Commit b8ae4865 authored by Hugh Dickins's avatar Hugh Dickins Committed by David S. Miller

[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
......@@ -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;
......
......@@ -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"
......
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