@@ -130,6 +130,7 @@ typedef struct DisasContext {
TCGv_i64 tmp1_i64;
sigjmp_buf jmpbuf;
+ TCGOp *prev_insn_end;
} DisasContext;
/* The environment in which user-only runs is constrained. */
@@ -2008,6 +2009,12 @@ static uint64_t advance_pc(CPUX86State *env, DisasContext *s, int num_bytes)
{
uint64_t pc = s->pc;
+ /* This is a subsequent insn that crosses a page boundary. */
+ if (s->base.num_insns > 1 &&
+ !is_same_page(&s->base, s->pc + num_bytes - 1)) {
+ siglongjmp(s->jmpbuf, 2);
+ }
+
s->pc += num_bytes;
if (unlikely(s->pc - s->pc_start > X86_MAX_INSN_LENGTH)) {
/* If the instruction's 16th byte is on a different page than the 1st, a
@@ -4669,6 +4676,8 @@ static target_ulong disas_insn(DisasContext *s, CPUState *cpu)
int modrm, reg, rm, mod, op, opreg, val;
target_ulong next_eip, tval;
target_ulong pc_start = s->base.pc_next;
+ bool orig_cc_op_dirty = s->cc_op_dirty;
+ CCOp orig_cc_op = s->cc_op;
s->pc_start = s->pc = pc_start;
s->override = -1;
@@ -4681,9 +4690,22 @@ static target_ulong disas_insn(DisasContext *s, CPUState *cpu)
s->rip_offset = 0; /* for relative ip address */
s->vex_l = 0;
s->vex_v = 0;
- if (sigsetjmp(s->jmpbuf, 0) != 0) {
+ switch (sigsetjmp(s->jmpbuf, 0)) {
+ case 0:
+ break;
+ case 1:
gen_exception_gpf(s);
return s->pc;
+ case 2:
+ /* Restore state that may affect the next instruction. */
+ s->cc_op_dirty = orig_cc_op_dirty;
+ s->cc_op = orig_cc_op;
+ s->base.num_insns--;
+ tcg_remove_ops_after(s->prev_insn_end);
+ s->base.is_jmp = DISAS_TOO_MANY;
+ return pc_start;
+ default:
+ g_assert_not_reached();
}
prefixes = 0;
@@ -8745,6 +8767,7 @@ static void i386_tr_insn_start(DisasContextBase *dcbase, CPUState *cpu)
{
DisasContext *dc = container_of(dcbase, DisasContext, base);
+ dc->prev_insn_end = tcg_last_op();
tcg_gen_insn_start(dc->base.pc_next, dc->cc_op);
}
@@ -8765,31 +8788,22 @@ static void i386_tr_translate_insn(DisasContextBase *dcbase, CPUState *cpu)
#endif
pc_next = disas_insn(dc, cpu);
-
- if (dc->flags & (HF_TF_MASK | HF_INHIBIT_IRQ_MASK)) {
- /* if single step mode, we generate only one instruction and
- generate an exception */
- /* if irq were inhibited with HF_INHIBIT_IRQ_MASK, we clear
- the flag and abort the translation to give the irqs a
- chance to happen */
- dc->base.is_jmp = DISAS_TOO_MANY;
- } else if ((tb_cflags(dc->base.tb) & CF_USE_ICOUNT)
- && ((pc_next & TARGET_PAGE_MASK)
- != ((pc_next + TARGET_MAX_INSN_SIZE - 1)
- & TARGET_PAGE_MASK)
- || (pc_next & ~TARGET_PAGE_MASK) == 0)) {
- /* Do not cross the boundary of the pages in icount mode,
- it can cause an exception. Do it only when boundary is
- crossed by the first instruction in the block.
- If current instruction already crossed the bound - it's ok,
- because an exception hasn't stopped this code.
- */
- dc->base.is_jmp = DISAS_TOO_MANY;
- } else if ((pc_next - dc->base.pc_first) >= (TARGET_PAGE_SIZE - 32)) {
- dc->base.is_jmp = DISAS_TOO_MANY;
- }
-
dc->base.pc_next = pc_next;
+
+ if (dc->base.is_jmp == DISAS_NEXT) {
+ if (dc->flags & (HF_TF_MASK | HF_INHIBIT_IRQ_MASK)) {
+ /*
+ * If single step mode, we generate only one instruction and
+ * generate an exception.
