summaryrefslogtreecommitdiff
path: root/arch/x86/kernel/msr.c
AgeCommit message (Collapse)AuthorFilesLines
2019-08-20x86/msr: Restrict MSR access when the kernel is locked downMatthew Garrett1-0/+8
Writing to MSRs should not be allowed if the kernel is locked down, since it could lead to execution of arbitrary code in kernel mode. Based on a patch by Kees Cook. Signed-off-by: Matthew Garrett <mjg59@google.com> Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Kees Cook <keescook@chromium.org> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> cc: x86@kernel.org Signed-off-by: James Morris <jmorris@namei.org>
2019-05-30treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 142Thomas Gleixner1-6/+1
Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation inc 675 mass ave cambridge ma 02139 usa either version 2 of the license or at your option any later version incorporated herein by reference extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 4 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Richard Fontana <rfontana@redhat.com> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190524100844.465381181@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-29x86: Clean up 'sizeof x' => 'sizeof(x)'Jordan Borgner1-4/+4
"sizeof(x)" is the canonical coding style used in arch/x86 most of the time. Fix the few places that didn't follow the convention. (Also do some whitespace cleanups in a few places while at it.) [ mingo: Rewrote the changelog. ] Signed-off-by: Jordan Borgner <mail@jordan-borgner.de> Cc: Borislav Petkov <bp@alien8.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20181028125828.7rgammkgzep2wpam@JordanDesktop Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-12-25x86/msr: Remove bogus cleanup from the error pathThomas Gleixner1-1/+0
The error cleanup which is invoked when the hotplug state setup failed tries to remove the failed state, which is broken. Fixes: 8fba38c937cd ("x86/msr: Convert to hotplug state machine") Reported-by: kernel test robot <fengguang.wu@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Sebastian Siewior <bigeasy@linutronix.de>
2016-11-23x86/msr: Convert to hotplug state machineSebastian Andrzej Siewior1-54/+15
Install the callbacks via the state machine and let the core invoke the callbacks on the already online CPUs. Move the callbacks to online/offline as there is no point in having the files around before the cpu is online and until its completely gone. [ tglx: Move the callbacks to online/offline ] Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: rt@linuxtronix.de Link: http://lkml.kernel.org/r/20161117183541.8588-4-bigeasy@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-01-30x86/cpufeature: Carve out X86_FEATURE_*Borislav Petkov1-1/+1
Move them to a separate header and have the following dependency: x86/cpufeatures.h <- x86/processor.h <- x86/cpufeature.h This makes it easier to use the header in asm code and not include the whole cpufeature.h and add guards for asm. Suggested-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1453842730-28463-5-git-send-email-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-12-23new helpers: no_seek_end_llseek{,_size}()Al Viro1-23/+1
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-10-18x86, msr: Use seek definitions instead of hard-coded valuesFabian Frederick1-2/+2
Replace 0/1 by SEEK_SET/SEEK_CUR. Signed-off-by: Fabian Frederick <fabf@skynet.be> Link: http://lkml.kernel.org/r/1413576120-27147-1-git-send-email-fabf@skynet.be Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-10-18x86, msr: Convert printk to pr_foo()Fabian Frederick1-2/+3
Also define pr_fmt. Signed-off-by: Fabian Frederick <fabf@skynet.be> Link: http://lkml.kernel.org/r/1413576110-27103-1-git-send-email-fabf@skynet.be Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-10-18x86, msr: Use PTR_ERR_OR_ZEROFabian Frederick1-1/+1
Replace IS_ERR/PTR_ERR Signed-off-by: Fabian Frederick <fabf@skynet.be> Link: http://lkml.kernel.org/r/1413576099-27059-1-git-send-email-fabf@skynet.be Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-03-20x86, msr: Fix CPU hotplug callback registrationSrivatsa S. Bhat1-7/+9
Subsystems that want to register CPU hotplug callbacks, as well as perform initialization for the CPUs that are already online, often do it as shown below: get_online_cpus(); for_each_online_cpu(cpu) init_cpu(cpu); register_cpu_notifier(&foobar_cpu_notifier); put_online_cpus(); This is wrong, since it is prone to ABBA deadlocks involving the cpu_add_remove_lock and the cpu_hotplug.lock (when running concurrently with CPU hotplug operations). Instead, the correct and race-free way of performing the callback registration is: cpu_notifier_register_begin(); for_each_online_cpu(cpu) init_cpu(cpu); /* Note the use of the double underscored version of the API */ __register_cpu_notifier(&foobar_cpu_notifier); cpu_notifier_register_done(); Fix the msr code in x86 by using this latter form of callback registration. Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@kernel.org> Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-10-08x86, msr: Use file_inode(), not f_mapping->hostAndre Richter1-1/+1
