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2017-10-21x86/intel_rdt: Fix potential deadlock during resctrl unmountReinette Chatre1-5/+5
Lockdep warns about a potential deadlock: [ 66.782842] ====================================================== [ 66.782888] WARNING: possible circular locking dependency detected [ 66.782937] 4.14.0-rc2-test-test+ #48 Not tainted [ 66.782983] ------------------------------------------------------ [ 66.783052] umount/336 is trying to acquire lock: [ 66.783117] (cpu_hotplug_lock.rw_sem){++++}, at: [<ffffffff81032395>] rdt_kill_sb+0x215/0x390 [ 66.783193] but task is already holding lock: [ 66.783244] (rdtgroup_mutex){+.+.}, at: [<ffffffff810321b6>] rdt_kill_sb+0x36/0x390 [ 66.783305] which lock already depends on the new lock. [ 66.783364] the existing dependency chain (in reverse order) is: [ 66.783419] -> #3 (rdtgroup_mutex){+.+.}: [ 66.783467] __lock_acquire+0x1293/0x13f0 [ 66.783509] lock_acquire+0xaf/0x220 [ 66.783543] __mutex_lock+0x71/0x9b0 [ 66.783575] mutex_lock_nested+0x1b/0x20 [ 66.783610] intel_rdt_online_cpu+0x3b/0x430 [ 66.783649] cpuhp_invoke_callback+0xab/0x8e0 [ 66.783687] cpuhp_thread_fun+0x7a/0x150 [ 66.783722] smpboot_thread_fn+0x1cc/0x270 [ 66.783764] kthread+0x16e/0x190 [ 66.783794] ret_from_fork+0x27/0x40 [ 66.783825] -> #2 (cpuhp_state){+.+.}: [ 66.783870] __lock_acquire+0x1293/0x13f0 [ 66.783906] lock_acquire+0xaf/0x220 [ 66.783938] cpuhp_issue_call+0x102/0x170 [ 66.783974] __cpuhp_setup_state_cpuslocked+0x154/0x2a0 [ 66.784023] __cpuhp_setup_state+0xc7/0x170 [ 66.784061] page_writeback_init+0x43/0x67 [ 66.784097] pagecache_init+0x43/0x4a [ 66.784131] start_kernel+0x3ad/0x3f7 [ 66.784165] x86_64_start_reservations+0x2a/0x2c [ 66.784204] x86_64_start_kernel+0x72/0x75 [ 66.784241] verify_cpu+0x0/0xfb [ 66.784270] -> #1 (cpuhp_state_mutex){+.+.}: [ 66.784319] __lock_acquire+0x1293/0x13f0 [ 66.784355] lock_acquire+0xaf/0x220 [ 66.784387] __mutex_lock+0x71/0x9b0 [ 66.784419] mutex_lock_nested+0x1b/0x20 [ 66.784454] __cpuhp_setup_state_cpuslocked+0x52/0x2a0 [ 66.784497] __cpuhp_setup_state+0xc7/0x170 [ 66.784535] page_alloc_init+0x28/0x30 [ 66.784569] start_kernel+0x148/0x3f7 [ 66.784602] x86_64_start_reservations+0x2a/0x2c [ 66.784642] x86_64_start_kernel+0x72/0x75 [ 66.784678] verify_cpu+0x0/0xfb [ 66.784707] -> #0 (cpu_hotplug_lock.rw_sem){++++}: [ 66.784759] check_prev_add+0x32f/0x6e0 [ 66.784794] __lock_acquire+0x1293/0x13f0 [ 66.784830] lock_acquire+0xaf/0x220 [ 66.784863] cpus_read_lock+0x3d/0xb0 [ 66.784896] rdt_kill_sb+0x215/0x390 [ 66.784930] deactivate_locked_super+0x3e/0x70 [ 66.784968] deactivate_super+0x40/0x60 [ 66.785003] cleanup_mnt+0x3f/0x80 [ 66.785034] __cleanup_mnt+0x12/0x20 [ 66.785070] task_work_run+0x8b/0xc0 [ 66.785103] exit_to_usermode_loop+0x94/0xa0 [ 66.786804] syscall_return_slowpath+0xe8/0x150 [ 66.788502] entry_SYSCALL_64_fastpath+0xab/0xad [ 66.790194] other info that might help us debug this: [ 66.795139] Chain exists of: cpu_hotplug_lock.rw_sem --> cpuhp_state --> rdtgroup_mutex [ 66.800035] Possible unsafe locking scenario: [ 66.803267] CPU0 CPU1 [ 66.804867] ---- ---- [ 66.806443] lock(rdtgroup_mutex); [ 66.808002] lock(cpuhp_state); [ 66.809565] lock(rdtgroup_mutex); [ 66.811110] lock(cpu_hotplug_lock.rw_sem); [ 66.812608] *** DEADLOCK *** [ 66.816983] 2 locks held by umount/336: [ 66.818418] #0: (&type->s_umount_key#35){+.+.}, at: [<ffffffff81229738>] deactivate_super+0x38/0x60 [ 66.819922] #1: (rdtgroup_mutex){+.+.}, at: [<ffffffff810321b6>] rdt_kill_sb+0x36/0x390 When the resctrl filesystem is unmounted the locks should be obtain in the locks in the same order as was done when the cpus came online: cpu_hotplug_lock before rdtgroup_mutex. This also requires to switch the static_branch_disable() calls to the _cpulocked variant because now cpu hotplug lock is held already. [ tglx: Switched to cpus_read_[un]lock ] Signed-off-by: Reinette Chatre <reinette.chatre@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com> Acked-by: Vikas Shivappa <vikas.shivappa@linux.intel.com> Acked-by: Fenghua Yu <fenghua.yu@intel.com> Acked-by: Tony Luck <tony.luck@intel.com> Link: https://lkml.kernel.org/r/cc292e76be073f7260604651711c47b09fd0dc81.1508490116.git.reinette.chatre@intel.com
2017-10-21x86/intel_rdt: Initialize bitmask of shareable resource if CDP enabledReinette Chatre1-0/+1
The platform informs via CPUID.(EAX=0x10, ECX=res#):EBX[31:0] (valid res# are only 1 for L3 and 2 for L2) which unit of the allocation may be used by other entities in the platform. This information is valid whether CDP (Code and Data Prioritization) is enabled or not. Ensure that the bitmask of shareable resource is initialized when CDP is enabled. Fixes: 0dd2d7494cd8 ("x86/intel_rdt: Show bitmask of shareable resource with other executing units" Signed-off-by: Reinette Chatre <reinette.chatre@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Fenghua Yu <fenghua.yu@intel.com> Acked-by: Vikas Shivappa <vikas.shivappa@linux.intel.com> Acked-by: Tony Luck <tony.luck@intel.com> Link: https://lkml.kernel.org/r/815747bddc820ca221a8924edaf4d1a7324547e4.1508490116.git.reinette.chatre@intel.com
2017-10-18x86/cpuid: Prevent out of bound access in do_clear_cpu_cap()Thomas Gleixner1-2/+8
