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| * | | | | x86/mm: Split read_cr3() into read_cr3_pa() and __read_cr3()Andy Lutomirski2017-06-1320-29/+79
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The kernel has several code paths that read CR3. Most of them assume that CR3 contains the PGD's physical address, whereas some of them awkwardly use PHYSICAL_PAGE_MASK to mask off low bits. Add explicit mask macros for CR3 and convert all of the CR3 readers. This will keep them from breaking when PCID is enabled. Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: xen-devel <xen-devel@lists.xen.org> Link: http://lkml.kernel.org/r/883f8fb121f4616c1c1427ad87350bb2f5ffeca1.1497288170.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | Merge branch 'sched/urgent' into x86/mm, to pick up dependent fixIngo Molnar2017-06-13318-1551/+2705
| |\ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Andy will need the following scheduler fix for the PCID series: 252d2a4117bc: sched/core: Idle_task_exit() shouldn't use switch_mm_irqs_off() So do a cross-merge. Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | x86/ldt: Rename ldt_struct::size to ::nr_entriesBorislav Petkov2017-06-086-30/+31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | ... because this is exactly what it is: the number of entries in the LDT. Calling it "size" is simply confusing and it is actually begging to be called "nr_entries" or somesuch, especially if you see constructs like: alloc_size = size * LDT_ENTRY_SIZE; since LDT_ENTRY_SIZE is the size of a single entry. There should be no functionality change resulting from this patch, as the before/after output from tools/testing/selftests/x86/ldt_gdt.c shows. Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Andy Lutomirski <luto@amacapital.net> 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/20170606173116.13977-1-bp@alien8.de [ Renamed 'n_entries' to 'nr_entries' ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | mm/vmstat: Make NR_TLB_REMOTE_FLUSH_RECEIVED available even on UPAndy Lutomirski2017-06-081-2/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This fixes CONFIG_SMP=n, CONFIG_DEBUG_TLBFLUSH=y without introducing further #ifdef soup. Caught by a Kbuild bot randconfig build. Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: ce4a4e565f52 ("x86/mm: Remove the UP asm/tlbflush.h code, always use the (formerly) SMP code") Link: http://lkml.kernel.org/r/76da9a3cc4415996f2ad2c905b93414add322021.1496673616.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | x86/mm, KVM: Teach KVM's VMX code that CR3 isn't a constantAndy Lutomirski2017-06-052-3/+37
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When PCID is enabled, CR3's PCID bits can change during context switches, so KVM won't be able to treat CR3 as a per-mm constant any more. I structured this like the existing CR4 handling. Under ordinary circumstances (PCID disabled or if the current PCID and the value that's already in the VMCS match), then we won't do an extra VMCS write, and we'll never do an extra direct CR3 read. The overhead should be minimal. I disallowed using the new helper in non-atomic context because PCID support will cause CR3 to stop being constant in non-atomic process context. (Frankly, it also scares me a bit that KVM ever treated CR3 as constant, but it looks like it was okay before.) Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Borislav Petkov <bpetkov@suse.de> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Michal Hocko <mhocko@suse.com> Cc: Nadav Amit <nadav.amit@gmail.com> Cc: Nadav Amit <namit@vmware.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: kvm@vger.kernel.org Cc: linux-mm@kvack.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | x86/mm: Be more consistent wrt PAGE_SHIFT vs PAGE_SIZE in tlb flush codeAndy Lutomirski2017-06-051-3/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Nadav pointed out that some code used PAGE_SIZE and other code used PAGE_SHIFT. Use PAGE_SHIFT instead of multiplying or dividing by PAGE_SIZE. Requested-by: Nadav Amit <nadav.amit@gmail.com> Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Borislav Petkov <bpetkov@suse.de> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Michal Hocko <mhocko@suse.com> Cc: Nadav Amit <nadav.amit@gmail.com> Cc: Nadav Amit <namit@vmware.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-mm@kvack.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | x86/mm: Rework lazy TLB to track the actual loaded mmAndy Lutomirski2017-06-056-144/+147
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Lazy TLB state is currently managed in a rather baroque manner. AFAICT, there are three possible states: - Non-lazy. This means that we're running a user thread or a kernel thread that has called use_mm(). current->mm == current->active_mm == cpu_tlbstate.active_mm and cpu_tlbstate.state == TLBSTATE_OK. - Lazy with user mm. We're running a kernel thread without an mm and we're borrowing an mm_struct. We have current->mm == NULL, current->active_mm == cpu_tlbstate.active_mm, cpu_tlbstate.state != TLBSTATE_OK (i.e. TLBSTATE_LAZY or 0). The current cpu is set in mm_cpumask(current->active_mm). CR3 points to current->active_mm->pgd. The TLB is up to date. - Lazy with init_mm. This happens when we call leave_mm(). We have current->mm == NULL, current->active_mm == cpu_tlbstate.active_mm, but that mm is only relelvant insofar as the scheduler is tracking it for refcounting. cpu_tlbstate.state != TLBSTATE_OK. The current cpu is clear in mm_cpumask(current->active_mm). CR3 points to swapper_pg_dir, i.e. init_mm->pgd. This patch simplifies the situation. Other than perf, x86 stops caring about current->active_mm at all. We have cpu_tlbstate.loaded_mm pointing to the mm that CR3 references. The TLB is always up to date for that mm. leave_mm() just switches us to init_mm. There are no longer any special cases for mm_cpumask, and switch_mm() switches mms without worrying about laziness. After this patch, cpu_tlbstate.state serves only to tell the TLB flush code whether it may switch to init_mm instead of doing a normal flush. This makes fairly extensive changes to xen_exit_mmap(), which used to look a bit like black magic. Perf is unchanged. With or without this change, perf may behave a bit erratically if it tries to read user memory in kernel thread context. We should build on this patch to teach perf to never look at user memory when cpu_tlbstate.loaded_mm != current->mm. Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Borislav Petkov <bpetkov@suse.de> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Michal Hocko <mhocko@suse.com> Cc: Nadav Amit <nadav.amit@gmail.com> Cc: Nadav Amit <namit@vmware.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-mm@kvack.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | x86/mm: Remove the UP asm/tlbflush.h code, always use the (formerly) SMP codeAndy Lutomirski2017-06-058-104/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The UP asm/tlbflush.h generates somewhat nicer code than the SMP version. Aside from that, it's fallen quite a bit behind the SMP code: - flush_tlb_mm_range() didn't flush individual pages if the range was small. - The lazy TLB code was much weaker. This usually wouldn't matter, but, if a kernel thread flushed its lazy "active_mm" more than once (due to reclaim or similar), it wouldn't be unlazied and would instead pointlessly flush repeatedly. - Tracepoints were missing. Aside from that, simply having the UP code around was a maintanence burden, since it means that any change to the TLB flush code had to make sure not to break it. Simplify everything by deleting the UP code. Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Borislav Petkov <bpetkov@suse.de> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Michal Hocko <mhocko@suse.com> Cc: Nadav Amit <nadav.amit@gmail.com> Cc: Nadav Amit <namit@vmware.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-mm@kvack.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | x86/mm: Use new merged flush logic in arch_tlbbatch_flush()Andy Lutomirski2017-06-051-6/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now there's only one copy of the local tlb flush logic for non-kernel pages on SMP kernels. The only functional change is that arch_tlbbatch_flush() will now leave_mm() on the local CPU if that CPU is in the batch and is in TLBSTATE_LAZY mode. Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Borislav Petkov <bpetkov@suse.de> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Michal Hocko <mhocko@suse.com> Cc: Nadav Amit <nadav.amit@gmail.com> Cc: Nadav Amit <namit@vmware.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-mm@kvack.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | x86/mm: Refactor flush_tlb_mm_range() to merge local and remote casesAndy Lutomirski2017-06-052-66/+48
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The local flush path is very similar to the remote flush path. Merge them. This is intended to make no difference to behavior whatsoever. It removes some code and will make future changes to the flushing mechanics simpler. This patch does remove one small optimization: flush_tlb_mm_range() now has an unconditional smp_mb() instead of using MOV to CR3 or INVLPG as a full barrier when applicable. I think this is okay for a few reasons. First, smp_mb() is quite cheap compared to the cost of a TLB flush. Second, this rearrangement makes a bigger optimization available: with some work on the SMP function call code, we could do the local and remote flushes in parallel. Third, I'm planning a rework of the TLB flush algorithm that will require an atomic operation at the beginning of each flush, and that operation will replace the smp_mb(). Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Borislav Petkov <bpetkov@suse.de> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Michal Hocko <mhocko@suse.com> Cc: Nadav Amit <nadav.amit@gmail.com> Cc: Nadav Amit <namit@vmware.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-mm@kvack.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | x86/mm: Change the leave_mm() condition for local TLB flushesAndy Lutomirski2017-06-051-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | On a remote TLB flush, we leave_mm() if we're TLBSTATE_LAZY. For a local flush_tlb_mm_range(), we leave_mm() if !current->mm. These are approximately the same condition -- the scheduler sets lazy TLB mode when switching to a thread with no mm. I'm about to merge the local and remote flush code, but for ease of verifying and bisecting the patch, I want the local and remote flush behavior to match first. This patch changes the local code to match the remote code. Signed-off-by: Andy Lutomirski <luto@kernel.org> Acked-by: Rik van Riel <riel@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Borislav Petkov <bpetkov@suse.de> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Michal Hocko <mhocko@suse.com> Cc: Nadav Amit <nadav.amit@gmail.com> Cc: Nadav Amit <namit@vmware.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-mm@kvack.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | x86/mm: Pass flush_tlb_info to flush_tlb_others() etcAndy Lutomirski2017-06-057-64/+61
