Commit aa37c51b authored by Dave Hansen's avatar Dave Hansen Committed by Peter Zijlstra
Browse files

x86/mm: Break out user address space handling 



The last patch broke out kernel address space handing into its own
helper.  Now, do the same for user address space handling.

Cc: x86@kernel.org
Cc: Jann Horn <jannh@google.com>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Signed-off-by: default avatarDave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20180928160223.9C4F6440@viggo.jf.intel.com
parent 8fed6200

arch/x86/mm/fault.c

+28 −19
Original line number Diff line number Diff line
@@ -966,6 +966,7 @@ bad_area_access_error(struct pt_regs *regs, unsigned long error_code, 
		__bad_area(regs, error_code, address, vma, SEGV_ACCERR);

}



/* Handle faults in the kernel portion of the address space */

static void

do_sigbus(struct pt_regs *regs, unsigned long error_code, unsigned long address,

	  u32 *pkey, unsigned int fault)
@@ -1254,13 +1255,10 @@ do_kern_addr_fault(struct pt_regs *regs, unsigned long hw_error_code, 
}

NOKPROBE_SYMBOL(do_kern_addr_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,

/* Handle faults in the user portion of the address space */

static inline

void do_user_addr_fault(struct pt_regs *regs,

			unsigned long hw_error_code,

			unsigned long address)

{

	unsigned long sw_error_code;
@@ -1274,17 +1272,6 @@ __do_page_fault(struct pt_regs *regs, unsigned long hw_error_code, 
	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_fault(regs, hw_error_code, address);

		return;

	}



	/* kprobes don't want to hook the spurious faults: */

	if (unlikely(kprobes_fault(regs)))

		return;
@@ -1488,6 +1475,28 @@ good_area: 


	check_v8086_mode(regs, address, tsk);

}

NOKPROBE_SYMBOL(do_user_addr_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(&current->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_fault(regs, hw_error_code, address);

	else

		do_user_addr_fault(regs, hw_error_code, address);

}

NOKPROBE_SYMBOL(__do_page_fault);



static nokprobe_inline void

CRA Git | Maintained and supported by SUSTech CRA and CCSE