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target/sparc: Correctly handle bus errors in page table walks

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Currently we use the ldl_phys() function to read page table entries.
With the unassigned_access hook in place, if these hit an unassigned
area of memory then the hook will cause us to wrongly generate
an exception with a fault address matching the address of the
page table entry.

Change to using address_space_ldl() so we can detect and correctly
handle bus errors and give them their correct behaviour of
causing a translation error with a suitable fault status register.

Note that this won't actually take effect until we switch the
over to using the do_translation_failed hook.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Tested-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Message-id: 20190801183012.17564-5-peter.maydell@linaro.org
This commit is contained in:
Peter Maydell 2019-08-01 19:30:09 +01:00
parent 776095d3cd
commit 3c818dfcc2
1 changed files with 20 additions and 4 deletions
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24
target/sparc/mmu_helper.c
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@ -98,6 +98,7 @@ static int get_physical_address(CPUSPARCState *env, hwaddr *physical,
int error_code = 0, is_dirty, is_user;
unsigned long page_offset;
CPUState *cs = env_cpu(env);
MemTxResult result;
is_user = mmu_idx == MMU_USER_IDX;
@ -120,7 +121,10 @@ static int get_physical_address(CPUSPARCState *env, hwaddr *physical,
/* SPARC reference MMU table walk: Context table->L1->L2->PTE */
/* Context base + context number */
pde_ptr = (env->mmuregs[1] << 4) + (env->mmuregs[2] << 2);
pde = ldl_phys(cs->as, pde_ptr);
pde = address_space_ldl(cs->as, pde_ptr, MEMTXATTRS_UNSPECIFIED, &result);
if (result != MEMTX_OK) {
return 4 << 2; /* Translation fault, L = 0 */
}
/* Ctx pde */
switch (pde & PTE_ENTRYTYPE_MASK) {
@ -132,7 +136,11 @@ static int get_physical_address(CPUSPARCState *env, hwaddr *physical,
return 4 << 2;
case 1: /* L0 PDE */
pde_ptr = ((address >> 22) & ~3) + ((pde & ~3) << 4);
pde = ldl_phys(cs->as, pde_ptr);
pde = address_space_ldl(cs->as, pde_ptr,
MEMTXATTRS_UNSPECIFIED, &result);
if (result != MEMTX_OK) {
return (1 << 8) | (4 << 2); /* Translation fault, L = 1 */
}
switch (pde & PTE_ENTRYTYPE_MASK) {
default:
@ -142,7 +150,11 @@ static int get_physical_address(CPUSPARCState *env, hwaddr *physical,
return (1 << 8) | (4 << 2);
case 1: /* L1 PDE */
pde_ptr = ((address & 0xfc0000) >> 16) + ((pde & ~3) << 4);
pde = ldl_phys(cs->as, pde_ptr);
pde = address_space_ldl(cs->as, pde_ptr,
MEMTXATTRS_UNSPECIFIED, &result);
if (result != MEMTX_OK) {
return (2 << 8) | (4 << 2); /* Translation fault, L = 2 */
}
switch (pde & PTE_ENTRYTYPE_MASK) {
default:
@ -152,7 +164,11 @@ static int get_physical_address(CPUSPARCState *env, hwaddr *physical,
return (2 << 8) | (4 << 2);
case 1: /* L2 PDE */
pde_ptr = ((address & 0x3f000) >> 10) + ((pde & ~3) << 4);
pde = ldl_phys(cs->as, pde_ptr);
pde = address_space_ldl(cs->as, pde_ptr,
MEMTXATTRS_UNSPECIFIED, &result);
if (result != MEMTX_OK) {
return (3 << 8) | (4 << 2); /* Translation fault, L = 3 */
}
switch (pde & PTE_ENTRYTYPE_MASK) {
default: