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authorHugh Dickins <hugh@veritas.com>2005-11-07 14:08:46 -0800
committerDavid S. Miller <davem@davemloft.net>2005-11-07 14:08:46 -0800
commitb8ae48656db860d4c83a29aa7b0588fc89361935 (patch)
treedbeee0739669c6e77799b5c3a88fa27326647e20
parent5a820fa7e1a34f12fec4e6766e5c335ae9427028 (diff)
downloadop-kernel-dev-b8ae48656db860d4c83a29aa7b0588fc89361935.zip
op-kernel-dev-b8ae48656db860d4c83a29aa7b0588fc89361935.tar.gz
[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: Hugh Dickins <hugh@veritas.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--arch/sparc64/kernel/setup.c12
-rw-r--r--arch/sparc64/kernel/signal32.c6
2 files changed, 12 insertions, 6 deletions
diff --git a/arch/sparc64/kernel/setup.c b/arch/sparc64/kernel/setup.c
index c1f3423..bf1849d 100644
--- a/arch/sparc64/kernel/setup.c
+++ b/arch/sparc64/kernel/setup.c
@@ -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;
diff --git a/arch/sparc64/kernel/signal32.c b/arch/sparc64/kernel/signal32.c
index aecccd0..009a86e 100644
--- a/arch/sparc64/kernel/signal32.c
+++ b/arch/sparc64/kernel/signal32.c
@@ -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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