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Commit b8ae4865 authored by Hugh Dickins's avatar Hugh Dickins Committed by David S. Miller
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[SPARC64] mm: don't re-evaluate *ptep 



sparc64 prom_callback and new_setup_frame32 each operates on a user page
table without holding lock, and no doubt they've good reason.  But I'd
feel more confident if they were to do a "pte = *ptep" and then operate
on pte, rather than re-evaluating *ptep.

Signed-off-by: default avatarHugh Dickins <hugh@veritas.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 5a820fa7

arch/sparc64/kernel/setup.c

+8 −4
Original line number Diff line number Diff line
@@ -154,6 +154,7 @@ int prom_callback(long *args) 
			pud_t *pudp;

			pmd_t *pmdp;

			pte_t *ptep;

			pte_t pte;



			for_each_process(p) {

				mm = p->mm;
@@ -178,8 +179,9 @@ int prom_callback(long *args) 
			 * being called from inside OBP.

			 */

			ptep = pte_offset_map(pmdp, va);

			if (pte_present(*ptep)) {

				tte = pte_val(*ptep);

			pte = *ptep;

			if (pte_present(pte)) {

				tte = pte_val(pte);

				res = PROM_TRUE;

			}

			pte_unmap(ptep);
@@ -218,6 +220,7 @@ int prom_callback(long *args) 
			pud_t *pudp;

			pmd_t *pmdp;

			pte_t *ptep;

			pte_t pte;

			int error;



			if ((va >= LOW_OBP_ADDRESS) && (va < HI_OBP_ADDRESS)) {
@@ -240,8 +243,9 @@ int prom_callback(long *args) 
			 * being called from inside OBP.

			 */

			ptep = pte_offset_kernel(pmdp, va);

			if (pte_present(*ptep)) {

				tte = pte_val(*ptep);

			pte = *ptep;

			if (pte_present(pte)) {

				tte = pte_val(pte);

				res = PROM_TRUE;

			}

			goto done;

arch/sparc64/kernel/signal32.c

+4 −2
Original line number Diff line number Diff line
@@ -863,6 +863,7 @@ static void new_setup_frame32(struct k_sigaction *ka, struct pt_regs *regs, 
		pud_t *pudp = pud_offset(pgdp, address);

		pmd_t *pmdp = pmd_offset(pudp, address);

		pte_t *ptep;

		pte_t pte;



		regs->u_regs[UREG_I7] = (unsigned long) (&(sf->insns[0]) - 2);
@@ -873,9 +874,10 @@ static void new_setup_frame32(struct k_sigaction *ka, struct pt_regs *regs, 


		preempt_disable();

		ptep = pte_offset_map(pmdp, address);

		if (pte_present(*ptep)) {

		pte = *ptep;

		if (pte_present(pte)) {

			unsigned long page = (unsigned long)

				page_address(pte_page(*ptep));

				page_address(pte_page(pte));



			wmb();

			__asm__ __volatile__("flush	%0 + %1"