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* stackprotector: update make rulesTejun Heo2009-02-09
| | | | | | | | | | | | | | | | | | Impact: no default -fno-stack-protector if stackp is enabled, cleanup Stackprotector make rules had the following problems. * cc support test and warning are scattered across makefile and kernel/panic.c. * -fno-stack-protector was always added regardless of configuration. Update such that cc support test and warning are contained in makefile and -fno-stack-protector is added iff stackp is turned off. While at it, prepare for 32bit support. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* Merge branch 'core/percpu' into stackprotectorIngo Molnar2009-01-18
|\ | | | | | | | | | | | | | | | | | | Conflicts: arch/x86/include/asm/pda.h arch/x86/include/asm/system.h Also, moved include/asm-x86/stackprotector.h to arch/x86/include/asm. Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * oops: increment the oops UUID every time we oopsArjan van de Ven2009-01-06
| | | | | | | | | | | | | | | | | | ... because we do want repeated same-oops to be seen by automated tools like kerneloops.org Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | Merge branch 'linus' into stackprotectorIngo Molnar2008-12-31
|\| | | | | | | | | | | Conflicts: arch/x86/include/asm/pda.h kernel/fork.c
| * Merge branch 'core/debug' into core/coreIngo Molnar2008-12-25
| |\
| | * debug warnings: eliminate warn_on_slowpath()Ingo Molnar2008-11-28
| | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: cleanup, eliminate code now that warn_on_slowpath() uses warn_slowpath(...,NULL), we can eliminate warn_on_slowpath() altogether and use warn_slowpath(). Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * debug warnings: print the DMI board info name in a WARN/WARN_ONArjan van de Ven2008-11-28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: extend WARN_ON() output with DMI_PRODUCT_NAME It's very useful for many low level WARN_ON's to find out which motherboard has the broken BIOS etc... this patch adds a printk to the WARN_ON code for this. On architectures without DMI, gcc should optimize the code out. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * debug warnings: consolidate warn_slowpath and warn_on_slowpathArjan van de Ven2008-11-28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: cleanup, code reduction warn_slowpath is a superset of warn_on_slowpath; just have warn_on_slowpath call warn_slowpath with a NULL 3rd argument. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | taint: add missing commentArjan van de Ven2008-12-01
| |/ | | | | | | | | | | | | | | | | The description for 'D' was missing in the comment... (causing me a minute of WTF followed by looking at more of the code) Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * Make panic= and panic_on_oops into core_paramsRusty Russell2008-10-21
| | | | | | | | | | | | | | This allows them to be examined and set after boot, plus means they actually give errors if they are misused (eg. panic=yes). Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
| * Merge git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging-2.6Linus Torvalds2008-10-17
| |\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging-2.6: (25 commits) staging: at76_usb wireless driver Staging: workaround build system bug Staging: Lindent sxg.c Staging: SLICOSS: Call pci_release_regions at driver exit Staging: SLICOSS: Fix remaining type names Staging: SLICOSS: Fix warnings due to static usage Staging: SLICOSS: lots of checkpatch fixes Staging: go7007 v4l fixes Staging: Fix gcc warnings in sxg Staging: add echo cancelation module Staging: add wlan-ng prism2 usb driver Staging: add w35und wifi driver Staging: USB/IP: add host driver Staging: USB/IP: add client driver Staging: USB/IP: add common functions needed Staging: add the go7007 video driver Staging: add me4000 pci data collection driver Staging: add me4000 firmware files Staging: add sxg network driver Staging: add Alacritech slicoss network driver ... Fixed up conflicts due to taint flags changes and MAINTAINERS cleanup in MAINTAINERS, include/linux/kernel.h and kernel/panic.c.
