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2020-08-04Merge tag 'uninit-macro-v5.9-rc1' of ↵Linus Torvalds1-5/+5
git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull uninitialized_var() macro removal from Kees Cook: "This is long overdue, and has hidden too many bugs over the years. The series has several "by hand" fixes, and then a trivial treewide replacement. - Clean up non-trivial uses of uninitialized_var() - Update documentation and checkpatch for uninitialized_var() removal - Treewide removal of uninitialized_var()" * tag 'uninit-macro-v5.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: compiler: Remove uninitialized_var() macro treewide: Remove uninitialized_var() usage checkpatch: Remove awareness of uninitialized_var() macro mm/debug_vm_pgtable: Remove uninitialized_var() usage f2fs: Eliminate usage of uninitialized_var() macro media: sur40: Remove uninitialized_var() usage KVM: PPC: Book3S PR: Remove uninitialized_var() usage clk: spear: Remove uninitialized_var() usage clk: st: Remove uninitialized_var() usage spi: davinci: Remove uninitialized_var() usage ide: Remove uninitialized_var() usage rtlwifi: rtl8192cu: Remove uninitialized_var() usage b43: Remove uninitialized_var() usage drbd: Remove uninitialized_var() usage x86/mm/numa: Remove uninitialized_var() usage docs: deprecated.rst: Add uninitialized_var()
2020-08-04Merge tag 'ras-core-2020-08-03' of ↵Linus Torvalds3-2/+4
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 RAS updates from Ingo Molnar: "Boris is on vacation and he asked us to send you the pending RAS bits: - Print the PPIN field on CPUs that fill them out - Fix an MCE injection bug - Simplify a kzalloc in dev_mcelog_init_device()" * tag 'ras-core-2020-08-03' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/mce, EDAC/mce_amd: Print PPIN in machine check records x86/mce/dev-mcelog: Use struct_size() helper in kzalloc() x86/mce/inject: Fix a wrong assignment of i_mce.status
2020-08-04Merge tag 'x86-platform-2020-08-03' of ↵Linus Torvalds2-105/+26
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 platform updates from Ingo Molnar: "The biggest change is the removal of SGI UV1 support, which allowed the removal of the legacy EFI old_mmap code as well. This removes quite a bunch of old code & quirks" * tag 'x86-platform-2020-08-03' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/efi: Remove unused EFI_UV1_MEMMAP code x86/platform/uv: Remove uv bios and efi code related to EFI_UV1_MEMMAP x86/efi: Remove references to no-longer-used efi_have_uv1_memmap() x86/efi: Delete SGI UV1 detection. x86/platform/uv: Remove efi=old_map command line option x86/platform/uv: Remove vestigial mention of UV1 platform from bios header x86/platform/uv: Remove support for UV1 platform from uv x86/platform/uv: Remove support for uv1 platform from uv_hub x86/platform/uv: Remove support for UV1 platform from uv_bau x86/platform/uv: Remove support for UV1 platform from uv_mmrs x86/platform/uv: Remove support for UV1 platform from x2apic_uv_x x86/platform/uv: Remove support for UV1 platform from uv_tlb x86/platform/uv: Remove support for UV1 platform from uv_time
2020-08-04Merge tag 'x86-misc-2020-08-03' of ↵Linus Torvalds1-0/+69
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 MSR filtering from Ingo Molnar: "Filter MSR writes from user-space by default, and print a syslog entry if they happen outside the allowed set of MSRs, which is a single one for now, MSR_IA32_ENERGY_PERF_BIAS. The plan is to eventually disable MSR writes by default (they can still be enabled via allow_writes=on)" * tag 'x86-misc-2020-08-03' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/msr: Filter MSR writes
2020-08-04Merge tag 'x86-microcode-2020-08-03' of ↵Linus Torvalds1-2/+0
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 microcode update from Ingo Molnar: "Remove the microcode loader's FW_LOADER coupling" * tag 'x86-microcode-2020-08-03' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/microcode: Do not select FW_LOADER
2020-08-04Merge tag 'x86-cpu-2020-08-03' of ↵Linus Torvalds5-21/+10
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 cpu updates from Ingo Molar: - prepare for Intel's new SERIALIZE instruction - enable split-lock debugging on more CPUs - add more Intel CPU models - optimize stack canary initialization a bit - simplify the Spectre logic a bit * tag 'x86-cpu-2020-08-03' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/cpu: Refactor sync_core() for readability x86/cpu: Relocate sync_core() to sync_core.h x86/cpufeatures: Add enumeration for SERIALIZE instruction x86/split_lock: Enable the split lock feature on Sapphire Rapids and Alder Lake CPUs x86/cpu: Add Lakefield, Alder Lake and Rocket Lake models to the to Intel CPU family x86/stackprotector: Pre-initialize canary for secondary CPUs x86/speculation: Merge one test in spectre_v2_user_select_mitigation()
2020-08-04Merge tag 'x86-core-2020-08-03' of ↵Linus Torvalds3-49/+54
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 debug fixlets from Ingo Molnar: "Improve x86 debuggability: print registers with the same log level as the backtrace" * tag 'x86-core-2020-08-03' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/dumpstack: Show registers dump with trace's log level x86/dumpstack: Add log_lvl to __show_regs() x86/dumpstack: Add log_lvl to show_iret_regs()
