summaryrefslogtreecommitdiff
path: root/arch/x86/kernel
AgeCommit message (Collapse)Author
2017-02-13x86/vm86: Fix unused variable warning if THP is disabledKirill A. Shutemov
GCC complains about unused variable 'vma' in mark_screen_rdonly() if THP is disabled: arch/x86/kernel/vm86_32.c: In function ‘mark_screen_rdonly’: arch/x86/kernel/vm86_32.c:180:26: warning: unused variable ‘vma’ [-Wunused-variable] struct vm_area_struct *vma = find_vma(mm, 0xA0000); That's silly. pmd_trans_huge() resolves to 0 when THP is disabled, so the whole block should be eliminated. Moving the variable declaration outside the if() block shuts GCC up. Reported-by: Jérémy Lefaure <jeremy.lefaure@lse.epita.fr> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Tested-by: Borislav Petkov <bp@suse.de> Cc: Carlos O'Donell <carlos@redhat.com> Link: http://lkml.kernel.org/r/20170213125228.63645-1-kirill.shutemov@linux.intel.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2017-02-11Merge branch 'x86-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Ingo Molnar: "Last minute x86 fixes: - Fix a softlockup detector warning and long delays if using ptdump with KASAN enabled. - Two more TSC-adjust fixes for interesting firmware interactions. - Two commits to fix an AMD CPU topology enumeration bug that caused a measurable gaming performance regression" * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/mm/ptdump: Fix soft lockup in page table walker x86/tsc: Make the TSC ADJUST sanitizing work for tsc_reliable x86/tsc: Avoid the large time jump when sanitizing TSC ADJUST x86/CPU/AMD: Fix Zen SMT topology x86/CPU/AMD: Bring back Compute Unit ID
2017-02-10x86/tsc: Make the TSC ADJUST sanitizing work for tsc_reliableThomas Gleixner
When the TSC is marked reliable then the synchronization check is skipped, but that also skips the TSC ADJUST sanitizing code. So on a machine with a wreckaged BIOS the TSC deviation between CPUs might go unnoticed. Let the TSC adjust sanitizing code run unconditionally and just skip the expensive synchronization checks when TSC is marked reliable. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Olof Johansson <olof@lixom.net> Link: http://lkml.kernel.org/r/20170209151231.491189912@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2017-02-10x86/tsc: Avoid the large time jump when sanitizing TSC ADJUSTThomas Gleixner
Olof reported that on a machine which has a BIOS wreckaged TSC the timestamps in dmesg are making a large jump because the TSC value is jumping forward after resetting the TSC ADJUST register to a sane value. This can be avoided by calling the TSC ADJUST saniziting function before initializing the per cpu sched clock machinery. That takes the offset into account and avoid the time jump. What cannot be avoided is that the 'Firmware Bug' warnings on the secondary CPUs are printed with the large time offsets because it would be too much effort and ugly hackery to print those warnings into a buffer and emit them after the adjustemt on the starting CPUs. It's a firmware bug and should be fixed in firmware. The weird timestamps are collateral damage and just illustrate the sillyness of the BIOS folks: [ 0.397445] smp: Bringing up secondary CPUs ... [ 0.402100] x86: Booting SMP configuration: [ 0.406343] .... node #0, CPUs: #1 [1265776479.930667] [Firmware Bug]: TSC ADJUST differs: Reference CPU0: -2978888639075328 CPU1: -2978888639183101 [1265776479.944664] TSC ADJUST synchronize: Reference CPU0: 0 CPU1: -2978888639183101 [ 0.508119] #2 [1265776480.032346] [Firmware Bug]: TSC ADJUST differs: Reference CPU0: -2978888639075328 CPU2: -2978888639183677 [1265776480.044192] TSC ADJUST synchronize: Reference CPU0: 0 CPU2: -2978888639183677 [ 0.607643] #3 [1265776480.131874] [Firmware Bug]: TSC ADJUST differs: Reference CPU0: -2978888639075328 CPU3: -2978888639184530 [1265776480.143720] TSC ADJUST synchronize: Reference CPU0: 0 CPU3: -2978888639184530 [ 0.707108] smp: Brought up 1 node, 4 CPUs [ 0.711271] smpboot: Total of 4 processors activated (21698.88 BogoMIPS) Reported-by: Olof Johansson <olof@lixom.net> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20170209151231.411460506@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2017-02-08Revert "x86/ioapic: Restore IO-APIC irq_chip retrigger callback"Linus Torvalds
This reverts commit 020eb3daaba2857b32c4cf4c82f503d6a00a67de. Gabriel C reports that it causes his machine to not boot, and we haven't tracked down the reason for it yet. Since the bug it fixes has been around for a longish time, we're better off reverting the fix for now. Gabriel says: "It hangs early and freezes with a lot RCU warnings. I bisected it down to : > Ruslan Ruslichenko (1): > x86/ioapic: Restore IO-APIC irq_chip retrigger callback Reverting this one fixes the problem for me.. The box is a PRIMERGY TX200 S5 , 2 socket , 2 x E5520 CPU(s) installed" and Ruslan and Thomas are currently stumped. Reported-and-bisected-by: Gabriel C <nix.or.die@gmail.com> Cc: Ruslan Ruslichenko <rruslich@cisco.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: stable@kernel.org # for the backport of the original commit Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-05x86/CPU/AMD: Fix Zen SMT topologyYazen Ghannam
After: a33d331761bc ("x86/CPU/AMD: Fix Bulldozer topology") our SMT scheduling topology for Fam17h systems is broken, because the ThreadId is included in the ApicId when SMT is enabled. So, without further decoding cpu_core_id is unique for each thread rather than the same for threads on the same core. This didn't affect systems with SMT disabled. Make cpu_core_id be what it is defined to be. Signed-off-by: Yazen Ghannam <Yazen.Ghannam@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: <stable@vger.kernel.org> # 4.9 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/20170205105022.8705-2-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-02-05x86/CPU/AMD: Bring back Compute Unit IDBorislav Petkov
Commit: a33d331761bc ("x86/CPU/AMD: Fix Bulldozer topology") restored the initial approach we had with the Fam15h topology of enumerating CU (Compute Unit) threads as cores. And this is still correct - they're beefier than HT threads but still have some shared functionality. Our current approach has a problem with the Mad Max Steam game, for example. Yves Dionne reported a certain "choppiness" while playing on v4.9.5. That problem stems most likely from the fact that the CU threads share resources within one CU and when we schedule to a thread of a different compute unit, this incurs latency due to migrating the working set to a different CU through the caches. When the thread siblings mask mirrors that aspect of the CUs and threads, the scheduler pays attention to it and tries to schedule within one CU first. Which takes care of the latency, of course. Reported-by: Yves Dionne <yves.dionne@gmail.com> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: <stable@vger.kernel.org> # 4.9 Cc: Brice Goglin <Brice.Goglin@inria.fr> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Yazen Ghannam <yazen.ghannam@amd.com> Link: http://lkml.kernel.org/r/20170205105022.8705-1-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-02-04Merge branch 'irq-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull irq fixes from Thomas Gleixner: - Prevent double activation of interrupt lines, which causes problems on certain interrupt controllers - Handle the fallout of the above because x86 (ab)uses the activation function to reconfigure interrupts under the hood. * 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/irq: Make irq activate operations symmetric irqdomain: Avoid activating interrupts more than once
2017-01-31x86/mce: Make timer handling more robustThomas Gleixner
Erik reported that on a preproduction hardware a CMCI storm triggers the BUG_ON in add_timer_on(). The reason is that the per CPU MCE timer is started by the CMCI logic before the MCE CPU hotplug callback starts the timer with add_timer_on(). So the timer is already queued which triggers the BUG. Using add_timer_on() is pretty pointless in this code because the timer is strictlty per CPU, initialized as pinned and all operations which arm the timer happen on the CPU to which the timer belongs. Simplify the whole machinery by using mod_timer() instead of add_timer_on() which avoids the problem because mod_timer() can handle already queued timers. Use __start_timer() everywhere so the earliest armed expiry time is preserved. Reported-by: Erik Veijola <erik.veijola@intel.com> Tested-by: Borislav Petkov <bp@alien8.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Borislav Petkov <bp@alien8.de> Cc: Tony Luck <tony.luck@intel.com> Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1701310936080.3457@nanos Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2017-01-31x86/irq: Make irq activate operations symmetricThomas Gleixner
The recent commit which prevents double activation of interrupts unearthed interesting code in x86. The code (ab)uses irq_domain_activate_irq() to reconfigure an already activated interrupt. That trips over the prevention code now. Fix it by deactivating the interrupt before activating the new configuration. Fixes: 08d85f3ea99f1 "irqdomain: Avoid activating interrupts more than once" Reported-and-tested-by: Mike Galbraith <efault@gmx.de> Reported-and-tested-by: Borislav Petkov <bp@alien8.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1701311901580.3457@nanos
2017-01-30x86/microcode: Do not access the initrd after it has been freedBorislav Petkov
When we look for microcode blobs, we first try builtin and if that doesn't succeed, we fallback to the initrd supplied to the kernel. However, at some point doing boot, that initrd gets jettisoned and we shouldn't access it anymore. But we do, as the below KASAN report shows. That's because find_microcode_in_initrd() doesn't check whether the initrd is still valid or not. So do that. ================================================================== BUG: KASAN: use-after-free in find_cpio_data Read of size 1 by task swapper/1/0 page:ffffea0000db9d40 count:0 mapcount:0 mapping: (null) index:0x1 flags: 0x100000000000000() raw: 0100000000000000 0000000000000000 0000000000000001 00000000ffffffff raw: dead000000000100 dead000000000200 0000000000000000 0000000000000000 page dumped because: kasan: bad access detected CPU: 1 PID: 0 Comm: swapper/1 Tainted: G W 4.10.0-rc5-debug-00075-g2dbde22 #3 Hardware name: Dell Inc. XPS 13 9360/0839Y6, BIOS 1.2.3 12/01/2016 Call Trace: dump_stack ? _atomic_dec_and_lock ? __dump_page kasan_report_error ? pointer ? find_cpio_data __asan_report_load1_noabort ? find_cpio_data find_cpio_data ? vsprintf ? dump_stack ? get_ucode_user ? print_usage_bug find_microcode_in_initrd __load_ucode_intel ? collect_cpu_info_early ? debug_check_no_locks_freed load_ucode_intel_ap ? collect_cpu_info ? trace_hardirqs_on ? flat_send_IPI_mask_allbutself load_ucode_ap ? get_builtin_firmware ? flush_tlb_func ? do_raw_spin_trylock ? cpumask_weight cpu_init ? trace_hardirqs_off ? play_dead_common ? native_play_dead ? hlt_play_dead ? syscall_init ? arch_cpu_idle_dead ? do_idle start_secondary start_cpu Memory state around the buggy address: ffff880036e74f00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff880036e74f80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >ffff880036e75000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff880036e75080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff880036e75100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ================================================================== Reported-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Tested-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Signed-off-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> Link: http://lkml.kernel.org/r/20170126165833.evjemhbqzaepirxo@pd.tnic Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-01-24x86/fpu/xstate: Fix xcomp_bv in XSAVES headerYu-cheng Yu
