Commit b20c8216 authored by Heiko Carstens's avatar Heiko Carstens Committed by Vasily Gorbik
Browse files

s390/mm,fault: move VM_FAULT_ERROR handling to do_exception() 



Get rid of do_fault_error() and move its contents to do_exception(),
which makes do_exception(). With removing do_fault_error() it is also
possible to get rid of the handle_fault_error_nolock() wrapper.
Instead rename do_no_context() to handle_fault_error_nolock().

In result the whole fault handling looks much more like on other
architectures.

Signed-off-by: default avatarHeiko Carstens <hca@linux.ibm.com>
Signed-off-by: default avatarVasily Gorbik <gor@linux.ibm.com>
parent 7c194d84

arch/s390/mm/fault.c

+34 −47
Original line number Diff line number Diff line
@@ -225,7 +225,7 @@ static void do_sigsegv(struct pt_regs *regs, int si_code) 
	force_sig_fault(SIGSEGV, si_code, (void __user *)get_fault_address(regs));

}



static void do_no_context(struct pt_regs *regs, int si_code)

static void handle_fault_error_nolock(struct pt_regs *regs, int si_code)

{

	enum fault_type fault_type;

	unsigned long address;
@@ -253,11 +253,6 @@ static void do_no_context(struct pt_regs *regs, int si_code) 
	die(regs, "Oops");

}



static inline void handle_fault_error_nolock(struct pt_regs *regs, int si_code)

{

	do_no_context(regs, si_code);

}



static void handle_fault_error(struct pt_regs *regs, int si_code)

{

	struct mm_struct *mm = current->mm;
@@ -271,31 +266,6 @@ static void do_sigbus(struct pt_regs *regs) 
	force_sig_fault(SIGBUS, BUS_ADRERR, (void __user *)get_fault_address(regs));

}



static void do_fault_error(struct pt_regs *regs, vm_fault_t fault)

{

	/* fault & VM_FAULT_ERROR */

	if (fault & VM_FAULT_OOM) {

		if (!user_mode(regs))

			do_no_context(regs, 0);

		else

			pagefault_out_of_memory();

	} else if (fault & VM_FAULT_SIGSEGV) {

		/* Kernel mode? Handle exceptions or die */

		if (!user_mode(regs))

			do_no_context(regs, 0);

		else

			do_sigsegv(regs, SEGV_MAPERR);

	} else if (fault & VM_FAULT_SIGBUS) {

		/* Kernel mode? Handle exceptions or die */

		if (!user_mode(regs))

			do_no_context(regs, 0);

		else

			do_sigbus(regs);

	} else {

		BUG();

	}

}



/*

 * This routine handles page faults.  It determines the address,

 * and the problem, and then passes it off to one of the appropriate
@@ -362,9 +332,9 @@ static void do_exception(struct pt_regs *regs, int access) 
		vma_end_read(vma);

	if (!(fault & VM_FAULT_RETRY)) {

		count_vm_vma_lock_event(VMA_LOCK_SUCCESS);

		if (likely(!(fault & VM_FAULT_ERROR)))

			fault = 0;

		goto out;

		if (unlikely(fault & VM_FAULT_ERROR))

			goto error;

		return;

	}

	count_vm_vma_lock_event(VMA_LOCK_RETRY);

	/* Quick path to respond to signals */
@@ -412,13 +382,14 @@ static void do_exception(struct pt_regs *regs, int access) 
	if (fault & VM_FAULT_COMPLETED) {

		if (gmap) {

			mmap_read_lock(mm);

			goto out_gmap;

			goto gmap;

		}

		fault = 0;

		goto out;

		return;

	}

	if (unlikely(fault & VM_FAULT_ERROR)) {

		mmap_read_unlock(mm);

		goto error;

	}

	if (unlikely(fault & VM_FAULT_ERROR))

		goto out_up;

	if (fault & VM_FAULT_RETRY) {

		if (IS_ENABLED(CONFIG_PGSTE) && gmap &&	(flags & FAULT_FLAG_RETRY_NOWAIT)) {

			/*
@@ -433,7 +404,7 @@ static void do_exception(struct pt_regs *regs, int access) 
		mmap_read_lock(mm);

		goto retry;

	}

out_gmap:

gmap:

	if (IS_ENABLED(CONFIG_PGSTE) && gmap) {

		address =  __gmap_link(gmap, current->thread.gmap_addr,

				       address);
@@ -441,15 +412,31 @@ static void do_exception(struct pt_regs *regs, int access) 
			return handle_fault_error(regs, SEGV_MAPERR);

		if (address == -ENOMEM) {

			fault = VM_FAULT_OOM;

			goto out_up;

			mmap_read_unlock(mm);

			goto error;

		}

	}

	fault = 0;

out_up:

	mmap_read_unlock(mm);

out:

	if (unlikely(fault))

		do_fault_error(regs, fault);

	return;

error:

	if (fault & VM_FAULT_OOM) {

		if (!user_mode(regs))

			handle_fault_error_nolock(regs, 0);

		else

			pagefault_out_of_memory();

	} else if (fault & VM_FAULT_SIGSEGV) {

		if (!user_mode(regs))

			handle_fault_error_nolock(regs, 0);

		else

			do_sigsegv(regs, SEGV_MAPERR);

	} else if (fault & VM_FAULT_SIGBUS) {

		if (!user_mode(regs))

			handle_fault_error_nolock(regs, 0);

		else

			do_sigbus(regs);

	} else {

		BUG();

	}

}



void do_protection_exception(struct pt_regs *regs)
@@ -477,7 +464,7 @@ void do_protection_exception(struct pt_regs *regs) 
		 * Low-address protection in kernel mode means

		 * NULL pointer write access in kernel mode.

		 */

		return do_no_context(regs, 0);

		return handle_fault_error_nolock(regs, 0);

	}

	if (unlikely(MACHINE_HAS_NX && teid.b56)) {

		regs->int_parm_long = (teid.addr * PAGE_SIZE) | (regs->psw.addr & PAGE_MASK);