2020-08-04Merge tag 'x86-cleanups-2020-08-03' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 cleanups from Ingo Molnar: "Misc cleanups all around the place" * tag 'x86-cleanups-2020-08-03' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/ioperm: Initialize pointer bitmap with NULL rather than 0 x86: uv: uv_hub.h: Delete duplicated word x86: cmpxchg_32.h: Delete duplicated word x86: bootparam.h: Delete duplicated word x86/mm: Remove the unused mk_kernel_pgd() #define x86/tsc: Remove unused "US_SCALE" and "NS_SCALE" leftover macros x86/ioapic: Remove unused "IOAPIC_AUTO" define x86/mm: Drop unused MAX_PHYSADDR_BITS x86/msr: Move the F15h MSRs where they belong x86/idt: Make idt_descr static initrd: Remove erroneous comment x86/mm/32: Fix -Wmissing prototypes warnings for init.c cpu/speculation: Add prototype for cpu_show_srbds() x86/mm: Fix -Wmissing-prototypes warnings for arch/x86/mm/init.c x86/asm: Unify __ASSEMBLY__ blocks x86/cpufeatures: Mark two free bits in word 3 x86/msr: Lift AMD family 0x15 power-specific MSRs
2020-08-04Merge tag 'x86-alternatives-2020-08-03' of ↵Linus Torvalds1-2/+2
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86/alternatives update from Ingo Molnar: "A single commit that improves the alternatives patching syslog debug output" * tag 'x86-alternatives-2020-08-03' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/alternatives: Add pr_fmt() to debug macros
2020-08-04Merge tag 'sched-core-2020-08-03' of ↵Linus Torvalds1-9/+41
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler updates from Ingo Molnar: - Improve uclamp performance by using a static key for the fast path - Add the "sched_util_clamp_min_rt_default" sysctl, to optimize for better power efficiency of RT tasks on battery powered devices. (The default is to maximize performance & reduce RT latencies.) - Improve utime and stime tracking accuracy, which had a fixed boundary of error, which created larger and larger relative errors as the values become larger. This is now replaced with more precise arithmetics, using the new mul_u64_u64_div_u64() helper in math64.h. - Improve the deadline scheduler, such as making it capacity aware - Improve frequency-invariant scheduling - Misc cleanups in energy/power aware scheduling - Add sched_update_nr_running tracepoint to track changes to nr_running - Documentation additions and updates - Misc cleanups and smaller fixes * tag 'sched-core-2020-08-03' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (54 commits) sched/doc: Factorize bits between sched-energy.rst & sched-capacity.rst sched/doc: Document capacity aware scheduling sched: Document arch_scale_*_capacity() arm, arm64: Fix selection of CONFIG_SCHED_THERMAL_PRESSURE Documentation/sysctl: Document uclamp sysctl knobs sched/uclamp: Add a new sysctl to control RT default boost value sched/uclamp: Fix a deadlock when enabling uclamp static key sched: Remove duplicated tick_nohz_full_enabled() check sched: Fix a typo in a comment sched/uclamp: Remove unnecessary mutex_init() arm, arm64: Select CONFIG_SCHED_THERMAL_PRESSURE sched: Cleanup SCHED_THERMAL_PRESSURE kconfig entry arch_topology, sched/core: Cleanup thermal pressure definition trace/events/sched.h: fix duplicated word linux/sched/mm.h: drop duplicated words in comments smp: Fix a potential usage of stale nr_cpus sched/fair: update_pick_idlest() Select group with lowest group_util when idle_cpus are equal sched: nohz: stop passing around unused "ticks" parameter. sched: Better document ttwu() sched: Add a tracepoint to track rq->nr_running ...
2020-08-04Merge tag 'perf-core-2020-08-03' of ↵Linus Torvalds5-13/+205
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf event updates from Ingo Molnar: "HW support updates: - Add uncore support for Intel Comet Lake - Add RAPL support for Hygon Fam18h - Add Intel "IIO stack to PMON mapping" support on Skylake-SP CPUs, which enumerates per device performance counters via sysfs and enables the perf stat --iiostat functionality - Add support for Intel "Architectural LBRs", which generalized the model specific LBR hardware tracing feature into a model-independent, architected performance monitoring feature. Usage is mostly seamless to tooling, as the pre-existing LBR features are kept, but there's a couple of advantages under the hood, such as faster context-switching, faster LBR reads, cleaner exposure of LBR features to guest kernels, etc. ( Since architectural LBRs are supported via XSAVE, there's related changes to the x86 FPU code as well. ) ftrace/perf updates: - Add support to add a text poke event to record changes to kernel text (i.e. self-modifying code) in order to support tracers like Intel PT decoding through jump labels, kprobes and ftrace trampolines. Misc cleanups, smaller fixes..." * tag 'perf-core-2020-08-03' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (47 commits) perf/x86/rapl: Add Hygon Fam18h RAPL support kprobes: Remove unnecessary module_mutex locking from kprobe_optimizer() x86/perf: Fix a typo perf: <linux/perf_event.h>: drop a duplicated word perf/x86/intel/lbr: Support XSAVES for arch LBR read perf/x86/intel/lbr: Support XSAVES/XRSTORS for LBR context switch x86/fpu/xstate: Add helpers for LBR dynamic supervisor feature x86/fpu/xstate: Support dynamic supervisor feature for LBR x86/fpu: Use proper mask to replace full instruction mask perf/x86: Remove task_ctx_size perf/x86/intel/lbr: Create kmem_cache for the LBR context data perf/core: Use kmem_cache to allocate the PMU specific data perf/core: Factor out functions to allocate/free the task_ctx_data perf/x86/intel/lbr: Support Architectural LBR perf/x86/intel/lbr: Factor out intel_pmu_store_lbr perf/x86/intel/lbr: Factor out rdlbr_all() and wrlbr_all() perf/x86/intel/lbr: Mark the {rd,wr}lbr_{to,from} wrappers __always_inline perf/x86/intel/lbr: Unify the stored format of LBR information perf/x86/intel/lbr: Support LBR_CTL perf/x86: Expose CPUID enumeration bits for arch LBR ...
