linux-user/mips: Improve do_break

Rename to do_tr_or_bp, as per the kernel function.
Add a 'trap' argument, akin to the kernel's si_code, but clearer.
The return value is always 0, so change the return value to void.
Use force_sig and force_sig_fault.

Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220107213243.212806-15-richard.henderson@linaro.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>

linux-user/mips/cpu_loop.c

@@ -40,29 +40,25 @@ enum {
     BRK_DIVZERO = 7
 };
 
-static int do_break(CPUMIPSState *env, target_siginfo_t *info,
-                    unsigned int code)
+static void do_tr_or_bp(CPUMIPSState *env, unsigned int code, bool trap)
 {
-    int ret = -1;
+    target_ulong pc = env->active_tc.PC;
 
     switch (code) {
     case BRK_OVERFLOW:
+        force_sig_fault(TARGET_SIGFPE, TARGET_FPE_INTOVF, pc);
+        break;
     case BRK_DIVZERO:
-        info->si_signo = TARGET_SIGFPE;
-        info->si_errno = 0;
-        info->si_code = (code == BRK_OVERFLOW) ? FPE_INTOVF : FPE_INTDIV;
-        queue_signal(env, info->si_signo, QEMU_SI_FAULT, &*info);
-        ret = 0;
+        force_sig_fault(TARGET_SIGFPE, TARGET_FPE_INTDIV, pc);
         break;
     default:
-        info->si_signo = TARGET_SIGTRAP;
-        info->si_errno = 0;
-        queue_signal(env, info->si_signo, QEMU_SI_FAULT, &*info);
-        ret = 0;
+        if (trap) {
+            force_sig(TARGET_SIGTRAP);
+        } else {
+            force_sig_fault(TARGET_SIGTRAP, TARGET_TRAP_BRKPT, pc);
+        }
         break;
     }
-
-    return ret;
 }
 
 void cpu_loop(CPUMIPSState *env)
@@ -205,6 +201,13 @@ done_syscall:
                 abi_ulong trap_instr;
                 unsigned int code;
 
+                /*
+                 * FIXME: It would be better to decode the trap number
+                 * during translate, and store it in error_code while
+                 * raising the exception.  We should not be re-reading
+                 * the opcode here.
+                 */
+
                 if (env->hflags & MIPS_HFLAG_M16) {
                     if (env->insn_flags & ASE_MICROMIPS) {
                         /* microMIPS mode */
@@ -257,9 +260,7 @@ done_syscall:
                     }
                 }
 
-                if (do_break(env, &info, code) != 0) {
-                    goto error;
-                }
+                do_tr_or_bp(env, code, false);
             }
             break;
         case EXCP_TRAP:
@@ -267,6 +268,13 @@ done_syscall:
                 abi_ulong trap_instr;
                 unsigned int code = 0;
 
+                /*
+                 * FIXME: It would be better to decode the trap number
+                 * during translate, and store it in error_code while
+                 * raising the exception.  We should not be re-reading
+                 * the opcode here.
+                 */
+
                 if (env->hflags & MIPS_HFLAG_M16) {
                     /* microMIPS mode */
                     abi_ulong instr[2];
@@ -293,9 +301,7 @@ done_syscall:
                     }
                 }
 
-                if (do_break(env, &info, code) != 0) {
-                    goto error;
-                }
+                do_tr_or_bp(env, code, true);
             }
             break;
         case EXCP_ATOMIC: