From: Dave Hansen <[email protected]>
The last patch broke out kernel address space handing into its own helper. Now, do the same for user address space handling. Signed-off-by: Dave Hansen <[email protected]> Cc: Sean Christopherson <[email protected]> Cc: "Peter Zijlstra (Intel)" <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Cc: Andy Lutomirski <[email protected]> --- b/arch/x86/mm/fault.c | 47 ++++++++++++++++++++++++++++------------------- 1 file changed, 28 insertions(+), 19 deletions(-) diff -puN arch/x86/mm/fault.c~pkeys-fault-warnings-01 arch/x86/mm/fault.c --- a/arch/x86/mm/fault.c~pkeys-fault-warnings-01 2018-09-07 11:21:46.663751901 -0700 +++ b/arch/x86/mm/fault.c 2018-09-07 11:21:46.667751901 -0700 @@ -1203,6 +1203,7 @@ static inline bool smap_violation(int er return true; } +/* Handle faults in the kernel portion of the address space */ static void do_kern_addr_space_fault(struct pt_regs *regs, unsigned long hw_error_code, unsigned long address) @@ -1252,14 +1253,11 @@ do_kern_addr_space_fault(struct pt_regs } NOKPROBE_SYMBOL(do_kern_addr_space_fault); -/* - * This routine handles page faults. It determines the address, - * and the problem, and then passes it off to one of the appropriate - * routines. - */ -static noinline void -__do_page_fault(struct pt_regs *regs, unsigned long hw_error_code, - unsigned long address) +/* Handle faults in the user portion of the address space */ +static inline +void do_user_addr_space_fault(struct pt_regs *regs, + unsigned long hw_error_code, + unsigned long address) { unsigned long sw_error_code; struct vm_area_struct *vma; @@ -1272,17 +1270,6 @@ __do_page_fault(struct pt_regs *regs, un tsk = current; mm = tsk->mm; - prefetchw(&mm->mmap_sem); - - if (unlikely(kmmio_fault(regs, address))) - return; - - /* Was the fault on kernel-controlled part of the address space? */ - if (unlikely(fault_in_kernel_space(address))) { - do_kern_addr_space_fault(regs, hw_error_code, address); - return; - } - /* kprobes don't want to hook the spurious faults: */ if (unlikely(kprobes_fault(regs))) return; @@ -1486,6 +1473,28 @@ good_area: check_v8086_mode(regs, address, tsk); } +NOKPROBE_SYMBOL(do_user_addr_space_fault); + +/* + * This routine handles page faults. It determines the address, + * and the problem, and then passes it off to one of the appropriate + * routines. + */ +static noinline void +__do_page_fault(struct pt_regs *regs, unsigned long hw_error_code, + unsigned long address) +{ + prefetchw(¤t->mm->mmap_sem); + + if (unlikely(kmmio_fault(regs, address))) + return; + + /* Was the fault on kernel-controlled part of the address space? */ + if (unlikely(fault_in_kernel_space(address))) + do_kern_addr_space_fault(regs, hw_error_code, address); + else + do_user_addr_space_fault(regs, hw_error_code, address); +} NOKPROBE_SYMBOL(__do_page_fault); static nokprobe_inline void _