2020-08-04Merge tag 'locking-core-2020-08-03' of ↵Linus Torvalds3-22/+16
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull locking updates from Ingo Molnar: - LKMM updates: mostly documentation changes, but also some new litmus tests for atomic ops. - KCSAN updates: the most important change is that GCC 11 now has all fixes in place to support KCSAN, so GCC support can be enabled again. Also more annotations. - futex updates: minor cleanups and simplifications - seqlock updates: merge preparatory changes/cleanups for the 'associated locks' facilities. - lockdep updates: - simplify IRQ trace event handling - add various new debug checks - simplify header dependencies, split out <linux/lockdep_types.h>, decouple lockdep from other low level headers some more - fix NMI handling - misc cleanups and smaller fixes * tag 'locking-core-2020-08-03' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (60 commits) kcsan: Improve IRQ state trace reporting lockdep: Refactor IRQ trace events fields into struct seqlock: lockdep assert non-preemptibility on seqcount_t write lockdep: Add preemption enabled/disabled assertion APIs seqlock: Implement raw_seqcount_begin() in terms of raw_read_seqcount() seqlock: Add kernel-doc for seqcount_t and seqlock_t APIs seqlock: Reorder seqcount_t and seqlock_t API definitions seqlock: seqcount_t latch: End read sections with read_seqcount_retry() seqlock: Properly format kernel-doc code samples Documentation: locking: Describe seqlock design and usage locking/qspinlock: Do not include atomic.h from qspinlock_types.h locking/atomic: Move ATOMIC_INIT into linux/types.h lockdep: Move list.h inclusion into lockdep.h locking/lockdep: Fix TRACE_IRQFLAGS vs. NMIs futex: Remove unused or redundant includes futex: Consistently use fshared as boolean futex: Remove needless goto's futex: Remove put_futex_key() rwsem: fix commas in initialisation docs: locking: Replace HTTP links with HTTPS ones ...
2020-08-04Merge tag 'irq-urgent-2020-08-02' of ↵Linus Torvalds2-0/+9
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull irq fixes from Ingo Molnar: "Fix a recent IRQ affinities regression, add in a missing debugfs printout that helps the debugging of IRQ affinity logic bugs, and fix a memory leak" * tag 'irq-urgent-2020-08-02' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: genirq/debugfs: Add missing irqchip flags genirq/affinity: Make affinity setting if activated opt-in irqdomain/treewide: Free firmware node after domain removal
2020-07-31Merge branch 'linus' into locking/core, to resolve conflictIngo Molnar5-18/+25
Conflicts: arch/arm/include/asm/percpu.h As Stephen Rothwell noted, there's a conflict between this commit in locking/core: a21ee6055c30 ("lockdep: Change hardirq{s_enabled,_context} to per-cpu variables") and this fresh upstream commit: aa54ea903abb ("ARM: percpu.h: fix build error") a21ee6055c30 is a simpler solution to the dependency problem and doesn't further increase header hell - so this conflict resolution effectively reverts aa54ea903abb and uses the a21ee6055c30 solution. Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-07-29x86/i8259: Use printk_deferred() to prevent deadlockThomas Gleixner1-1/+1
0day reported a possible circular locking dependency: Chain exists of: &irq_desc_lock_class --> console_owner --> &port_lock_key Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&port_lock_key); lock(console_owner); lock(&port_lock_key); lock(&irq_desc_lock_class); The reason for this is a printk() in the i8259 interrupt chip driver which is invoked with the irq descriptor lock held, which reverses the lock operations vs. printk() from arbitrary contexts. Switch the printk() to printk_deferred() to avoid that. Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/87365abt2v.fsf@nanos.tec.linutronix.de
2020-07-28Merge tag 'v5.8-rc7' into perf/core, to pick up fixesIngo Molnar15-68/+110
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-07-27genirq/affinity: Make affinity setting if activated opt-inThomas Gleixner1-0/+4
John reported that on a RK3288 system the perf per CPU interrupts are all affine to CPU0 and provided the analysis: "It looks like what happens is that because the interrupts are not per-CPU in the hardware, armpmu_request_irq() calls irq_force_affinity() while the interrupt is deactivated and then request_irq() with IRQF_PERCPU | IRQF_NOBALANCING. Now when irq_startup() runs with IRQ_STARTUP_NORMAL, it calls irq_setup_affinity() which returns early because IRQF_PERCPU and IRQF_NOBALANCING are set, leaving the interrupt on its original CPU." This was broken by the recent commit which blocked interrupt affinity setting in hardware before activation of the interrupt. While this works in general, it does not work for this particular case. As contrary to the initial analysis not all interrupt chip drivers implement an activate callback, the safe cure is to make the deferred interrupt affinity setting at activation time opt-in. Implement the necessary core logic and make the two irqchip implementations for which this is required opt-in. In hindsight this would have been the right thing to do, but ... Fixes: baedb87d1b53 ("genirq/affinity: Handle affinity setting on inactive interrupts correctly") Reported-by: John Keeping <john@metanate.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Marc Zyngier <maz@kernel.org> Acked-by: Marc Zyngier <maz@kernel.org> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/87blk4tzgm.fsf@nanos.tec.linutronix.de
2020-07-27x86/cpu: Relocate sync_core() to sync_core.hRicardo Neri2-0/+2
Having sync_core() in processor.h is problematic since it is not possible to check for hardware capabilities via the *cpu_has() family of macros. The latter needs the definitions in processor.h. It also looks more intuitive to relocate the function to sync_core.h. This changeset does not make changes in functionality. Signed-off-by: Ricardo Neri <ricardo.neri-calderon@linux.intel.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Tony Luck <tony.luck@intel.com> Link: https://lore.kernel.org/r/20200727043132.15082-3-ricardo.neri-calderon@linux.intel.com
2020-07-27Merge tag 'v5.8-rc7' into x86/cpu, to pick up fixesIngo Molnar5-18/+25
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-07-26Merge branch 'x86/urgent' into x86/cleanupsIngo Molnar29-170/+202
