From 0d6cada9708e9d2e2104f7946fe9970342cae33e Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Wed, 20 Nov 2019 13:28:27 -0500 Subject: [PATCH] target/sparc: Correctly handle bus errors in page table walks 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. Backports commit 3c818dfcc271f5ba298b06f33466ab30f9a28349 from qemu --- qemu/target/sparc/mmu_helper.c | 24 ++++++++++++++++++++---- 1 file changed, 20 insertions(+), 4 deletions(-) diff --git a/qemu/target/sparc/mmu_helper.c b/qemu/target/sparc/mmu_helper.c index 17d62209..fdea39c2 100644 --- a/qemu/target/sparc/mmu_helper.c +++ b/qemu/target/sparc/mmu_helper.c @@ -96,6 +96,7 @@ 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; @@ -118,7 +119,10 @@ 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) { @@ -130,7 +134,11 @@ 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: @@ -140,7 +148,11 @@ 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: @@ -150,7 +162,11 @@ 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: