operations and struct file_operations constificationHelge Deller
- move some file_operations structs into the .rodata section - move static strings from policy_types[] array into the .rodata section - fix generic seq_operations usages, so that those structs may be defined as "const" as well [akpm@osdl.org: couple of fixes] Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-04[PATCH] severing module.h->sched.hAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2006-12-01Driver core: show drivers in /sys/module/Kay Sievers
Show the drivers, which belong to the module: $ ls -l /sys/module/usbcore/drivers/ hub -> ../../../bus/usb/drivers/hub usb -> ../../../bus/usb/drivers/usb usbfs -> ../../../bus/usb/drivers/usbfs Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-10-30[PATCH] ndiswrapper: don't set the module->taints flagsRandy Dunlap
For ndiswrapper, don't set the module->taints flags, just set the kernel global tainted flag. This should allow ndiswrapper to continue to use GPL symbols. Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Cc: Florin Malita <fmalita@gmail.com> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-28[PATCH] Add missing space in module.c for taintskernelJan Dittmer
Obvious fix. Signed-off-by: Jan Dittmer <jdi@l4x.org> Acked-by: Florin Malita <fmalita@gmail.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>
2006-10-11[PATCH] fix Module taint flags listing in Oops/panicFlorin Malita
Module taint flags listing in Oops/panic has a couple of issues: * taint_flags() doesn't null-terminate the buffer after printing the flags * per-module taints are only set if the kernel is not already tainted (with that particular flag) => only the first offending module gets its taint info correctly updated Some additional changes: * 'license_gplok' is no longer needed - equivalent to !(taints & TAINT_PROPRIETARY_MODULE) - so we can drop it from struct module * exporting module taint info via /proc/module: pwc 88576 0 - Live 0xf8c32000 evilmod 6784 1 pwc, Live 0xf8bbf000 (PF) Signed-off-by: Florin Malita <fmalita@gmail.com> Cc: "Randy.Dunlap" <rdunlap@xenotime.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-03[PATCH] Create kallsyms_lookup_size_offset()Franck Bui-Huu
Some uses of kallsyms_lookup() do not need to find out the name of a symbol and its module's name it belongs. This is specially true in arch specific code, which needs to unwind the stack to show the back trace during oops (mips is an example). In this specific case, we just need to retreive the function's size and the offset of the active intruction inside it. Adds a new entry "kallsyms_lookup_size_offset()" This new entry does exactly the same as kallsyms_lookup() but does not require any buffers to store any names. It returns 0 if it fails otherwise 1. Signed-off-by: Franck Bui-Huu <vagabon.xyz@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>
2006-10-02[PATCH] list module taint flags in Oops/panicRandy Dunlap
When listing loaded modules during an oops or panic, also list each module's Tainted flags if non-zero (P: Proprietary or F: Forced load only). If a module is did not taint the kernel, it is just listed like usbcore but if it did taint the kernel, it is listed like wizmodem(PF) Example: [ 3260.121718] Unable to handle kernel NULL pointer dereference at 0000000000000000 RIP: [ 3260.121729] [<ffffffff8804c099>] :dump_test:proc_dump_test+0x99/0xc8 [ 3260.121742] PGD fe8d067 PUD 264a6067 PMD 0 [ 3260.121748] Oops: 0002 [1] SMP [ 3260.121753] CPU 1 [ 3260.121756] Modules linked in: dump_test(P) snd_pcm_oss snd_mixer_oss snd_seq snd_seq_device ide_cd generic ohci1394 snd_hda_intel snd_hda_codec snd_pcm snd_timer snd ieee1394 snd_page_alloc piix ide_core arcmsr aic79xx scsi_transport_spi usblp [ 3260.121785] Pid: 5556, comm: bash Tainted: P 2.6.18-git10 #1 [Alternatively, I can look into listing tainted flags with 'lsmod', but that won't help in oopsen/panics so much.] [akpm@osdl.org: cleanup] Signed-off-by: Randy Dunlap <rdunlap@xenotime.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-29[PATCH] /sys/modules: allow full length section namesIan S. Nelson
I've been using systemtap for some debugging and I noticed that it can't probe a lot of modules. Turns out it's kind of silly, the sections section of /sys/module is limited to 32byte filenames and many of the actual sections are a a bit longer than that. [akpm@osdl.org: rewrite to use dymanic allocation] Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-26[PATCH] load_module: no BUG if module_subsys uninitializedEd Swierk