Refresh the branch for a dependent commit. Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-07-25Merge tag 'v5.8-rc6' into locking/core, to pick up fixesIngo Molnar6-46/+28
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-07-25x86/split_lock: Enable the split lock feature on Sapphire Rapids and Alder ↵Fenghua Yu1-0/+2
Lake CPUs Add Sapphire Rapids and Alder Lake processors to CPU list to enumerate and enable the split lock feature. Signed-off-by: Fenghua Yu <fenghua.yu@intel.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Tony Luck <tony.luck@intel.com> Link: https://lore.kernel.org/r/1595634320-79689-1-git-send-email-fenghua.yu@intel.com
2020-07-25Merge tag 'v5.8-rc6' into x86/cpu, to refresh the branch before adding new ↵Ingo Molnar25-153/+178
commits Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-07-23irqdomain/treewide: Free firmware node after domain removalJon Derrick1-0/+5
Commit 711419e504eb ("irqdomain: Add the missing assignment of domain->fwnode for named fwnode") unintentionally caused a dangling pointer page fault issue on firmware nodes that were freed after IRQ domain allocation. Commit e3beca48a45b fixed that dangling pointer issue by only freeing the firmware node after an IRQ domain allocation failure. That fix no longer frees the firmware node immediately, but leaves the firmware node allocated after the domain is removed. The firmware node must be kept around through irq_domain_remove, but should be freed it afterwards. Add the missing free operations after domain removal where where appropriate. Fixes: e3beca48a45b ("irqdomain/treewide: Keep firmware node unconditionally allocated") Signed-off-by: Jon Derrick <jonathan.derrick@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by: Bjorn Helgaas <bhelgaas@google.com> # drivers/pci Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/1595363169-7157-1-git-send-email-jonathan.derrick@intel.com
2020-07-23x86/dumpstack: Show registers dump with trace's log levelDmitry Safonov1-5/+5
show_trace_log_lvl() provides x86 platform-specific way to unwind backtrace with a given log level. Unfortunately, registers dump(s) are not printed with the same log level - instead, KERN_DEFAULT is always used. Arista's switches uses quite common setup with rsyslog, where only urgent messages goes to console (console_log_level=KERN_ERR), everything else goes into /var/log/ as the console baud-rate often is indecently slow (9600 bps). Backtrace dumps without registers printed have proven to be as useful as morning standups. Furthermore, in order to introduce KERN_UNSUPPRESSED (which I believe is still the most elegant way to fix raciness of sysrq[1]) the log level should be passed down the stack to register dumping functions. Besides, there is a potential use-case for printing traces with KERN_DEBUG level [2] (where registers dump shouldn't appear with higher log level). After all preparations are done, provide log_lvl parameter for show_regs_if_on_stack() and wire up to actual log level used as an argument for show_trace_log_lvl(). [1]: https://lore.kernel.org/lkml/20190528002412.1625-1-dima@arista.com/ [2]: https://lore.kernel.org/linux-doc/20190724170249.9644-1-dima@arista.com/ Signed-off-by: Dmitry Safonov <dima@arista.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Petr Mladek <pmladek@suse.com> Link: https://lkml.kernel.org/r/20200629144847.492794-4-dima@arista.com
2020-07-23x86/dumpstack: Add log_lvl to __show_regs()Dmitry Safonov3-42/+47
show_trace_log_lvl() provides x86 platform-specific way to unwind backtrace with a given log level. Unfortunately, registers dump(s) are not printed with the same log level - instead, KERN_DEFAULT is always used. Arista's switches uses quite common setup with rsyslog, where only urgent messages goes to console (console_log_level=KERN_ERR), everything else goes into /var/log/ as the console baud-rate often is indecently slow (9600 bps). Backtrace dumps without registers printed have proven to be as useful as morning standups. Furthermore, in order to introduce KERN_UNSUPPRESSED (which I believe is still the most elegant way to fix raciness of sysrq[1]) the log level should be passed down the stack to register dumping functions. Besides, there is a potential use-case for printing traces with KERN_DEBUG level [2] (where registers dump shouldn't appear with higher log level). Add log_lvl parameter to __show_regs(). Keep the used log level intact to separate visible change. [1]: https://lore.kernel.org/lkml/20190528002412.1625-1-dima@arista.com/ [2]: https://lore.kernel.org/linux-doc/20190724170249.9644-1-dima@arista.com/ Signed-off-by: Dmitry Safonov <dima@arista.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Petr Mladek <pmladek@suse.com> Link: https://lkml.kernel.org/r/20200629144847.492794-3-dima@arista.com
2020-07-23x86/dumpstack: Add log_lvl to show_iret_regs()Dmitry Safonov2-5/+5
show_trace_log_lvl() provides x86 platform-specific way to unwind backtrace with a given log level. Unfortunately, registers dump(s) are not printed with the same log level - instead, KERN_DEFAULT is always used. Arista's switches uses quite common setup with rsyslog, where only urgent messages goes to console (console_log_level=KERN_ERR), everything else goes into /var/log/ as the console baud-rate often is indecently slow (9600 bps). Backtrace dumps without registers printed have proven to be as useful as morning standups. Furthermore, in order to introduce KERN_UNSUPPRESSED (which I believe is still the most elegant way to fix raciness of sysrq[1]) the log level should be passed down the stack to register dumping functions. Besides, there is a potential use-case for printing traces with KERN_DEBUG level [2] (where registers dump shouldn't appear with higher log level). Add log_lvl parameter to show_iret_regs() as a preparation to add it to __show_regs() and show_regs_if_on_stack(). [1]: https://lore.kernel.org/lkml/20190528002412.1625-1-dima@arista.com/ [2]: https://lore.kernel.org/linux-doc/20190724170249.9644-1-dima@arista.com/ Signed-off-by: Dmitry Safonov <dima@arista.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Petr Mladek <pmladek@suse.com> Link: https://lkml.kernel.org/r/20200629144847.492794-2-dima@arista.com
2020-07-23x86/dumpstack: Dump user space code correctly againThomas Gleixner1-10/+17
H.J. reported that post 5.7 a segfault of a user space task does not longer dump the Code bytes when /proc/sys/debug/exception-trace is enabled. It prints 'Code: Bad RIP value.' instead. This was broken by a recent change which made probe_kernel_read() reject non-kernel addresses. Update show_opcodes() so it retrieves user space opcodes via copy_from_user_nmi(). Fixes: 98a23609b103 ("maccess: always use strict semantics for probe_kernel_read") Reported-by: H.J. Lu <hjl.tools@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/87h7tz306w.fsf@nanos.tec.linutronix.de
2020-07-23x86/stacktrace: Fix reliable check for empty user task stacksJosh Poimboeuf1-5/+0
If a user task's stack is empty, or if it only has user regs, ORC reports it as a reliable empty stack. But arch_stack_walk_reliable() incorrectly treats it as unreliable. That happens because the only success path for user tasks is inside the loop, which only iterates on non-empty stacks. Generally, a user task must end in a user regs frame, but an empty stack is an exception to that rule. Thanks to commit 71c95825289f ("x86/unwind/orc: Fix error handling in __unwind_start()"), unwind_start() now sets state->error appropriately. So now for both ORC and FP unwinders, unwind_done() and !unwind_error() always means the end of the stack was successfully reached. So the success path for kthreads is no longer needed -- it can also be used for empty user tasks. Reported-by: Wang ShaoBo <bobo.shaobowang@huawei.com> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Wang ShaoBo <bobo.shaobowang@huawei.com> Link: https://lkml.kernel.org/r/f136a4e5f019219cbc4f4da33b30c2f44fa65b84.1594994374.git.jpoimboe@redhat.com
2020-07-23x86/unwind/orc: Fix ORC for newly forked tasksJosh Poimboeuf1-2/+6
The ORC unwinder fails to unwind newly forked tasks which haven't yet run on the CPU. It correctly reads the 'ret_from_fork' instruction pointer from the stack, but it incorrectly interprets that value as a call stack address rather than a "signal" one, so the address gets incorrectly decremented in the call to orc_find(), resulting in bad ORC data. Fix it by forcing 'ret_from_fork' frames to be signal frames. Reported-by: Wang ShaoBo <bobo.shaobowang@huawei.com> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Wang ShaoBo <bobo.shaobowang@huawei.com> Link: https://lkml.kernel.org/r/f91a8778dde8aae7f71884b5df2b16d552040441.1594994374.git.jpoimboe@redhat.com
2020-07-22Merge branch 'sched/urgent'Peter Zijlstra6-46/+28
2020-07-22x86, vmlinux.lds: Page-align end of ..page_aligned sectionsJoerg Roedel1-0/+1
On x86-32 the idt_table with 256 entries needs only 2048 bytes. It is page-aligned, but the end of the .bss..page_aligned section is not guaranteed to be page-aligned. As a result, objects from other .bss sections may end up on the same 4k page as the idt_table, and will accidentially get mapped read-only during boot, causing unexpected page-faults when the kernel writes to them. This could be worked around by making the objects in the page aligned sections page sized, but that's wrong. Explicit sections which store only page aligned objects have an implicit guarantee that the object is alone in the page in which it is placed. That works for all objects except the last one. That's inconsistent. Enforcing page sized objects for these sections would wreckage memory sanitizers, because the object becomes artificially larger than it should be and out of bound access becomes legit. Align the end of the .bss..page_aligned and .data..page_aligned section on page-size so all objects places in these sections are guaranteed to have their own page. [ tglx: Amended changelog ] Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Kees Cook <keescook@chromium.org> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20200721093448.10417-1-joro@8bytes.org
2020-07-20copy_xstate_to_kernel: Fix typo which caused GDB regressionKevin Buettner1-1/+1
This fixes a regression encountered while running the gdb.base/corefile.exp test in GDB's test suite. In my testing, the typo prevented the sw_reserved field of struct fxregs_state from being output to the kernel XSAVES area. Thus the correct mask corresponding to XCR0 was not present in the core file for GDB to interrogate, resulting in the following behavior: [kev@f32-1 gdb]$ ./gdb -q testsuite/outputs/gdb.base/corefile/corefile testsuite/outputs/gdb.base/corefile/corefile.core Reading symbols from testsuite/outputs/gdb.base/corefile/corefile... [New LWP 232880] warning: Unexpected size of section `.reg-xstate/232880' in core file. With the typo fixed, the test works again as expected. Signed-off-by: Kevin Buettner <kevinb@redhat.com> Fixes: 9e4636545933 ("copy_xstate_to_kernel(): don't leave parts of destination uninitialized") Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Dave Airlie <airlied@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-07-19Merge tag 'x86-urgent-2020-07-19' of ↵Linus Torvalds3-17/+6
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into master Pull x86 fixes from Thomas Gleixner: "A pile of fixes for x86: - Fix the I/O bitmap invalidation on XEN PV, which was overlooked in the recent ioperm/iopl rework. This caused the TSS and XEN's I/O bitmap to get out of sync. - Use the proper vectors for HYPERV. - Make disabling of stack protector for the entry code work with GCC builds which enable stack protector by default. Removing the option is not sufficient, it needs an explicit -fno-stack-protector to shut it off. - Mark check_user_regs() noinstr as it is called from noinstr code. The missing annotation causes it to be placed in the text section which makes it instrumentable. - Add the missing interrupt disable in exc_alignment_check() - Fixup a XEN_PV build dependency in the 32bit entry code - A few fixes to make the Clang integrated assembler happy - Move EFI stub build to the right place for out of tree builds - Make prepare_exit_to_usermode() static. It's not longer called from ASM code" * tag 'x86-urgent-2020-07-19' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/boot: Don't add the EFI stub to targets x86/entry: Actually disable stack protector x86/ioperm: Fix io bitmap invalidation on Xen PV x86: math-emu: Fix up 'cmp' insn for clang ias x86/entry: Fix vectors to IDTENTRY_SYSVEC for CONFIG_HYPERV x86/entry: Add compatibility with IAS x86/entry/common: Make prepare_exit_to_usermode() static x86/entry: Mark check_user_regs() noinstr x86/traps: Disable interrupts in exc_aligment_check() x86/entry/32: Fix XEN_PV build dependency
2020-07-18x86/ioperm: Fix io bitmap invalidation on Xen PVAndy Lutomirski2-17/+4
