david.venhoff/QEMU-Nyx-fork
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

s390x/tcg: MVO: Fault-safe handling

Browse Source 
Each operand can have a maximum length of 16. Make sure to prepare all
reads/writes before writing.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: David Hildenbrand <david@redhat.com>
This commit is contained in:
David Hildenbrand 2019-09-05 19:36:30 +02:00
parent bb36ed88e9
commit ab89acd0b7
1 changed files with 15 additions and 12 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

27
target/s390x/mem_helper.c
View File

@ -522,31 +522,34 @@ void HELPER(mvn)(CPUS390XState *env, uint32_t l, uint64_t dest, uint64_t src)
/* move with offset */ /* move with offset */
void HELPER(mvo)(CPUS390XState *env, uint32_t l, uint64_t dest, uint64_t src) void HELPER(mvo)(CPUS390XState *env, uint32_t l, uint64_t dest, uint64_t src)
{ {
const int mmu_idx = cpu_mmu_index(env, false);
/* MVO always processes one more byte than specified - maximum is 16 */
const int len_dest = (l >> 4) + 1;
const int len_src = (l & 0xf) + 1;
uintptr_t ra = GETPC(); uintptr_t ra = GETPC();
int len_dest = l >> 4;
int len_src = l & 0xf;
uint8_t byte_dest, byte_src; uint8_t byte_dest, byte_src;
int i; S390Access srca, desta;
int i, j;
src += len_src; srca = access_prepare(env, src, len_src, MMU_DATA_LOAD, mmu_idx, ra);
dest += len_dest; desta = access_prepare(env, dest, len_dest, MMU_DATA_STORE, mmu_idx, ra);
/* Handle rightmost byte */ /* Handle rightmost byte */
byte_src = cpu_ldub_data_ra(env, src, ra); byte_dest = cpu_ldub_data_ra(env, dest + len_dest - 1, ra);
byte_dest = cpu_ldub_data_ra(env, dest, ra); byte_src = access_get_byte(env, &srca, len_src - 1, ra);
byte_dest = (byte_dest & 0x0f) | (byte_src << 4); byte_dest = (byte_dest & 0x0f) | (byte_src << 4);
cpu_stb_data_ra(env, dest, byte_dest, ra); access_set_byte(env, &desta, len_dest - 1, byte_dest, ra);
/* Process remaining bytes from right to left */ /* Process remaining bytes from right to left */
for (i = 1; i <= len_dest; i++) { for (i = len_dest - 2, j = len_src - 2; i >= 0; i--, j--) {
byte_dest = byte_src >> 4; byte_dest = byte_src >> 4;
if (len_src - i >= 0) { if (j >= 0) {
byte_src = cpu_ldub_data_ra(env, src - i, ra); byte_src = access_get_byte(env, &srca, j, ra);
} else { } else {
byte_src = 0; byte_src = 0;
} }
byte_dest |= byte_src << 4; byte_dest |= byte_src << 4;
cpu_stb_data_ra(env, dest - i, byte_dest, ra); access_set_byte(env, &desta, i, byte_dest, ra);
} }
} }