take compat_sys_old_getrlimit() to native syscall

... and sanitize the ifdefs in there
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

arch/powerpc/include/asm/compat.h

@@ -109,7 +109,6 @@ struct compat_statfs {
 	int		f_spare[4];
 };
 
-#define COMPAT_RLIM_OLD_INFINITY	0x7fffffff
 #define COMPAT_RLIM_INFINITY		0xffffffff
 
 typedef u32		compat_old_sigset_t;

arch/s390/include/asm/compat.h

@@ -178,7 +178,6 @@ struct compat_statfs64 {
 	u32		f_spare[4];
 };
 
-#define COMPAT_RLIM_OLD_INFINITY	0x7fffffff
 #define COMPAT_RLIM_INFINITY		0xffffffff
 
 typedef u32		compat_old_sigset_t;	/* at least 32 bits */

arch/x86/include/asm/compat.h

@@ -116,7 +116,6 @@ struct compat_statfs {
 	int		f_spare[4];
 };
 
-#define COMPAT_RLIM_OLD_INFINITY	0x7fffffff
 #define COMPAT_RLIM_INFINITY		0xffffffff
 
 typedef u32		compat_old_sigset_t;	/* at least 32 bits */

include/linux/syscalls.h

@@ -650,7 +650,7 @@ asmlinkage long sys_olduname(struct oldold_utsname __user *);
 
 asmlinkage long sys_getrlimit(unsigned int resource,
 				struct rlimit __user *rlim);
-#if defined(COMPAT_RLIM_OLD_INFINITY) || !(defined(CONFIG_IA64))
+#ifdef __ARCH_WANT_SYS_OLD_GETRLIMIT
 asmlinkage long sys_old_getrlimit(unsigned int resource, struct rlimit __user *rlim);
 #endif
 asmlinkage long sys_setrlimit(unsigned int resource,

kernel/compat.c

@@ -468,35 +468,6 @@ COMPAT_SYSCALL_DEFINE2(setrlimit, unsigned int, resource,
 	return do_prlimit(current, resource, &r, NULL);
 }
 
-#ifdef COMPAT_RLIM_OLD_INFINITY
-
-COMPAT_SYSCALL_DEFINE2(old_getrlimit, unsigned int, resource,
-		       struct compat_rlimit __user *, rlim)
-{
-	struct rlimit r;
-	int ret;
-	mm_segment_t old_fs = get_fs();
-
-	set_fs(KERNEL_DS);
-	ret = sys_old_getrlimit(resource, (struct rlimit __user *)&r);
-	set_fs(old_fs);
-
-	if (!ret) {
-		if (r.rlim_cur > COMPAT_RLIM_OLD_INFINITY)
-			r.rlim_cur = COMPAT_RLIM_INFINITY;
-		if (r.rlim_max > COMPAT_RLIM_OLD_INFINITY)
-			r.rlim_max = COMPAT_RLIM_INFINITY;
-
-		if (!access_ok(VERIFY_WRITE, rlim, sizeof(*rlim)) ||
-		    __put_user(r.rlim_cur, &rlim->rlim_cur) ||
-		    __put_user(r.rlim_max, &rlim->rlim_max))
-			return -EFAULT;
-	}
-	return ret;
-}
-
-#endif
-
 COMPAT_SYSCALL_DEFINE2(getrlimit, unsigned int, resource,
 		       struct compat_rlimit __user *, rlim)
 {

kernel/sys.c

@@ -1328,6 +1328,30 @@ SYSCALL_DEFINE2(old_getrlimit, unsigned int, resource,
 	return copy_to_user(rlim, &x, sizeof(x)) ? -EFAULT : 0;
 }
 
+#ifdef CONFIG_COMPAT
+COMPAT_SYSCALL_DEFINE2(old_getrlimit, unsigned int, resource,
+		       struct compat_rlimit __user *, rlim)
+{
+	struct rlimit r;
+
+	if (resource >= RLIM_NLIMITS)
+		return -EINVAL;
+
+	task_lock(current->group_leader);
+	r = current->signal->rlim[resource];
+	task_unlock(current->group_leader);
+	if (r.rlim_cur > 0x7FFFFFFF)
+		r.rlim_cur = 0x7FFFFFFF;
+	if (r.rlim_max > 0x7FFFFFFF)
+		r.rlim_max = 0x7FFFFFFF;
+
+	if (put_user(r.rlim_cur, &rlim->rlim_cur) ||
+	    put_user(r.rlim_max, &rlim->rlim_max))
+		return -EFAULT;
+	return 0;
+}
+#endif
+
 #endif
 
 static inline bool rlim64_is_infinity(__u64 rlim64)