The compacted-format XSAVES area is determined at boot time and never changed after. The field xsave.header.xcomp_bv indicates which components are in the fixed XSAVES format. In fpstate_init() we did not set xcomp_bv to reflect the XSAVES format since at the time there is no valid data. However, after we do copy_init_fpstate_to_fpregs() in fpu__clear(), as in commit: b22cbe404a9c x86/fpu: Fix invalid FPU ptrace state after execve() and when __fpu_restore_sig() does fpu__restore() for a COMPAT-mode app, a #GP occurs. This can be easily triggered by doing valgrind on a COMPAT-mode "Hello World," as reported by Joakim Tjernlund and others: https://bugzilla.kernel.org/show_bug.cgi?id=190061 Fix it by setting xcomp_bv correctly. This patch also moves the xcomp_bv initialization to the proper place, which was in copyin_to_xsaves() as of: 4c833368f0bf x86/fpu: Set the xcomp_bv when we fake up a XSAVES area which fixed the bug too, but it's more efficient and cleaner to initialize things once per boot, not for every signal handling operation. Reported-by: Kevin Hao <haokexin@gmail.com> Reported-by: Joakim Tjernlund <Joakim.Tjernlund@infinera.com> Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@suse.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ravi V. Shankar <ravi.v.shankar@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: haokexin@gmail.com Link: http://lkml.kernel.org/r/1485212084-4418-1-git-send-email-yu-cheng.yu@intel.com [ Combined it with 4c833368f0bf. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-01-23x86/fpu: Set the xcomp_bv when we fake up a XSAVES areaKevin Hao
I got the following calltrace on a Apollo Lake SoC with 32-bit kernel: WARNING: CPU: 2 PID: 261 at arch/x86/include/asm/fpu/internal.h:363 fpu__restore+0x1f5/0x260 [...] Hardware name: Intel Corp. Broxton P/NOTEBOOK, BIOS APLIRVPA.X64.0138.B35.1608091058 08/09/2016 Call Trace: dump_stack() __warn() ? fpu__restore() warn_slowpath_null() fpu__restore() __fpu__restore_sig() fpu__restore_sig() restore_sigcontext.isra.9() sys_sigreturn() do_int80_syscall_32() entry_INT80_32() The reason is that a #GP occurs when executing XRSTORS. The root cause is that we forget to set the xcomp_bv when we fake up the XSAVES area in the copyin_to_xsaves() function. Signed-off-by: Kevin Hao <haokexin@gmail.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Yu-cheng Yu <yu-cheng.yu@intel.com> Link: http://lkml.kernel.org/r/1485075023-30161-1-git-send-email-haokexin@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2017-01-23x86/microcode/intel: Drop stashed AP patch pointer optimizationBorislav Petkov
This was meant to save us the scanning of the microcode containter in the initrd since the first AP had already done that but it can also hurt us: Imagine a single hyperthreaded CPU (Intel(R) Atom(TM) CPU N270, for example) which updates the microcode on the BSP but since the microcode engine is shared between the two threads, the update on CPU1 doesn't happen because it has already happened on CPU0 and we don't find a newer microcode revision on CPU1. Which doesn't set the intel_ucode_patch pointer and at initrd jettisoning time we don't save the microcode patch for later application. Now, when we suspend to RAM, the loaded microcode gets cleared so we need to reload but there's no patch saved in the cache. Removing the optimization fixes this issue and all is fine and dandy. Fixes: 06b8534cb728 ("x86/microcode: Rework microcode loading") Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20170120202955.4091-2-bp@alien8.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2017-01-18x86/ioapic: Restore IO-APIC irq_chip retrigger callbackRuslan Ruslichenko
commit d32932d02e18 removed the irq_retrigger callback from the IO-APIC chip and did not add it to the new IO-APIC-IR irq chip. Unfortunately the software resend fallback is not enabled on X86, so edge interrupts which are received during the lazy disabled state of the interrupt line are not retriggered and therefor lost. Restore the callbacks. [ tglx: Massaged changelog ] Fixes: d32932d02e18 ("x86/irq: Convert IOAPIC to use hierarchical irqdomain interfaces") Signed-off-by: Ruslan Ruslichenko <rruslich@cisco.com> Cc: xe-linux-external@cisco.com Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/1484662432-13580-1-git-send-email-rruslich@cisco.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2017-01-15Merge branch 'x86-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Ingo Molnar: "Misc fixes: - unwinder fixes - AMD CPU topology enumeration fixes - microcode loader fixes - x86 embedded platform fixes - fix for a bootup crash that may trigger when clearcpuid= is used with invalid values" * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/mpx: Use compatible types in comparison to fix sparse error x86/tsc: Add the Intel Denverton Processor to native_calibrate_tsc() x86/entry: Fix the end of the stack for newly forked tasks x86/unwind: Include __schedule() in stack traces x86/unwind: Disable KASAN checks for non-current tasks x86/unwind: Silence warnings for non-current tasks x86/microcode/intel: Use correct buffer size for saving microcode data x86/microcode/intel: Fix allocation size of struct ucode_patch x86/microcode/intel: Add a helper which gives the microcode revision x86/microcode: Use native CPUID to tickle out microcode revision x86/CPU: Add native CPUID variants returning a single datum x86/boot: Add missing declaration of string functions x86/CPU/AMD: Fix Bulldozer topology x86/platform/intel-mid: Rename 'spidev' to 'mrfld_spidev' x86/cpu: Fix typo in the comment for Anniedale x86/cpu: Fix bootup crashes by sanitizing the argument of the 'clearcpuid=' command-line option
2017-01-14x86/tsc: Add the Intel Denverton Processor to native_calibrate_tsc()Len Brown
The Intel Denverton microserver uses a 25 MHz TSC crystal, so we can derive its exact [*] TSC frequency using CPUID and some arithmetic, eg.: TSC: 1800 MHz (25000000 Hz * 216 / 3 / 1000000) [*] 'exact' is only as good as the crystal, which should be +/- 20ppm Signed-off-by: Len Brown <len.brown@intel.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/306899f94804aece6d8fa8b4223ede3b48dbb59c.1484287748.git.len.brown@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-01-12x86/unwind: Disable KASAN checks for non-current tasksJosh Poimboeuf