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Rather than passing all the contents of flush_tlb_info to flush_tlb_others(), pass a pointer to the structure directly. For consistency, this also removes the unnecessary cpu parameter from uv_flush_tlb_others() to make its signature match the other *flush_tlb_others() functions. This serves two purposes: - It will dramatically simplify future patches that change struct flush_tlb_info, which I'm planning to do. - struct flush_tlb_info is an adequate description of what to do for a local flush, too, so by reusing it we can remove duplicated code between local and remove flushes in a future patch. Signed-off-by: Andy Lutomirski <luto@kernel.org> Acked-by: Rik van Riel <riel@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Borislav Petkov <bpetkov@suse.de> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Michal Hocko <mhocko@suse.com> Cc: Nadav Amit <nadav.amit@gmail.com> Cc: Nadav Amit <namit@vmware.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-mm@kvack.org [ Fix build warning. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | Merge tag 'v4.12-rc4' into x86/mm, to pick up fixesIngo Molnar2017-06-05439-2644/+4909
| |\ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | | mm, x86/mm: Make the batched unmap TLB flush API more genericAndy Lutomirski2017-05-245-18/+54
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | try_to_unmap_flush() used to open-code a rather x86-centric flush sequence: local_flush_tlb() + flush_tlb_others(). Rearrange the code so that the arch (only x86 for now) provides arch_tlbbatch_add_mm() and arch_tlbbatch_flush() and the core code calls those functions instead. I'll want this for x86 because, to enable address space ids, I can't support the flush_tlb_others() mode used by exising try_to_unmap_flush() implementation with good performance. I can support the new API fairly easily, though. I imagine that other architectures may be in a similar position. Architectures with strong remote flush primitives (arm64?) may have even worse performance problems with flush_tlb_others() the way that try_to_unmap_flush() uses it. Signed-off-by: Andy Lutomirski <luto@kernel.org> Acked-by: Kees Cook <keescook@chromium.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Borislav Petkov <bpetkov@suse.de> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Michal Hocko <mhocko@suse.com> Cc: Nadav Amit <nadav.amit@gmail.com> Cc: Nadav Amit <namit@vmware.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Sasha Levin <sasha.levin@oracle.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/19f25a8581f9fb77876b7ff3b001f89835e34ea3.1495492063.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | | x86/mm: Reduce indentation in flush_tlb_func()Andy Lutomirski2017-05-241-16/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The leave_mm() case can just exit the function early so we don't need to indent the entire remainder of the function. Signed-off-by: Andy Lutomirski <luto@kernel.org> Acked-by: Kees Cook <keescook@chromium.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Borislav Petkov <bpetkov@suse.de> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Michal Hocko <mhocko@suse.com> Cc: Nadav Amit <nadav.amit@gmail.com> Cc: Nadav Amit <namit@vmware.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/97901ddcc9821d7bc7b296d2918d1179f08aaf22.1495492063.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | | x86/mm: Reimplement flush_tlb_page() using flush_tlb_mm_range()Andy Lutomirski2017-05-242-28/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | flush_tlb_page() was very similar to flush_tlb_mm_range() except that it had a couple of issues: - It was missing an smp_mb() in the case where current->active_mm != mm. (This is a longstanding bug reported by Nadav Amit) - It was missing tracepoints and vm counter updates. The only reason that I can see for keeping it at as a separate function is that it could avoid a few branches that flush_tlb_mm_range() needs to decide to flush just one page. This hardly seems worthwhile. If we decide we want to get rid of those branches again, a better way would be to introduce an __flush_tlb_mm_range() helper and make both flush_tlb_page() and flush_tlb_mm_range() use it. Signed-off-by: Andy Lutomirski <luto@kernel.org> Acked-by: Kees Cook <keescook@chromium.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Borislav Petkov <bpetkov@suse.de> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Michal Hocko <mhocko@suse.com> Cc: Nadav Amit <nadav.amit@gmail.com> Cc: Nadav Amit <namit@vmware.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/3cc3847cf888d8907577569b8bac3f01992ef8f9.1495492063.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | | | | | | | Merge branch 'x86-microcode-for-linus' of ↵Linus Torvalds2017-07-033-6/+34
|\ \ \ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 microcode updates from Ingo Molnar: "The main changes are a fix early microcode application for resume-from-RAM, plus a 32-bit initrd placement fix - by Borislav Petkov" * 'x86-microcode-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/microcode: Make a couple of symbols static x86/microcode/intel: Save pointer to ucode patch for early AP loading x86/microcode: Look for the initrd at the correct address on 32-bit
| * | | | | | | | x86/microcode: Make a couple of symbols staticColin Ian King2017-06-262-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The helper function __load_ucode_amd() and pointer intel_ucode_patch do not need to be in global scope, so make them static. Fixes those sparse warnings: "symbol '__load_ucode_amd' was not declared. Should it be static?" "symbol 'intel_ucode_patch' was not declared. Should it be static?" Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20170622095736.11937-1-colin.king@canonical.com