+ * If irq were inhibited with HF_INHIBIT_IRQ_MASK, we clear
+ * the flag and abort the translation to give the irqs a
+ * chance to happen.
+ */
+ dc->base.is_jmp = DISAS_TOO_MANY;
+ } else if (!is_same_page(&dc->base, pc_next)) {
+ dc->base.is_jmp = DISAS_TOO_MANY;
+ }
+ }
}
static void i386_tr_tb_stop(DisasContextBase *dcbase, CPUState *cpu)
new file mode 100644
@@ -0,0 +1,75 @@
+#include "../multiarch/noexec.c.inc"
+
+static void *arch_mcontext_pc(const mcontext_t *ctx)
+{
+ return (void *)ctx->gregs[REG_RIP];
+}
+
+int arch_mcontext_arg(const mcontext_t *ctx)
+{
+ return ctx->gregs[REG_RDI];
+}
+
+static void arch_flush(void *p, int len)
+{
+}
+
+extern char noexec_1[];
+extern char noexec_2[];
+extern char noexec_end[];
+
+asm("noexec_1:\n"
+ " movq $1,%rdi\n" /* %rdi is 0 on entry, set 1. */
+ "noexec_2:\n"
+ " movq $2,%rdi\n" /* %rdi is 0/1; set 2. */
+ " ret\n"
+ "noexec_end:");
+
+int main(void)
+{
+ struct noexec_test noexec_tests[] = {
+ {
+ .name = "fallthrough",
+ .test_code = noexec_1,
+ .test_len = noexec_end - noexec_1,
+ .page_ofs = noexec_1 - noexec_2,
+ .entry_ofs = noexec_1 - noexec_2,
+ .expected_si_ofs = 0,
+ .expected_pc_ofs = 0,
+ .expected_arg = 1,
+ },
+ {
+ .name = "jump",
+ .test_code = noexec_1,
+ .test_len = noexec_end - noexec_1,
+ .page_ofs = noexec_1 - noexec_2,
+ .entry_ofs = 0,
+ .expected_si_ofs = 0,
+ .expected_pc_ofs = 0,
+ .expected_arg = 0,
+ },
+ {
+ .name = "fallthrough [cross]",
+ .test_code = noexec_1,
+ .test_len = noexec_end - noexec_1,
+ .page_ofs = noexec_1 - noexec_2 - 2,
+ .entry_ofs = noexec_1 - noexec_2 - 2,
+ .expected_si_ofs = 0,
+ .expected_pc_ofs = -2,
+ .expected_arg = 1,
+ },
+ {
+ .name = "jump [cross]",
+ .test_code = noexec_1,
+ .test_len = noexec_end - noexec_1,
+ .page_ofs = noexec_1 - noexec_2 - 2,
+ .entry_ofs = -2,
+ .expected_si_ofs = 0,
+ .expected_pc_ofs = -2,
+ .expected_arg = 0,
+ },
+ };
+
+ return test_noexec(noexec_tests,
+ sizeof(noexec_tests) / sizeof(noexec_tests[0]));
+}
@@ -10,6 +10,7 @@ include $(SRC_PATH)/tests/tcg/i386/Makefile.target
ifeq ($(filter %-linux-user, $(TARGET)),$(TARGET))
X86_64_TESTS += vsyscall
+X86_64_TESTS += noexec
TESTS=$(MULTIARCH_TESTS) $(X86_64_TESTS) test-x86_64
else
TESTS=$(MULTIARCH_TESTS)
@@ -23,5 +24,5 @@ test-x86_64: LDFLAGS+=-lm -lc
test-x86_64: test-i386.c test-i386.h test-i386-shift.h test-i386-muldiv.h
$(CC) $(CFLAGS) $< -o $@ $(LDFLAGS)
-vsyscall: $(SRC_PATH)/tests/tcg/x86_64/vsyscall.c
+%: $(SRC_PATH)/tests/tcg/x86_64/%.c
$(CC) $(CFLAGS) $< -o $@ $(LDFLAGS)