There are a handful of callers to save_stack_trace_tsk() and show_stack() which try to unwind the stack of a task other than current. In such cases, it's remotely possible that the task is running on one CPU while the unwinder is reading its stack from another CPU, causing the unwinder to see stack corruption. These cases seem to be mostly harmless. The unwinder has checks which prevent it from following bad pointers beyond the bounds of the stack. So it's not really a bug as long as the caller understands that unwinding another task will not always succeed. In such cases, it's possible that the unwinder may read a KASAN-poisoned region of the stack. Account for that by using READ_ONCE_NOCHECK() when reading the stack of another task. Use READ_ONCE() when reading the stack of the current task, since KASAN warnings can still be useful for finding bugs in that case. Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Jones <davej@codemonkey.org.uk> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Miroslav Benes <mbenes@suse.cz> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/4c575eb288ba9f73d498dfe0acde2f58674598f1.1483978430.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-01-12x86/unwind: Silence warnings for non-current tasksJosh Poimboeuf
There are a handful of callers to save_stack_trace_tsk() and show_stack() which try to unwind the stack of a task other than current. In such cases, it's remotely possible that the task is running on one CPU while the unwinder is reading its stack from another CPU, causing the unwinder to see stack corruption. These cases seem to be mostly harmless. The unwinder has checks which prevent it from following bad pointers beyond the bounds of the stack. So it's not really a bug as long as the caller understands that unwinding another task will not always succeed. Since stack "corruption" on another task's stack isn't necessarily a bug, silence the warnings when unwinding tasks other than current. Reported-by: Dave Jones <davej@codemonkey.org.uk> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andy Lutomirski <luto@amacapital.net> 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: Dmitry Vyukov <dvyukov@google.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Miroslav Benes <mbenes@suse.cz> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/00d8c50eea3446c1524a2a755397a3966629354c.1483978430.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-01-09x86/microcode/intel: Use correct buffer size for saving microcode dataJunichi Nomura
In generic_load_microcode(), curr_mc_size is the size of the last allocated buffer and since we have this performance "optimization" there to vmalloc a new buffer only when the current one is bigger, curr_mc_size ends up becoming the size of the biggest buffer we've seen so far. However, we end up saving the microcode patch which matches our CPU and its size is not curr_mc_size but the respective mc_size during the iteration while we're staring at it. So save that mc_size into a separate variable and use it to store the previously found microcode buffer. Without this fix, we could get oops like this: BUG: unable to handle kernel paging request at ffffc9000e30f000 IP: __memcpy+0x12/0x20 ... Call Trace: ? kmemdup+0x43/0x60 __alloc_microcode_buf+0x44/0x70 save_microcode_patch+0xd4/0x150 generic_load_microcode+0x1b8/0x260 request_microcode_user+0x15/0x20 microcode_write+0x91/0x100 __vfs_write+0x34/0x120 vfs_write+0xc1/0x130 SyS_write+0x56/0xc0 do_syscall_64+0x6c/0x160 entry_SYSCALL64_slow_path+0x25/0x25 Fixes: 06b8534cb728 ("x86/microcode: Rework microcode loading") Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: http://lkml.kernel.org/r/4f33cbfd-44f2-9bed-3b66-7446cd14256f@ce.jp.nec.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2017-01-09x86/microcode/intel: Fix allocation size of struct ucode_patchJunichi Nomura
We allocate struct ucode_patch here. @size is the size of microcode data and used for kmemdup() later in this function. Fixes: 06b8534cb728 ("x86/microcode: Rework microcode loading") Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: http://lkml.kernel.org/r/7a730dc9-ac17-35c4-fe76-dfc94e5ecd95@ce.jp.nec.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2017-01-09x86/microcode/intel: Add a helper which gives the microcode revisionBorislav Petkov
Since on Intel we're required to do CPUID(1) first, before reading the microcode revision MSR, let's add a special helper which does the required steps so that we don't forget to do them next time, when we want to read the microcode revision. Signed-off-by: Borislav Petkov <bp@suse.de> Link: http://lkml.kernel.org/r/20170109114147.5082-4-bp@alien8.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2017-01-09x86/microcode: Use native CPUID to tickle out microcode revisionBorislav Petkov
Intel supplies the microcode revision value in MSR 0x8b (IA32_BIOS_SIGN_ID) after CPUID(1) has been executed. Execute it each time before reading that MSR. It used to do sync_core() which did do CPUID but c198b121b1a1 ("x86/asm: Rewrite sync_core() to use IRET-to-self") changed the sync_core() implementation so we better make the microcode loading case explicit, as the SDM documents it. Reported-and-tested-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: http://lkml.kernel.org/r/20170109114147.5082-3-bp@alien8.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2017-01-06Merge branch 'stable/for-linus-4.10' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/konrad/swiotlb Pull swiotlb fixes from Konrad Rzeszutek Wilk: "This has one fix to make i915 work when using Xen SWIOTLB, and a feature from Geert to aid in debugging of devices that can't do DMA outside the 32-bit address space. The feature from Geert is on top of v4.10 merge window commit (specifically you pulling my previous branch), as his changes were dependent on the Documentation/ movement patches. I figured it would just easier than me trying than to cherry-pick the Documentation patches to satisfy git. The patches have been soaking since 12/20, albeit I updated the last patch due to linux-next catching an compiler error and adding an Tested-and-Reported-by tag" * 'stable/for-linus-4.10' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/swiotlb: swiotlb: Export swiotlb_max_segment to users swiotlb: Add swiotlb=noforce debug option swiotlb: Convert swiotlb_force from int to enum x86, swiotlb: Simplify pci_swiotlb_detect_override()