| * | | | | | | | x86/microcode/intel: Save pointer to ucode patch for early AP loadingBorislav Petkov2017-06-201-4/+21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Normally, when the initrd is gone, we can't search it for microcode blobs to apply anymore. For that we need to stash away the patch in our own storage. And save_microcode_in_initrd_intel() looks like the proper place to do that from. So in order for early loading to work, invalidate the intel_ucode_patch pointer to the patch *before* scanning the initrd one last time. If the scanning code finds a microcode patch, it will assign that pointer again, this time with our own storage's address. This way, early microcode application during resume-from-RAM works too, even after the initrd is long gone. Tested-by: Dominik Brodowski <linux@dominikbrodowski.net> 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/20170614140626.4462-2-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | | | x86/microcode: Look for the initrd at the correct address on 32-bitBorislav Petkov2017-06-201-0/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Early during boot, the BSP finds the ramdisk's position from boot_params but by the time the APs get to boot, the BSP has continued in the mean time and has potentially managed to relocate that ramdisk. And in that case, the APs need to find the ramdisk at its new position, in *physical* memory as they're running before paging has been enabled. Thus, get the updated physical location of the ramdisk which is in the relocated_ramdisk variable. 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/20170614140626.4462-1-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | | | | | | | | Merge branch 'x86-hyperv-for-linus' of ↵Linus Torvalds2017-07-032-10/+23
|\ \ \ \ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 hyperv updates from Ingo Molnar: "Avoid boot time TSC calibration on Hyper-V hosts, to improve calibration robustness. (Vitaly Kuznetsov)" * 'x86-hyperv-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/hyperv: Read TSC frequency from a synthetic MSR x86/hyperv: Check frequency MSRs presence according to the specification
| * | | | | | | | | x86/hyperv: Read TSC frequency from a synthetic MSRVitaly Kuznetsov2017-06-221-0/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It was found that SMI_TRESHOLD of 50000 is not enough for Hyper-V guests in nested environment and falling back to counting jiffies is not an option for Gen2 guests as they don't have PIT. As Hyper-V provides TSC frequency in a synthetic MSR we can just use this information instead of doing a error prone calibration. Reported-and-tested-by: Ladi Prosek <lprosek@redhat.com> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Jork Loeser <jloeser@microsoft.com> Cc: devel@linuxdriverproject.org Cc: "K. Y. Srinivasan" <kys@microsoft.com> Link: http://lkml.kernel.org/r/20170622100730.18112-3-vkuznets@redhat.com
| * | | | | | | | | x86/hyperv: Check frequency MSRs presence according to the specificationVitaly Kuznetsov2017-06-222-10/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Hyper-V TLFS specifies two bits which should be checked before accessing frequency MSRs: - AccessFrequencyMsrs (BIT(11) in EAX) which indicates if we have access to frequency MSRs. - FrequencyMsrsAvailable (BIT(8) in EDX) which indicates is these MSRs are present. Rename and specify these bits accordingly. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Ladi Prosek <lprosek@redhat.com> Cc: Jork Loeser <jloeser@microsoft.com> Cc: devel@linuxdriverproject.org Cc: "K. Y. Srinivasan" <kys@microsoft.com> Link: http://lkml.kernel.org/r/20170622100730.18112-2-vkuznets@redhat.com
* | | | | | | | | | Merge branch 'x86-debug-for-linus' of ↵Linus Torvalds2017-07-031-1/+1
|\ \ \ \ \ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 debug update from Ingo Molnar: "A single fix for an off-by one bug in test_nmi_ipi() that probably doesn't matter in practice" * 'x86-debug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/nmi: Fix timeout test in test_nmi_ipi()
| * | | | | | | | | | x86/nmi: Fix timeout test in test_nmi_ipi()Dan Carpenter2017-06-201-1/+1
| | |/ / / / / / / / | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We're supposed to exit the loop with "timeout" set to zero. Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Acked-by: Don Zickus <dzickus@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: kernel-janitors@vger.kernel.org Fixes: 99e8b9ca90d6 ("x86, NMI: Add NMI IPI selftest") Link: http://lkml.kernel.org/r/20170619105304.GA23995@elgon.mountain Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | | | | | | | | | Merge branch 'x86-cleanups-for-linus' of ↵Linus Torvalds2017-07-032-1/+2
|\ \ \ \ \ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 cleanups from Ingo Molnar: "Two small cleanups" * 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/paravirt: Remove unnecessary return from void function x86/boot: Add missing strchr() declaration
| * | | | | | | | | | x86/paravirt: Remove unnecessary return from void functionAnton Vasilyev2017-06-241-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The patch removes unnecessary return from void function. Found by Linux Driver Verification project (linuxtesting.org). Signed-off-by: Anton Vasilyev <vasilyev@ispras.ru> Cc: Alok Kataria <akataria@vmware.com> Cc: Chris Wright <chrisw@sous-sol.org> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: ldv-project@linuxtesting.org Cc: virtualization@lists.linux-foundation.org Link: http://lkml.kernel.org/r/1498234993-1320-1-git-send-email-vasilyev@ispras.ru Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | | | | | x86/boot: Add missing strchr() declarationTommy Nguyen2017-06-241-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The Sparse static analyzer emits this warning: symbol 'strchr' was not declared. Should it be static? This patch adds the appropriate extern declaration to string.h to fix the warning. Signed-off-by: Tommy Nguyen <remyabel@gmail.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/20170623143601.GA20743@NoChina Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | | | | | | | | | | Merge branch 'x86-boot-for-linus' of ↵Linus Torvalds2017-07-036-87/+145
