When compiled with clang, the following statement gets converted into a
movaps instructions.
mem->u[0] = 5; mem->u[1] = 6; mem->u[2] = 7; mem->u[3] = 8;
Since mem is an unaligned pointer to sse_union, we get a GP when
running. Let's avoid using a pointer to sse_union at all, since doing so
implies that the pointer is aligned to 128 bits.
Fixes: e5e76263b5 ("x86: add additional test cases for sse exceptions to
emulator.c")
Signed-off-by: Jacob Xu <jacobhxu@xxxxxxxxxx>
---
x86/emulator.c | 67 +++++++++++++++++++++++++-------------------------
1 file changed, 33 insertions(+), 34 deletions(-)
diff --git a/x86/emulator.c b/x86/emulator.c
index 9705073..1d5c172 100644
--- a/x86/emulator.c
+++ b/x86/emulator.c
@@ -645,37 +645,34 @@ static void test_muldiv(long *mem)
typedef unsigned __attribute__((vector_size(16))) sse128;
-typedef union {
- sse128 sse;
- unsigned u[4];
-} sse_union;
-
-static bool sseeq(sse_union *v1, sse_union *v2)
+static bool sseeq(uint32_t *v1, uint32_t *v2)
{
bool ok = true;
int i;
for (i = 0; i < 4; ++i) {
- ok &= v1->u[i] == v2->u[i];
+ ok &= v1[i] == v2[i];
}
return ok;
}
-static __attribute__((target("sse2"))) void test_sse(sse_union *mem)
+static __attribute__((target("sse2"))) void test_sse(uint32_t *mem)
{
- sse_union v;
+ sse128 vv;
+ uint32_t *v = (uint32_t *)&vv;
write_cr0(read_cr0() & ~6); /* EM, TS */
write_cr4(read_cr4() | 0x200); /* OSFXSR */
+ memset(&vv, 0, sizeof(vv));
#define TEST_RW_SSE(insn) do { \
- v.u[0] = 1; v.u[1] = 2; v.u[2] = 3; v.u[3] = 4; \
- asm(insn " %1, %0" : "=m"(*mem) : "x"(v.sse)); \
- report(sseeq(&v, mem), insn " (read)"); \
- mem->u[0] = 5; mem->u[1] = 6; mem->u[2] = 7; mem->u[3] = 8; \
- asm(insn " %1, %0" : "=x"(v.sse) : "m"(*mem)); \
- report(sseeq(&v, mem), insn " (write)"); \
+ v[0] = 1; v[1] = 2; v[2] = 3; v[3] = 4; \
+ asm(insn " %1, %0" : "=m"(*mem) : "x"(vv) : "memory"); \
+ report(sseeq(v, mem), insn " (read)"); \
+ mem[0] = 5; mem[1] = 6; mem[2] = 7; mem[3] = 8; \
+ asm(insn " %1, %0" : "=x"(vv) : "m"(*mem) : "memory"); \
+ report(sseeq(v, mem), insn " (write)"); \
} while (0)
TEST_RW_SSE("movdqu");
@@ -704,40 +701,41 @@ static void cross_movups_handler(struct ex_regs *regs)
static __attribute__((target("sse2"))) void test_sse_exceptions(void *cross_mem)
{
- sse_union v;
- sse_union *mem;
+ sse128 vv;
+ uint32_t *v = (uint32_t *)&vv;
+ uint32_t *mem;
uint8_t *bytes = cross_mem; // aligned on PAGE_SIZE*2
void *page2 = (void *)(&bytes[4096]);
struct pte_search search;
pteval_t orig_pte;
// setup memory for unaligned access
- mem = (sse_union *)(&bytes[8]);
+ mem = (uint32_t *)(&bytes[8]);
// test unaligned access for movups, movupd and movaps
- v.u[0] = 1; v.u[1] = 2; v.u[2] = 3; v.u[3] = 4;
- mem->u[0] = 5; mem->u[1] = 6; mem->u[2] = 7; mem->u[3] = 8;
- asm("movups %1, %0" : "=m"(*mem) : "x"(v.sse));
- report(sseeq(&v, mem), "movups unaligned");
-
- v.u[0] = 1; v.u[1] = 2; v.u[2] = 3; v.u[3] = 4;
- mem->u[0] = 5; mem->u[1] = 6; mem->u[2] = 7; mem->u[3] = 8;
- asm("movupd %1, %0" : "=m"(*mem) : "x"(v.sse));
- report(sseeq(&v, mem), "movupd unaligned");
+ v[0] = 1; v[1] = 2; v[2] = 3; v[3] = 4;
+ mem[0] = 5; mem[1] = 6; mem[2] = 8; mem[3] = 9;
+ asm("movups %1, %0" : "=m"(*mem) : "x"(vv) : "memory");
+ report(sseeq(v, mem), "movups unaligned");
+
+ v[0] = 1; v[1] = 2; v[2] = 3; v[3] = 4;
+ mem[0] = 5; mem[1] = 6; mem[2] = 7; mem[3] = 8;
+ asm("movupd %1, %0" : "=m"(*mem) : "x"(vv) : "memory");
+ report(sseeq(v, mem), "movupd unaligned");
exceptions = 0;
handle_exception(GP_VECTOR, unaligned_movaps_handler);
asm("movaps %1, %0\n\t unaligned_movaps_cont:"
- : "=m"(*mem) : "x"(v.sse));
+ : "=m"(*mem) : "x"(vv));
handle_exception(GP_VECTOR, 0);
report(exceptions == 1, "unaligned movaps exception");
// setup memory for cross page access
- mem = (sse_union *)(&bytes[4096-8]);
- v.u[0] = 1; v.u[1] = 2; v.u[2] = 3; v.u[3] = 4;
- mem->u[0] = 5; mem->u[1] = 6; mem->u[2] = 7; mem->u[3] = 8;
+ mem = (uint32_t *)(&bytes[4096-8]);
+ v[0] = 1; v[1] = 2; v[2] = 3; v[3] = 4;
+ mem[0] = 5; mem[1] = 6; mem[2] = 7; mem[3] = 8;
- asm("movups %1, %0" : "=m"(*mem) : "x"(v.sse));
- report(sseeq(&v, mem), "movups unaligned crosspage");
+ asm("movups %1, %0" : "=m"(*mem) : "x"(vv) : "memory");
+ report(sseeq(v, mem), "movups unaligned crosspage");
// invalidate second page
search = find_pte_level(current_page_table(), page2, 1);
@@ -747,7 +745,8 @@ static __attribute__((target("sse2"))) void test_sse_exceptions(void *cross_mem)
exceptions = 0;
handle_exception(PF_VECTOR, cross_movups_handler);
- asm("movups %1, %0\n\t cross_movups_cont:" : "=m"(*mem) : "x"(v.sse));
+ asm("movups %1, %0\n\t cross_movups_cont:" : "=m"(*mem) : "x"(vv) :
+ "memory");
handle_exception(PF_VECTOR, 0);
report(exceptions == 1, "movups crosspage exception");
--
2.31.1.607.g51e8a6a459-goog
