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2020-06-12x86/entry: Make NMI use IDTENTRY_RAWThomas Gleixner1-1/+1
For no reason other than beginning brainmelt, IDTENTRY_NMI was mapped to IDTENTRY_IST. This is not a problem on 64bit because the IST default entry point maps to IDTENTRY_RAW which does not any entry handling. The surplus function declaration for the noist C entry point is unused and as there is no ASM code emitted for NMI this went unnoticed. On 32bit IDTENTRY_IST maps to a regular IDTENTRY which does the normal entry handling. That is clearly the wrong thing to do for NMI. Map it to IDTENTRY_RAW to unbreak it. The IDTENTRY_NMI mapping needs to stay to avoid emitting ASM code. Fixes: 6271fef00b34 ("x86/entry: Convert NMI to IDTENTRY_NMI") Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org> Debugged-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/CA+G9fYvF3cyrY+-iw_SZtpN-i2qA2BruHg4M=QYECU2-dNdsMw@mail.gmail.com
2020-06-12x86/entry: Treat BUG/WARN as NMI-like entriesAndy Lutomirski1-26/+38
BUG/WARN are cleverly optimized using UD2 to handle the BUG/WARN out of line in an exception fixup. But if BUG or WARN is issued in a funny RCU context, then the idtentry_enter...() path might helpfully WARN that the RCU context is invalid, which results in infinite recursion. Split the BUG/WARN handling into an nmi_enter()/nmi_exit() path in exc_invalid_op() to increase the chance to survive the experience. [ tglx: Make the declaration match the implementation ] Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/f8fe40e0088749734b4435b554f73eee53dcf7a8.1591932307.git.luto@kernel.org
2020-06-12Merge tag 'locking-kcsan-2020-06-11' of ↵Linus Torvalds3-1/+16
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull the Kernel Concurrency Sanitizer from Thomas Gleixner: "The Kernel Concurrency Sanitizer (KCSAN) is a dynamic race detector, which relies on compile-time instrumentation, and uses a watchpoint-based sampling approach to detect races. The feature was under development for quite some time and has already found legitimate bugs. Unfortunately it comes with a limitation, which was only understood late in the development cycle: It requires an up to date CLANG-11 compiler CLANG-11 is not yet released (scheduled for June), but it's the only compiler today which handles the kernel requirements and especially the annotations of functions to exclude them from KCSAN instrumentation correctly. These annotations really need to work so that low level entry code and especially int3 text poke handling can be completely isolated. A detailed discussion of the requirements and compiler issues can be found here: https://lore.kernel.org/lkml/CANpmjNMTsY_8241bS7=XAfqvZHFLrVEkv_uM4aDUWE_kh3Rvbw@mail.gmail.com/ We came to the conclusion that trying to work around compiler limitations and bugs again would end up in a major trainwreck, so requiring a working compiler seemed to be the best choice. For Continous Integration purposes the compiler restriction is manageable and that's where most xxSAN reports come from. For a change this limitation might make GCC people actually look at their bugs. Some issues with CSAN in GCC are 7 years old and one has been 'fixed' 3 years ago with a half baken solution which 'solved' the reported issue but not the underlying problem. The KCSAN developers also ponder to use a GCC plugin to become independent, but that's not something which will show up in a few days. Blocking KCSAN until wide spread compiler support is available is not a really good alternative because the continuous growth of lockless optimizations in the kernel demands proper tooling support" * tag 'locking-kcsan-2020-06-11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (76 commits) compiler_types.h, kasan: Use __SANITIZE_ADDRESS__ instead of CONFIG_KASAN to decide inlining compiler.h: Move function attributes to compiler_types.h compiler.h: Avoid nested statement expression in data_race() compiler.h: Remove data_race() and unnecessary checks from {READ,WRITE}_ONCE() kcsan: Update Documentation to change supported compilers kcsan: Remove 'noinline' from __no_kcsan_or_inline kcsan: Pass option tsan-instrument-read-before-write to Clang kcsan: Support distinguishing volatile accesses kcsan: Restrict supported compilers kcsan: Avoid inserting __tsan_func_entry/exit if possible ubsan, kcsan: Don't combine sanitizer with kcov on clang objtool, kcsan: Add kcsan_disable_current() and kcsan_enable_current_nowarn() kcsan: Add __kcsan_{enable,disable}_current() variants checkpatch: Warn about data_race() without comment kcsan: Use GFP_ATOMIC under spin lock Improve KCSAN documentation a bit kcsan: Make reporting aware of KCSAN tests kcsan: Fix function matching in report kcsan: Change data_race() to no longer require marking racing accesses kcsan: Move kcsan_{disable,enable}_current() to kcsan-checks.h ...