2017-01-06x86/CPU/AMD: Fix Bulldozer topologyBorislav Petkov
The following commit: 8196dab4fc15 ("x86/cpu: Get rid of compute_unit_id") ... broke the initial strategy for Bulldozer-based cores' topology, where we consider each thread of a compute unit a standalone core and not a HT or SMT thread. Revert to the firmware-supplied core_id numbering and do not make them thread siblings as we don't consider them for such even if they technically are, more or less. Reported-and-tested-by: Brice Goglin <Brice.Goglin@inria.fr> Tested-by: Yazen Ghannam <yazen.ghannam@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: <stable@vger.kernel.org> # v4.6+ 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: Thomas Gleixner <tglx@linutronix.de> Fixes: 8196dab4fc15 ("x86/cpu: Get rid of compute_unit_id") Link: http://lkml.kernel.org/r/20170105092638.5247-1-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-01-05x86/cpu: Fix bootup crashes by sanitizing the argument of the 'clearcpuid=' ↵Lukasz Odzioba
command-line option A negative number can be specified in the cmdline which will be used as setup_clear_cpu_cap() argument. With that we can clear/set some bit in memory predceeding boot_cpu_data/cpu_caps_cleared which may cause kernel to misbehave. This patch adds lower bound check to setup_disablecpuid(). Boris Petkov reproduced a crash: [ 1.234575] BUG: unable to handle kernel paging request at ffffffff858bd540 [ 1.236535] IP: memcpy_erms+0x6/0x10 Signed-off-by: Lukasz Odzioba <lukasz.odzioba@intel.com> Acked-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: andi.kleen@intel.com Cc: bp@alien8.de Cc: dave.hansen@linux.intel.com Cc: luto@kernel.org Cc: slaoub@gmail.com Fixes: ac72e7888a61 ("x86: add generic clearcpuid=... option") Link: http://lkml.kernel.org/r/1482933340-11857-1-git-send-email-lukasz.odzioba@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-12-26x86/mce/AMD: Make the init code more robustThomas Gleixner
If mce_device_init() fails then the mce device pointer is NULL and the AMD mce code happily dereferences it. Add a sanity check. Reported-by: Markus Trippelsdorf <markus@trippelsdorf.de> Reported-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-25Merge branch 'timers-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timer type cleanups from Thomas Gleixner: "This series does a tree wide cleanup of types related to timers/timekeeping. - Get rid of cycles_t and use a plain u64. The type is not really helpful and caused more confusion than clarity - Get rid of the ktime union. The union has become useless as we use the scalar nanoseconds storage unconditionally now. The 32bit timespec alike storage got removed due to the Y2038 limitations some time ago. That leaves the odd union access around for no reason. Clean it up. Both changes have been done with coccinelle and a small amount of manual mopping up" * 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: ktime: Get rid of ktime_equal() ktime: Cleanup ktime_set() usage ktime: Get rid of the union clocksource: Use a plain u64 instead of cycle_t
2016-12-25Merge branch 'smp-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull SMP hotplug notifier removal from Thomas Gleixner: "This is the final cleanup of the hotplug notifier infrastructure. The series has been reintgrated in the last two days because there came a new driver using the old infrastructure via the SCSI tree. Summary: - convert the last leftover drivers utilizing notifiers - fixup for a completely broken hotplug user - prevent setup of already used states - removal of the notifiers - treewide cleanup of hotplug state names - consolidation of state space There is a sphinx based documentation pending, but that needs review from the documentation folks" * 'smp-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: irqchip/armada-xp: Consolidate hotplug state space irqchip/gic: Consolidate hotplug state space coresight/etm3/4x: Consolidate hotplug state space cpu/hotplug: Cleanup state names cpu/hotplug: Remove obsolete cpu hotplug register/unregister functions staging/lustre/libcfs: Convert to hotplug state machine scsi/bnx2i: Convert to hotplug state machine scsi/bnx2fc: Convert to hotplug state machine cpu/hotplug: Prevent overwriting of callbacks x86/msr: Remove bogus cleanup from the error path bus: arm-ccn: Prevent hotplug callback leak perf/x86/intel/cstate: Prevent hotplug callback leak ARM/imx/mmcd: Fix broken cpu hotplug handling scsi: qedi: Convert to hotplug state machine
2016-12-25clocksource: Use a plain u64 instead of cycle_tThomas Gleixner
There is no point in having an extra type for extra confusion. u64 is unambiguous. Conversion was done with the following coccinelle script: @rem@ @@ -typedef u64 cycle_t; @fix@ typedef cycle_t; @@ -cycle_t +u64 Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: John Stultz <john.stultz@linaro.org>
2016-12-25cpu/hotplug: Cleanup state namesThomas Gleixner
When the state names got added a script was used to add the extra argument to the calls. The script basically converted the state constant to a string, but the cleanup to convert these strings into meaningful ones did not happen. Replace all the useless strings with 'subsys/xxx/yyy:state' strings which are used in all the other places already. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sebastian Siewior <bigeasy@linutronix.de> Link: http://lkml.kernel.org/r/20161221192112.085444152@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-12-25x86/msr: Remove bogus cleanup from the error pathThomas Gleixner
