linux-user/i386: Fix -mregparm=3 for signal delivery

Since v2.6.19, the kernel has supported -mregparm=3.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

linux-user/i386/signal.c

diff --git a/linux-user/i386/signal.c b/linux-user/i386/signal.c
index 3271ebd..6763b4b 100644
--- a/linux-user/i386/signal.c
+++ b/linux-user/i386/signal.c
@@ -405,8 +405,6 @@
     if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0))
         goto give_sigsegv;
 
-    __put_user(sig, &frame->sig);
-
     setup_sigcontext(&frame->sc, &frame->fpstate, env, set->sig[0],
             frame_addr + offsetof(struct sigframe, fpstate));
 
@@ -428,6 +426,13 @@
     env->regs[R_ESP] = frame_addr;
     env->eip = ka->_sa_handler;
 
+    /* Store argument for both -mregparm=3 and standard. */
+    env->regs[R_EAX] = sig;
+    __put_user(sig, &frame->sig);
+    /* The kernel clears EDX and ECX even though there is only one arg. */
+    env->regs[R_EDX] = 0;
+    env->regs[R_ECX] = 0;
+
     cpu_x86_load_seg(env, R_DS, __USER_DS);
     cpu_x86_load_seg(env, R_ES, __USER_DS);
     cpu_x86_load_seg(env, R_SS, __USER_DS);
@@ -449,9 +454,6 @@
                     target_sigset_t *set, CPUX86State *env)
 {
     abi_ulong frame_addr;
-#ifndef TARGET_X86_64
-    abi_ulong addr;
-#endif
     struct rt_sigframe *frame;
     int i;
 
@@ -461,14 +463,6 @@
     if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0))
         goto give_sigsegv;
 
-    /* These fields are only in rt_sigframe on 32 bit */
-#ifndef TARGET_X86_64
-    __put_user(sig, &frame->sig);
-    addr = frame_addr + offsetof(struct rt_sigframe, info);
-    __put_user(addr, &frame->pinfo);
-    addr = frame_addr + offsetof(struct rt_sigframe, uc);
-    __put_user(addr, &frame->puc);
-#endif
     if (ka->sa_flags & TARGET_SA_SIGINFO) {
         frame->info = *info;
     }
@@ -508,9 +502,13 @@
     env->eip = ka->_sa_handler;
 
 #ifndef TARGET_X86_64
+    /* Store arguments for both -mregparm=3 and standard. */
     env->regs[R_EAX] = sig;
+    __put_user(sig, &frame->sig);
     env->regs[R_EDX] = frame_addr + offsetof(struct rt_sigframe, info);
+    __put_user(env->regs[R_EDX], &frame->pinfo);
     env->regs[R_ECX] = frame_addr + offsetof(struct rt_sigframe, uc);
+    __put_user(env->regs[R_ECX], &frame->puc);
 #else
     env->regs[R_EAX] = 0;
     env->regs[R_EDI] = sig;