2020-06-12Merge tag 'x86-urgent-2020-06-11' of ↵Linus Torvalds7-63/+78
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull more x86 updates from Thomas Gleixner: "A set of fixes and updates for x86: - Unbreak paravirt VDSO clocks. While the VDSO code was moved into lib for sharing a subtle check for the validity of paravirt clocks got replaced. While the replacement works perfectly fine for bare metal as the update of the VDSO clock mode is synchronous, it fails for paravirt clocks because the hypervisor can invalidate them asynchronously. Bring it back as an optional function so it does not inflict this on architectures which are free of PV damage. - Fix the jiffies to jiffies64 mapping on 64bit so it does not trigger an ODR violation on newer compilers - Three fixes for the SSBD and *IB* speculation mitigation maze to ensure consistency, not disabling of some *IB* variants wrongly and to prevent a rogue cross process shutdown of SSBD. All marked for stable. - Add yet more CPU models to the splitlock detection capable list !@#%$! - Bring the pr_info() back which tells that TSC deadline timer is enabled. - Reboot quirk for MacBook6,1" * tag 'x86-urgent-2020-06-11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/vdso: Unbreak paravirt VDSO clocks lib/vdso: Provide sanity check for cycles (again) clocksource: Remove obsolete ifdef x86_64: Fix jiffies ODR violation x86/speculation: PR_SPEC_FORCE_DISABLE enforcement for indirect branches. x86/speculation: Prevent rogue cross-process SSBD shutdown x86/speculation: Avoid force-disabling IBPB based on STIBP and enhanced IBRS. x86/cpu: Add Sapphire Rapids CPU model number x86/split_lock: Add Icelake microserver and Tigerlake CPU models x86/apic: Make TSC deadline timer detection message visible x86/reboot/quirks: Add MacBook6,1 reboot quirk
2020-06-11Rebase locking/kcsan to locking/urgentThomas Gleixner3-1/+16
Merge the state of the locking kcsan branch before the read/write_once() and the atomics modifications got merged. Squash the fallout of the rebase on top of the read/write once and atomic fallback work into the merge. The history of the original branch is preserved in tag locking-kcsan-2020-06-02. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2020-06-11x86/mce/dev-mcelog: Fix -Wstringop-truncation warning about strncpy()Tony Luck1-1/+1
The kbuild test robot reported this warning: arch/x86/kernel/cpu/mce/dev-mcelog.c: In function 'dev_mcelog_init_device': arch/x86/kernel/cpu/mce/dev-mcelog.c:346:2: warning: 'strncpy' output \ truncated before terminating nul copying 12 bytes from a string of the \ same length [-Wstringop-truncation] This is accurate, but I don't care that the trailing NUL character isn't copied. The string being copied is just a magic number signature so that crash dump tools can be sure they are decoding the right blob of memory. Use memcpy() instead of strncpy(). Fixes: d8ecca4043f2 ("x86/mce/dev-mcelog: Dynamically allocate space for machine check records") Reported-by: kbuild test robot <lkp@intel.com> Signed-off-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20200527182808.27737-1-tony.luck@intel.com
2020-06-11x86/{mce,mm}: Unmap the entire page if the whole page is affected and poisonedTony Luck1-4/+14
An interesting thing happened when a guest Linux instance took a machine check. The VMM unmapped the bad page from guest physical space and passed the machine check to the guest. Linux took all the normal actions to offline the page from the process that was using it. But then guest Linux crashed because it said there was a second machine check inside the kernel with this stack trace: do_memory_failure set_mce_nospec set_memory_uc _set_memory_uc change_page_attr_set_clr cpa_flush clflush_cache_range_opt This was odd, because a CLFLUSH instruction shouldn't raise a machine check (it isn't consuming the data). Further investigation showed that the VMM had passed in another machine check because is appeared that the guest was accessing the bad page. Fix is to check the scope of the poison by checking the MCi_MISC register. If the entire page is affected, then unmap the page. If only part of the page is affected, then mark the page as uncacheable. This assumes that VMMs will do the logical thing and pass in the "whole page scope" via the MCi_MISC register (since they unmapped the entire page). [ bp: Adjust to x86/entry changes. ] Fixes: 284ce4011ba6 ("x86/memory_failure: Introduce {set, clear}_mce_nospec()") Reported-by: Jue Wang <juew@google.com> Signed-off-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Jue Wang <juew@google.com> Cc: <stable@vger.kernel.org> Link: https://lkml.kernel.org/r/20200520163546.GA7977@agluck-desk2.amr.corp.intel.com
2020-06-11Merge branch 'x86/entry' into ras/coreThomas Gleixner100-1523/+2048
to fixup conflicts in arch/x86/kernel/cpu/mce/core.c so MCE specific follow up patches can be applied without creating a horrible merge conflict afterwards.
