diff options
Diffstat (limited to 'arch/x86/mm')
| -rw-r--r-- | arch/x86/mm/fault.c | 41 | ||||
| -rw-r--r-- | arch/x86/mm/init.c | 23 |
2 files changed, 41 insertions, 23 deletions
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index 3aaeffc..7a517bb 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -51,7 +51,7 @@ kmmio_fault(struct pt_regs *regs, unsigned long addr) return 0; } -static inline int __kprobes notify_page_fault(struct pt_regs *regs) +static inline int __kprobes kprobes_fault(struct pt_regs *regs) { int ret = 0; @@ -1048,7 +1048,7 @@ __do_page_fault(struct pt_regs *regs, unsigned long error_code) return; /* kprobes don't want to hook the spurious faults: */ - if (notify_page_fault(regs)) + if (kprobes_fault(regs)) return; /* * Don't take the mm semaphore here. If we fixup a prefetch @@ -1060,23 +1060,8 @@ __do_page_fault(struct pt_regs *regs, unsigned long error_code) } /* kprobes don't want to hook the spurious faults: */ - if (unlikely(notify_page_fault(regs))) + if (unlikely(kprobes_fault(regs))) return; - /* - * It's safe to allow irq's after cr2 has been saved and the - * vmalloc fault has been handled. - * - * User-mode registers count as a user access even for any - * potential system fault or CPU buglet: - */ - if (user_mode_vm(regs)) { - local_irq_enable(); - error_code |= PF_USER; - flags |= FAULT_FLAG_USER; - } else { - if (regs->flags & X86_EFLAGS_IF) - local_irq_enable(); - } if (unlikely(error_code & PF_RSVD)) pgtable_bad(regs, error_code, address); @@ -1088,8 +1073,6 @@ __do_page_fault(struct pt_regs *regs, unsigned long error_code) } } - perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address); - /* * If we're in an interrupt, have no user context or are running * in an atomic region then we must not take the fault: @@ -1099,6 +1082,24 @@ __do_page_fault(struct pt_regs *regs, unsigned long error_code) return; } + /* + * It's safe to allow irq's after cr2 has been saved and the + * vmalloc fault has been handled. + * + * User-mode registers count as a user access even for any + * potential system fault or CPU buglet: + */ + if (user_mode_vm(regs)) { + local_irq_enable(); + error_code |= PF_USER; + flags |= FAULT_FLAG_USER; + } else { + if (regs->flags & X86_EFLAGS_IF) + local_irq_enable(); + } + + perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address); + if (error_code & PF_WRITE) flags |= FAULT_FLAG_WRITE; diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c index 04664cd..ce32017 100644 --- a/arch/x86/mm/init.c +++ b/arch/x86/mm/init.c @@ -399,8 +399,25 @@ static unsigned long __init init_range_memory_mapping( return mapped_ram_size; } -/* (PUD_SHIFT-PMD_SHIFT)/2 */ -#define STEP_SIZE_SHIFT 5 +static unsigned long __init get_new_step_size(unsigned long step_size) +{ + /* + * Explain why we shift by 5 and why we don't have to worry about + * 'step_size << 5' overflowing: + * + * initial mapped size is PMD_SIZE (2M). + * We can not set step_size to be PUD_SIZE (1G) yet. + * In worse case, when we cross the 1G boundary, and + * PG_LEVEL_2M is not set, we will need 1+1+512 pages (2M + 8k) + * to map 1G range with PTE. Use 5 as shift for now. + * + * Don't need to worry about overflow, on 32bit, when step_size + * is 0, round_down() returns 0 for start, and that turns it + * into 0x100000000ULL. + */ + return step_size << 5; +} + void __init init_mem_mapping(void) { unsigned long end, real_end, start, last_start; @@ -449,7 +466,7 @@ void __init init_mem_mapping(void) min_pfn_mapped = last_start >> PAGE_SHIFT; /* only increase step_size after big range get mapped */ if (new_mapped_ram_size > mapped_ram_size) - step_size <<= STEP_SIZE_SHIFT; + step_size = get_new_step_size(step_size); mapped_ram_size += new_mapped_ram_size; } |