do_clear_cpu_cap() allocates a bitmap to keep track of disabled feature dependencies. That bitmap is sized NCAPINTS * BITS_PER_INIT. The possible 'features' which can be handed in are larger than this, because after the capabilities the bug 'feature' bits occupy another 32bit. Not really obvious... So clearing any of the misfeature bits, as 32bit does for the F00F bug, accesses that bitmap out of bounds thereby corrupting the stack. Size the bitmap proper and add a sanity check to catch accidental out of bound access. Fixes: 0b00de857a64 ("x86/cpuid: Add generic table for CPUID dependencies") Reported-by: kernel test robot <xiaolong.ye@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Andi Kleen <ak@linux.intel.com> Cc: Borislav Petkov <bp@alien8.de> Link: https://lkml.kernel.org/r/20171018022023.GA12058@yexl-desktop
2017-10-18x86/microcode/intel: Disable late loading on model 79Borislav Petkov1-0/+19
Blacklist Broadwell X model 79 for late loading due to an erratum. Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Tony Luck <tony.luck@intel.com> Cc: <stable@vger.kernel.org> 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/20171018111225.25635-1-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-10-17x86/fpu: Parse clearcpuid= as early XSAVE argumentAndi Kleen1-9/+7
With a followon patch we want to make clearcpuid affect the XSAVE configuration. But xsave is currently initialized before arguments are parsed. Move the clearcpuid= parsing into the special early xsave argument parsing code. Since clearcpuid= contains a = we need to keep the old __setup around as a dummy, otherwise it would end up as a environment variable in init's environment. Signed-off-by: Andi Kleen <ak@linux.intel.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20171013215645.23166-4-andi@firstfloor.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-10-17x86/cpuid: Add generic table for CPUID dependenciesAndi Kleen2-0/+114
Some CPUID features depend on other features. Currently it's possible to to clear dependent features, but not clear the base features, which can cause various interesting problems. This patch implements a generic table to describe dependencies between CPUID features, to be used by all code that clears CPUID. Some subsystems (like XSAVE) had an own implementation of this, but it's better to do it all in a single place for everyone. Then clear_cpu_cap and setup_clear_cpu_cap always look up this table and clear all dependencies too. This is intended to be a practical table: only for features that make sense to clear. If someone for example clears FPU, or other features that are essentially part of the required base feature set, not much is going to work. Handling that is right now out of scope. We're only handling features which can be usefully cleared. Signed-off-by: Andi Kleen <ak@linux.intel.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Jonathan McDowell <noodles@earth.li> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20171013215645.23166-3-andi@firstfloor.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-10-16x86/cpu/intel_cacheinfo: Remove redundant assignment to 'this_leaf'Colin Ian King1-1/+0
The 'this_leaf' variable is assigned a value that is never read and it is updated a little later with a newer value, hence we can remove the redundant assignment. Cleans up the following Clang warning: Value stored to 'this_leaf' is never read Signed-off-by: Colin Ian King <colin.king@canonical.com> Reviewed-by: Borislav Petkov <bp@suse.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: kernel-janitors@vger.kernel.org Link: http://lkml.kernel.org/r/20171015160203.12332-1-colin.king@canonical.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-10-14Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds1-9/+18
Pull x86 fixes from Ingo Molnar: "A landry list of fixes: - fix reboot breakage on some PCID-enabled system - fix crashes/hangs on some PCID-enabled systems - fix microcode loading on certain older CPUs - various unwinder fixes - extend an APIC quirk to more hardware systems and disable APIC related warning on virtualized systems - various Hyper-V fixes - a macro definition robustness fix - remove jprobes IRQ disabling - various mem-encryption fixes" * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/microcode: Do the family check first x86/mm: Flush more aggressively in lazy TLB mode x86/apic: Update TSC_DEADLINE quirk with additional SKX stepping x86/apic: Silence "FW_BUG TSC_DEADLINE disabled due to Errata" on hypervisors x86/mm: Disable various instrumentations of mm/mem_encrypt.c and mm/tlb.c x86/hyperv: Fix hypercalls with extended CPU ranges for TLB flushing x86/hyperv: Don't use percpu areas for pcpu_flush/pcpu_flush_ex structures x86/hyperv: Clear vCPU banks between calls to avoid flushing unneeded vCPUs x86/unwind: Disable unwinder warnings on 32-bit x86/unwind: Align stack pointer in unwinder dump x86/unwind: Use MSB for frame pointer encoding on 32-bit x86/unwind: Fix dereference of untrusted pointer x86/alternatives: Fix alt_max_short macro to really be a max() x86/mm/64: Fix reboot interaction with CR4.PCIDE kprobes/x86: Remove IRQ disabling from jprobe handlers kprobes/x86: Set up frame pointer in kprobe trampoline
2017-10-14x86/microcode: Do the family check firstBorislav Petkov1-9/+18
On CPUs like AMD's Geode, for example, we shouldn't even try to load microcode because they do not support the modern microcode loading interface. However, we do the family check *after* the other checks whether the loader has been disabled on the command line or whether we're running in a guest. So move the family checks first in order to exit early if we're being loaded on an unsupported family. Reported-and-tested-by: Sven Glodowski <glodi1@arcor.de> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: <stable@vger.kernel.org> # 4.11.. Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://bugzilla.suse.com/show_bug.cgi?id=1061396 Link: http://lkml.kernel.org/r/20171012112316.977-1-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-10-05x86/mce: Convert timers to use timer_setup()Kees Cook1-8/+5