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>
2016-12-24Replace <asm/uaccess.h> with <linux/uaccess.h> globallyLinus Torvalds
This was entirely automated, using the script by Al: PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*<asm/uaccess.h>' sed -i -e "s!$PATT!#include <linux/uaccess.h>!" \ $(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h) to do the replacement at the end of the merge window. Requested-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-23Merge branch 'x86-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Ingo Molnar: "There's a number of fixes: - a round of fixes for CPUID-less legacy CPUs - a number of microcode loader fixes - i8042 detection robustization fixes - stack dump/unwinder fixes - x86 SoC platform driver fixes - a GCC 7 warning fix - virtualization related fixes" * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (24 commits) Revert "x86/unwind: Detect bad stack return address" x86/paravirt: Mark unused patch_default label x86/microcode/AMD: Reload proper initrd start address x86/platform/intel/quark: Add printf attribute to imr_self_test_result() x86/platform/intel-mid: Switch MPU3050 driver to IIO x86/alternatives: Do not use sync_core() to serialize I$ x86/topology: Document cpu_llc_id x86/hyperv: Handle unknown NMIs on one CPU when unknown_nmi_panic x86/asm: Rewrite sync_core() to use IRET-to-self x86/microcode/intel: Replace sync_core() with native_cpuid() Revert "x86/boot: Fail the boot if !M486 and CPUID is missing" x86/asm/32: Make sync_core() handle missing CPUID on all 32-bit kernels x86/cpu: Probe CPUID leaf 6 even when cpuid_level == 6 x86/tools: Fix gcc-7 warning in relocs.c x86/unwind: Dump stack data on warnings x86/unwind: Adjust last frame check for aligned function stacks x86/init: Fix a couple of comment typos x86/init: Remove i8042_detect() from platform ops Input: i8042 - Trust firmware a bit more when probing on X86 x86/init: Add i8042 state to the platform data ...
2016-12-23Revert "x86/unwind: Detect bad stack return address"Josh Poimboeuf
Revert the following commit: b6959a362177 ("x86/unwind: Detect bad stack return address") ... because Andrey Konovalov reported an unwinder warning: WARNING: unrecognized kernel stack return address ffffffffa0000001 at ffff88006377fa18 in a.out:4467 The unwind was initiated from an interrupt which occurred while running in the generated code for a kprobe. The unwinder printed the warning because it expected regs->ip to point to a valid text address, but instead it pointed to the generated code. Eventually we may want come up with a way to identify generated kprobe code so the unwinder can know that it's a valid return address. Until then, just remove the warning. Reported-by: Andrey Konovalov <andreyknvl@google.com> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> 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: Linus Torvalds <torvalds@linux-foundation.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/02f296848fbf49fb72dfeea706413ecbd9d4caf6.1482418739.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-12-22Merge branch 'x86-cache-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 cache allocation interface from Thomas Gleixner: "This provides support for Intel's Cache Allocation Technology, a cache partitioning mechanism. The interface is odd, but the hardware interface of that CAT stuff is odd as well. We tried hard to come up with an abstraction, but that only allows rather simple partitioning, but no way of sharing and dealing with the per package nature of this mechanism. In the end we decided to expose the allocation bitmaps directly so all combinations of the hardware can be utilized. There are two ways of associating a cache partition: - Task A task can be added to a resource group. It uses the cache partition associated to the group. - CPU All tasks which are not member of a resource group use the group to which the CPU they are running on is associated with. That allows for simple CPU based partitioning schemes. The main expected user sare: - Virtualization so a VM can only trash only the associated part of the cash w/o disturbing others - Real-Time systems to seperate RT and general workloads. - Latency sensitive enterprise workloads - In theory this also can be used to protect against cache side channel attacks" [ Intel RDT is "Resource Director Technology". The interface really is rather odd and very specific, which delayed this pull request while I was thinking about it. The pull request itself came in early during the merge window, I just delayed it until things had calmed down and I had more time. But people tell me they'll use this, and the good news is that it is _so_ specific that it's rather independent of anything else, and no user is going to depend on the interface since it's pretty rare. So if push comes to shove, we can just remove the interface and nothing will break ] * 'x86-cache-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (31 commits) x86/intel_rdt: Implement show_options() for resctrlfs x86/intel_rdt: Call intel_rdt_sched_in() with preemption disabled x86/intel_rdt: Update task closid immediately on CPU in rmdir and unmount x86/intel_rdt: Fix setting of closid when adding CPUs to a group x86/intel_rdt: Update percpu closid immeditately on CPUs affected by changee x86/intel_rdt: Reset per cpu closids on unmount x86/intel_rdt: Select KERNFS when enabling INTEL_RDT_A x86/intel_rdt: Prevent deadlock against hotplug lock x86/intel_rdt: Protect info directory from removal x86/intel_rdt: Add info files to Documentation x86/intel_rdt: Export the minimum number of set mask bits in sysfs x86/intel_rdt: Propagate error in rdt_mount() properly x86/intel_rdt: Add a missing #include MAINTAINERS: Add maintainer for Intel RDT resource allocation x86/intel_rdt: Add scheduler hook x86/intel_rdt: Add schemata file x86/intel_rdt: Add tasks files x86/intel_rdt: Add cpus file x86/intel_rdt: Add mkdir to resctrl file system x86/intel_rdt: Add "info" files to resctrl file system ...