|\ \ \ \ \ \ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 boot updates from Ingo Molnar: "The main changes in this cycle were KASLR improvements for rare environments with special boot options, by Baoquan He. Also misc smaller changes/cleanups" * 'x86-boot-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/debug: Extend the lower bound of crash kernel low reservations x86/boot: Remove unused copy_*_gs() functions x86/KASLR: Use the right memcpy() implementation Documentation/kernel-parameters.txt: Update 'memmap=' boot option description x86/KASLR: Handle the memory limit specified by the 'memmap=' and 'mem=' boot options x86/KASLR: Parse all 'memmap=' boot option entries
| * | | | | | | | | | | x86/debug: Extend the lower bound of crash kernel low reservationsJiri Bohac2017-06-221-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The following change in 2013: 0212f9159694 ("x86: Add Crash kernel low reservation") ... introduced reserve_crashkernel_low(). This function is used to reserve crash kernel memory either if crashkernel=size,low is given on the command line or if the region reserved by reserve_crashkernel is entirely above 4G. reserve_crashkernel_low() tries to find a block of 'low_size' bytes. But there seems to be no good reason to restrict the lower bound of the range to 'low_size'. Make memblock_find_in_range() search from the start of memory. Signed-off-by: Jiri Bohac <jbohac@suse.cz> Cc: Eric Biederman <ebiederm@xmission.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Yinghai Lu <yinghai@kernel.org> Link: http://lkml.kernel.org/r/20170616161602.2r7birrf2y3ylv6v@dwarf.suse.cz Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | | | | | | x86/boot: Remove unused copy_*_gs() functionsJiri Slaby2017-06-051-20/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | copy_from_gs() and copy_to_gs() are unused in the boot code. They have actually never been used -- they were always commented out since their addition in 2007: 5be865661516 ("String-handling functions for the new x86 setup code.") So remove them -- they can be restored from history if needed. Signed-off-by: Jiri Slaby <jslaby@suse.cz> 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/20170531081243.5709-1-jslaby@suse.cz Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | | | | | | x86/KASLR: Use the right memcpy() implementationArnd Bergmann2017-05-311-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The decompressor has its own implementation of the string functions, but has to include the right header to get those, while implicitly including linux/string.h may result in a link error: arch/x86/boot/compressed/kaslr.o: In function `choose_random_location': kaslr.c:(.text+0xf51): undefined reference to `_mmx_memcpy' This has appeared now as KASLR started using memcpy(), via: d52e7d5a952c ("x86/KASLR: Parse all 'memmap=' boot option entries") Other files in the decompressor already do the same thing. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Baoquan He <bhe@redhat.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Garnier <thgarnie@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20170530091446.1000183-1-arnd@arndb.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | | | | | | Documentation/kernel-parameters.txt: Update 'memmap=' boot option descriptionBaoquan He2017-05-241-0/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In commit: 9710f581bb4c ("x86, mm: Let "memmap=" take more entries one time") ... 'memmap=' was changed to adopt multiple, comma delimited values in a single entry, so update the related description. In the special case of only specifying size value without an offset, like memmap=nn[KMG], memmap behaves similarly to mem=nn[KMG], so update it too here. Furthermore, for memmap=nn[KMG]$ss[KMG], an escape character needs be added before '$' for some bootloaders. E.g in grub2, if we specify memmap=100M$5G as suggested by the documentation, "memmap=100MG" gets passed to the kernel. Clarify all this. Signed-off-by: Baoquan He <bhe@redhat.com> Acked-by: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: dan.j.williams@intel.com Cc: douly.fnst@cn.fujitsu.com Cc: dyoung@redhat.com Cc: m.mizuma@jp.fujitsu.com Link: http://lkml.kernel.org/r/1494654390-23861-4-git-send-email-bhe@redhat.com [ Various spelling fixes. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | | | | | | x86/KASLR: Handle the memory limit specified by the 'memmap=' and 'mem=' ↵Baoquan He2017-05-241-18/+50
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | boot options The 'mem=' boot option limits the max address a system can use - any memory region above the limit will be removed. Furthermore, the 'memmap=nn[KMG]' variant (with no offset specified) has the same behaviour as 'mem='. KASLR needs to consider this when choosing the random position for decompressing the kernel. Do it. Tested-by: Masayoshi Mizuma <m.mizuma@jp.fujitsu.com> Signed-off-by: Baoquan He <bhe@redhat.com> Acked-by: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: dan.j.williams@intel.com Cc: douly.fnst@cn.fujitsu.com Cc: dyoung@redhat.com Link: http://lkml.kernel.org/r/1494654390-23861-3-git-send-email-bhe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | | | | | | x86/KASLR: Parse all 'memmap=' boot option entriesBaoquan He2017-05-243-55/+91
| | |_|_|/ / / / / / / | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In commit: f28442497b5c ("x86/boot: Fix KASLR and memmap= collision") ... the memmap= option is parsed so that KASLR can avoid those reserved regions. It uses cmdline_find_option() to get the value if memmap= is specified, however the problem is that cmdline_find_option() can only find the last entry if multiple memmap entries are provided. This is not correct. Address this by checking each command line token for a "memmap=" match and parse each instance instead of using cmdline_find_option(). Signed-off-by: Baoquan He <bhe@redhat.com> Acked-by: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: dan.j.williams@intel.com Cc: douly.fnst@cn.fujitsu.com Cc: dyoung@redhat.com Cc: m.mizuma@jp.fujitsu.com Link: http://lkml.kernel.org/r/1494654390-23861-2-git-send-email-bhe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | | | | | | | | | | Merge branch 'x86-asm-for-linus' of ↵Linus Torvalds2017-07-031-2/+5
|\ \ \ \ \ \ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 asm updates from Ingo Molnar: "A single commit micro-optimizing short user copies on certain Intel CPUs" * 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/uaccess: Optimize copy_user_enhanced_fast_string() for short strings
| * | | | | | | | | | | x86/uaccess: Optimize copy_user_enhanced_fast_string() for short stringsPaolo Abeni2017-06-301-2/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | According to the Intel datasheet, the REP MOVSB instruction exposes a pretty heavy setup cost (50 ticks), which hurts short string copy operations. This change tries to avoid this cost by calling the explicit loop available in the unrolled code for strings shorter than 64 bytes. The 64 bytes cutoff value is arbitrary from the code logic point of view - it has been selected based on measurements, as the largest value that still ensures a measurable gain. Micro benchmarks of the __copy_from_user() function with lengths in the [0-63] range show this performance gain (shorter the string, larger the gain): - in the [55%-4%] range on Intel Xeon(R) CPU E5-2690 v4 - in the [72%-9%] range on Intel Core i7-4810MQ Other tested CPUs - namely Intel Atom S1260 and AMD Opteron 8216 - show no difference, because they do not expose the ERMS feature bit. Signed-off-by: Paolo Abeni <pabeni@redhat.com> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Alan Cox <gnomes@lxorguk.ukuu.org.uk> 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: Hannes Frederic Sowa <hannes@stressinduktion.org> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Kees Cook <keescook@chromium.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/4533a1d101fd460f80e21329a34928fad521c1d4.1498744345.git.pabeni@redhat.com [ Clarified the changelog. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | | | | | | | | | | | Merge branch 'x86-apic-for-linus' of ↵Linus Torvalds2017-07-034-26/+4
|\ \ \ \ \ \ \ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 apic updates from Ingo Molnar: "Janitorial changes: removal of an unused function plus __init annotations" * 'x86-apic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/apic: Make arch_init_msi/htirq_domain __init x86/apic: Make init_legacy_irqs() __init x86/ioapic: Remove unused IO_APIC_irq_trigger() function
| * | | | | | | | | | | | x86/apic: Make arch_init_msi/htirq_domain __initDou Liyang2017-06-222-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | These two functions are only called by arch_early_irq_init(), which is an __init function, so mark them __init as well. Signed-off-by: Dou Liyang <douly.fnst@cn.fujitsu.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/1498101341-10182-1-git-send-email-douly.fnst@cn.fujitsu.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | | | | | | | x86/apic: Make init_legacy_irqs() __initDou Liyang2017-06-221-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This function is only called by arch_early_irq_init(), which is an __init function, so mark the child function __init as well. In addition mark it inline for the !CONFIG_X86_IO_APIC case. Signed-off-by: Dou Liyang <douly.fnst@cn.fujitsu.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/1498040061-5332-1-git-send-email-douly.fnst@cn.fujitsu.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | | | | | | | x86/ioapic: Remove unused IO_APIC_irq_trigger() functionMatthias Kaehlcke2017-05-261-22/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The function isn't used since commit: 5ad274d41c1b ("x86/irq: Remove unused old IOAPIC irqdomain interfaces") Removing it fixes the following warning when building with clang: arch/x86/kernel/apic/io_apic.c:1219:19: error: unused function 'IO_APIC_irq_trigger' [-Werror,-Wunused-function] Signed-off-by: Matthias Kaehlcke <mka@chromium.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Douglas Anderson <dianders@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20170522232035.187985-1-mka@chromium.org Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* | | | | | | | | | | | | Merge branch 'timers-nohz-for-linus' of ↵Linus Torvalds2017-07-032-23/+42
|\ \ \ \ \ \ \ \ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull nohz updates from Ingo Molnar: "The main changes in this cycle relate to fixing another bad (but sporadic and hard to detect) interaction between the dynticks scheduler tick and hrtimers, plus related improvements to better detection and handling of similar problems - by Frédéric Weisbecker" * 'timers-nohz-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: nohz: Fix spurious warning when hrtimer and clockevent get out of sync nohz: Fix buggy tick delay on IRQ storms nohz: Reset next_tick cache even when the timer has no regs nohz: Fix collision between tick and other hrtimers, again nohz: Add hrtimer sanity check
