The we never allow i/o from user-only, and the tss check
that helper_check_io does will always fail. Use an ifdef
within gen_check_io and return false, indicating that an
exception is known to be raised.
Reviewed-by: Philippe Mathieu-Daudé <f4...@amsat.org>
Signed-off-by: Richard Henderson <richard.hender...@linaro.org>
---
target/i386/helper.h | 2 +-
target/i386/tcg/seg_helper.c | 28 ----------------------------
target/i386/tcg/sysemu/seg_helper.c | 29 +++++++++++++++++++++++++++++
target/i386/tcg/translate.c | 11 +++++++++++
4 files changed, 41 insertions(+), 29 deletions(-)
diff --git a/target/i386/helper.h b/target/i386/helper.h
index 47d0d67699..3fd0253298 100644
--- a/target/i386/helper.h
+++ b/target/i386/helper.h
@@ -86,7 +86,6 @@ DEF_HELPER_1(rdtsc, void, env)
DEF_HELPER_1(rdtscp, void, env)
DEF_HELPER_FLAGS_1(rdpmc, TCG_CALL_NO_WG, noreturn, env)
-DEF_HELPER_FLAGS_3(check_io, TCG_CALL_NO_WG, void, env, i32, i32)
DEF_HELPER_3(outb, void, env, i32, i32)
DEF_HELPER_2(inb, tl, env, i32)
DEF_HELPER_3(outw, void, env, i32, i32)
@@ -95,6 +94,7 @@ DEF_HELPER_3(outl, void, env, i32, i32)
DEF_HELPER_2(inl, tl, env, i32)
#ifndef CONFIG_USER_ONLY
+DEF_HELPER_FLAGS_3(check_io, TCG_CALL_NO_WG, void, env, i32, i32)
DEF_HELPER_FLAGS_4(bpt_io, TCG_CALL_NO_WG, void, env, i32, i32, tl)
DEF_HELPER_2(svm_check_intercept, void, env, i32)
DEF_HELPER_4(svm_check_io, void, env, i32, i32, i32)
diff --git a/target/i386/tcg/seg_helper.c b/target/i386/tcg/seg_helper.c
index 69d6e8f602..2f6cdc8239 100644
--- a/target/i386/tcg/seg_helper.c
+++ b/target/i386/tcg/seg_helper.c
@@ -2416,31 +2416,3 @@ void helper_verw(CPUX86State *env, target_ulong
selector1)
}
CC_SRC = eflags | CC_Z;
}
-
-/* check if Port I/O is allowed in TSS */
-void helper_check_io(CPUX86State *env, uint32_t addr, uint32_t size)
-{
- uintptr_t retaddr = GETPC();
- uint32_t io_offset, val, mask;
-
- /* TSS must be a valid 32 bit one */
- if (!(env->tr.flags & DESC_P_MASK) ||
- ((env->tr.flags >> DESC_TYPE_SHIFT) & 0xf) != 9 ||
- env->tr.limit < 103) {
- goto fail;
- }
- io_offset = cpu_lduw_kernel_ra(env, env->tr.base + 0x66, retaddr);
- io_offset += (addr >> 3);
- /* Note: the check needs two bytes */
- if ((io_offset + 1) > env->tr.limit) {
- goto fail;
- }
- val = cpu_lduw_kernel_ra(env, env->tr.base + io_offset, retaddr);
- val >>= (addr & 7);
- mask = (1 << size) - 1;
- /* all bits must be zero to allow the I/O */
- if ((val & mask) != 0) {
- fail:
- raise_exception_err_ra(env, EXCP0D_GPF, 0, retaddr);
- }
-}
diff --git a/target/i386/tcg/sysemu/seg_helper.c
b/target/i386/tcg/sysemu/seg_helper.c
index e0d7b32b82..82c0856c41 100644
--- a/target/i386/tcg/sysemu/seg_helper.c
+++ b/target/i386/tcg/sysemu/seg_helper.c
@@ -23,6 +23,7 @@
#include "exec/helper-proto.h"
#include "exec/cpu_ldst.h"
#include "tcg/helper-tcg.h"
+#include "../seg_helper.h"
#ifdef TARGET_X86_64
void helper_syscall(CPUX86State *env, int next_eip_addend)
@@ -123,3 +124,31 @@ void x86_cpu_do_interrupt(CPUState *cs)
env->old_exception = -1;
}
}
+
+/* check if Port I/O is allowed in TSS */
+void helper_check_io(CPUX86State *env, uint32_t addr, uint32_t size)
+{
+ uintptr_t retaddr = GETPC();
+ uint32_t io_offset, val, mask;
+
+ /* TSS must be a valid 32 bit one */
+ if (!(env->tr.flags & DESC_P_MASK) ||
+ ((env->tr.flags >> DESC_TYPE_SHIFT) & 0xf) != 9 ||
+ env->tr.limit < 103) {
+ goto fail;
+ }
+ io_offset = cpu_lduw_kernel_ra(env, env->tr.base + 0x66, retaddr);
+ io_offset += (addr >> 3);
+ /* Note: the check needs two bytes */
+ if ((io_offset + 1) > env->tr.limit) {
+ goto fail;
+ }
+ val = cpu_lduw_kernel_ra(env, env->tr.base + io_offset, retaddr);
+ val >>= (addr & 7);
+ mask = (1 << size) - 1;
+ /* all bits must be zero to allow the I/O */
+ if ((val & mask) != 0) {
+ fail:
+ raise_exception_err_ra(env, EXCP0D_GPF, 0, retaddr);
+ }
+}
diff --git a/target/i386/tcg/translate.c b/target/i386/tcg/translate.c
index 860c75c2b1..bcc642bf6e 100644
--- a/target/i386/tcg/translate.c
+++ b/target/i386/tcg/translate.c
@@ -193,6 +193,7 @@ typedef struct DisasContext {
{ qemu_build_not_reached(); }
#ifdef CONFIG_USER_ONLY
+STUB_HELPER(check_io, TCGv_env env, TCGv_i32 port, TCGv_i32 size)
STUB_HELPER(clgi, TCGv_env env)
STUB_HELPER(flush_page, TCGv_env env, TCGv addr)
STUB_HELPER(hlt, TCGv_env env, TCGv_i32 pc_ofs)
@@ -217,6 +218,7 @@ static void gen_jr(DisasContext *s, TCGv dest);
static void gen_jmp(DisasContext *s, target_ulong eip);
static void gen_jmp_tb(DisasContext *s, target_ulong eip, int tb_num);
static void gen_op(DisasContext *s1, int op, MemOp ot, int d);
+static void gen_exception_gpf(DisasContext *s);
/* i386 arith/logic operations */
enum {
@@ -681,6 +683,14 @@ static void gen_helper_out_func(MemOp ot, TCGv_i32 v,
TCGv_i32 n)
static bool gen_check_io(DisasContext *s, MemOp ot, TCGv_i32 port,
uint32_t svm_flags)
{
+#ifdef CONFIG_USER_ONLY
+ /*
+ * We do not implement the iopriv(2) syscall, so the TSS check
+ * will always fail.
+ */
+ gen_exception_gpf(s);
+ return false;
+#else
if (PE(s) && (CPL(s) > IOPL(s) || VM86(s))) {
gen_helper_check_io(cpu_env, port, tcg_constant_i32(1 << ot));
}
@@ -699,6 +709,7 @@ static bool gen_check_io(DisasContext *s, MemOp ot,
TCGv_i32 port,
tcg_constant_i32(next_eip - cur_eip));
}
return true;
+#endif
}
static inline void gen_movs(DisasContext *s, MemOp ot)
--
2.25.1