2016-12-22x86/paravirt: Mark unused patch_default labelPeter Zijlstra
A bugfix commit: 45dbea5f55c0 ("x86/paravirt: Fix native_patch()") ... introduced a harmless warning: arch/x86/kernel/paravirt_patch_32.c: In function 'native_patch': arch/x86/kernel/paravirt_patch_32.c:71:1: error: label 'patch_default' defined but not used [-Werror=unused-label] Fix it by annotating the label as __maybe_unused. Reported-by: Arnd Bergmann <arnd@arndb.de> Reported-by: Piotr Gregor <piotrgregor@rsyncme.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> 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: Thomas Gleixner <tglx@linutronix.de> Fixes: 45dbea5f55c0 ("x86/paravirt: Fix native_patch()") Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-12-21x86/microcode/AMD: Reload proper initrd start addressBorislav Petkov
When we switch to virtual addresses and, especially after reserve_initrd()->relocate_initrd() have run, we have the updated initrd address in initrd_start. Use initrd_start then instead of the address which has been passed to us through boot params. (That still gets used when we're running the very early routines on the BSP). Reported-and-tested-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: http://lkml.kernel.org/r/20161220144012.lc4cwrg6dphqbyqu@pd.tnic Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-12-20x86/alternatives: Do not use sync_core() to serialize I$Borislav Petkov
We use sync_core() in the alternatives code to stop speculative execution of prefetched instructions because we are potentially changing them and don't want to execute stale bytes. What it does on most machines is call CPUID which is a serializing instruction. And that's expensive. However, the instruction cache is serialized when we're on the local CPU and are changing the data through the same virtual address. So then, we don't need the serializing CPUID but a simple control flow change. Last being accomplished with a CALL/RET which the noinline causes. Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Andy Lutomirski <luto@kernel.org> Cc: Andrew Cooper <andrew.cooper3@citrix.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Brian Gerst <brgerst@gmail.com> Cc: Henrique de Moraes Holschuh <hmh@hmh.eng.br> Cc: Matthew Whitehead <tedheadster@gmail.com> Cc: One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20161203150258.vwr5zzco7ctgc4pe@pd.tnic Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-12-20x86/hyperv: Handle unknown NMIs on one CPU when unknown_nmi_panicVitaly Kuznetsov
There is a feature in Hyper-V ('Debug-VM --InjectNonMaskableInterrupt') which injects NMI to the guest. We may want to crash the guest and do kdump on this NMI by enabling unknown_nmi_panic. To make kdump succeed we need to allow the kdump kernel to re-establish VMBus connection so it will see VMBus devices (storage, network,..). To properly unload VMBus making it possible to start over during kdump we need to do the following: - Send an 'unload' message to the hypervisor. This can be done on any CPU so we do this the crashing CPU. - Receive the 'unload finished' reply message. WS2012R2 delivers this message to the CPU which was used to establish VMBus connection during module load and this CPU may differ from the CPU sending 'unload'. Receiving a VMBus message means the following: - There is a per-CPU slot in memory for one message. This slot can in theory be accessed by any CPU. - We get an interrupt on the CPU when a message was placed into the slot. - When we read the message we need to clear the slot and signal the fact to the hypervisor. In case there are more messages to this CPU pending the hypervisor will deliver the next message. The signaling is done by writing to an MSR so this can only be done on the appropriate CPU. To avoid doing cross-CPU work on crash we have vmbus_wait_for_unload() function which checks message slots for all CPUs in a loop waiting for the 'unload finished' messages. However, there is an issue which arises when these conditions are met: - We're crashing on a CPU which is different from the one which was used to initially contact the hypervisor. - The CPU which was used for the initial contact is blocked with interrupts disabled and there is a message pending in the message slot. In this case we won't be able to read the 'unload finished' message on the crashing CPU. This is reproducible when we receive unknown NMIs on all CPUs simultaneously: the first CPU entering panic() will proceed to crash and all other CPUs will stop themselves with interrupts disabled. The suggested solution is to handle unknown NMIs for Hyper-V guests on the first CPU which gets them only. This will allow us to rely on VMBus interrupt handler being able to receive the 'unload finish' message in case it is delivered to a different CPU. The issue is not reproducible on WS2016 as Debug-VM delivers NMI to the boot CPU only, WS2012R2 and earlier Hyper-V versions are affected. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Acked-by: K. Y. Srinivasan <kys@microsoft.com> Cc: devel@linuxdriverproject.org Cc: Haiyang Zhang <haiyangz@microsoft.com> Link: http://lkml.kernel.org/r/20161202100720.28121-1-vkuznets@redhat.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-12-19swiotlb: Convert swiotlb_force from int to enumGeert Uytterhoeven
Convert the flag swiotlb_force from an int to an enum, to prepare for the advent of more possible values. Suggested-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2016-12-19x86, swiotlb: Simplify pci_swiotlb_detect_override()Geert Uytterhoeven
At the end of the function, the local variable use_swiotlb has always the same value as the global variable swiotlb. Hence drop the local variable completely. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2016-12-19x86/microcode/intel: Replace sync_core() with native_cpuid()Andy Lutomirski