As discussed in [1], exchange f_mapping->host with file_inode(). This is a bug, but happens to be non-manifest in this case. [1] http://lkml.kernel.org/r/20131007190357.GA13318@ZenIV.linux.org.uk Signed-off-by: Andre Richter <andre.o.richter@gmail.com> Link: http://lkml.kernel.org/r/1381224142-3267-1-git-send-email-andre.o.richter@gmail.com Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2013-07-15x86: delete __cpuinit usage from all x86 filesPaul Gortmaker1-3/+3
The __cpuinit type of throwaway sections might have made sense some time ago when RAM was more constrained, but now the savings do not offset the cost and complications. For example, the fix in commit 5e427ec2d0 ("x86: Fix bit corruption at CPU resume time") is a good example of the nasty type of bugs that can be created with improper use of the various __init prefixes. After a discussion on LKML[1] it was decided that cpuinit should go the way of devinit and be phased out. Once all the users are gone, we can then finally remove the macros themselves from linux/init.h. Note that some harmless section mismatch warnings may result, since notify_cpu_starting() and cpu_up() are arch independent (kernel/cpu.c) are flagged as __cpuinit -- so if we remove the __cpuinit from arch specific callers, we will also get section mismatch warnings. As an intermediate step, we intend to turn the linux/init.h cpuinit content into no-ops as early as possible, since that will get rid of these warnings. In any case, they are temporary and harmless. This removes all the arch/x86 uses of the __cpuinit macros from all C files. x86 only had the one __CPUINIT used in assembly files, and it wasn't paired off with a .previous or a __FINIT, so we can delete it directly w/o any corresponding additional change there. [1] https://lkml.org/lkml/2013/5/20/589 Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: x86@kernel.org Acked-by: Ingo Molnar <mingo@kernel.org> Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: H. Peter Anvin <hpa@linux.intel.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2013-02-28more file_inode() open-coded instancesAl Viro1-5/+4
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-01-24x86/msr: Add capabilities checkAlan Cox1-0/+3
At the moment the MSR driver only relies upon file system checks. This means that anything as root with any capability set can write to MSRs. Historically that wasn't very interesting but on modern processors the MSRs are such that writing to them provides several ways to execute arbitary code in kernel space. Sample code and documentation on doing this is circulating and MSR attacks are used on Windows 64bit rootkits already. In the Linux case you still need to be able to open the device file so the impact is fairly limited and reduces the security of some capability and security model based systems down towards that of a generic "root owns the box" setup. Therefore they should require CAP_SYS_RAWIO to prevent an elevation of capabilities. The impact of this is fairly minimal on most setups because they don't have heavy use of capabilities. Those using SELinux, SMACK or AppArmor rules might want to consider if their rulesets on the MSR driver could be tighter. Signed-off-by: Alan Cox <alan@linux.intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Horses <stable@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-09-23Use get_online_cpus to avoid races involving CPU hotplugSilas Boyd-Wickizer1-0/+5
If arch/x86/kernel/msr.c is a module, a CPU might offline or online between the for_each_online_cpu(i) loop and the call to register_hotcpu_notifier in msr_init or the call to unregister_hotcpu_notifier in msr_exit. The potential races can lead to leaks/duplicates, attempts to destroy non-existant devices, or random pointer dereferences. For example, in msr_init if: for_each_online_cpu(i) { err = msr_device_create(i); if (err != 0) goto out_class; } <----- CPU offlines register_hotcpu_notifier(&msr_class_cpu_notifier); and the CPU never onlines before msr_exit, then the module will never call msr_device_destroy for the associated CPU. This fix surrounds for_each_online_cpu and register_hotcpu_notifier or unregister_hotcpu_notifier with get_online_cpus+put_online_cpus. Tested on a VM. Signed-off-by: Silas Boyd-Wickizer <sbw@mit.edu> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2012-03-28Disintegrate asm/system.h for X86David Howells1-1/+0
Disintegrate asm/system.h for X86. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: H. Peter Anvin <hpa@zytor.com> cc: x86@kernel.org
2012-01-04switch device_get_devnode() and ->devnode() to umode_t *Al Viro1-1/+1
both callers of device_get_devnode() are only interested in lower 16bits and nobody tries to return anything wider than 16bit anyway. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-11-17BKL: remove extraneous #include <smp_lock.h>Arnd Bergmann1-1/+0