2020-06-11x86/entry: Unbreak __irqentry_text_start/end magicThomas Gleixner4-18/+2
The entry rework moved interrupt entry code from the irqentry to the noinstr section which made the irqentry section empty. This breaks boundary checks which rely on the __irqentry_text_start/end markers to find out whether a function in a stack trace is interrupt/exception entry code. This affects the function graph tracer and filter_irq_stacks(). As the IDT entry points are all sequentialy emitted this is rather simple to unbreak by injecting __irqentry_text_start/end as global labels. To make this work correctly: - Remove the IRQENTRY_TEXT section from the x86 linker script - Define __irqentry so it breaks the build if it's used - Adjust the entry mirroring in PTI - Remove the redundant kprobes and unwinder bound checks Reported-by: Qian Cai <cai@lca.pw> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2020-06-11x86/entry: Re-order #DB handler to avoid *SAN instrumentationPeter Zijlstra1-28/+27
vmlinux.o: warning: objtool: exc_debug()+0xbb: call to clear_ti_thread_flag.constprop.0() leaves .noinstr.text section vmlinux.o: warning: objtool: noist_exc_debug()+0x55: call to clear_ti_thread_flag.constprop.0() leaves .noinstr.text section Rework things so that handle_debug() looses the noinstr and move the clear_thread_flag() into that. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20200603114052.127756554@infradead.org
2020-06-11x86/idt: Consolidate idt functionalityThomas Gleixner1-25/+38
- Move load_current_idt() out of line and replace the hideous comment with a lockdep assert. This allows to make idt_table and idt_descr static. - Mark idt_table read only after the IDT initialization is complete. - Shuffle code around to consolidate the #ifdef sections into one. - Adapt the F00F bug code. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20200528145523.084915381@linutronix.de
2020-06-11x86/idt: Cleanup trap_init()Thomas Gleixner2-9/+18
No point in having all the IDT cruft in trap_init(). Move it into the IDT code and fixup the comments. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20200528145522.992376498@linutronix.de
2020-06-11x86/idt: Use proper constants for table sizeThomas Gleixner1-1/+2
Use the actual struct size to calculate the IDT table size instead of hardcoded values. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20200528145522.898591501@linutronix.de
2020-06-11x86/idt: Add comments about early #PF handlingThomas Gleixner1-2/+8
The difference between 32 and 64 bit vs. early #PF handling is not documented. Replace the FIXME at idt_setup_early_pf() with proper comments. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20200528145522.807135882@linutronix.de
2020-06-11x86/idt: Mark init only functions __initThomas Gleixner1-2/+2
Since 8175cfbbbfcb ("x86/idt: Remove update_intr_gate()") set_intr_gate() and idt_setup_from_table() are only called from __init functions. Mark them as well. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20200528145522.715816477@linutronix.de
2020-06-11x86/entry: Rename trace_hardirqs_off_prepare()Peter Zijlstra3-4/+4
The typical pattern for trace_hardirqs_off_prepare() is: ENTRY lockdep_hardirqs_off(); // because hardware ... do entry magic instrumentation_begin(); trace_hardirqs_off_prepare(); ... do actual work trace_hardirqs_on_prepare(); lockdep_hardirqs_on_prepare(); instrumentation_end(); ... do exit magic lockdep_hardirqs_on(); which shows that it's named wrong, rename it to trace_hardirqs_off_finish(), as it concludes the hardirq_off transition. Also, given that the above is the only correct order, make the traditional all-in-one trace_hardirqs_off() follow suit. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20200529213321.415774872@infradead.org
2020-06-11x86/entry: Remove DBn stacksPeter Zijlstra2-8/+2
Both #DB itself, as all other IST users (NMI, #MC) now clear DR7 on entry. Combined with not allowing breakpoints on entry/noinstr/NOKPROBE text and no single step (EFLAGS.TF) inside the #DB handler should guarantee no nested #DB. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20200529213321.303027161@infradead.org
2020-06-11x86/entry: Remove debug IDT frobbingPeter Zijlstra3-56/+0
This is all unused now. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20200529213321.245019500@infradead.org
2020-06-11x86/entry: Optimize local_db_save() for virtPeter Zijlstra1-4/+22
Because DRn access is 'difficult' with virt; but the DR7 read is cheaper than a cacheline miss on native, add a virt specific fast path to local_db_save(), such that when breakpoints are not in use to avoid touching DRn entirely. Suggested-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20200529213321.187833200@infradead.org
2020-06-11x86/entry, mce: Disallow #DB during #MCPeter Zijlstra1-0/+12
#MC is fragile as heck, don't tempt fate. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20200529213321.131187767@infradead.org
2020-06-11x86/entry, nmi: Disable #DBPeter Zijlstra1-52/+3
Instead of playing stupid games with IST stacks, fully disallow #DB during NMIs. There is absolutely no reason to allow them, and killing this saves a heap of trouble. #DB is already forbidden on noinstr and CEA, so there can't be a #DB before this. Disabling it right after nmi_enter() ensures that the full NMI code is protected. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20200529213321.069223695@infradead.org
2020-06-11x86/entry: Introduce local_db_{save,restore}()Peter Zijlstra1-16/+2
In order to allow other exceptions than #DB to disable breakpoints, provide common helpers. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20200529213321.012060983@infradead.org
2020-06-11x86/hw_breakpoint: Prevent data breakpoints on user_pcid_flush_maskLai Jiangshan1-0/+11
The per-CPU user_pcid_flush_mask is used in the low level entry code. A data breakpoint can cause #DB recursion. Protect the full cpu_tlbstate structure for simplicity. Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20200526014221.2119-5-laijs@linux.alibaba.com Link: https://lkml.kernel.org/r/20200529213320.955117574@infradead.org
2020-06-11x86/hw_breakpoint: Prevent data breakpoints on per_cpu cpu_tss_rwLai Jiangshan1-0/+9
cpu_tss_rw is not directly referenced by hardware, but cpu_tss_rw is accessed in CPU entry code, especially when #DB shifts its stacks. If a data breakpoint would be set on cpu_tss_rw.x86_tss.ist[IST_INDEX_DB], it would cause recursive #DB ending up in a double fault. Add it to the list of protected items. Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20200526014221.2119-4-laijs@linux.alibaba.com Link: https://lkml.kernel.org/r/20200529213320.897976479@infradead.org
2020-06-11x86/hw_breakpoint: Prevent data breakpoints on direct GDTLai Jiangshan1-8/+22
A data breakpoint on the GDT can be fatal and must be avoided. The GDT in the CPU entry area is already protected, but not the direct GDT. Add the necessary protection. Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20200526014221.2119-3-laijs@linux.alibaba.com Link: https://lkml.kernel.org/r/20200529213320.840953950@infradead.org
2020-06-11x86/hw_breakpoint: Add within_area() to check data breakpointsLai Jiangshan1-2/+11
Add a within_area() helper to checking whether the data breakpoints overlap with cpu_entry_area. It will be used to completely prevent data breakpoints on GDT, IDT, or TSS. Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20200526014221.2119-2-laijs@linux.alibaba.com Link: https://lkml.kernel.org/r/20200529213320.784524504@infradead.org
2020-06-11x86/entry: Move paranoid irq tracing out of ASM codeThomas Gleixner3-0/+17
The last step to remove the irq tracing cruft from ASM. Ignore #DF as the maschine is going to die anyway. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Andy Lutomirski <luto@kernel.org> Link: https://lore.kernel.org/r/20200521202120.414043330@linutronix.de
2020-06-11x86/entry: Remove the apic/BUILD interrupt leftoversThomas Gleixner1-3/+4