In preparation for unconditionally passing the struct timer_list pointer to all timer callbacks, switch to using the new timer_setup() and from_timer() to pass the timer pointer explicitly. Adjust sanity-check WARN to make sure the triggering timer matches the current CPU timer. Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Borislav Petkov <bp@alien8.de> Cc: Tony Luck <tony.luck@intel.com> Cc: linux-edac@vger.kernel.org Link: https://lkml.kernel.org/r/20171005005425.GA23950@beast
2017-10-05x86/mce: Hide mca_cfgBorislav Petkov2-0/+9
Now that lguest is gone, put it in the internal header which should be used only by MCA/RAS code. Add missing header guards while at it. No functional change. Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20171002092836.22971-3-bp@alien8.de
2017-10-05x86/intel_rdt: Remove redundant assignmentJithu Joseph1-1/+0
The assignment to the 'files' variable is immediately overwritten in the following line. Remove the older assignment, which was meant specifially for creating control groups files. Fixes: c7d9aac61311 ("x86/intel_rdt/cqm: Add mkdir support for RDT monitoring") Reported-by: Reinette Chatre <reinette.chatre@intel.com> Signed-off-by: Jithu Joseph <jithu.joseph@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Fenghua Yu <fenghua.yu@intel.com> Cc: tony.luck@intel.com Cc: vikas.shivappa@intel.com Link: https://lkml.kernel.org/r/1507157337-18118-1-git-send-email-jithu.joseph@intel.com
2017-10-05x86/intel_rdt/cqm: Make integer rmid_limbo_count staticColin Ian King1-1/+1
rmid_limbo_count is local to the source and does not need to be in global scope, so make it static. Cleans up sparse warning: symbol 'rmid_limbo_count' was not declared. Should it be static? Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: kernel-janitors@vger.kernel.org Link: https://lkml.kernel.org/r/20171002145931.27479-1-colin.king@canonical.com
2017-10-03x86/boot: Spell out "boot CPU" for BPJean Delvare1-2/+2
It's not obvious to everybody that BP stands for boot processor. At least it was not for me. And BP is also a CPU register on x86, so it is ambiguous. Spell out "boot CPU" everywhere instead. Signed-off-by: Jean Delvare <jdelvare@suse.de> Cc: Alok Kataria <akataria@vmware.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-09-27x86/intel_rdt: Add diagnostics when making directoriesTony Luck1-6/+22
Mostly this is about running out of RMIDs or CLOSIDs. Other errors are various internal errors. Signed-off-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Vikas Shivappa <vikas.shivappa@intel.com> Cc: Boris Petkov <bp@suse.de> Cc: Reinette Chatre <reinette.chatre@intel.com> Link: https://lkml.kernel.org/r/027cf1ffb3a3695f2d54525813a1d644887353cf.1506382469.git.tony.luck@intel.com
2017-09-27x86/intel_rdt: Add diagnostics when writing the cpus fileTony Luck1-3/+12
Can't add a cpu to a monitor group unless it belongs to parent group. Can't delete cpus from the default group. Signed-off-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Vikas Shivappa <vikas.shivappa@intel.com> Cc: Boris Petkov <bp@suse.de> Cc: Reinette Chatre <reinette.chatre@intel.com> Link: https://lkml.kernel.org/r/757a869a25e9fc1b7a2e9bc43e1159455c1964a0.1506382469.git.tony.luck@intel.com
2017-09-27x86/intel_rdt: Add diagnostics when writing the tasks fileTony Luck2-6/+11
About the only tricky case is trying to move a task into a monitor group that is a subdirectory of a different control group. But cover the simple cases too. Signed-off-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Vikas Shivappa <vikas.shivappa@intel.com> Cc: Boris Petkov <bp@suse.de> Cc: Reinette Chatre <reinette.chatre@intel.com> Link: https://lkml.kernel.org/r/f1841cce6a242aed37cb926dee8942727331bf78.1506382469.git.tony.luck@intel.com
2017-09-27x86/intel_rdt: Add diagnostics when writing the schemata fileTony Luck1-11/+38
Save helpful descriptions of what went wrong when writing a schemata file. Signed-off-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Vikas Shivappa <vikas.shivappa@intel.com> Cc: Boris Petkov <bp@suse.de> Cc: Reinette Chatre <reinette.chatre@intel.com> Link: https://lkml.kernel.org/r/9d6cef757dc88639c8ab47f1e7bc1b081a84bb88.1506382469.git.tony.luck@intel.com
2017-09-27x86/intel_rdt: Add framework for better RDT UI diagnosticsTony Luck2-0/+63
Commands are given to the resctrl file system by making/removing directories, or by writing to files. When something goes wrong the user is generally left wondering why they got: bash: echo: write error: Invalid argument Add a new file "last_cmd_status" to the "info" directory that will give the user some better clues on what went wrong. Provide functions to clear and update last_cmd_status which check that we hold the rdtgroup_mutex. [ tglx: Made last_cmd_status static and folded back the hunk from patch 3 which replaces the open coded access to last_cmd_status with the accessor function ] Signed-off-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Vikas Shivappa <vikas.shivappa@intel.com> Cc: Boris Petkov <bp@suse.de> Cc: Reinette Chatre <reinette.chatre@intel.com> Link: https://lkml.kernel.org/r/edc4e0e9741eee89bba569f0021b1b2662fd9508.1506382469.git.tony.luck@intel.com
2017-09-17x86/mm/32: Move setup_clear_cpu_cap(X86_FEATURE_PCID) earlierAndy Lutomirski2-8/+8