tss_invalidate_io_bitmap() wasn't wired up properly through the pvop machinery, so the TSS and Xen's io bitmap would get out of sync whenever disabling a valid io bitmap. Add a new pvop for tss_invalidate_io_bitmap() to fix it. This is XSA-329. Fixes: 22fe5b0439dd ("x86/ioperm: Move TSS bitmap update to exit to user work") Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Juergen Gross <jgross@suse.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/d53075590e1f91c19f8af705059d3ff99424c020.1595030016.git.luto@kernel.org
2020-07-18genirq/affinity: Handle affinity setting on inactive interrupts correctlyThomas Gleixner1-17/+5
Setting interrupt affinity on inactive interrupts is inconsistent when hierarchical irq domains are enabled. The core code should just store the affinity and not call into the irq chip driver for inactive interrupts because the chip drivers may not be in a state to handle such requests. X86 has a hacky workaround for that but all other irq chips have not which causes problems e.g. on GIC V3 ITS. Instead of adding more ugly hacks all over the place, solve the problem in the core code. If the affinity is set on an inactive interrupt then: - Store it in the irq descriptors affinity mask - Update the effective affinity to reflect that so user space has a consistent view - Don't call into the irq chip driver This is the core equivalent of the X86 workaround and works correctly because the affinity setting is established in the irq chip when the interrupt is activated later on. Note, that this is only effective when hierarchical irq domains are enabled by the architecture. Doing it unconditionally would break legacy irq chip implementations. For hierarchial irq domains this works correctly as none of the drivers can have a dependency on affinity setting in inactive state by design. Remove the X86 workaround as it is not longer required. Fixes: 02edee152d6e ("x86/apic/vector: Ignore set_affinity call for inactive interrupts") Reported-by: Ali Saidi <alisaidi@amazon.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Ali Saidi <alisaidi@amazon.com> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20200529015501.15771-1-alisaidi@amazon.com Link: https://lkml.kernel.org/r/877dv2rv25.fsf@nanos.tec.linutronix.de
2020-07-17x86/efi: Remove references to no-longer-used efi_have_uv1_memmap()steve.wahl@hpe.com1-9/+0
In removing UV1 support, efi_have_uv1_memmap is no longer used. Signed-off-by: Steve Wahl <steve.wahl@hpe.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lkml.kernel.org/r/20200713212955.786177105@hpe.com
2020-07-17x86/platform/uv: Remove support for UV1 platform from x2apic_uv_xsteve.wahl@hpe.com1-96/+26
UV1 is not longer supported. Signed-off-by: Steve Wahl <steve.wahl@hpe.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20200713212954.846026992@hpe.com
2020-07-16treewide: Remove uninitialized_var() usageKees Cook1-5/+5
Using uninitialized_var() is dangerous as it papers over real bugs[1] (or can in the future), and suppresses unrelated compiler warnings (e.g. "unused variable"). If the compiler thinks it is uninitialized, either simply initialize the variable or make compiler changes. In preparation for removing[2] the[3] macro[4], remove all remaining needless uses with the following script: git grep '\buninitialized_var\b' | cut -d: -f1 | sort -u | \ xargs perl -pi -e \ 's/\buninitialized_var\(([^\)]+)\)/\1/g; s:\s*/\* (GCC be quiet|to make compiler happy) \*/$::g;' drivers/video/fbdev/riva/riva_hw.c was manually tweaked to avoid pathological white-space. No outstanding warnings were found building allmodconfig with GCC 9.3.0 for x86_64, i386, arm64, arm, powerpc, powerpc64le, s390x, mips, sparc64, alpha, and m68k. [1] https://lore.kernel.org/lkml/20200603174714.192027-1-glider@google.com/ [2] https://lore.kernel.org/lkml/CA+55aFw+Vbj0i=1TGqCR5vQkCzWJ0QxK6CernOU6eedsudAixw@mail.gmail.com/ [3] https://lore.kernel.org/lkml/CA+55aFwgbgqhbp1fkxvRKEpzyR5J8n1vKT1VZdz9knmPuXhOeg@mail.gmail.com/ [4] https://lore.kernel.org/lkml/CA+55aFz2500WfbKXAx8s67wrm9=yVJu65TpLgN_ybYNv0VEOKA@mail.gmail.com/ Reviewed-by: Leon Romanovsky <leonro@mellanox.com> # drivers/infiniband and mlx4/mlx5 Acked-by: Jason Gunthorpe <jgg@mellanox.com> # IB Acked-by: Kalle Valo <kvalo@codeaurora.org> # wireless drivers Reviewed-by: Chao Yu <yuchao0@huawei.com> # erofs Signed-off-by: Kees Cook <keescook@chromium.org>
2020-07-14irqdomain/treewide: Keep firmware node unconditionally allocatedThomas Gleixner3-12/+17
Quite some non OF/ACPI users of irqdomains allocate firmware nodes of type IRQCHIP_FWNODE_NAMED or IRQCHIP_FWNODE_NAMED_ID and free them right after creating the irqdomain. The only purpose of these FW nodes is to convey name information. When this was introduced the core code did not store the pointer to the node in the irqdomain. A recent change stored the firmware node pointer in irqdomain for other reasons and missed to notice that the usage sites which do the alloc_fwnode/create_domain/free_fwnode sequence are broken by this. Storing a dangling pointer is dangerous itself, but in case that the domain is destroyed later on this leads to a double free. Remove the freeing of the firmware node after creating the irqdomain from all affected call sites to cure this. Fixes: 711419e504eb ("irqdomain: Add the missing assignment of domain->fwnode for named fwnode") Reported-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: Marc Zyngier <maz@kernel.org> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/873661qakd.fsf@nanos.tec.linutronix.de
2020-07-10x86/entry: Fix NMI vs IRQ state trackingPeter Zijlstra2-16/+10
While the nmi_enter() users did trace_hardirqs_{off_prepare,on_finish}() there was no matching lockdep_hardirqs_*() calls to complete the picture. Introduce idtentry_{enter,exit}_nmi() to enable proper IRQ state tracking across the NMIs. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Ingo Molnar <mingo@kernel.org> Link: https://lkml.kernel.org/r/20200623083721.216740948@infradead.org
2020-07-09x86/traps: Disable interrupts in exc_aligment_check()Thomas Gleixner1-0/+2
exc_alignment_check() fails to disable interrupts before returning to the entry code. Fixes: ca4c6a9858c2 ("x86/traps: Make interrupt enable/disable symmetric in C code") Reported-by: syzbot+0889df9502bc0f112b31@syzkaller.appspotmail.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Andy Lutomirski <luto@kernel.org> Link: https://lkml.kernel.org/r/20200708192934.076519438@linutronix.de
