From: Joerg Roedel <jroedel@xxxxxxx> Subject: mm: remove vmalloc_sync_(un)mappings() These functions are not needed anymore because the vmalloc and ioremap mappings are now synchronized when they are created or teared down. Remove all callers and function definitions. Link: http://lkml.kernel.org/r/20200515140023.25469-7-joro@xxxxxxxxxx Signed-off-by: Joerg Roedel <jroedel@xxxxxxx> Tested-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx> Acked-by: Andy Lutomirski <luto@xxxxxxxxxx> Acked-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx> Cc: Arnd Bergmann <arnd@xxxxxxxx> Cc: Christoph Hellwig <hch@xxxxxx> Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> Cc: "H . Peter Anvin" <hpa@xxxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxx> Cc: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx> Cc: Michal Hocko <mhocko@xxxxxxxxxx> Cc: "Rafael J. Wysocki" <rjw@xxxxxxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Cc: Vlastimil Babka <vbabka@xxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- arch/x86/mm/fault.c | 37 ------------------------------------- drivers/acpi/apei/ghes.c | 6 ------ include/linux/vmalloc.h | 2 -- kernel/notifier.c | 1 - kernel/trace/trace.c | 12 ------------ mm/nommu.c | 12 ------------ mm/vmalloc.c | 21 --------------------- 7 files changed, 91 deletions(-) --- a/arch/x86/mm/fault.c~mm-remove-vmalloc_sync_unmappings +++ a/arch/x86/mm/fault.c @@ -214,26 +214,6 @@ void arch_sync_kernel_mappings(unsigned } } -static void vmalloc_sync(void) -{ - unsigned long address; - - if (SHARED_KERNEL_PMD) - return; - - arch_sync_kernel_mappings(VMALLOC_START, VMALLOC_END); -} - -void vmalloc_sync_mappings(void) -{ - vmalloc_sync(); -} - -void vmalloc_sync_unmappings(void) -{ - vmalloc_sync(); -} - /* * 32-bit: * @@ -336,23 +316,6 @@ out: #else /* CONFIG_X86_64: */ -void vmalloc_sync_mappings(void) -{ - /* - * 64-bit mappings might allocate new p4d/pud pages - * that need to be propagated to all tasks' PGDs. - */ - sync_global_pgds(VMALLOC_START & PGDIR_MASK, VMALLOC_END); -} - -void vmalloc_sync_unmappings(void) -{ - /* - * Unmappings never allocate or free p4d/pud pages. - * No work is required here. - */ -} - /* * 64-bit: * --- a/drivers/acpi/apei/ghes.c~mm-remove-vmalloc_sync_unmappings +++ a/drivers/acpi/apei/ghes.c @@ -167,12 +167,6 @@ int ghes_estatus_pool_init(int num_ghes) if (!addr) goto err_pool_alloc; - /* - * New allocation must be visible in all pgd before it can be found by - * an NMI allocating from the pool. - */ - vmalloc_sync_mappings(); - rc = gen_pool_add(ghes_estatus_pool, addr, PAGE_ALIGN(len), -1); if (rc) goto err_pool_add; --- a/include/linux/vmalloc.h~mm-remove-vmalloc_sync_unmappings +++ a/include/linux/vmalloc.h @@ -130,8 +130,6 @@ extern int remap_vmalloc_range_partial(s extern int remap_vmalloc_range(struct vm_area_struct *vma, void *addr, unsigned long pgoff); -void vmalloc_sync_mappings(void); -void vmalloc_sync_unmappings(void); /* * Architectures can set this mask to a combination of PGTBL_P?D_MODIFIED values --- a/kernel/notifier.c~mm-remove-vmalloc_sync_unmappings +++ a/kernel/notifier.c @@ -519,7 +519,6 @@ NOKPROBE_SYMBOL(notify_die); int register_die_notifier(struct notifier_block *nb) { - vmalloc_sync_mappings(); return atomic_notifier_chain_register(&die_chain, nb); } EXPORT_SYMBOL_GPL(register_die_notifier); --- a/kernel/trace/trace.c~mm-remove-vmalloc_sync_unmappings +++ a/kernel/trace/trace.c @@ -8527,18 +8527,6 @@ static int allocate_trace_buffers(struct allocate_snapshot = false; #endif - /* - * Because of some magic with the way alloc_percpu() works on - * x86_64, we need to synchronize the pgd of all the tables, - * otherwise the trace events that happen in x86_64 page fault - * handlers can't cope with accessing the chance that a - * alloc_percpu()'d memory might be touched in the page fault trace - * event. Oh, and we need to audit all other alloc_percpu() and vmalloc() - * calls in tracing, because something might get triggered within a - * page fault trace event! - */ - vmalloc_sync_mappings(); - return 0; } --- a/mm/nommu.c~mm-remove-vmalloc_sync_unmappings +++ a/mm/nommu.c @@ -371,18 +371,6 @@ void vm_unmap_aliases(void) } EXPORT_SYMBOL_GPL(vm_unmap_aliases); -/* - * Implement a stub for vmalloc_sync_[un]mapping() if the architecture - * chose not to have one. - */ -void __weak vmalloc_sync_mappings(void) -{ -} - -void __weak vmalloc_sync_unmappings(void) -{ -} - struct vm_struct *alloc_vm_area(size_t size, pte_t **ptes) { BUG(); --- a/mm/vmalloc.c~mm-remove-vmalloc_sync_unmappings +++ a/mm/vmalloc.c @@ -1354,12 +1354,6 @@ static bool __purge_vmap_area_lazy(unsig return false; /* - * First make sure the mappings are removed from all page-tables - * before they are freed. - */ - vmalloc_sync_unmappings(); - - /* * TODO: to calculate a flush range without looping. * The list can be up to lazy_max_pages() elements. */ @@ -3089,21 +3083,6 @@ int remap_vmalloc_range(struct vm_area_s } EXPORT_SYMBOL(remap_vmalloc_range); -/* - * Implement stubs for vmalloc_sync_[un]mappings () if the architecture chose - * not to have one. - * - * The purpose of this function is to make sure the vmalloc area - * mappings are identical in all page-tables in the system. - */ -void __weak vmalloc_sync_mappings(void) -{ -} - -void __weak vmalloc_sync_unmappings(void) -{ -} - static int f(pte_t *pte, unsigned long addr, void *data) { pte_t ***p = data; _