Otherwise we might have the PCID feature bit set during cpu_init(). This is just for robustness. I haven't seen any actual bugs here. Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bpetkov@suse.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: cba4671af755 ("x86/mm: Disable PCID on 32-bit kernels") Link: http://lkml.kernel.org/r/b16dae9d6b0db5d9801ddbebbfd83384097c61f3.1505663533.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-09-15x86/cpu/AMD: Fix erratum 1076 (CPB bit)Borislav Petkov1-0/+11
CPUID Fn8000_0007_EDX[CPB] is wrongly 0 on models up to B1. But they do support CPB (AMD's Core Performance Boosting cpufreq CPU feature), so fix that. Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sherry Hurwitz <sherry.hurwitz@amd.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20170907170821.16021-1-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-09-13x86/hyper-V: Allocate the IDT entry early in bootK. Y. Srinivasan1-2/+2
Allocate the hypervisor callback IDT entry early in the boot sequence. The previous code would allocate the entry as part of registering the handler when the vmbus driver loaded, and this caused a problem for the IDT cleanup that Thomas is working on for v4.15. Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: apw@canonical.com Cc: devel@linuxdriverproject.org Cc: gregkh@linuxfoundation.org Cc: jasowang@redhat.com Cc: olaf@aepfle.de Link: http://lkml.kernel.org/r/20170908231557.2419-1-kys@exchange.microsoft.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-09-13x86/mm/64: Initialize CR4.PCIDE earlyAndy Lutomirski1-42/+7
cpu_init() is weird: it's called rather late (after early identification and after most MMU state is initialized) on the boot CPU but is called extremely early (before identification) on secondary CPUs. It's called just late enough on the boot CPU that its CR4 value isn't propagated to mmu_cr4_features. Even if we put CR4.PCIDE into mmu_cr4_features, we'd hit two problems. First, we'd crash in the trampoline code. That's fixable, and I tried that. It turns out that mmu_cr4_features is totally ignored by secondary_start_64(), though, so even with the trampoline code fixed, it wouldn't help. This means that we don't currently have CR4.PCIDE reliably initialized before we start playing with cpu_tlbstate. This is very fragile and tends to cause boot failures if I make even small changes to the TLB handling code. Make it more robust: initialize CR4.PCIDE earlier on the boot CPU and propagate it to secondary CPUs in start_secondary(). ( Yes, this is ugly. I think we should have improved mmu_cr4_features to actually control CR4 during secondary bootup, but that would be fairly intrusive at this stage. ) Signed-off-by: Andy Lutomirski <luto@kernel.org> Reported-by: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com> Tested-by: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com> Cc: Borislav Petkov <bpetkov@suse.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Fixes: 660da7c9228f ("x86/mm: Enable CR4.PCIDE on supported systems") Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-09-07Merge branch 'x86-platform-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds1-0/+1
Pull x86 platform updates from Ingo Molnar: "The main changes include various Hyper-V optimizations such as faster hypercalls and faster/better TLB flushes - and there's also some Intel-MID cleanups" * 'x86-platform-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: tracing/hyper-v: Trace hyperv_mmu_flush_tlb_others() x86/hyper-v: Support extended CPU ranges for TLB flush hypercalls x86/platform/intel-mid: Make several arrays static, to make code smaller MAINTAINERS: Add missed file for Hyper-V x86/hyper-v: Use hypercall for remote TLB flush hyper-v: Globalize vp_index x86/hyper-v: Implement rep hypercalls hyper-v: Use fast hypercall for HVCALL_SIGNAL_EVENT x86/hyper-v: Introduce fast hypercall implementation x86/hyper-v: Make hv_do_hypercall() inline x86/hyper-v: Include hyperv/ only when CONFIG_HYPERV is set x86/platform/intel-mid: Make 'bt_sfi_data' const x86/platform/intel-mid: Make IRQ allocation a bit more flexible x86/platform/intel-mid: Group timers callbacks together
2017-09-06x86/mm: Document how CR4.PCIDE restore worksAndy Lutomirski1-0/+13
While debugging a problem, I thought that using cr4_set_bits_and_update_boot() to restore CR4.PCIDE would be helpful. It turns out to be counterproductive. Add a comment documenting how this works. Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-06x86/mm: Reinitialize TLB state on hotplug and resumeAndy Lutomirski1-0/+2
When Linux brings a CPU down and back up, it switches to init_mm and then loads swapper_pg_dir into CR3. With PCID enabled, this has the side effect of masking off the ASID bits in CR3. This can result in some confusion in the TLB handling code. If we bring a CPU down and back up with any ASID other than 0, we end up with the wrong ASID active on the CPU after resume. This could cause our internal state to become corrupt, although major corruption is unlikely because init_mm doesn't have any user pages. More obviously, if CONFIG_DEBUG_VM=y, we'll trip over an assertion in the next context switch. The result of *that* is a failure to resume from suspend with probability 1 - 1/6^(cpus-1). Fix it by reinitializing cpu_tlbstate on resume and CPU bringup. Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Reported-by: Jiri Kosina <jikos@kernel.org> Fixes: 10af6235e0d3 ("x86/mm: Implement PCID based optimization: try to preserve old TLB entries using PCID") Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-05Merge tag 'char-misc-4.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-miscLinus Torvalds1-3/+9
