On Thu, 2018-12-13 at 10:44 +0000, James Morse wrote: > The kernel should already handle this, as we don't trust the bootloader to > clean > up either. > > In arch/arm64/mm/proc.S::__cpu_setup() > > /* > > * __cpu_setup > > * > > * Initialise the processor for turning the MMU on. Return in x0 the > > * value of the SCTLR_EL1 register. > > */ > > .pushsection ".idmap.text", "awx" > > ENTRY(__cpu_setup) > > tlbi vmalle1 // Invalidate local > > TLB > > dsb nsh > > This is called from stext, which then branches to __primary_switch(), which > calls __enable_mmu() where you see this problem. It shouldn't not be possible > to > allocate new tlb entries between these points... > > Do you have CONFIG_RANDOMIZE_BASE disabled? This causes enable_mmu() to be > called twice, the extra tlb maintenance is in __primary_switch. > (if it works with this turned off, it points to the extra off/tlbi/on > sequence). Yes, CONFIG_RANDOMIZE_BASE is NOT set. > > > > diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S > > index 4471f570a295..5196f3d729de 100644 > > --- a/arch/arm64/kernel/head.S > > +++ b/arch/arm64/kernel/head.S > > @@ -771,6 +771,10 @@ ENTRY(__enable_mmu) > > msr ttbr0_el1, x2 // load TTBR0 > > msr ttbr1_el1, x1 // load TTBR1 > > isb > > + dsb nshst > > + tlbi vmalle1 // invalidate > > TLB > > + dsb nsh > > + isb > > msr sctlr_el1, x0 > > isb > > The overall change here is that we do extra maintenance later. > > Can move this around to bisect where the TLB entries are either coming from, > or > failing-to-be invalidated? > Do your first and kdump kernels have the same VA_BITS/PAGE_SIZE? Yes, CONFIG_ARM64_VA_BITS=48 CONFIG_ARM64_PAGE_SHIFT=16 # CONFIG_ARM64_4K_PAGES is not set # CONFIG_ARM64_16K_PAGES is not set CONFIG_ARM64_64K_PAGES=y > As a stab in the dark, (totally untested): > ------------------------------%<------------------------------ > diff --git a/arch/arm64/mm/proc.S b/arch/arm64/mm/proc.S > index 2c75b0b903ae..a5f3b7314bda 100644 > --- a/arch/arm64/mm/proc.S > +++ b/arch/arm64/mm/proc.S > @@ -406,9 +406,6 @@ ENDPROC(idmap_kpti_install_ng_mappings) > */ > .pushsection ".idmap.text", "awx" > ENTRY(__cpu_setup) > - tlbi vmalle1 // Invalidate local TLB > - dsb nsh > - > mov x0, #3 << 20 > msr cpacr_el1, x0 // Enable FP/ASIMD > mov x0, #1 << 12 // Reset mdscr_el1 and disable > @@ -465,5 +462,10 @@ ENTRY(__cpu_setup) > 1: > #endif /* CONFIG_ARM64_HW_AFDBM */ > msr tcr_el1, x10 > + isb > + > + tlbi vmalle1 // Invalidate local TLB > + dsb nsh > + > ret // return to head.S > ENDPROC(__cpu_setup) > ------------------------------%<------------------------------ > This patch works well too. _______________________________________________ kexec mailing list kexec@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/kexec