| * | | | | | | | | | | | | nohz: Fix spurious warning when hrtimer and clockevent get out of syncFrederic Weisbecker2017-06-131-2/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The sanity check ensuring that the tick expiry cache (ts->next_tick) is actually in sync with the hardware clock (dev->next_event) makes the wrong assumption that the clock can't be programmed later than the hrtimer deadline. In fact the clock hardware can be programmed later on some conditions such as: * The hrtimer deadline is already in the past. * The hrtimer deadline is earlier than the minimum delay supported by the hardware. Such conditions can be met when we program the tick, for example if the last jiffies update hasn't been seen by the current CPU yet, we may program the hrtimer to a deadline that is earlier than ktime_get() because last_jiffies_update is our timestamp base to compute the next tick. As a result, we can randomly observe such warning: WARNING: CPU: 5 PID: 0 at kernel/time/tick-sched.c:794 tick_nohz_stop_sched_tick kernel/time/tick-sched.c:791 [inline] Call Trace: tick_nohz_irq_exit tick_irq_exit irq_exit exiting_irq smp_call_function_interrupt smp_call_function_single_interrupt call_function_single_interrupt Therefore, let's rather make sure that the tick expiry cache is sync'ed with the tick hrtimer deadline, against which it is not supposed to drift away. The clock hardware instead has its own will and can't be used as a reliable comparison point. Reported-and-tested-by: Sasha Levin <alexander.levin@verizon.com> Reported-and-tested-by: Abdul Haleem <abdhalee@linux.vnet.ibm.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: James Hartsock <hartsjc@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tim Wright <tim@binbash.co.uk> Link: http://lkml.kernel.org/r/1497326654-14122-1-git-send-email-fweisbec@gmail.com [ Minor readability edit. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | | | | | | | | nohz: Fix buggy tick delay on IRQ stormsFrederic Weisbecker2017-06-051-19/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When the tick is stopped and we reach the dynticks evaluation code on IRQ exit, we perform a soft tick restart if we observe an expired timer from there. It means we program the nearest possible tick but we stay in dynticks mode (ts->tick_stopped = 1) because we may need to stop the tick again after that expired timer is handled. Now this solution works most of the time but if we suffer an IRQ storm and those interrupts trigger faster than the hardware clockevents min delay, our tick won't fire until that IRQ storm is finished. Here is the problem: on IRQ exit we reprog the timer to at least NOW() + min_clockevents_delay. Another IRQ fires before the tick so we reschedule again to NOW() + min_clockevents_delay, etc... The tick is eternally rescheduled min_clockevents_delay ahead. A solution is to simply remove this soft tick restart. After all the normal dynticks evaluation path can handle 0 delay just fine. And by doing that we benefit from the optimization branch which avoids clock reprogramming if the clockevents deadline hasn't changed since the last reprog. This fixes our issue because we don't do repetitive clock reprog that always add hardware min delay. As a side effect it should even optimize the 0 delay path in general. Reported-and-tested-by: Octavian Purdila <octavian.purdila@nxp.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1496328429-13317-1-git-send-email-fweisbec@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | | | | | | | | nohz: Reset next_tick cache even when the timer has no regsFrederic Weisbecker2017-05-301-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Handle tick interrupts whose regs are NULL, out of general paranoia. It happens when hrtimer_interrupt() is called from non-interrupt contexts, such as hotplug CPU down events. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | | | | | | | | nohz: Fix collision between tick and other hrtimers, againFrederic Weisbecker2017-05-172-6/+33
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This restores commit: 24b91e360ef5: ("nohz: Fix collision between tick and other hrtimers") ... which got reverted by commit: 558e8e27e73f: ('Revert "nohz: Fix collision between tick and other hrtimers"') ... due to a regression where CPUs spuriously stopped ticking. The bug happened when a tick fired too early past its expected expiration: on IRQ exit the tick was scheduled again to the same deadline but skipped reprogramming because ts->next_tick still kept in cache the deadline. This has been fixed now with resetting ts->next_tick from the tick itself. Extra care has also been taken to prevent from obsolete values throughout CPU hotplug operations. When the tick is stopped and an interrupt occurs afterward, we check on that interrupt exit if the next tick needs to be rescheduled. If it doesn't need any update, we don't want to do anything. In order to check if the tick needs an update, we compare it against the clockevent device deadline. Now that's a problem because the clockevent device is at a lower level than the tick itself if it is implemented on top of hrtimer. Every hrtimer share this clockevent device. So comparing the next tick deadline against the clockevent device deadline is wrong because the device may be programmed for another hrtimer whose deadline collides with the tick. As a result we may end up not reprogramming the tick accidentally. In a worst case scenario under full dynticks mode, the tick stops firing as it is supposed to every 1hz, leaving /proc/stat stalled: Task in a full dynticks CPU ---------------------------- * hrtimer A is queued 2 seconds ahead * the tick is stopped, scheduled 1 second ahead * tick fires 1 second later * on tick exit, nohz schedules the tick 1 second ahead but sees the clockevent device is already programmed to that deadline, fooled by hrtimer A, the tick isn't rescheduled. * hrtimer A is cancelled before its deadline * tick never fires again until an interrupt happens... In order to fix this, store the next tick deadline to the tick_sched local structure and reuse that value later to check whether we need to reprogram the clock after an interrupt. On the other hand, ts->sleep_length still wants to know about the next clock event and not just the tick, so we want to improve the related comment to avoid confusion. Reported-and-tested-by: Tim Wright <tim@binbash.co.uk> Reported-and-tested-by: Pavel Machek <pavel@ucw.cz> Reported-by: James Hartsock <hartsjc@redhat.