Invoking load_module() before param_sysfs_init() is called crashes in mod_sysfs_setup(), since the kset in module_subsys is not initialized yet. In my case, net-pf-1 is getting modprobed as a result of hotplug trying to create a UNIX socket. Calls to hotplug begin after the topology_init initcall. Another patch for the same symptom (module_subsys-initialize-earlier.patch) moves param_sysfs_init() to the subsys initcalls, but this is still not early enough in the boot process in some cases. In particular, topology_init() causes /sbin/hotplug to run, which requests net-pf-1 (the UNIX socket protocol) which can be compiled as a module. Moving param_sysfs_init() to the postcore initcalls fixes this particular race, but there might well be other cases where a usermodehelper causes a module to load earlier still. The patch makes load_module() return an error rather than crashing the kernel if invoked before module_subsys is initialized. Cc: Mark Huang <mlhuang@cs.princeton.edu> Cc: Greg KH <greg@kroah.com> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-15[PATCH] null-terminate over-long /proc/kallsyms symbolsAndreas Gruenbacher
Got a customer bug report (https://bugzilla.novell.com/190296) about kernel symbols longer than 127 characters which end up in a string buffer that is not NULL terminated, leading to garbage in /proc/kallsyms. Using strlcpy prevents this from happening, even though such symbols still won't come out right. A better fix would be to not use a fixed-size buffer, but it's probably not worth the trouble. (Modversion'ed symbols even have a length limit of 60.) [bunk@stusta.de: build fix] Signed-off-by: Andreas Gruenbacher <agruen@suse.de> Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03[PATCH] lockdep: coreIngo Molnar
Do 'make oldconfig' and accept all the defaults for new config options - reboot into the kernel and if everything goes well it should boot up fine and you should have /proc/lockdep and /proc/lockdep_stats files. Typically if the lock validator finds some problem it will print out voluminous debug output that begins with "BUG: ..." and which syslog output can be used by kernel developers to figure out the precise locking scenario. What does the lock validator do? It "observes" and maps all locking rules as they occur dynamically (as triggered by the kernel's natural use of spinlocks, rwlocks, mutexes and rwsems). Whenever the lock validator subsystem detects a new locking scenario, it validates this new rule against the existing set of rules. If this new rule is consistent with the existing set of rules then the new rule is added transparently and the kernel continues as normal. If the new rule could create a deadlock scenario then this condition is printed out. When determining validity of locking, all possible "deadlock scenarios" are considered: assuming arbitrary number of CPUs, arbitrary irq context and task context constellations, running arbitrary combinations of all the existing locking scenarios. In a typical system this means millions of separate scenarios. This is why we call it a "locking correctness" validator - for all rules that are observed the lock validator proves it with mathematical certainty that a deadlock could not occur (assuming that the lock validator implementation itself is correct and its internal data structures are not corrupted by some other kernel subsystem). [see more details and conditionals of this statement in include/linux/lockdep.h and Documentation/lockdep-design.txt] Furthermore, this "all possible scenarios" property of the validator also enables the finding of complex, highly unlikely multi-CPU multi-context races via single single-context rules, increasing the likelyhood of finding bugs drastically. In practical terms: the lock validator already found a bug in the upstream kernel that could only occur on systems with 3 or more CPUs, and which needed 3 very unlikely code sequences to occur at once on the 3 CPUs. That bug was found and reported on a single-CPU system (!). So in essence a race will be found "piecemail-wise", triggering all the necessary components for the race, without having to reproduce the race scenario itself! In its short existence the lock validator found and reported many bugs before they actually caused a real deadlock. To further increase the efficiency of the validator, the mapping is not per "lock instance", but per "lock-class". For example, all struct inode objects in the kernel have inode->inotify_mutex. If there are 10,000 inodes cached, then there are 10,000 lock objects. But ->inotify_mutex is a single "lock type", and all locking activities that occur against ->inotify_mutex are "unified" into this single lock-class. The advantage of the lock-class approach is that all historical ->inotify_mutex uses are mapped into a single (and as narrow as possible) set of locking rules - regardless of how many different tasks or inode structures it took to build this set of rules. The set of rules persist during the lifetime of the kernel. To see the rough magnitude of checking that the lock validator does, here's a portion of /proc/lockdep_stats, fresh after bootup: lock-classes: 694 [max: 2048] direct dependencies: 1598 [max: 8192] indirect dependencies: 17896 all direct dependencies: 16206 dependency chains: 1910 [max: 8192] in-hardirq chains: 17 in-softirq chains: 105 in-process chains: 1065 stack-trace entries: 38761 [max: 131072] combined max dependencies: 2033928 hardirq-safe locks: 24 hardirq-unsafe locks: 176 softirq-safe locks: 53 softirq-unsafe locks: 137 irq-safe locks: 59 irq-unsafe locks: 176 The lock validator has observed 1598 actual single-thread locking patterns, and has validated all possible 2033928 distinct locking scenarios. More details about the design of the lock validator can be found in Documentation/lockdep-design.txt, which can also found at: http://redhat.com/~mingo/lockdep-patches/lockdep-design.txt [bunk@stusta.de: cleanups] Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Arjan van de Ven <arjan@linux.intel.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>