Pull char/misc driver updates from Greg KH: "Here is the big char/misc driver update for 4.14-rc1. Lots of different stuff in here, it's been an active development cycle for some reason. Highlights are: - updated binder driver, this brings binder up to date with what shipped in the Android O release, plus some more changes that happened since then that are in the Android development trees. - coresight updates and fixes - mux driver file renames to be a bit "nicer" - intel_th driver updates - normal set of hyper-v updates and changes - small fpga subsystem and driver updates - lots of const code changes all over the driver trees - extcon driver updates - fmc driver subsystem upadates - w1 subsystem minor reworks and new features and drivers added - spmi driver updates Plus a smattering of other minor driver updates and fixes. All of these have been in linux-next with no reported issues for a while" * tag 'char-misc-4.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (244 commits) ANDROID: binder: don't queue async transactions to thread. ANDROID: binder: don't enqueue death notifications to thread todo. ANDROID: binder: Don't BUG_ON(!spin_is_locked()). ANDROID: binder: Add BINDER_GET_NODE_DEBUG_INFO ioctl ANDROID: binder: push new transactions to waiting threads. ANDROID: binder: remove proc waitqueue android: binder: Add page usage in binder stats android: binder: fixup crash introduced by moving buffer hdr drivers: w1: add hwmon temp support for w1_therm drivers: w1: refactor w1_slave_show to make the temp reading functionality separate drivers: w1: add hwmon support structures eeprom: idt_89hpesx: Support both ACPI and OF probing mcb: Fix an error handling path in 'chameleon_parse_cells()' MCB: add support for SC31 to mcb-lpc mux: make device_type const char: virtio: constify attribute_group structures. Documentation/ABI: document the nvmem sysfs files lkdtm: fix spelling mistake: "incremeted" -> "incremented" perf: cs-etm: Fix ETMv4 CONFIGR entry in perf.data file nvmem: include linux/err.h from header ...
2017-09-04Merge branch 'x86-apic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds5-61/+9
Pull x86 apic updates from Thomas Gleixner: "This update provides: - Cleanup of the IDT management including the removal of the extra tracing IDT. A first step to cleanup the vector management code. - The removal of the paravirt op adjust_exception_frame. This is a XEN specific issue, but merged through this branch to avoid nasty merge collisions - Prevent dmesg spam about the TSC DEADLINE bug, when the CPU has disabled the TSC DEADLINE timer in CPUID. - Adjust a debug message in the ioapic code to print out the information correctly" * 'x86-apic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (51 commits) x86/idt: Fix the X86_TRAP_BP gate x86/xen: Get rid of paravirt op adjust_exception_frame x86/eisa: Add missing include x86/idt: Remove superfluous ALIGNment x86/apic: Silence "FW_BUG TSC_DEADLINE disabled due to Errata" on CPUs without the feature x86/idt: Remove the tracing IDT leftovers x86/idt: Hide set_intr_gate() x86/idt: Simplify alloc_intr_gate() x86/idt: Deinline setup functions x86/idt: Remove unused functions/inlines x86/idt: Move interrupt gate initialization to IDT code x86/idt: Move APIC gate initialization to tables x86/idt: Move regular trap init to tables x86/idt: Move IST stack based traps to table init x86/idt: Move debug stack init to table based x86/idt: Switch early trap init to IDT tables x86/idt: Prepare for table based init x86/idt: Move early IDT setup out of 32-bit asm x86/idt: Move early IDT handler setup to IDT code x86/idt: Consolidate IDT invalidation ...
2017-09-04Merge branch 'x86-cache-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds6-267/+2233
Pull x86 cache quality monitoring update from Thomas Gleixner: "This update provides a complete rewrite of the Cache Quality Monitoring (CQM) facility. The existing CQM support was duct taped into perf with a lot of issues and the attempts to fix those turned out to be incomplete and horrible. After lengthy discussions it was decided to integrate the CQM support into the Resource Director Technology (RDT) facility, which is the obvious choise as in hardware CQM is part of RDT. This allowed to add Memory Bandwidth Monitoring support on top. As a result the mechanisms for allocating cache/memory bandwidth and the corresponding monitoring mechanisms are integrated into a single management facility with a consistent user interface" * 'x86-cache-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (37 commits) x86/intel_rdt: Turn off most RDT features on Skylake x86/intel_rdt: Add command line options for resource director technology x86/intel_rdt: Move special case code for Haswell to a quirk function x86/intel_rdt: Remove redundant ternary operator on return x86/intel_rdt/cqm: Improve limbo list processing x86/intel_rdt/mbm: Fix MBM overflow handler during CPU hotplug x86/intel_rdt: Modify the intel_pqr_state for better performance x86/intel_rdt/cqm: Clear the default RMID during hotcpu x86/intel_rdt: Show bitmask of shareable resource with other executing units x86/intel_rdt/mbm: Handle counter overflow x86/intel_rdt/mbm: Add mbm counter initialization x86/intel_rdt/mbm: Basic counting of MBM events (total and local) x86/intel_rdt/cqm: Add CPU hotplug support x86/intel_rdt/cqm: Add sched_in support x86/intel_rdt: Introduce rdt_enable_key for scheduling x86/intel_rdt/cqm: Add mount,umount support x86/intel_rdt/cqm: Add rmdir support x86/intel_rdt: Separate the ctrl bits from rmdir x86/intel_rdt/cqm: Add mon_data x86/intel_rdt: Prepare for RDT monitor data support ...