| | * Staging: add TAINT_CRAP for all drivers/staging codeGreg Kroah-Hartman2008-10-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We need to add a flag for all code that is in the drivers/staging/ directory to prevent all other kernel developers from worrying about issues here, and to notify users that the drivers might not be as good as they are normally used to. Based on code from Andreas Gruenbacher and Jeff Mahoney to provide a TAINT flag for the support level of a kernel module in the Novell enterprise kernel release. This is the kernel portion of this feature, the ability for the flag to be set needs to be done in the build process and will happen in a follow-up patch. Cc: Andreas Gruenbacher <agruen@suse.de> Cc: Jeff Mahoney <jeffm@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| * | taint: fix kernel-docRandy Dunlap2008-10-16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Move print_tainted() kernel-doc to avoid the following error: Error(/var/linsrc/mmotm-2008-1002-1617//kernel/panic.c:155): cannot understand prototype: 'struct tnt ' Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Cc: Andi Kleen <andi@firstfloor.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | Make the taint flags reliableAndi Kleen2008-10-16
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It's somewhat unlikely that it happens, but right now a race window between interrupts or machine checks or oopses could corrupt the tainted bitmap because it is modified in a non atomic fashion. Convert the taint variable to an unsigned long and use only atomic bit operations on it. Unfortunately this means the intvec sysctl functions cannot be used on it anymore. It turned out the taint sysctl handler could actually be simplified a bit (since it only increases capabilities) so this patch actually removes code. [akpm@linux-foundation.org: remove unneeded include] Signed-off-by: Andi Kleen <ak@linux.intel.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | Merge branch 'linus' into stackprotectorIngo Molnar2008-10-15
|\| | | | | | | | | | | Conflicts: arch/x86/kernel/Makefile include/asm-x86/pda.h
| * Add a WARN() macro; this is WARN_ON() + printk argumentsArjan van de Ven2008-07-25
| | | | | | | | | | | | | | | | | | | | | | | | | | Add a WARN() macro that acts like WARN_ON(), with the added feature that it takes a printk like argument that is printed as part of the warning message. [akpm@linux-foundation.org: fix printk arguments] [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Cc: Greg KH <greg@kroah.com> Cc: Jiri Slaby <jirislaby@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | stackprotector: remove self-testIngo Molnar2008-07-13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | turns out gcc generates such stackprotector-failure sequences in certain circumstances: movq -8(%rbp), %rax # D.16032, xorq %gs:40, %rax #, jne .L17 #, leave ret .L17: call __stack_chk_fail # .size __stack_chk_test_func, .-__stack_chk_test_func .section .init.text,"ax",@progbits .type panic_setup, @function panic_setup: pushq %rbp # note that there's no jump back to the failing context after the call to __stack_chk_fail - i.e. it has a ((noreturn)) attribute. Which is fair enough in the normal case but kills the self-test. (as we cannot reliably return in the self-test) Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | x86: simplify stackprotector self-checkArjan van de Ven2008-07-13
| | | | | | | | | | | | | | | | Clean up the code by removing no longer needed code; make sure the pda is updated and kept in sync Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | stackprotector: better self-testArjan van de Ven2008-07-11
| | | | | | | | | | | | | | | | | | | | check stackprotector functionality by manipulating the canary briefly during bootup. far more robust than trying to overflow the stack. (which is architecture dependent, etc.) Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | stackprotector: turn not having the right gcc into a #warningArjan van de Ven2008-05-26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If the user selects the stack-protector config option, but does not have a gcc that has the right bits enabled (for example because it isn't build with a glibc that supports TLS, as is common for cross-compilers, but also because it may be too old), then the runtime test fails right now. This patch adds a warning message for this scenario. This warning accomplishes two goals 1) the user is informed that the security option he selective isn't available 2) the user is suggested to turn of the CONFIG option that won't work for him, and would make the runtime test fail anyway. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* | panic.c: fix whitespace additionsDaniel Walker2008-05-26
| | | | | | | | | | | | | | | | trivial: remove white space addition in stack protector Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* | x86: add CONFIG_CC_STACKPROTECTOR self-testArjan van de Ven2008-05-26
| | | | | | | | | | | | | | | | | | | | | | This patch adds a simple self-test capability to the stackprotector feature. The test deliberately overflows a stack buffer and then checks if the canary trap function gets called. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* | panic: print out stacktrace if DEBUG_BUGVERBOSEIngo Molnar2008-05-26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | if CONFIG_DEBUG_BUGVERBOSE is set then the user most definitely wanted to see as much information about kernel crashes as possible - so give them at least a stack dump. this is particularly useful for stackprotector related panics, where the stacktrace can give us the exact location of the (attempted) attack. Pointed out by pageexec@freemail.hu in the stackprotector breakage threads. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* | panic: print more informative messages on stackprotect failureIngo Molnar2008-05-26
|/ | | | | | | | | | | | | | pointed out by pageexec@freemail.hu: we just simply panic() when there's a stackprotector attack - giving the attacked person no information about what kernel code the attack went against. print out the attacked function. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* Taint kernel after WARN_ON(condition)Nur Hussein2008-04-29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The kernel is sent to tainted within the warn_on_slowpath() function, and whenever a warning occurs the new taint flag 'W' is set. This is useful to know if a warning occurred before a BUG by preserving the warning as a flag in the taint state. This does not work on architectures where WARN_ON has its own definition. These archs are: 1. s390 2. superh 3. avr32 4. parisc The maintainers of these architectures have been added in the Cc: list in this email to alert them to the situation. The documentation in oops-tracing.txt has been updated to include the new flag. Signed-off-by: Nur Hussein <nurhussein@gmail.com> Cc: Arjan van de Ven <arjan@infradead.org> Cc: "Randy.Dunlap" <rdunlap@xenotime.net> Cc: Ingo Molnar <mingo@elte.hu> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Kyle McMartin <kyle@mcmartin.ca> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Haavard Skinnemoen <hskinnemoen@atmel.com> Cc: Paul Mundt <lethal@linux-sh.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* ACPI: Taint kernel on ACPI table override (format corrected)Éric Piel2008-02-06
| | | | | | | | When an ACPI table is overridden (for now this can happen only for DSDT) display a big warning and taint the kernel with flag A. Signed-off-by: Eric Piel <eric.piel@tremplin-utc.net> Signed-off-by: Len Brown <len.brown@intel.com>
* debug: add the end-of-trace marker and the module list toArjan van de Ven2008-01-30
| | | | | | | | | | | | | | | | | | Unlike oopses, WARN_ON() currently does't print the loaded modules list. This makes it harder to take action on certain bug reports. For example, recently there were a set of WARN_ON()s reported in the mac80211 stack, which were just signalling a driver bug. It takes then anther round trip to the bug reporter (if he responds at all) to find out which driver is at fault. Another issue is that, unlike oopses, WARN_ON() doesn't currently printk the helpful "cut here" line, nor the "end of trace" marker. Now that WARN_ON() is out of line, the size increase due to this is minimal and it's worth adding. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* debug: move WARN_ON() out of lineArjan van de Ven2008-01-30
| | | | | | | | | | | | | | | | | | | | | | | | | A quick grep shows that there are currently 1145 instances of WARN_ON in the kernel. Currently, WARN_ON is pretty much entirely inlined, which makes it hard to enhance it without growing the size of the kernel (and getting Andrew unhappy). This patch build on top of Olof's patch that introduces __WARN, and places the slowpath out of line. It also uses Ingo's suggestion to not use __FUNCTION__ but to use kallsyms to do the lookup; this saves a ton of extra space since gcc doesn't need to store the function string twice now: 3936367 833603 624736 5394706 525112 vmlinux.before 3917508 833603 624736 5375847 520767 vmlinux-slowpath 15Kb savings... Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> CC: Andrew Morton <akpm@linux-foundation.org> CC: Olof Johansson <olof@lixom.net> Acked-by: Matt Meckall <mpm@selenic.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* debug: add end-of-oops markerArjan van de Ven2007-12-20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Right now it's nearly impossible for parsers that collect kernel crashes from logs or emails (such as www.kerneloops.org) to detect the end-of-oops condition. In addition, it's not currently possible to detect whether or not 2 oopses that look alike are actually the same oops reported twice, or are truly two unique oopses. This patch adds an end-of-oops marker, and makes the end marker include a very simple 64-bit random ID to be able to detect duplicate reports. Normally, this ID is calculated as a late_initcall() (in the hope that at that time there is enough entropy to get a unique enough ID); however for early oopses the oops_exit() function needs to generate the ID on the fly. We do this all at the _end_ of an oops printout, so this does not impact our ability to get the most important portions of a crash out to the console first. [ Sidenote: the already existing oopses-since-bootup counter we print during crashes serves as the differentiator between multiple oopses that trigger during the same bootup. ] Tested on 32-bit and 64-bit x86. Artificially injected very early crashes as well, as expected they result in this constant ID after multiple bootups: ---[ end trace ca143223eefdc828 ]--- ---[ end trace ca143223eefdc828 ]--- because the random pools are still all zero. But it all still works fine and causes no additional problems (which is the main goal of instrumentation code). Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* trivial comment wording/typo fix regarding taint flagsDaniel Roesen2007-10-19
| | | | | Signed-off-by: Daniel Roesen <dr@cluenet.de> Signed-off-by: Adrian Bunk <bunk@kernel.org>
* whitespace fixes: panic handlingDaniel Walker2007-10-18
| | | | | | Signed-off-by: Daniel Walker <dwalker@mvista.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Report that kernel is tainted if there was an OOPSPavel Emelianov2007-07-17
| | | | | | | | | | | | | | If the kernel OOPSed or BUGed then it probably should be considered as tainted. Thus, all subsequent OOPSes and SysRq dumps will report the tainted kernel. This saves a lot of time explaining oddities in the calltraces. Signed-off-by: Pavel Emelianov <xemul@openvz.org> Acked-by: Randy Dunlap <randy.dunlap@oracle.com> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> [ Added parisc patch from Matthew Wilson -Linus ] Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [PATCH] Add TAINT_USER and ability to set taint flags from userspaceTheodore Ts'o2007-02-11
| | | | | | | | | | | | | | | | | | | | | Allow taint flags to be set from userspace by writing to /proc/sys/kernel/tainted, and add a new taint flag, TAINT_USER, to be used when userspace has potentially done something dangerous that might compromise the kernel. This will allow support personnel to ask further questions about what may have caused the user taint flag to have been set. For example, they might examine the logs of the realtime JVM to see if the Java program has used the really silly, stupid, dangerous, and completely-non-portable direct access to physical memory feature which MUST be implemented according to the Real-Time Specification for Java (RTSJ). Sigh. What were those silly people at Sun thinking? [akpm@osdl.org: build fix] [bunk@stusta.de: cleanup] Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> 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>
* [PATCH] x86: Clean up x86 NMI sysctlsAndi Kleen2006-09-29
| | | | | | | | | Use prototypes in headers Don't define panic_on_unrecovered_nmi for all architectures Cc: dzickus@redhat.com Signed-off-by: Andi Kleen <ak@suse.de>
* [PATCH] Add the __stack_chk_fail() functionArjan van de Ven2006-09-26
| | | | | | | | | | | | | GCC emits a call to a __stack_chk_fail() function when the stack canary is not matching the expected value. Since this is a bad security issue; lets panic the kernel rather than limping along; the kernel really can't be trusted anymore when this happens. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andi Kleen <ak@suse.de> CC: Andi Kleen <ak@suse.de>
* [PATCH] x86: Allow users to force a panic on NMIDon Zickus2006-09-26
| | | | | | | | | | | | | | | | | | | | | To quote Alan Cox: The default Linux behaviour on an NMI of either memory or unknown is to continue operation. For many environments such as scientific computing it is preferable that the box is taken out and the error dealt with than an uncorrected parity/ECC error get propogated. A small number of systems do generate NMI's for bizarre random reasons such as power management so the default is unchanged. In other respects the new proc/sys entry works like the existing panic controls already in that directory. This is separate to the edac support - EDAC allows supported chipsets to handle ECC errors well, this change allows unsupported cases to at least panic rather than cause problems further down the line. Signed-off-by: Don Zickus <dzickus@redhat.com> Signed-off-by: Andi Kleen <ak@suse.de>
* [PATCH] lockdep: do not touch console state when tainting the kernelIngo Molnar2006-09-06
| | | | | | | | Remove an unintended console_verbose() side-effect from add_taint(). Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] panic.c build fixAndrew Morton2006-08-14
| | | | | | | | | kernel/panic.c: In function 'add_taint': kernel/panic.c:176: warning: implicit declaration of function 'debug_locks_off' Cc: Andi Kleen <ak@muc.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* [PATCH] lockdep: disable lock debugging when kernel state becomes untrustedArjan van de Ven2006-07-10
| | | | | | | | | | | | | | | | | | | | | | | Disable lockdep debugging in two situations where the integrity of the kernel no longer is guaranteed: when oopsing and when hitting a tainting-condition. The goal is to not get weird lockdep traces that don't make sense or are otherwise undebuggable, to not waste time. Lockdep assumes that the previous state it knows about is valid to operate, which is why lockdep turns itself off after the first violation it reports, after that point it can no longer make that assumption. A kernel oops means that the integrity of the kernel compromised; in addition anything lockdep would report is of lesser importance than the oops. All the tainting conditions are of similar integrity-violating nature and also make debugging/diagnosing more difficult. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* Remove obsolete #include <linux/config.h>Jörn Engel2006-06-30
| | | | | Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de> Signed-off-by: Adrian Bunk <bunk@stusta.de>
* [PATCH] the scheduled unexport of panic_timeoutAdrian Bunk2006-04-11
| | | | | | | | Implement the scheduled unexport of panic_timeout. Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Notifier chain update: API changesAlan Stern2006-03-27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* [PATCH] pause_on_oops command line optionAndrew Morton2006-03-23
| | | | | | | | | | | | | | | | | Attempt to fix the problem wherein people's oops reports scroll off the screen due to repeated oopsing or to oopses on other CPUs. If this happens the user can reboot with the `pause_on_oops=<seconds>' option. It will allow the first oopsing CPU to print an oops record just a single time. Second oopsing attempts, or oopses on other CPUs will cause those CPUs to enter a tight loop until the specified number of seconds have elapsed. The patch implements the infrastructure generically in the expectation that architectures other than x86 will find it useful. Cc: Dave Jones <davej@codemonkey.org.uk> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] prevent recursive panic from softlockup watchdogJan Beulich2006-02-10
| | | | | | | | | When panic_timeout is zero, suppress triggering a nested panic due to soft lockup detection. Signed-off-by: Jan Beulich <jbeulich@novell.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] s390: cleanup KconfigMartin Schwidefsky2006-01-06
| | | | | | | | | | Sanitize some s390 Kconfig options. We have ARCH_S390, ARCH_S390X, ARCH_S390_31, 64BIT, S390_SUPPORT and COMPAT. Replace these 6 options by S390, 64BIT and COMPAT. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Call emergency_reboot from panicEric W. Biederman2005-07-26
| | | | | | | | We know the system is in trouble so there is no question if this is an emergecy :) Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] kdump: Use real pt_regs from exceptionAlexander Nyberg2005-06-25
| | | | | | | | | | | | | | | | | | | | | Makes kexec_crashdump() take a pt_regs * as an argument. This allows to get exact register state at the point of the crash. If we come from direct panic assertion NULL will be passed and the current registers saved before crashdump. This hooks into two places: die(): check the conditions under which we will panic when calling do_exit and go there directly with the pt_regs that caused the fatal fault. die_nmi(): If we receive an NMI lockup while in the kernel use the pt_regs and go directly to crash_kexec(). We're probably nested up badly at this point so this might be the only chance to escape with proper information. Signed-off-by: Alexander Nyberg <alexn@telia.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] kexec: add kexec syscallsEric W. Biederman2005-06-25
| | | | | | | | | | | | | | | | | | | | This patch introduces the architecture independent implementation the sys_kexec_load, the compat_sys_kexec_load system calls. Kexec on panic support has been integrated into the core patch and is relatively clean. In addition the hopefully architecture independent option crashkernel=size@location has been docuemented. It's purpose is to reserve space for the panic kernel to live, and where no DMA transfer will ever be setup to access. Signed-off-by: Eric Biederman <ebiederm@xmission.com> Signed-off-by: Alexander Nyberg <alexn@telia.com> Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Vivek Goyal <vgoyal@in.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [SPARC]: Stop-A printk cleanupTom 'spot' Callaway2005-04-24
| | | | | | | | | | | | This patch is incredibly trivial, but it does resolve some of the user confusion as to what "L1-A" actually is. Clarify printk message to refer to Stop-A (L1-A). Gentoo has a virtually identical patch in their kernel sources. Signed-off-by: Tom 'spot' Callaway <tcallawa@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* Linux-2.6.12-rc2v2.6.12-rc2Linus Torvalds2005-04-16
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
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