Remove all the code which was there to emit the system vector stubs. All users are gone. Move the now unused GET_CR2_INTO macro muck to head_64.S where the last user is. Fixup the eye hurting comment there while at it. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Andy Lutomirski <luto@kernel.org> Link: https://lore.kernel.org/r/20200521202119.927433002@linutronix.de
2020-06-11x86/entry: Convert reschedule interrupt to IDTENTRY_SYSVEC_SIMPLEThomas Gleixner3-33/+5
The scheduler IPI does not need the full interrupt entry handling logic when the entry is from kernel mode. Use IDTENTRY_SYSVEC_SIMPLE and spare all the overhead. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Andy Lutomirski <luto@kernel.org> Link: https://lore.kernel.org/r/20200521202119.835425642@linutronix.de
2020-06-11x86/entry: Convert various hypervisor vectors to IDTENTRY_SYSVECThomas Gleixner2-17/+14
Convert various hypervisor vectors to IDTENTRY_SYSVEC: - Implement the C entry point with DEFINE_IDTENTRY_SYSVEC - Emit the ASM stub with DECLARE_IDTENTRY_SYSVEC - Remove the ASM idtentries in 64-bit - Remove the BUILD_INTERRUPT entries in 32-bit - Remove the old prototypes No functional change. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Andy Lutomirski <luto@kernel.org> Reviewed-by: Wei Liu <wei.liu@kernel.org> Link: https://lore.kernel.org/r/20200521202119.647997594@linutronix.de
2020-06-11x86/entry: Convert KVM vectors to IDTENTRY_SYSVEC*Thomas Gleixner2-21/+9
Convert KVM specific system vectors to IDTENTRY_SYSVEC*: The two empty stub handlers which only increment the stats counter do no need to run on the interrupt stack. Use IDTENTRY_SYSVEC_SIMPLE for them. The wakeup handler does more work and runs on the interrupt stack. None of these handlers need to save and restore the irq_regs pointer. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Paolo Bonzini <pbonzini@redhat.com> Acked-by: Andy Lutomirski <luto@kernel.org> Link: https://lore.kernel.org/r/20200521202119.555715519@linutronix.de
2020-06-11x86/entry: Convert various system vectorsThomas Gleixner5-26/+23
Convert various system vectors to IDTENTRY_SYSVEC: - Implement the C entry point with DEFINE_IDTENTRY_SYSVEC - Emit the ASM stub with DECLARE_IDTENTRY_SYSVEC - Remove the ASM idtentries in 64-bit - Remove the BUILD_INTERRUPT entries in 32-bit - Remove the old prototypes No functional change. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Andy Lutomirski <luto@kernel.org> Link: https://lore.kernel.org/r/20200521202119.464812973@linutronix.de
2020-06-11x86/entry: Convert SMP system vectors to IDTENTRY_SYSVECThomas Gleixner3-19/+14
Convert SMP system vectors to IDTENTRY_SYSVEC: - Implement the C entry point with DEFINE_IDTENTRY_SYSVEC - Emit the ASM stub with DECLARE_IDTENTRY_SYSVEC - Remove the ASM idtentries in 64-bit - Remove the BUILD_INTERRUPT entries in 32-bit - Remove the old prototypes No functional change. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Andy Lutomirski <luto@kernel.org> Link: https://lore.kernel.org/r/20200521202119.372234635@linutronix.de
2020-06-11x86/entry: Convert APIC interrupts to IDTENTRY_SYSVECThomas Gleixner3-25/+11
Convert APIC interrupts to IDTENTRY_SYSVEC: - Implement the C entry point with DEFINE_IDTENTRY_SYSVEC - Emit the ASM stub with DECLARE_IDTENTRY_SYSVEC - Remove the ASM idtentries in 64-bit - Remove the BUILD_INTERRUPT entries in 32-bit - Remove the old prototypes No functional change. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Andy Lutomirski <luto@kernel.org> Link: https://lore.kernel.org/r/20200521202119.280728850@linutronix.de
2020-06-11x86/entry: Use idtentry for interruptsThomas Gleixner3-36/+17
Replace the extra interrupt handling code and reuse the existing idtentry machinery. This moves the irq stack switching on 64-bit from ASM to C code; 32-bit already does the stack switching in C. This requires to remove HAVE_IRQ_EXIT_ON_IRQ_STACK as the stack switch is not longer in the low level entry code. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Andy Lutomirski <luto@kernel.org> Link: https://lore.kernel.org/r/20200521202119.078690991@linutronix.de