2017-09-04Merge branch 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds5-4/+117
Pull x86 mm changes from Ingo Molnar: "PCID support, 5-level paging support, Secure Memory Encryption support The main changes in this cycle are support for three new, complex hardware features of x86 CPUs: - Add 5-level paging support, which is a new hardware feature on upcoming Intel CPUs allowing up to 128 PB of virtual address space and 4 PB of physical RAM space - a 512-fold increase over the old limits. (Supercomputers of the future forecasting hurricanes on an ever warming planet can certainly make good use of more RAM.) Many of the necessary changes went upstream in previous cycles, v4.14 is the first kernel that can enable 5-level paging. This feature is activated via CONFIG_X86_5LEVEL=y - disabled by default. (By Kirill A. Shutemov) - Add 'encrypted memory' support, which is a new hardware feature on upcoming AMD CPUs ('Secure Memory Encryption', SME) allowing system RAM to be encrypted and decrypted (mostly) transparently by the CPU, with a little help from the kernel to transition to/from encrypted RAM. Such RAM should be more secure against various attacks like RAM access via the memory bus and should make the radio signature of memory bus traffic harder to intercept (and decrypt) as well. This feature is activated via CONFIG_AMD_MEM_ENCRYPT=y - disabled by default. (By Tom Lendacky) - Enable PCID optimized TLB flushing on newer Intel CPUs: PCID is a hardware feature that attaches an address space tag to TLB entries and thus allows to skip TLB flushing in many cases, even if we switch mm's. (By Andy Lutomirski) All three of these features were in the works for a long time, and it's coincidence of the three independent development paths that they are all enabled in v4.14 at once" * 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (65 commits) x86/mm: Enable RCU based page table freeing (CONFIG_HAVE_RCU_TABLE_FREE=y) x86/mm: Use pr_cont() in dump_pagetable() x86/mm: Fix SME encryption stack ptr handling kvm/x86: Avoid clearing the C-bit in rsvd_bits() x86/CPU: Align CR3 defines x86/mm, mm/hwpoison: Clear PRESENT bit for kernel 1:1 mappings of poison pages acpi, x86/mm: Remove encryption mask from ACPI page protection type x86/mm, kexec: Fix memory corruption with SME on successive kexecs x86/mm/pkeys: Fix typo in Documentation/x86/protection-keys.txt x86/mm/dump_pagetables: Speed up page tables dump for CONFIG_KASAN=y x86/mm: Implement PCID based optimization: try to preserve old TLB entries using PCID x86: Enable 5-level paging support via CONFIG_X86_5LEVEL=y x86/mm: Allow userspace have mappings above 47-bit x86/mm: Prepare to expose larger address space to userspace x86/mpx: Do not allow MPX if we have mappings above 47-bit x86/mm: Rename tasksize_32bit/64bit to task_size_32bit/64bit() x86/xen: Redefine XEN_ELFNOTE_INIT_P2M using PUD_SIZE * PTRS_PER_PUD x86/mm/dump_pagetables: Fix printout of p4d level x86/mm/dump_pagetables: Generalize address normalization x86/boot: Fix memremap() related build failure ...
