sparc64: clean up compat_sigset_t.seta handling

Use compat_sigset_t rather than opencode the array
Drop "switch (_NSIG_WORDS)" as we know this is always 1
Introduce BUILD_BUG_ON() to catch if this changes

As a side-effect of this fix following sparse warnings:
signal32.c:220:60: warning: invalid access past the end of 'seta' (12 8)
signal32.c:220:42: warning: invalid access past the end of 'seta' (8 8)
signal32.c:219:60: warning: invalid access past the end of 'seta' (20 8)
signal32.c:219:42: warning: invalid access past the end of 'seta' (16 8)
signal32.c:218:60: warning: invalid access past the end of 'seta' (28 8)
signal32.c:218:42: warning: invalid access past the end of 'seta' (24 8)
signal32.c:309:68: warning: invalid access past the end of 'seta' (12 8)
signal32.c:309:46: warning: invalid access past the end of 'seta' (8 8)
signal32.c:308:68: warning: invalid access past the end of 'seta' (20 8)
signal32.c:308:46: warning: invalid access past the end of 'seta' (16 8)
signal32.c:307:68: warning: invalid access past the end of 'seta' (28 8)
signal32.c:307:46: warning: invalid access past the end of 'seta' (24 8)

They all pointed to code that was never executed - so no bugs fixed.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 17 insertions, 38 deletions

diff --git a/arch/sparc/kernel/signal32.c b/arch/sparc/kernel/signal32.c
index ab33c99c8bc4..62deba7be1a9 100644
--- a/arch/sparc/kernel/signal32.c
+++ b/arch/sparc/kernel/signal32.c
@@ -146,7 +146,7 @@ void do_sigreturn32(struct pt_regs *regs)
         unsigned int psr;
         unsigned pc, npc;
         sigset_t set;
-        unsigned seta[_COMPAT_NSIG_WORDS];
+        compat_sigset_t seta;
         int err, i;
         
         /* Always make any pending restarted system calls return -EINTR */
@@ -210,17 +210,13 @@ void do_sigreturn32(struct pt_regs *regs)
                 if (restore_rwin_state(compat_ptr(rwin_save)))
                         goto segv;
         }
-        err |= __get_user(seta[0], &sf->info.si_mask);
-        err |= copy_from_user(seta+1, &sf->extramask,
+        err |= __get_user(seta.sig[0], &sf->info.si_mask);
+        err |= copy_from_user(&seta.sig[1], &sf->extramask,
                               (_COMPAT_NSIG_WORDS - 1) * sizeof(unsigned int));
         if (err)
                 goto segv;
-        switch (_NSIG_WORDS) {
-                case 4: set.sig[3] = seta[6] + (((long)seta[7]) << 32);
-                case 3: set.sig[2] = seta[4] + (((long)seta[5]) << 32);
-                case 2: set.sig[1] = seta[2] + (((long)seta[3]) << 32);
-                case 1: set.sig[0] = seta[0] + (((long)seta[1]) << 32);
-        }
+
+        set.sig[0] = seta.sig[0] + (((long)seta.sig[1]) << 32);
         set_current_blocked(&set);
         return;
 
@@ -304,12 +300,7 @@ asmlinkage void do_rt_sigreturn32(struct pt_regs *regs)
                         goto segv;
         }
 
-        switch (_NSIG_WORDS) {
-                case 4: set.sig[3] = seta.sig[6] + (((long)seta.sig[7]) << 32);
-                case 3: set.sig[2] = seta.sig[4] + (((long)seta.sig[5]) << 32);
-                case 2: set.sig[1] = seta.sig[2] + (((long)seta.sig[3]) << 32);
-                case 1: set.sig[0] = seta.sig[0] + (((long)seta.sig[1]) << 32);
-        }
+        set.sig[0] = seta.sig[0] + (((long)seta.sig[1]) << 32);
         set_current_blocked(&set);
         return;
 segv:
@@ -418,7 +409,7 @@ static int setup_frame32(struct ksignal *ksig, struct pt_regs *regs,
         void __user *tail;
         int sigframe_size;
         u32 psr;
-        unsigned int seta[_COMPAT_NSIG_WORDS];
+        compat_sigset_t seta;
 
         /* 1. Make sure everything is clean */
         synchronize_user_stack();
@@ -482,18 +473,14 @@ static int setup_frame32(struct ksignal *ksig, struct pt_regs *regs,
                 err |= __put_user(0, &sf->rwin_save);
         }
 
-        switch (_NSIG_WORDS) {
-        case 4: seta[7] = (oldset->sig[3] >> 32);
-                seta[6] = oldset->sig[3];
-        case 3: seta[5] = (oldset->sig[2] >> 32);
-                seta[4] = oldset->sig[2];
-        case 2: seta[3] = (oldset->sig[1] >> 32);
-                seta[2] = oldset->sig[1];
-        case 1: seta[1] = (oldset->sig[0] >> 32);
-                seta[0] = oldset->sig[0];
-        }
-        err |= __put_user(seta[0], &sf->info.si_mask);
-        err |= __copy_to_user(sf->extramask, seta + 1,
+        /* If these change we need to know - assignments to seta relies on these sizes */
+        BUILD_BUG_ON(_NSIG_WORDS != 1);
+        BUILD_BUG_ON(_COMPAT_NSIG_WORDS != 2);
+        seta.sig[1] = (oldset->sig[0] >> 32);
+        seta.sig[0] = oldset->sig[0];
+
+        err |= __put_user(seta.sig[0], &sf->info.si_mask);
+        err |= __copy_to_user(sf->extramask, &seta.sig[1],
                               (_COMPAT_NSIG_WORDS - 1) * sizeof(unsigned int));
 
         if (!wsaved) {
@@ -623,16 +610,8 @@ static int setup_rt_frame32(struct ksignal *ksig, struct pt_regs *regs,
         /* Setup sigaltstack */
         err |= __compat_save_altstack(&sf->stack, regs->u_regs[UREG_FP]);
 
-        switch (_NSIG_WORDS) {
-        case 4: seta.sig[7] = (oldset->sig[3] >> 32);
-                seta.sig[6] = oldset->sig[3];
-        case 3: seta.sig[5] = (oldset->sig[2] >> 32);
-                seta.sig[4] = oldset->sig[2];
-        case 2: seta.sig[3] = (oldset->sig[1] >> 32);
-                seta.sig[2] = oldset->sig[1];
-        case 1: seta.sig[1] = (oldset->sig[0] >> 32);
-                seta.sig[0] = oldset->sig[0];
-        }
+        seta.sig[1] = (oldset->sig[0] >> 32);
+        seta.sig[0] = oldset->sig[0];
         err |= __copy_to_user(&sf->mask, &seta, sizeof(compat_sigset_t));
 
         if (!wsaved) {