2020-07-08Merge branch 'sched/urgent'Peter Zijlstra20-107/+150
2020-07-08perf/x86/intel/lbr: Support XSAVES/XRSTORS for LBR context switchKan Liang1-1/+1
In the LBR call stack mode, LBR information is used to reconstruct a call stack. To get the complete call stack, perf has to save/restore all LBR registers during a context switch. Due to a large number of the LBR registers, this process causes a high CPU overhead. To reduce the CPU overhead during a context switch, use the XSAVES/XRSTORS instructions. Every XSAVE area must follow a canonical format: the legacy region, an XSAVE header and the extended region. Although the LBR information is only kept in the extended region, a space for the legacy region and XSAVE header is still required. Add a new dedicated structure for LBR XSAVES support. Before enabling XSAVES support, the size of the LBR state has to be sanity checked, because: - the size of the software structure is calculated from the max number of the LBR depth, which is enumerated by the CPUID leaf for Arch LBR. The size of the LBR state is enumerated by the CPUID leaf for XSAVE support of Arch LBR. If the values from the two CPUID leaves are not consistent, it may trigger a buffer overflow. For example, a hypervisor may unconsciously set inconsistent values for the two emulated CPUID. - unlike other state components, the size of an LBR state depends on the max number of LBRs, which may vary from generation to generation. Expose the function xfeature_size() for the sanity check. The LBR XSAVES support will be disabled if the size of the LBR state enumerated by CPUID doesn't match with the size of the software structure. The XSAVE instruction requires 64-byte alignment for state buffers. A new macro is added to reflect the alignment requirement. A 64-byte aligned kmem_cache is created for architecture LBR. Currently, the structure for each state component is maintained in fpu/types.h. The structure for the new LBR state component should be maintained in the same place. Move structure lbr_entry to fpu/types.h as well for broader sharing. Add dedicated lbr_save/lbr_restore functions for LBR XSAVES support, which invokes the corresponding xstate helpers to XSAVES/XRSTORS LBR information at the context switch when the call stack mode is enabled. Since the XSAVES/XRSTORS instructions will be eventually invoked, the dedicated functions is named with '_xsaves'/'_xrstors' postfix. Signed-off-by: Kan Liang <kan.liang@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Dave Hansen <dave.hansen@intel.com> Link: https://lkml.kernel.org/r/1593780569-62993-23-git-send-email-kan.liang@linux.intel.com
2020-07-08x86/fpu/xstate: Add helpers for LBR dynamic supervisor featureKan Liang1-0/+72
The perf subsystem will only need to save/restore the LBR state. However, the existing helpers save all supported supervisor states to a kernel buffer, which will be unnecessary. Two helpers are introduced to only save/restore requested dynamic supervisor states. The supervisor features in XFEATURE_MASK_SUPERVISOR_SUPPORTED and XFEATURE_MASK_SUPERVISOR_UNSUPPORTED mask cannot be saved/restored using these helpers. The helpers will be used in the following patch. Signed-off-by: Kan Liang <kan.liang@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Dave Hansen <dave.hansen@intel.com> Link: https://lkml.kernel.org/r/1593780569-62993-22-git-send-email-kan.liang@linux.intel.com
2020-07-08x86/fpu/xstate: Support dynamic supervisor feature for LBRKan Liang1-5/+10
Last Branch Records (LBR) registers are used to log taken branches and other control flows. In perf with call stack mode, LBR information is used to reconstruct a call stack. To get the complete call stack, perf has to save/restore all LBR registers during a context switch. Due to the large number of the LBR registers, e.g., the current platform has 96 LBR registers, this process causes a high CPU overhead. To reduce the CPU overhead during a context switch, an LBR state component that contains all the LBR related registers is introduced in hardware. All LBR registers can be saved/restored together using one XSAVES/XRSTORS instruction. However, the kernel should not save/restore the LBR state component at each context switch, like other state components, because of the following unique features of LBR: - The LBR state component only contains valuable information when LBR is enabled in the perf subsystem, but for most of the time, LBR is disabled. - The size of the LBR state component is huge. For the current platform, it's 808 bytes. If the kernel saves/restores the LBR state at each context switch, for most of the time, it is just a waste of space and cycles. To efficiently support the LBR state component, it is desired to have: - only context-switch the LBR when the LBR feature is enabled in perf. - only allocate an LBR-specific XSAVE buffer on demand. (Besides the LBR state, a legacy region and an XSAVE header have to be included in the buffer as well. There is a total of (808+576) byte overhead for the LBR-specific XSAVE buffer. The overhead only happens when the perf is actively using LBRs. There is still a space-saving, on average, when it replaces the constant 808 bytes of overhead for every task, all the time on the systems that support architectural LBR.) - be able to use XSAVES/XRSTORS for accessing LBR at run time. However, the IA32_XSS should not be adjusted at run time. (The XCR0 | IA32_XSS are used to determine the requested-feature bitmap (RFBM) of XSAVES.) A solution, called dynamic supervisor feature, is introduced to address this issue, which - does not allocate a buffer in each task->fpu; - does not save/restore a state component at each context switch; - sets the bit corresponding to the dynamic supervisor feature in IA32_XSS at boot time, and avoids setting it at run time. - dynamically allocates a specific buffer for a state component on demand, e.g. only allocates LBR-specific XSAVE buffer when LBR is enabled in perf. (Note: The buffer has to include the LBR state component, a legacy region and a XSAVE header space.) (Implemented in a later patch) - saves/restores a state component on demand, e.g. manually invokes the XSAVES/XRSTORS instruction to save/restore the LBR state to/from the buffer when perf is active and a call stack is required. (Implemented in a later patch) A new mask XFEATURE_MASK_DYNAMIC and a helper xfeatures_mask_dynamic() are introduced to indicate the dynamic supervisor feature. For the systems which support the Architecture LBR, LBR is the only dynamic supervisor feature for now. For the previous systems, there is no dynamic supervisor feature available. Signed-off-by: Kan Liang <kan.liang@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Dave Hansen <dave.hansen@intel.com> Link: https://lkml.kernel.org/r/1593780569-62993-21-git-send-email-kan.liang@linux.intel.com