The Intel microcode driver is using sync_core() to mean "do CPUID with EAX=1". I want to rework sync_core(), but first the Intel microcode driver needs to stop depending on its current behavior. Reported-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br> Signed-off-by: Andy Lutomirski <luto@kernel.org> Acked-by: Borislav Petkov <bp@alien8.de> Cc: Juergen Gross <jgross@suse.com> Cc: One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Brian Gerst <brgerst@gmail.com> Cc: Matthew Whitehead <tedheadster@gmail.com> Cc: Andrew Cooper <andrew.cooper3@citrix.com> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: xen-devel <Xen-devel@lists.xen.org> Link: http://lkml.kernel.org/r/535a025bb91fed1a019c5412b036337ad239e5bb.1481307769.git.luto@kernel.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-12-19x86/cpu: Probe CPUID leaf 6 even when cpuid_level == 6Andy Lutomirski
A typo (or mis-merge?) resulted in leaf 6 only being probed if cpuid_level >= 7. Fixes: 2ccd71f1b278 ("x86/cpufeature: Move some of the scattered feature bits to x86_capability") Signed-off-by: Andy Lutomirski <luto@kernel.org> Acked-by: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Link: http://lkml.kernel.org/r/6ea30c0e9daec21e488b54761881a6dfcf3e04d0.1481825597.git.luto@kernel.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-12-19x86/unwind: Dump stack data on warningsJosh Poimboeuf
The unwinder warnings are good at finding unexpected unwinder issues, but they often don't give enough data to be able to fully diagnose them. Print a one-time stack dump when a warning is detected. Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Andy Lutomirski <luto@amacapital.net> Link: http://lkml.kernel.org/r/15607370e3ddb1732b6a73d5c65937864df16ac8.1481904011.git.jpoimboe@redhat.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-12-19x86/unwind: Adjust last frame check for aligned function stacksJosh Poimboeuf
Somehow, CONFIG_PARAVIRT=n convinces gcc to change the x86_64_start_kernel() prologue from: 0000000000000129 <x86_64_start_kernel>: 129: 55 push %rbp 12a: 48 89 e5 mov %rsp,%rbp to: 0000000000000124 <x86_64_start_kernel>: 124: 4c 8d 54 24 08 lea 0x8(%rsp),%r10 129: 48 83 e4 f0 and $0xfffffffffffffff0,%rsp 12d: 41 ff 72 f8 pushq -0x8(%r10) 131: 55 push %rbp 132: 48 89 e5 mov %rsp,%rbp This is an unusual pattern which aligns rsp (though in this case it's already aligned) and saves the start_cpu() return address again on the stack before storing the frame pointer. The unwinder assumes the last stack frame header is at a certain offset, but the above code breaks that assumption, resulting in the following warning: WARNING: kernel stack frame pointer at ffffffff82e03f40 in swapper:0 has bad value (null) Fix it by checking for the last task stack frame at the aligned offset in addition to the normal unaligned offset. Fixes: acb4608ad186 ("x86/unwind: Create stack frames for saved syscall registers") Reported-by: Borislav Petkov <bp@alien8.de> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andy Lutomirski <luto@amacapital.net> Link: http://lkml.kernel.org/r/9d7b4eb8cf55a7d6002cb738f25c23e7429c99a0.1481904011.git.jpoimboe@redhat.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-12-19x86/init: Remove i8042_detect() from platform opsDmitry Torokhov
Now that i8042 uses flag in legacy platform data, i8042_detect() is no longer used and can be removed. Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Tested-by: Takashi Iwai <tiwai@suse.de> Acked-by: Marcos Paulo de Souza <marcos.souza.org@gmail.com> Cc: linux-input@vger.kernel.org Link: http://lkml.kernel.org/r/1481317061-31486-4-git-send-email-dmitry.torokhov@gmail.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-12-19x86/init: Add i8042 state to the platform dataDmitry Torokhov
Add i8042 state to the platform data to help i8042 driver make decision whether to probe for i8042 or not. We recognize 3 states: platform/subarch ca not possible have i8042 (as is the case with Inrel MID platform), firmware (such as ACPI) reports that i8042 is absent from the device, or i8042 may be present and the driver should probe for it. The intent is to allow i8042 driver abort initialization on x86 if PNP data (absence of both keyboard and mouse PNP devices) agrees with firmware data. It will also allow us to remove i8042_detect later. Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Tested-by: Takashi Iwai <tiwai@suse.de> Acked-by: Marcos Paulo de Souza <marcos.souza.org@gmail.com> Cc: linux-input@vger.kernel.org Link: http://lkml.kernel.org/r/1481317061-31486-2-git-send-email-dmitry.torokhov@gmail.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-12-19x86/microcode/AMD: Use native_cpuid() in load_ucode_amd_bsp()Boris Ostrovsky
When CONFIG_PARAVIRT is selected, cpuid() becomes a call. Since for 32-bit kernels load_ucode_amd_bsp() is executed before paging is enabled the call cannot be completed (as kernel virtual addresses are not reachable yet). Use native_cpuid() instead which is an asm wrapper for the CPUID instruction. Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Jürgen Gross <jgross@suse.com> Link: http://lkml.kernel.org/r/1481906392-3847-1-git-send-email-boris.ostrovsky@oracle.com Link: http://lkml.kernel.org/r/20161218164414.9649-5-bp@alien8.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-12-19x86/microcode/AMD: Do not load when running on a hypervisorBorislav Petkov
Doing so is completely void of sense for multiple reasons so prevent it. Set dis_ucode_ldr to true and thus disable the microcode loader by default to address xen pv guests which execute the AP path but not the BSP path. By having it turned off by default, the APs won't run into the loader either. Also, check CPUID(1).ECX[31] which hypervisors set. Well almost, not the xen pv one. That one gets the aforementioned "fix". Also, improve the detection method by caching the final decision whether to continue loading in dis_ucode_ldr and do it once on the BSP. The APs then simply test that value. Signed-off-by: Borislav Petkov <bp@suse.de> Tested-by: Juergen Gross <jgross@suse.com> Tested-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Acked-by: Juergen Gross <jgross@suse.com> Link: http://lkml.kernel.org/r/20161218164414.9649-4-bp@alien8.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>