Commit e6c8290a authored by Benjamin Herrenschmidt's avatar Benjamin Herrenschmidt Committed by Michael Ellerman
Browse files

powerpc/mm: Move error_code checks for bad faults earlier 



There's no point looking for the VMA etc.. when we already know
we are going to fail.

This adds some code to set "code" for the si_code but that will
be gone in subsequent patches.

Signed-off-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
parent 41b464e5

arch/powerpc/mm/fault.c

+20 −15
Original line number Diff line number Diff line
@@ -237,6 +237,26 @@ static int __do_page_fault(struct pt_regs *regs, unsigned long address, 
	if (unlikely(debugger_fault_handler(regs)))

		goto bail;



#if defined(CONFIG_6xx)

	if (error_code & 0x95700000) {

		/* an error such as lwarx to I/O controller space,

		   address matching DABR, eciwx, etc. */

		code = SEGV_ACCERR;

		goto bad_area_nosemaphore;

	}

#endif /* CONFIG_6xx */

#if defined(CONFIG_8xx)

        /* The MPC8xx seems to always set 0x80000000, which is

         * "undefined".  Of those that can be set, this is the only

         * one which seems bad.

         */

	if (error_code & 0x10000000) {

                /* Guarded storage error. */

		code = SEGV_ACCERR;

		goto bad_area_nosemaphore;

	}

#endif /* CONFIG_8xx */



	/*

	 * The kernel should never take an execute fault nor should it

	 * take a page fault to a kernel address.
@@ -351,21 +371,6 @@ static int __do_page_fault(struct pt_regs *regs, unsigned long address, 


good_area:

	code = SEGV_ACCERR;

#if defined(CONFIG_6xx)

	if (error_code & 0x95700000)

		/* an error such as lwarx to I/O controller space,

		   address matching DABR, eciwx, etc. */

		goto bad_area;

#endif /* CONFIG_6xx */

#if defined(CONFIG_8xx)

        /* The MPC8xx seems to always set 0x80000000, which is

         * "undefined".  Of those that can be set, this is the only

         * one which seems bad.

         */

	if (error_code & 0x10000000)

                /* Guarded storage error. */

		goto bad_area;

#endif /* CONFIG_8xx */



	if (is_exec) {

		/*