arch: sparc: prom: looping issue, need additional length check in the outside looping

When "cp >= barg_buf + BARG_LEN-2", it breaks internel looping 'while',
but outside loop 'for' still has effect, so "*cp++ = ' '" will continue
repeating which may cause memory overflow.

So need additional length check for it in the outside looping.

Also beautify the related code which found by "./scripts/checkpatch.pl"

Signed-off-by: Chen Gang <gang.chen@asianux.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 7 insertions, 5 deletions

diff --git a/arch/sparc/prom/bootstr_32.c b/arch/sparc/prom/bootstr_32.c
index f5ec32e0d419..d2b49d2365e7 100644
--- a/arch/sparc/prom/bootstr_32.c
+++ b/arch/sparc/prom/bootstr_32.c
@@ -23,23 +23,25 @@ prom_getbootargs(void)
                 return barg_buf;
         }
 
-        switch(prom_vers) {
+        switch (prom_vers) {
         case PROM_V0:
                 cp = barg_buf;
                 /* Start from 1 and go over fd(0,0,0)kernel */
-                for(iter = 1; iter < 8; iter++) {
+                for (iter = 1; iter < 8; iter++) {
                         arg = (*(romvec->pv_v0bootargs))->argv[iter];
                         if (arg == NULL)
                                 break;
-                        while(*arg != 0) {
+                        while (*arg != 0) {
                                 /* Leave place for space and null. */
-                                if(cp >= barg_buf + BARG_LEN-2){
+                                if (cp >= barg_buf + BARG_LEN - 2)
                                         /* We might issue a warning here. */
                                         break;
-                                }
                                 *cp++ = *arg++;
                         }
                         *cp++ = ' ';
+                        if (cp >= barg_buf + BARG_LEN - 1)
+                                /* We might issue a warning here. */
+                                break;
                 }
                 *cp = 0;
                 break;