[patch] mips, mips64 signal trampoline

["Kip Walker" <kwalker@broadcom.com>]

It looks like the RA setup by setup_frame and setup_rt_frame in
arch/mips64/kernel/signal.c and signal32.c can be wrong.  Same for
arch/mips/kernel/signal.c

signal32.c, 32-bit signal.c: sa_restorer is overriden
signal.c: regs->regs[31] is pointed at the sigframe's code, even though
there isn't code in the frame, and a comment says that sa_restorer is
always used.

Patch for 2.4 attached.

Kip

Index: arch/mips64/kernel/signal.c
===================================================================
RCS file: /home/cvs/linux/arch/mips64/kernel/signal.c,v
retrieving revision 1.19.2.5
diff -u -r1.19.2.5 signal.c
--- arch/mips64/kernel/signal.c 18 Sep 2002 13:03:07 -0000      1.19.2.5
+++ arch/mips64/kernel/signal.c 18 Oct 2002 15:11:25 -0000
@@ -338,13 +338,12 @@
        regs->regs[ 5] = 0;
        regs->regs[ 6] = (unsigned long) &frame->sf_sc;
        regs->regs[29] = (unsigned long) frame;
-       regs->regs[31] = (unsigned long) frame->sf_code;
        regs->cp0_epc = regs->regs[25] = (unsigned long) ka->sa.sa_handler;
 
 #if DEBUG_SIG
        printk("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%p\n",
               current->comm, current->pid,
-              frame, regs->cp0_epc, frame->sf_code);
+              frame, regs->cp0_epc, regs->regs[31]);
 #endif
         return;
 
@@ -402,13 +401,12 @@
        regs->regs[ 5] = (unsigned long) &frame->rs_info;
        regs->regs[ 6] = (unsigned long) &frame->rs_uc;
        regs->regs[29] = (unsigned long) frame;
-       regs->regs[31] = (unsigned long) frame->rs_code;
        regs->cp0_epc = regs->regs[25] = (unsigned long) ka->sa.sa_handler;
 
 #if DEBUG_SIG
        printk("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%p\n",
               current->comm, current->pid,
-              frame, regs->cp0_epc, frame->rs_code);
+              frame, regs->cp0_epc, regs->regs[31]);
 #endif
        return;
 
Index: arch/mips64/kernel/signal32.c
===================================================================
RCS file: /home/cvs/linux/arch/mips64/kernel/signal32.c,v
retrieving revision 1.20.2.9
diff -u -r1.20.2.9 signal32.c
--- arch/mips64/kernel/signal32.c       2 Oct 2002 12:21:45 -0000       1.20.2.9
+++ arch/mips64/kernel/signal32.c       18 Oct 2002 15:11:25 -0000
@@ -589,6 +589,7 @@
                err |= __put_user(0x0000000c                 ,
                                  frame->sf_code + 1);
                flush_cache_sigtramp((unsigned long) frame->sf_code);
+               regs->regs[31] = (unsigned long) frame->sf_code;
        }
 
        err |= setup_sigcontext(regs, &frame->sf_sc);
@@ -610,7 +611,6 @@
        regs->regs[ 5] = 0;
        regs->regs[ 6] = (unsigned long) &frame->sf_sc;
        regs->regs[29] = (unsigned long) frame;
-       regs->regs[31] = (unsigned long) frame->sf_code;
        regs->cp0_epc = regs->regs[25] = (unsigned long) ka->sa.sa_handler;
 
 #if DEBUG_SIG
@@ -653,6 +653,7 @@
                err |= __put_user(0x0000000c                 ,
                                  frame->rs_code + 1);
                flush_cache_sigtramp((unsigned long) frame->rs_code);
+               regs->regs[31] = (unsigned long) frame->rs_code;
        }
 
        /* Convert (siginfo_t -> siginfo_t32) and copy to user. */
@@ -687,7 +688,6 @@
        regs->regs[ 5] = (unsigned long) &frame->rs_info;
        regs->regs[ 6] = (unsigned long) &frame->rs_uc;
        regs->regs[29] = (unsigned long) frame;
-       regs->regs[31] = (unsigned long) frame->rs_code;
        regs->cp0_epc = regs->regs[25] = (unsigned long) ka->sa.sa_handler;
 
 #if DEBUG_SIG