linux-user: i386: Use trapnr which returns from cpu_exec() instead of exception_index

Commit Message

Chen Gang Sept. 26, 2020, 10:39 a.m. UTC

From: Chen Gang <[e-mail]>

After return from cpu_exec(), the exception_index is already set 0 in
cpu_handle_exception(), so we need the trapnr which returns from
cpu_exec() for trapno of target sigcontext.

Signed-off-by: Chen Gang <[e-mail]>
---
 include/hw/core/cpu.h      |  2 ++
 linux-user/i386/cpu_loop.c | 15 +++++++--------
 linux-user/i386/signal.c   |  4 ++--
 3 files changed, 11 insertions(+), 10 deletions(-)

Comments

Richard Henderson Sept. 27, 2020, 5:54 p.m. UTC | #1

On 9/26/20 3:39 AM, [e-mail] wrote:
> +++ b/include/hw/core/cpu.h
> @@ -458,6 +458,8 @@ struct CPUState {
>  
>      /* track IOMMUs whose translations we've cached in the TCG TLB */
>      GArray *iommu_notifiers;
> +
> +    int trapnr;

Don't put this here.  It belongs in CPUX86State, possibly with #ifdef
CONFIG_USER_ONLY.



>  void cpu_loop(CPUX86State *env)
>  {
>      CPUState *cs = env_cpu(env);
> -    int trapnr;

Why are you removing the local variable?


r~

Patch

diff --git a/include/hw/core/cpu.h b/include/hw/core/cpu.h
index 8f145733ce..390e27d9e1 100644
--- a/include/hw/core/cpu.h
+++ b/include/hw/core/cpu.h
@@ -458,6 +458,8 @@  struct CPUState {
 
     /* track IOMMUs whose translations we've cached in the TCG TLB */
     GArray *iommu_notifiers;
+
+    int trapnr;
 };
 
 typedef QTAILQ_HEAD(CPUTailQ, CPUState) CPUTailQ;
diff --git a/linux-user/i386/cpu_loop.c b/linux-user/i386/cpu_loop.c
index 70cde417e6..f0db088221 100644
--- a/linux-user/i386/cpu_loop.c
+++ b/linux-user/i386/cpu_loop.c
@@ -198,17 +198,16 @@  static void emulate_vsyscall(CPUX86State *env)
 void cpu_loop(CPUX86State *env)
 {
     CPUState *cs = env_cpu(env);
-    int trapnr;
     abi_ulong pc;
     abi_ulong ret;
 
     for(;;) {
         cpu_exec_start(cs);
-        trapnr = cpu_exec(cs);
+        cs->trapnr = cpu_exec(cs);
         cpu_exec_end(cs);
         process_queued_cpu_work(cs);
 
-        switch(trapnr) {
+        switch (cs->trapnr) {
         case 0x80:
             /* linux syscall from int $0x80 */
             ret = do_syscall(env,
@@ -273,7 +272,7 @@  void cpu_loop(CPUX86State *env)
         case EXCP00_DIVZ:
 #ifndef TARGET_X86_64
             if (env->eflags & VM_MASK) {
-                handle_vm86_trap(env, trapnr);
+                handle_vm86_trap(env, cs->trapnr);
                 break;
             }
 #endif
@@ -283,11 +282,11 @@  void cpu_loop(CPUX86State *env)
         case EXCP03_INT3:
 #ifndef TARGET_X86_64
             if (env->eflags & VM_MASK) {
-                handle_vm86_trap(env, trapnr);
+                handle_vm86_trap(env, cs->trapnr);
                 break;
             }
 #endif
-            if (trapnr == EXCP01_DB) {
+            if (cs->trapnr == EXCP01_DB) {
                 gen_signal(env, TARGET_SIGTRAP, TARGET_TRAP_BRKPT, env->eip);
             } else {
                 gen_signal(env, TARGET_SIGTRAP, TARGET_SI_KERNEL, 0);
@@ -297,7 +296,7 @@  void cpu_loop(CPUX86State *env)
         case EXCP05_BOUND:
 #ifndef TARGET_X86_64
             if (env->eflags & VM_MASK) {
-                handle_vm86_trap(env, trapnr);
+                handle_vm86_trap(env, cs->trapnr);
                 break;
             }
 #endif
@@ -318,7 +317,7 @@  void cpu_loop(CPUX86State *env)
         default:
             pc = env->segs[R_CS].base + env->eip;
             EXCP_DUMP(env, "qemu: 0x%08lx: unhandled CPU exception 0x%x - aborting\n",
-                      (long)pc, trapnr);
+                      (long)pc, cs->trapnr);
             abort();
         }
         process_pending_signals(env);
diff --git a/linux-user/i386/signal.c b/linux-user/i386/signal.c
index 97a39204cc..c184d28d22 100644
--- a/linux-user/i386/signal.c
+++ b/linux-user/i386/signal.c
@@ -215,7 +215,7 @@  static void setup_sigcontext(struct target_sigcontext *sc,
     __put_user(env->regs[R_EDX], &sc->edx);
     __put_user(env->regs[R_ECX], &sc->ecx);
     __put_user(env->regs[R_EAX], &sc->eax);
-    __put_user(cs->exception_index, &sc->trapno);
+    __put_user(cs->trapnr, &sc->trapno);
     __put_user(env->error_code, &sc->err);
     __put_user(env->eip, &sc->eip);
     __put_user(env->segs[R_CS].selector, (unsigned int *)&sc->cs);
@@ -251,7 +251,7 @@  static void setup_sigcontext(struct target_sigcontext *sc,
     __put_user(env->regs[14], &sc->r14);
     __put_user(env->regs[15], &sc->r15);
 
-    __put_user(cs->exception_index, &sc->trapno);
+    __put_user(cs->trapnr, &sc->trapno);
     __put_user(env->error_code, &sc->err);
     __put_user(env->eip, &sc->rip);