4.14-stable review patch. If anyone has any objections, please let me know.
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From: Dave Hansen dave.hansen@linux.intel.com
commit 50fb83a62cf472dc53ba23bd3f7bd6c1b2b3b53e upstream.
For flushing the TLB, the ASID which has been programmed into the hardware must be known. That differs from what is in 'cpu_tlbstate'.
Add functions to transform the 'cpu_tlbstate' values into to the one programmed into the hardware (CR3).
It's not easy to include mmu_context.h into tlbflush.h, so just move the CR3 building over to tlbflush.h.
Signed-off-by: Dave Hansen dave.hansen@linux.intel.com Signed-off-by: Thomas Gleixner tglx@linutronix.de Cc: Andy Lutomirski luto@kernel.org Cc: Boris Ostrovsky boris.ostrovsky@oracle.com Cc: Borislav Petkov bp@alien8.de Cc: Brian Gerst brgerst@gmail.com Cc: David Laight David.Laight@aculab.com Cc: Denys Vlasenko dvlasenk@redhat.com Cc: Eduardo Valentin eduval@amazon.com Cc: Greg KH gregkh@linuxfoundation.org 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: Will Deacon will.deacon@arm.com Cc: aliguori@amazon.com Cc: daniel.gruss@iaik.tugraz.at Cc: hughd@google.com Cc: keescook@google.com Cc: linux-mm@kvack.org Signed-off-by: Ingo Molnar mingo@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- arch/x86/include/asm/mmu_context.h | 29 +---------------------------- arch/x86/include/asm/tlbflush.h | 26 ++++++++++++++++++++++++++ arch/x86/mm/tlb.c | 8 ++++---- 3 files changed, 31 insertions(+), 32 deletions(-)
--- a/arch/x86/include/asm/mmu_context.h +++ b/arch/x86/include/asm/mmu_context.h @@ -291,33 +291,6 @@ static inline bool arch_vma_access_permi }
/* - * If PCID is on, ASID-aware code paths put the ASID+1 into the PCID - * bits. This serves two purposes. It prevents a nasty situation in - * which PCID-unaware code saves CR3, loads some other value (with PCID - * == 0), and then restores CR3, thus corrupting the TLB for ASID 0 if - * the saved ASID was nonzero. It also means that any bugs involving - * loading a PCID-enabled CR3 with CR4.PCIDE off will trigger - * deterministically. - */ - -static inline unsigned long build_cr3(struct mm_struct *mm, u16 asid) -{ - if (static_cpu_has(X86_FEATURE_PCID)) { - VM_WARN_ON_ONCE(asid > 4094); - return __sme_pa(mm->pgd) | (asid + 1); - } else { - VM_WARN_ON_ONCE(asid != 0); - return __sme_pa(mm->pgd); - } -} - -static inline unsigned long build_cr3_noflush(struct mm_struct *mm, u16 asid) -{ - VM_WARN_ON_ONCE(asid > 4094); - return __sme_pa(mm->pgd) | (asid + 1) | CR3_NOFLUSH; -} - -/* * This can be used from process context to figure out what the value of * CR3 is without needing to do a (slow) __read_cr3(). * @@ -326,7 +299,7 @@ static inline unsigned long build_cr3_no */ static inline unsigned long __get_current_cr3_fast(void) { - unsigned long cr3 = build_cr3(this_cpu_read(cpu_tlbstate.loaded_mm), + unsigned long cr3 = build_cr3(this_cpu_read(cpu_tlbstate.loaded_mm)->pgd, this_cpu_read(cpu_tlbstate.loaded_mm_asid));
/* For now, be very restrictive about when this can be called. */ --- a/arch/x86/include/asm/tlbflush.h +++ b/arch/x86/include/asm/tlbflush.h @@ -69,6 +69,32 @@ static inline u64 inc_mm_tlb_gen(struct return atomic64_inc_return(&mm->context.tlb_gen); }
+/* + * If PCID is on, ASID-aware code paths put the ASID+1 into the PCID bits. + * This serves two purposes. It prevents a nasty situation in which + * PCID-unaware code saves CR3, loads some other value (with PCID == 0), + * and then restores CR3, thus corrupting the TLB for ASID 0 if the saved + * ASID was nonzero. It also means that any bugs involving loading a + * PCID-enabled CR3 with CR4.PCIDE off will trigger deterministically. + */ +struct pgd_t; +static inline unsigned long build_cr3(pgd_t *pgd, u16 asid) +{ + if (static_cpu_has(X86_FEATURE_PCID)) { + VM_WARN_ON_ONCE(asid > 4094); + return __sme_pa(pgd) | (asid + 1); + } else { + VM_WARN_ON_ONCE(asid != 0); + return __sme_pa(pgd); + } +} + +static inline unsigned long build_cr3_noflush(pgd_t *pgd, u16 asid) +{ + VM_WARN_ON_ONCE(asid > 4094); + return __sme_pa(pgd) | (asid + 1) | CR3_NOFLUSH; +} + #ifdef CONFIG_PARAVIRT #include <asm/paravirt.h> #else --- a/arch/x86/mm/tlb.c +++ b/arch/x86/mm/tlb.c @@ -128,7 +128,7 @@ void switch_mm_irqs_off(struct mm_struct * isn't free. */ #ifdef CONFIG_DEBUG_VM - if (WARN_ON_ONCE(__read_cr3() != build_cr3(real_prev, prev_asid))) { + if (WARN_ON_ONCE(__read_cr3() != build_cr3(real_prev->pgd, prev_asid))) { /* * If we were to BUG here, we'd be very likely to kill * the system so hard that we don't see the call trace. @@ -195,7 +195,7 @@ void switch_mm_irqs_off(struct mm_struct if (need_flush) { this_cpu_write(cpu_tlbstate.ctxs[new_asid].ctx_id, next->context.ctx_id); this_cpu_write(cpu_tlbstate.ctxs[new_asid].tlb_gen, next_tlb_gen); - write_cr3(build_cr3(next, new_asid)); + write_cr3(build_cr3(next->pgd, new_asid));
/* * NB: This gets called via leave_mm() in the idle path @@ -208,7 +208,7 @@ void switch_mm_irqs_off(struct mm_struct trace_tlb_flush_rcuidle(TLB_FLUSH_ON_TASK_SWITCH, TLB_FLUSH_ALL); } else { /* The new ASID is already up to date. */ - write_cr3(build_cr3_noflush(next, new_asid)); + write_cr3(build_cr3_noflush(next->pgd, new_asid));
/* See above wrt _rcuidle. */ trace_tlb_flush_rcuidle(TLB_FLUSH_ON_TASK_SWITCH, 0); @@ -288,7 +288,7 @@ void initialize_tlbstate_and_flush(void) !(cr4_read_shadow() & X86_CR4_PCIDE));
/* Force ASID 0 and force a TLB flush. */ - write_cr3(build_cr3(mm, 0)); + write_cr3(build_cr3(mm->pgd, 0));
/* Reinitialize tlbstate. */ this_cpu_write(cpu_tlbstate.loaded_mm_asid, 0);