2020-06-11x86/irq: Rework handle_irq() for 64-bitThomas Gleixner2-2/+11
To consolidate the interrupt entry/exit code vs. the other exceptions make handle_irq() an inline and handle both 64-bit and 32-bit mode. Preparatory change to move irq stack switching for 64-bit to C which allows to consolidate the entry exit handling by reusing the idtentry machinery both in ASM and C. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Andy Lutomirski <luto@kernel.org> Link: https://lore.kernel.org/r/20200521202118.889972748@linutronix.de
2020-06-11x86/irq: Convey vector as argument and not in ptregsThomas Gleixner3-12/+35
Device interrupts which go through do_IRQ() or the spurious interrupt handler have their separate entry code on 64 bit for no good reason. Both 32 and 64 bit transport the vector number through ORIG_[RE]AX in pt_regs. Further the vector number is forced to fit into an u8 and is complemented and offset by 0x80 so it's in the signed character range. Otherwise GAS would expand the pushq to a 5 byte instruction for any vector > 0x7F. Treat the vector number like an error code and hand it to the C function as argument. This allows to get rid of the extra entry code in a later step. Simplify the error code push magic by implementing the pushq imm8 via a '.byte 0x6a, vector' sequence so GAS is not able to screw it up. As the pushq imm8 is sign extending the resulting error code needs to be truncated to 8 bits in C code. Originally-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Andy Lutomirski <luto@kernel.org> Link: https://lore.kernel.org/r/20200521202118.796915981@linutronix.de
2020-06-11x86/irq: Use generic irq_regs implementationThomas Gleixner1-3/+0
The only difference is the name of the per-CPU variable: irq_regs vs. __irq_regs, but the accessor functions are identical. Remove the pointless copy and use the generic variant. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Andy Lutomirski <luto@kernel.org> Link: https://lore.kernel.org/r/20200521202118.704169051@linutronix.de
2020-06-11x86/entry: Switch page fault exception to IDTENTRY_RAWThomas Gleixner2-8/+11
Convert page fault exceptions to IDTENTRY_RAW: - Implement the C entry point with DEFINE_IDTENTRY_RAW - Add the CR2 read into the exception handler - Add the idtentry_enter/exit_cond_rcu() invocations in in the regular page fault handler and in the async PF part. - Emit the ASM stub with DECLARE_IDTENTRY_RAW - Remove the ASM idtentry in 64-bit - Remove the CR2 read from 64-bit - Remove the open coded ASM entry code in 32-bit - Fix up the XEN/PV code - Remove the old prototypes No functional change. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Andy Lutomirski <luto@kernel.org> Link: https://lore.kernel.org/r/20200521202118.238455120@linutronix.de
2020-06-11x86/entry/64: Move do_softirq_own_stack() to CThomas Gleixner1-0/+6
The first step to get rid of the ENTER/LEAVE_IRQ_STACK ASM macro maze. Use the new C code helpers to move do_softirq_own_stack() out of ASM code. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Andy Lutomirski <luto@kernel.org> Link: https://lore.kernel.org/r/20200521202117.870911120@linutronix.de
2020-06-11x86/idtentry: Switch to conditional RCU handlingThomas Gleixner2-7/+7
Switch all idtentry_enter/exit() users over to the new conditional RCU handling scheme and make the user mode entries in #DB, #INT3 and #MCE use the user mode idtentry functions. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Andy Lutomirski <luto@kernel.org> Link: https://lore.kernel.org/r/20200521202117.382387286@linutronix.de
2020-06-11x86/entry: Fix allnoconfig build warningIngo Molnar1-1/+1
The following commit: 095b7a3e7745 ("x86/entry: Convert double fault exception to IDTENTRY_DF") introduced a new build warning on 64-bit allnoconfig kernels, that have CONFIG_VMAP_STACK disabled: arch/x86/kernel/traps.c:332:16: warning: unused variable ‘address’ [-Wunused-variable] This variable is only used if CONFIG_VMAP_STACK is defined, so make it dependent on that, not CONFIG_X86_64. Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Alexandre Chartre <alexandre.chartre@oracle.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de>
