powerpc/xmon: Add __printf annotation to xmon_printf()

This allows the compiler to verify the format strings vs the types of
the arguments.

Update the other prototype declarations in asm/xmon.h.

Silence warnings (triggered at W=1) by adding relevant __printf
attribute. Move #define at bottom of the file to prevent conflict with
gcc attribute.

Solves the original warning:

  arch/powerpc/xmon/nonstdio.c:178:2: error: function might be
  possible candidate for ‘gnu_printf’ format attribute

In turn this uncovered many formatting errors in xmon.c, all fixed in
this patch.

Signed-off-by: Mathieu Malaterre <malat@debian.org>
[mpe: Always use px not p, fixup the 44x specific code, tweak change log]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

1 files changed, 4 insertions, 4 deletions

diff --git a/arch/powerpc/xmon/nonstdio.h b/arch/powerpc/xmon/nonstdio.h
index 2202ec61972c..e8deac6c84e2 100644
--- a/arch/powerpc/xmon/nonstdio.h
+++ b/arch/powerpc/xmon/nonstdio.h
@@ -1,13 +1,13 @@
 /* SPDX-License-Identifier: GPL-2.0 */
 #define EOF	(-1)
 
-#define printf	xmon_printf
-#define putchar	xmon_putchar
-
 extern void xmon_set_pagination_lpp(unsigned long lpp);
 extern void xmon_start_pagination(void);
 extern void xmon_end_pagination(void);
 extern int xmon_putchar(int c);
 extern void xmon_puts(const char *);
 extern char *xmon_gets(char *, int);
-extern void xmon_printf(const char *, ...);
+extern __printf(1, 2) void xmon_printf(const char *fmt, ...);
+
+#define printf	xmon_printf
+#define putchar	xmon_putchar