2017-09-04Merge branch 'x86-microcode-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds2-14/+18
Pull x86 microcode loading updates from Ingo Molnar: "Update documentation, improve robustness and fix a memory leak" * 'x86-microcode-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/microcode/intel: Improve microcode patches saving flow x86/microcode: Document the three loading methods x86/microcode/AMD: Free unneeded patch before exit from update_cache()
2017-09-04Merge branch 'x86-cpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds2-22/+36
Pull x86 cpuid updates from Ingo Molnar: "AMD F17h related updates" * 'x86-cpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/cpu/amd: Hide unused legacy_fixup_core_id() function x86/cpu/amd: Derive L3 shared_cpu_map from cpu_llc_shared_mask x86/cpu/amd: Limit cpu_core_id fixup to families older than F17h
2017-09-04Merge branch 'ras-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds1-7/+2
Pull RAS fix from Ingo Molnar: "A single change fixing SMCA bank initialization on systems that don't have CPU0 enabled" * 'ras-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/mce/AMD: Allow any CPU to initialize the smca_banks array
2017-08-31Merge branch 'x86/mm' into x86/platform, to pick up TLB flush dependencyIngo Molnar9-10/+138
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-08-29x86/idt: Simplify alloc_intr_gate()Thomas Gleixner1-7/+2
The only users of alloc_intr_gate() are hypervisors, which both check the used_vectors bitmap whether they have allocated the gate already. Move that check into alloc_intr_gate() and simplify the users. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Juergen Gross <jgross@suse.com> Reviewed-by: K. Y. Srinivasan <kys@microsoft.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: Steven Rostedt <rostedt@goodmis.org> Link: http://lkml.kernel.org/r/20170828064959.580830286@linutronix.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-08-29x86/idt: Create file for IDT related codeThomas Gleixner1-9/+0
IDT related code lives scattered around in various places. Create a new source file in arch/x86/kernel/idt.c to hold it. Move the idt_tables and descriptors to it for a start. Follow up patches will gradually move more code over. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Link: http://lkml.kernel.org/r/20170828064958.367081121@linutronix.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-08-29x86/mce: Remove duplicated tracing interrupt codeThomas Gleixner3-45/+7
Machine checks are not really high frequency events. The extra two NOP5s for the disabled tracepoints are noise vs. the heavy lifting which needs to be done in the MCE handler. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Link: http://lkml.kernel.org/r/20170828064957.144301907@linutronix.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-08-29x86/microcode/intel: Improve microcode patches saving flowBorislav Petkov1-13/+14
Avoid potentially dereferencing a NULL pointer when saving a microcode patch for early loading on the application processors. While at it, drop the IS_ERR() checking in favor of simpler, NULL-ptr checks which are sufficient and rename __alloc_microcode_buf() to memdup_patch() to more precisely denote what it does. No functionality change. Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: kernel-janitors@vger.kernel.org Link: http://lkml.kernel.org/r/20170825100456.n236w3jebteokfd6@pd.tnic
2017-08-28Merge 4.13-rc7 into char-misc-nextGreg Kroah-Hartman4-6/+21
We want the binder fix in here as well for testing and merge issues. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-08-26Merge branch 'linus' into x86/mm to pick up fixes and to fix conflictsIngo Molnar5-20/+48
Conflicts: arch/x86/kernel/head64.c arch/x86/mm/mmap.c Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-08-25x86/intel_rdt: Turn off most RDT features on SkylakeTony Luck1-0/+3
Errata list is included in this document: https://www.intel.com/content/dam/www/public/us/en/documents/specification-updates/6th-gen-x-series-spec-update.pdf with more details in: https://www.intel.com/content/www/us/en/processors/xeon/scalable/xeon-scalable-spec-update.html But the tl;dr summary (using tags from first of the documents) is: SKZ4 MBM does not accurately track write bandwidth SKZ17 CMT counters may not count accurately SKZ18 CAT may not restrict cacheline allocation under certain conditions SKZ19 MBM counters may undercount Disable all these features on Skylake models. Users who understand the errata may re-enable using boot command line options. Signed-off-by: Tony Luck <tony.luck@intel.com> Cc: Fenghua" <fenghua.yu@intel.com> Cc: Ravi V" <ravi.v.shankar@intel.com> Cc: "Peter Zijlstra" <peterz@infradead.org> Cc: "Stephane Eranian" <eranian@google.com> Cc: "Andi Kleen" <ak@linux.intel.com> Cc: "David Carrillo-Cisneros" <davidcc@google.com> Cc: Vikas Shivappa <vikas.shivappa@linux.intel.com> Link: http://lkml.kernel.org/r/3aea0a3bae219062c812668bd9b7b8f1a25003ba.1503512900.git.tony.luck@intel.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2017-08-25x86/intel_rdt: Add command line options for resource director technologyTony Luck1-8/+88
Command line options allow us to ignore features that we don't want. Also we can re-enable options that have been disabled on a platform (so long as the underlying h/w actually supports the option). [ tglx: Marked the option array __initdata and the helper function __init ] Signed-off-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Fenghua" <fenghua.yu@intel.com> Cc: Ravi V" <ravi.v.shankar@intel.com> Cc: "Peter Zijlstra" <peterz@infradead.org> Cc: "Stephane Eranian" <eranian@google.com> Cc: "Andi Kleen" <ak@linux.intel.com> Cc: "David Carrillo-Cisneros" <davidcc@google.com> Cc: Vikas Shivappa <vikas.shivappa@linux.intel.com> Link: http://lkml.kernel.org/r/0c37b0d4dbc30977a3c1cee08b66420f83662694.1503512900.git.tony.luck@intel.com
2017-08-25x86/intel_rdt: Move special case code for Haswell to a quirk functionTony Luck1-24/+28
No functional change, but lay the ground work for other per-model quirks. Signed-off-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Fenghua" <fenghua.yu@intel.com> Cc: Ravi V" <ravi.v.shankar@intel.com> Cc: "Peter Zijlstra" <peterz@infradead.org> Cc: "Stephane Eranian" <eranian@google.com> Cc: "Andi Kleen" <ak@linux.intel.com> Cc: "David Carrillo-Cisneros" <davidcc@google.com> Cc: Vikas Shivappa <vikas.shivappa@linux.intel.com> Link: http://lkml.kernel.org/r/f195a83751b5f8b1d8a78bd3c1914300c8fa3142.1503512900.git.tony.luck@intel.com