The big kernel lock has been removed from all these files at some point, leaving only the #include. Remove this too as a cleanup. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-27x86: convert cpu notifier to return encapsulate errno valueAkinobu Mita1-1/+1
By the previous modification, the cpu notifier can return encapsulate errno value. This converts the cpu notifiers for msr, cpuid, and therm_throt. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-03-30include cleanup: Update gfp.h and slab.h includes to prepare for breaking ↵Tejun Heo1-0/+1
implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-01-27x86, msr/cpuid: Pass the number of minors when unregistering MSR and CPUID ↵Russ Anderson1-1/+1
drivers. Pass the number of minors when unregistering MSR and CPUID drivers. Reported-by: Dean Nelson <dnelson@redhat.com> Signed-off-by: Dean Nelson <dnelson@redhat.com> LKML-Reference: <20100127023722.GA22305@sgi.com> Signed-off-by: Russ Anderson <rja@sgi.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-12-16x86, msr/cpuid: Register enough minors for the MSR and CPUID driversH. Peter Anvin1-2/+2
register_chrdev() hardcodes registering 256 minors, presumably to avoid breaking old drivers. However, we need to register enough minors so that we have all possible CPUs. checkpatch warns on this patch, but the patch is correct: NR_CPUS here is a static *upper bound* on the *maximum CPU index* (not *number of CPUs!*) and that is what we want. Reported-and-tested-by: Russ Anderson <rja@sgi.com> Cc: Tejun Heo <tj@kernel.org> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Takashi Iwai <tiwai@suse.de> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Signed-off-by: H. Peter Anvin <hpa@zytor.com> LKML-Reference: <tip-*@git.kernel.org>
2009-12-14x86, msr: Remove incorrect, duplicated code in the MSR driverH. Peter Anvin1-3/+2
The MSR driver would compute the values for cpu and c at declaration, and then again in the body of the function. This isn't merely redundant, but unsafe, since cpu might not refer to a valid CPU at that point. Remove the unnecessary and dangerous references in the declarations. This code now matches the equivalent code in the CPUID driver. Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-12-06Merge branch 'x86-cpu-for-linus' of ↵Linus Torvalds1-10/+6
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'x86-cpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: x86, msr, cpumask: Use struct cpumask rather than the deprecated cpumask_t x86, cpuid: Simplify the code in cpuid_open x86, cpuid: Remove the bkl from cpuid_open() x86, msr: Remove the bkl from msr_open() x86: AMD Geode LX optimizations x86, msr: Unify rdmsr_on_cpus/wrmsr_on_cpus
2009-10-08x86, msr: Remove the bkl from msr_open()Frederic Weisbecker1-10/+6
Remove the big kernel lock from msr_open() as it doesn't protect anything there. The only racy event that can happen here is a concurrent cpu shutdown. So let's look at what could be racy during/after the above event: - The cpu_online() check is racy, but the bkl doesn't help about that anyway it disables preemption but we may be chcking another cpu than the current one. Also the cpu can still become offlined between open and read calls. - The cpu_data(cpu) returns a safe pointer too. It won't be released on cpu offlining. But some fields can be changed from arch/x86/kernel/smpboot.c:remove_siblinginfo() : - phys_proc_id - cpu_core_id Those are not read from msr_open(). What we are checking is the x86_capability that is left untouched on offlining. So this removal looks safe. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: John Kacur <jkacur@redhat.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Sven-Thorsten Dietrich <sdietrich@suse.de> LKML-Reference: <1254944602-7382-1-git-send-email-fweisbec@gmail.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-09-19Driver-Core: extend devnode callbacks to provide permissionsKay Sievers1-2/+2
This allows subsytems to provide devtmpfs with non-default permissions for the device node. Instead of the default mode of 0600, null, zero, random, urandom, full, tty, ptmx now have a mode of 0666, which allows non-privileged processes to access standard device nodes in case no other userspace process applies the expected permissions. This also fixes a wrong assignment in pktcdvd and a checkpatch.pl complain. Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-09-01x86, msr: Export the register-setting MSR functions via /dev/*/msrH. Peter Anvin1-0/+51
Make it possible to access the all-register-setting/getting MSR functions via the MSR driver. This is implemented as an ioctl() on the standard MSR device node. Signed-off-by: H. Peter Anvin <hpa@zytor.com> Cc: Borislav Petkov <petkovbb@gmail.com>
2009-09-01x86, msr: Have the _safe MSR functions return -EIO, not -EFAULTH. Peter Anvin1-8/+2