2020-07-08x86/fpu: Use proper mask to replace full instruction maskKan Liang1-0/+39
When saving xstate to a kernel/user XSAVE area with the XSAVE family of instructions, the current code applies the 'full' instruction mask (-1), which tries to XSAVE all possible features. This method relies on hardware to trim 'all possible' down to what is enabled in the hardware. The code works well for now. However, there will be a problem, if some features are enabled in hardware, but are not suitable to be saved into all kernel XSAVE buffers, like task->fpu, due to performance consideration. One such example is the Last Branch Records (LBR) state. The LBR state only contains valuable information when LBR is explicitly enabled by the perf subsystem, and the size of an LBR state is large (808 bytes for now). To avoid both CPU overhead and space overhead at each context switch, the LBR state should not be saved into task->fpu like other state components. It should be saved/restored on demand when LBR is enabled in the perf subsystem. Current copy_xregs_to_* will trigger a buffer overflow for such cases. Three sites use the '-1' instruction mask which must be updated. Two are saving/restoring the xstate to/from a kernel-allocated XSAVE buffer and can use 'xfeatures_mask_all', which will save/restore all of the features present in a normal task FPU buffer. The last one saves the register state directly to a user buffer. It could also use 'xfeatures_mask_all'. Just as it was with the '-1' argument, any supervisor states in the mask will be filtered out by the hardware and not saved to the buffer. But, to be more explicit about what is expected to be saved, use xfeatures_mask_user() for the instruction mask. KVM includes the header file fpu/internal.h. To avoid 'undefined xfeatures_mask_all' compiling issue, move copy_fpregs_to_fpstate() to fpu/core.c and export it, because: - The xfeatures_mask_all is indirectly used via copy_fpregs_to_fpstate() by KVM. The function which is directly used by other modules should be exported. - The copy_fpregs_to_fpstate() is a function, while xfeatures_mask_all is a variable for the "internal" FPU state. It's safer to export a function than a variable, which may be implicitly changed by others. - The copy_fpregs_to_fpstate() is a big function with many checks. The removal of the inline keyword should not impact the performance. Signed-off-by: Kan Liang <kan.liang@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Dave Hansen <dave.hansen@intel.com> Link: https://lkml.kernel.org/r/1593780569-62993-20-git-send-email-kan.liang@linux.intel.com
2020-07-06x86/entry: Rename idtentry_enter/exit_cond_rcu() to idtentry_enter/exit()Andy Lutomirski2-6/+6
They were originally called _cond_rcu because they were special versions with conditional RCU handling. Now they're the standard entry and exit path, so the _cond_rcu part is just confusing. Drop it. Also change the signature to make them more extensible and more foolproof. No functional change -- it's pure refactoring. Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/247fc67685263e0b673e1d7f808182d28ff80359.1593795633.git.luto@kernel.org
2020-07-05x86/ldt: use "pr_info_once()" instead of open-coding it badlyLinus Torvalds1-10/+1
Using a mutex for "print this warning only once" is so overdesigned as to be actively offensive to my sensitive stomach. Just use "pr_info_once()" that already does this, although in a (harmlessly) racy manner that can in theory cause the message to be printed twice if more than one CPU races on that "is this the first time" test. [ If somebody really cares about that harmless data race (which sounds very unlikely indeed), that person can trivially fix printk_once() by using a simple atomic access, preferably with an optimistic non-atomic test first before even bothering to treat the pointless "make sure it is _really_ just once" case. A mutex is most definitely never the right primitive to use for something like this. ] Yes, this is a small and meaningless detail in a code path that hardly matters. But let's keep some code quality standards here, and not accept outrageously bad code. Link: https://lore.kernel.org/lkml/CAHk-=wgV9toS7GU3KmNpj8hCS9SeF+A0voHS8F275_mgLhL4Lw@mail.gmail.com/ Cc: Andy Lutomirski <luto@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-07-05Merge tag 'x86-urgent-2020-07-05' of ↵Linus Torvalds5-4/+66
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Thomas Gleixner: "A series of fixes for x86: - Reset MXCSR in kernel_fpu_begin() to prevent using a stale user space value. - Prevent writing MSR_TEST_CTRL on CPUs which are not explicitly whitelisted for split lock detection. Some CPUs which do not support it crash even when the MSR is written to 0 which is the default value. - Fix the XEN PV fallout of the entry code rework - Fix the 32bit fallout of the entry code rework - Add more selftests to ensure that these entry problems don't come back. - Disable 16 bit segments on XEN PV. It's not supported because XEN PV does not implement ESPFIX64" * tag 'x86-urgent-2020-07-05' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/ldt: Disable 16-bit segments on Xen PV x86/entry/32: Fix #MC and #DB wiring on x86_32 x86/entry/xen: Route #DB correctly on Xen PV x86/entry, selftests: Further improve user entry sanity checks x86/entry/compat: Clear RAX high bits on Xen PV SYSENTER selftests/x86: Consolidate and fix get/set_eflags() helpers selftests/x86/syscall_nt: Clear weird flags after each test selftests/x86/syscall_nt: Add more flag combinations x86/entry/64/compat: Fix Xen PV SYSENTER frame setup x86/entry: Move SYSENTER's regs->sp and regs->flags fixups into C x86/entry: Assert that syscalls are on the right stack x86/split_lock: Don't write MSR_TEST_CTRL on CPUs that aren't whitelisted x86/fpu: Reset MXCSR to default in kernel_fpu_begin()
generated by cgit v1.2.3 (git 2.39.0) at 2024-11-26 05:13:58 +0300