2017-08-20Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds3-6/+18
Pull x86 fixes from Thomas Gleixner: "Another pile of small fixes and updates for x86: - Plug a hole in the SMAP implementation which misses to clear AC on NMI entry - Fix the norandmaps/ADDR_NO_RANDOMIZE logic so the command line parameter works correctly again - Use the proper accessor in the startup64 code for next_early_pgt to prevent accessing of invalid addresses and faulting in the early boot code. - Prevent CPU hotplug lock recursion in the MTRR code - Unbreak CPU0 hotplugging - Rename overly long CPUID bits which got introduced in this cycle - Two commits which mark data 'const' and restrict the scope of data and functions to file scope by making them 'static'" * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86: Constify attribute_group structures x86/boot/64/clang: Use fixup_pointer() to access 'next_early_pgt' x86/elf: Remove the unnecessary ADDR_NO_RANDOMIZE checks x86: Fix norandmaps/ADDR_NO_RANDOMIZE x86/mtrr: Prevent CPU hotplug lock recursion x86: Mark various structures and functions as 'static' x86/cpufeature, kvm/svm: Rename (shorten) the new "virtualized VMSAVE/VMLOAD" CPUID flag x86/smpboot: Unbreak CPU0 hotplug x86/asm/64: Clear AC on NMI entries
2017-08-18x86: Constify attribute_group structuresArvind Yadav2-3/+3
attribute_groups are not supposed to change at runtime and none of the groups is modified. Mark the non-const structs as const. [ tglx: Folded into one big patch ] Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: tony.luck@intel.com Cc: bp@alien8.de Link: http://lkml.kernel.org/r/1500550238-15655-2-git-send-email-arvind.yadav.cs@gmail.com
2017-08-17x86/mm, mm/hwpoison: Clear PRESENT bit for kernel 1:1 mappings of poison pagesTony Luck1-0/+43
Speculative processor accesses may reference any memory that has a valid page table entry. While a speculative access won't generate a machine check, it will log the error in a machine check bank. That could cause escalation of a subsequent error since the overflow bit will be then set in the machine check bank status register. Code has to be double-plus-tricky to avoid mentioning the 1:1 virtual address of the page we want to map out otherwise we may trigger the very problem we are trying to avoid. We use a non-canonical address that passes through the usual Linux table walking code to get to the same "pte". Thanks to Dave Hansen for reviewing several iterations of this. Also see: http://marc.info/?l=linux-mm&m=149860136413338&w=2 Signed-off-by: Tony Luck <tony.luck@intel.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Borislav Petkov <bp@suse.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Elliott, Robert (Persistent Memory) <elliott@hpe.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-mm@kvack.org Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/20170816171803.28342-1-tony.luck@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-08-16x86/intel_rdt: Remove redundant ternary operator on returnColin Ian King1-1/+1
The use of the ternary operator is redundant as ret can never be non-zero at that point. Instead, just return nbytes. Detected by CoverityScan, CID#1452658 ("Logically dead code") Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Vikas Shivappa <vikas.shivappa@linux.intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: kernel-janitors@vger.kernel.org Link: http://lkml.kernel.org/r/20170808092859.13021-1-colin.king@canonical.com
2017-08-16x86/intel_rdt/cqm: Improve limbo list processingVikas Shivappa3-122/+133
During a mkdir, the entire limbo list is synchronously checked on each package for free RMIDs by sending IPIs. With a large number of RMIDs (SKL has 192) this creates a intolerable amount of work in IPIs. Replace the IPI based checking of the limbo list with asynchronous worker threads on each package which periodically scan the limbo list and move the RMIDs that have: llc_occupancy < threshold_occupancy on all packages to the free list. mkdir now returns -ENOSPC if the free list and the limbo list ere empty or returns -EBUSY if there are RMIDs on the limbo list and the free list is empty. Getting rid of the IPIs also simplifies the data structures and the serialization required for handling the lists. [ tglx: Rewrote changelog ... ] Signed-off-by: Vikas Shivappa <vikas.shivappa@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: ravi.v.shankar@intel.com Cc: tony.luck@intel.com Cc: fenghua.yu@intel.com Cc: peterz@infradead.org Cc: eranian@google.com Cc: vikas.shivappa@intel.com Cc: ak@linux.intel.com Cc: davidcc@google.com Link: http://lkml.kernel.org/r/1502845243-20454-3-git-send-email-vikas.shivappa@linux.intel.com
2017-08-16x86/intel_rdt/mbm: Fix MBM overflow handler during CPU hotplugVikas Shivappa4-6/+6
When a CPU is dying, the overflow worker is canceled and rescheduled on a different CPU in the same domain. But if the timer is already about to expire this essentially doubles the interval which might result in a non detected overflow. Cancel the overflow worker and reschedule it immediately on a different CPU in same domain. The work could be flushed as well, but that would reschedule it on the same CPU. [ tglx: Rewrote changelog once again ] Reported-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Vikas Shivappa <vikas.shivappa@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: ravi.v.shankar@intel.com Cc: tony.luck@intel.com Cc: fenghua.yu@intel.com Cc: peterz@infradead.org Cc: eranian@google.com Cc: vikas.shivappa@intel.com Cc: ak@linux.intel.com Cc: davidcc@google.com Link: http://lkml.kernel.org/r/1502845243-20454-2-git-send-email-vikas.shivappa@linux.intel.com
2017-08-15x86/mtrr: Prevent CPU hotplug lock recursionThomas Gleixner1-3/+15
Larry reported a CPU hotplug lock recursion in the MTRR code. ============================================ WARNING: possible recursive locking detected systemd-udevd/153 is trying to acquire lock: (cpu_hotplug_lock.rw_sem){.+.+.+}, at: [<c030fc26>] stop_machine+0x16/0x30 but task is already holding lock: (cpu_hotplug_lock.rw_sem){.+.+.+}, at: [<c0234353>] mtrr_add_page+0x83/0x470 .... cpus_read_lock+0x48/0x90 stop_machine+0x16/0x30 mtrr_add_page+0x18b/0x470 mtrr_add+0x3e/0x70 mtrr_add_page() holds the hotplug rwsem already and calls stop_machine() which acquires it again. Call stop_machine_cpuslocked() instead. Reported-and-tested-by: Larry Finger <Larry.Finger@lwfinger.net> Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1708140920250.1865@nanos Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: Borislav Petkov <bp@suse.de>