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Rik van Riel <riel@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/1492783255-5051-2-git-send-email-fweisbec@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | | | | | | | | nohz: Add hrtimer sanity checkFrederic Weisbecker2017-05-171-2/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | | | | | | | | | | | | | Merge branch 'sched-core-for-linus' of ↵Linus Torvalds2017-07-03156-2621/+3658
|\ \ \ \ \ \ \ \ \ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler updates from Ingo Molnar: "The main changes in this cycle were: - Add the SYSTEM_SCHEDULING bootup state to move various scheduler debug checks earlier into the bootup. This turns silent and sporadically deadly bugs into nice, deterministic splats. Fix some of the splats that triggered. (Thomas Gleixner) - A round of restructuring and refactoring of the load-balancing and topology code (Peter Zijlstra) - Another round of consolidating ~20 of incremental scheduler code history: this time in terms of wait-queue nomenclature. (I didn't get much feedback on these renaming patches, and we can still easily change any names I might have misplaced, so if anyone hates a new name, please holler and I'll fix it.) (Ingo Molnar) - sched/numa improvements, fixes and updates (Rik van Riel) - Another round of x86/tsc scheduler clock code improvements, in hope of making it more robust (Peter Zijlstra) - Improve NOHZ behavior (Frederic Weisbecker) - Deadline scheduler improvements and fixes (Luca Abeni, Daniel Bristot de Oliveira) - Simplify and optimize the topology setup code (Lauro Ramos Venancio) - Debloat and decouple scheduler code some more (Nicolas Pitre) - Simplify code by making better use of llist primitives (Byungchul Park) - ... plus other fixes and improvements" * 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (103 commits) sched/cputime: Refactor the cputime_adjust() code sched/debug: Expose the number of RT/DL tasks that can migrate sched/numa: Hide numa_wake_affine() from UP build sched/fair: Remove effective_load() sched/numa: Implement NUMA node level wake_affine() sched/fair: Simplify wake_affine() for the single socket case sched/numa: Override part of migrate_degrades_locality() when idle balancing sched/rt: Move RT related code from sched/core.c to sched/rt.c sched/deadline: Move DL related code from sched/core.c to sched/deadline.c sched/cpuset: Only offer CONFIG_CPUSETS if SMP is enabled sched/fair: Spare idle load balancing on nohz_full CPUs nohz: Move idle balancer registration to the idle path sched/loadavg: Generalize "_idle" naming to "_nohz" sched/core: Drop the unused try_get_task_struct() helper function sched/fair: WARN() and refuse to set buddy when !se->on_rq sched/debug: Fix SCHED_WARN_ON() to return a value on !CONFIG_SCHED_DEBUG as well sched/wait: Disambiguate wq_entry->task_list and wq_head->task_list naming sched/wait: Move bit_wait_table[] and related functionality from sched/core.c to sched/wait_bit.c sched/wait: Split out the wait_bit*() APIs from <linux/wait.h> into <linux/wait_bit.h> sched/wait: Re-adjust macro line continuation backslashes in <linux/wait.h> ...
| * | | | | | | | | | | | | | sched/cputime: Refactor the cputime_adjust() codeGustavo A. R. Silva2017-06-301-11/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Address a Coverity false positive, which is caused by overly convoluted code: Value assigned to variable 'utime' at line 619:utime = rtime; is overwritten at line 642:utime = rtime - stime; before it can be used. This makes such variable assignment useless. Remove this variable assignment and refactor the code related. Addresses-Coverity-ID: 1371643 Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com> Cc: Frans Klaver <fransklaver@gmail.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Stanislaw Gruszka <sgruszka@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Wanpeng Li <wanpeng.li@hotmail.com> Link: http://lkml.kernel.org/r/20170629184128.GA5271@embeddedgus Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | | | | | | | | | sched/debug: Expose the number of RT/DL tasks that can migrateDaniel Bristot de Oliveira2017-06-301-2/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add the value of the rt_rq.rt_nr_migratory and dl_rq.dl_nr_migratory to the sched_debug output, for instance: rt_rq[0]: .rt_nr_running : 2 .rt_nr_migratory : 1 <--- Like this .rt_throttled : 0 .rt_time : 828.645877 .rt_runtime : 1000.000000 This is useful to debug problems related to the RT/DL schedulers. This also fixes the format of some variables, that were unsigned, rather than signed. Signed-off-by: Daniel Bristot de Oliveira <bristot@redhat.com> Cc: Clark Williams <williams@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luis Claudio R. Goncalves <lgoncalv@redhat.com> Cc: Luiz Capitulino <lcapitulino@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-rt-users <linux-rt-users@vger.kernel.org> Link: http://lkml.kernel.org/r/7896f71cada54ee7dd8507bb666063a2e051c3d4.1498482127.git.bristot@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>