2020-06-11x86/entry: Convert double fault exception to IDTENTRY_DFThomas Gleixner3-11/+20
Convert #DF to IDTENTRY_DF - Implement the C entry point with DEFINE_IDTENTRY_DF - Emit the ASM stub with DECLARE_IDTENTRY_DF on 64bit - Remove the ASM idtentry in 64bit - Adjust the 32bit shim code - Fixup the XEN/PV code - Remove the old prototypes No functional change. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Andy Lutomirski <luto@kernel.org> Link: https://lkml.kernel.org/r/20200505135315.583415264@linutronix.de
2020-06-11x86/mce: Address objtools noinstr complaintsThomas Gleixner3-7/+21
Mark the relevant functions noinstr, use the plain non-instrumented MSR accessors. The only odd part is the instrumentation_begin()/end() pair around the indirect machine_check_vector() call as objtool can't figure that out. The possible invoked functions are annotated correctly. Also use notrace variant of nmi_enter/exit(). If MCEs happen then hardware latency tracing is the least of the worries. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Andy Lutomirski <luto@kernel.org> Link: https://lkml.kernel.org/r/20200505135315.476734898@linutronix.de
2020-06-11x86/traps: Address objtool noinstr complaints in #DBThomas Gleixner1-2/+8
The functions invoked from handle_debug() can be instrumented. Tell objtool about it. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Andy Lutomirski <luto@kernel.org> Link: https://lkml.kernel.org/r/20200505135315.380927730@linutronix.de
2020-06-11x86/traps: Restructure #DB handlingThomas Gleixner1-34/+35
Now that there are separate entry points, move the kernel/user_mode specifc checks into the entry functions so the common handling code does not need the extra mode checks. Make the code more readable while at it. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Andy Lutomirski <luto@kernel.org> Link: https://lkml.kernel.org/r/20200505135315.283276272@linutronix.de
2020-06-11x86/entry: Implement user mode C entry points for #DB and #MCEThomas Gleixner2-23/+87
The MCE entry point uses the same mechanism as the IST entry point for now. For #DB split the inner workings and just keep the nmi_enter/exit() magic in the IST variant. Fixup the ASM code to emit the proper noist_##cfunc call. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Andy Lutomirski <luto@kernel.org> Link: https://lkml.kernel.org/r/20200505135315.177564104@linutronix.de
2020-06-11x86/entry: Convert Debug exception to IDTENTRY_DBThomas Gleixner2-12/+17
Convert #DB to IDTENTRY_ERRORCODE: - Implement the C entry point with DEFINE_IDTENTRY_DB - Emit the ASM stub with DECLARE_IDTENTRY - Remove the ASM idtentry in 64bit - Remove the open coded ASM entry code in 32bit - Fixup the XEN/PV code - Remove the old prototypes No functional change. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Andy Lutomirski <luto@kernel.org> Link: https://lkml.kernel.org/r/20200505135314.900297476@linutronix.de
2020-06-11x86/db: Split out dr6/7 handlingPeter Zijlstra2-24/+57
DR6/7 should be handled before nmi_enter() is invoked and restore after nmi_exit() to minimize the exposure. Split it out into helper inlines and bring it into the correct order. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com> Acked-by: Andy Lutomirski <luto@kernel.org> Link: https://lkml.kernel.org/r/20200505135314.808628211@linutronix.de
2020-06-11x86/nmi: Protect NMI entry against instrumentationThomas Gleixner2-10/+11
Mark all functions in the fragile code parts noinstr or force inlining so they can't be instrumented. Also make the hardware latency tracer invocation explicit outside of non-instrumentable section. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Andy Lutomirski <luto@kernel.org> Link: https://lkml.kernel.org/r/20200505135314.716186134@linutronix.de
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