2006-07-03[PATCH] lockdep: add is_module_address()Ingo Molnar
Add is_module_address() method - to be used by lockdep. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Cc: Rusty Russell <rusty@rustcorp.com.au> 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>
2006-06-28[PATCH] load_module() cleanupAndrew Morton
Undo bizarre declaration in load_module(). Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-28[PATCH] Add EXPORT_UNUSED_SYMBOL and EXPORT_UNUSED_SYMBOL_GPLArjan van de Ven
Temporarily add EXPORT_UNUSED_SYMBOL and EXPORT_UNUSED_SYMBOL_GPL. These will be used as a transition measure for symbols that aren't used in the kernel and are on the way out. When a module uses such a symbol, a warning is printk'd at modprobe time. The main reason for removing unused exports is size: eacho export takes roughly between 100 and 150 bytes of kernel space in the binary. This patch gives users the option to immediately get this size gain via a config option. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26Merge git://git.kernel.org/pub/scm/linux/kernel/git/sam/kbuildLinus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/sam/kbuild: (40 commits) kbuild: trivial fixes in Makefile kbuild: adding symbols in Kconfig and defconfig to TAGS kbuild: replace abort() with exit(1) kbuild: support for %.symtypes files kbuild: fix silentoldconfig recursion kbuild: add option for stripping modules while installing them kbuild: kill some false positives from modpost kbuild: export-symbol usage report generator kbuild: fix make -rR breakage kbuild: append -dirty for updated but uncommited changes kbuild: append git revision for all untagged commits kbuild: fix module.symvers parsing in modpost kbuild: ignore make's built-in rules & variables kbuild: bugfix with initramfs kbuild: modpost build fix kbuild: check license compatibility when building modules kbuild: export-type enhancement to modpost.c kbuild: add dependency on kernel.release to the package targets kbuild: `make kernelrelease' speedup kconfig: KCONFIG_OVERWRITECONFIG ...
2006-06-26[PATCH] x86_64: reliable stack trace supportJan Beulich
These are the generic bits needed to enable reliable stack traces based on Dwarf2-like (.eh_frame) unwind information. Subsequent patches will enable x86-64 and i386 to make use of this. Thanks to Andi Kleen and Ingo Molnar, who pointed out several possibilities for improvement. Signed-off-by: Jan Beulich <jbeulich@novell.com> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-25[PATCH] ensure NULL deref can't possibly happen in is_exported()Jesper Juhl
If CONFIG_KALLSYMS is defined and if it should happen that is_exported() is given a NULL 'mod' and lookup_symbol(name, __start___ksymtab, __stop___ksymtab) returns 0, then we'll end up dereferencing a NULL pointer. Signed-off-by: Jesper Juhl <jesper.juhl@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>
2006-06-09kbuild: check license compatibility when building modulesSam Ravnborg
Modules that uses GPL symbols can no longer be build with kbuild, the build will fail during the modpost step. When a GPL-incompatible module uses a EXPORT_SYMBOL_GPL_FUTURE symbol then warn during modpost so author are actually notified. The actual license compatibility check is shared with the kernel to make sure it is in sync. Patch originally from: Andreas Gruenbacher <agruen@suse.de> and Ram Pai <linuxram@us.ibm.com> Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2006-05-15[PATCH] symbol_put_addr() locks kernelTrent Piepho
Even since a previous patch: Fix race between CONFIG_DEBUG_SLABALLOC and modules Sun, 27 Jun 2004 17:55:19 +0000 (17:55 +0000) http://www.kernel.org/git/?p=linux/kernel/git/torvalds/old-2.6-bkcvs.git;a=commit;h=92b3db26d31cf21b70e3c1eadc56c179506d8fbe The function symbol_put_addr() will deadlock the kernel. symbol_put_addr() would acquire modlist_lock, then while holding the lock call two functions kernel_text_address() and module_text_address() which also try to acquire the same lock. This deadlocks the kernel of course. This patch changes symbol_put_addr() to not acquire the modlist_lock, it doesn't need it since it never looks at the module list directly. Also, it now uses core_kernel_text() instead of kernel_text_address(). The latter has an additional check for addr inside a module, but we don't need to do that since we call module_text_address() (the same function kernel_text_address uses) ourselves. Signed-off-by: Trent Piepho <xyzzy@speakeasy.org> Cc: Zwane Mwaikambo <zwane@fsmlabs.com> Acked-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Johannes Stezenbach <js@linuxtv.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>