For some reason, the _safe MSR functions returned -EFAULT, not -EIO. However, the only user which cares about the return code as anything other than a boolean is the MSR driver, which wants -EIO. Change it to -EIO across the board. Signed-off-by: H. Peter Anvin <hpa@zytor.com> Cc: Jeremy Fitzhardinge <jeremy@xensource.com> Cc: Chris Wright <chrisw@sous-sol.org> Cc: Alok Kataria <akataria@vmware.com> Cc: Rusty Russell <rusty@rustcorp.com.au>
2009-06-16Driver Core: x86: add nodename for cpuid and msr drivers.Kay Sievers1-0/+6
This adds support to the x86 cpuid and msr drivers to report the proper device name to userspace for their devices. Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Jan Blunck <jblunck@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-01-12x86: msr.c fix style problemsJaswinder Singh Rajput1-1/+1
Impact: cleanup Fix: WARNING: Use #include <linux/uaccess.h> instead of <asm/uaccess.h> total: 0 errors, 1 warnings Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-03x86: cleanup some remaining usages of NR_CPUS where s/b nr_cpu_idsMike Travis1-1/+1
Impact: Reduce future system panics due to cpumask operations using NR_CPUS Insure that code does not look at bits >= nr_cpu_ids as when cpumasks are allocated based on nr_cpu_ids, these extra bits will not be defined. Also some other minor updates: * change in to use cpu accessor function set_cpu_present() instead of directly accessing cpu_present_map w/cpu_clear() [arch/x86/kernel/reboot.c] * use cpumask_of() instead of &cpumask_of_cpu() [arch/x86/kernel/reboot.c] * optimize some cpu_mask_to_apicid_and functions. Signed-off-by: Mike Travis <travis@sgi.com> Acked-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-16device create: misc: convert device_create_drvdata to device_createGreg Kroah-Hartman1-2/+2
Now that device_create() has been audited, rename things back to the original call to be sane. Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-08-26x86: msr: correct return value on partial operationsH. Peter Anvin1-10/+18
Return the correct return value when the MSR driver partially completes a request (we should return the number of bytes actually read or written, instead of the error code.) Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2008-08-26x86: msr: propagate errors from smp_call_function_single()H. Peter Anvin1-4/+10
Propagate error (-ENXIO) from smp_call_function_single(). These errors can happen when a CPU is unplugged while the MSR driver is open. Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2008-08-15x86, msr: fix NULL pointer deref due to msr_open on nonexistent CPUsDarrick J. Wong1-1/+1
msr_open tests for someone trying to open a device for a nonexistent CPU. However, the function always returns 0, not ret like it should, hence userspace can BUG the kernel trivially. This bug was introduced by the cdev lock_kernel pushdown patch last May. The BUG can be reproduced with these commands: # mknod fubar c 202 8 <-- pick a number less than NR_CPUS that is not the number of an online CPU # cat fubar Signed-off-by: Darrick J. Wong <djwong@us.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-22device create: x86: convert device_create to device_create_drvdataGreg Kroah-Hartman1-2/+2
device_create() is race-prone, so use the race-free device_create_drvdata() instead as device_create() is going away. Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-05-19x86: cdev lock_kernel() pushdownJonathan Corbet1-4/+12
Push the cdev lock_kernel() call down into the x86 msr and cpuid drivers. Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2008-04-20PM: Remove destroy_suspended_device()Rafael J. Wysocki1-3/+1
After 2.6.24 there was a plan to make the PM core acquire all device semaphores during a suspend/hibernation to protect itself from concurrent operations involving device objects. That proved to be too heavy-handed and we found a better way to achieve the goal, but before it happened, we had introduced the functions device_pm_schedule_removal() and destroy_suspended_device() to allow drivers to "safely" destroy a suspended device and we had adapted some drivers to use them. Now that these functions are no longer necessary, it seems reasonable to remove them and modify their users to use the normal device unregistration instead. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-04-17x86: coding style fixes to arch/x86/kernel/msr.cPaolo Ciarrocchi1-2/+2
Before: total: 2 errors, 0 warnings, 231 lines checked After: total: 0 errors, 0 warnings, 231 lines checked No code changed: arch/x86/kernel/msr.o: text data bss dec hex filename 1199 12 4 1215 4bf msr.o.before 1199 12 4 1215 4bf msr.o.after md5: 604be0d07d829bc52a9346babd084bdc msr.o.before.asm 604be0d07d829bc52a9346babd084bdc msr.o.after.asm Signed-off-by: Paolo Ciarrocchi <paolo.ciarrocchi@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-04x86: cpuid, msr: use inode mutex instead of big kernel lockH. Peter Anvin1-5/+9
Instead of grabbing the BKL on seek, use the inode mutex in the style of generic_file_llseek(). Signed-off-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-02-01x86: fix section mismatch warnings when referencing notifiersSam Ravnborg1-1/+1
Fix the following warnings: WARNING: arch/x86/kernel/built-in.o(.exit.text+0xf8): Section mismatch in reference from the function msr_exit() to the variable .cpuinit.data:msr_class_cpu_notifier WARNING: arch/x86/kernel/built-in.o(.exit.text+0x158): Section mismatch in reference from the function cpuid_exit() to the variable .cpuinit.data:cpuid_class_cpu_notifier WARNING: arch/x86/kernel/built-in.o(.exit.text+0x171): Section mismatch in reference from the function microcode_exit() to the variable .cpuinit.data:mc_cpu_notifier In all three cases there were a function annotated __exit that referenced a variable annotated __cpuinitdata. The fix was to replace the annotation of the notifier with __refdata to tell modpost that the reference to a _cpuinit function in the notifier are OK. The unregister call that references the notifier variable will simple delete the function pointer so there is no problem ignoring the reference. Note: This looks like another case where __cpuinit has been used as replacement for proper use of CONFIG_HOTPLUG_CPU to decide what code are used for HOTPLUG_CPU. Signed-off-by: Sam Ravnborg <sam@ravnborg.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25PM: Acquire device locks on suspendRafael J. Wysocki1-3/+3
This patch reorganizes the way suspend and resume notifications are sent to drivers. The major changes are that now the PM core acquires every device semaphore before calling the methods, and calls to device_add() during suspends will fail, while calls to device_del() during suspends will block. It also provides a way to safely remove a suspended device with the help of the PM core, by using the device_pm_schedule_removal() callback introduced specifically for this purpose, and updates two drivers (msr and cpuid) that need to use it. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-10-19x86: convert cpuinfo_x86 array to a per_cpu arrayMike Travis1-1/+1
cpu_data is currently an array defined using NR_CPUS. This means that we overallocate since we will rarely really use maximum configured cpus. When NR_CPU count is raised to 4096 the size of cpu_data becomes 3,145,728 bytes. These changes were adopted from the sparc64 (and ia64) code. An additional field was added to cpuinfo_x86 to be a non-ambiguous cpu index. This corresponds to the index into a cpumask_t as well as the per_cpu index. It's used in various places like show_cpuinfo(). cpu_data is defined to be the boot_cpu_data structure for the NON-SMP case. Signed-off-by: Mike Travis <travis@sgi.com> Acked-by: Christoph Lameter <clameter@sgi.com> Cc: Andi Kleen <ak@suse.de> Cc: James Bottomley <James.Bottomley@steeleye.com> Cc: Dmitry Torokhov <dtor@mail.ru> Cc: "Antonino A. Daplas" <adaplas@pol.net> Cc: Mark M. Hoffman <mhoffman@lightlink.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-19x86 msr driver: Misc cpuinit annotationsSatyam Sharma1-1/+1
msr_class_cpu_callback() can be marked __cpuinit, being the notifier callback for a __cpuinitdata notifier_block. So can be marked msr_device_create() too, called only from the newly-__cpuinit msr_class_cpu_callback() or from __init-marked msr_init(). Signed-off-by: Satyam Sharma <satyam@infradead.org> Cc: Andi Kleen <ak@suse.de> Acked-by: H. Peter Anvin <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-19cpu hotplug: msr: fix cpu hotplug error handlingAkinobu Mita1-15/+20
Do msr_device_create() in CPU_UP_PREPARE instead of CPU_ONLINE. Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: Gautham R Shenoy <ego@in.ibm.com> Cc: Oleg Nesterov <oleg@tv-sign.ru> Cc: Andi Kleen <ak@suse.de> Cc: Jan Beulich <jbeulich@novell.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-17i386: Misc cpuinit annotationsSatyam Sharma1-2/+2
msr_class_cpu_callback() can be marked __cpuinit, being the notifier callback for a __cpuinitdata notifier_block. So can be marked msr_device_create() too, called only from the newly-__cpuinit msr_class_cpu_callback() or from __init-marked msr_init(). [ tglx: arch/x86 adaptation ] Signed-off-by: Satyam Sharma <satyam@infradead.org> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-13Delete filenames in comments.Dave Jones1-2/+0
Since the x86 merge, lots of files that referenced their own filenames are no longer correct. Rather than keep them up to date, just delete them, as they add no real value. Additionally: - fix up comment formatting in scx200_32.c - Remove a credit from myself in setup_64.c from a time when we had no SCM - remove longwinded history from tsc_32.c which can be figured out from git. Signed-off-by: Dave Jones <davej@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-11i386: move kernelThomas Gleixner1-0/+224
Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>