lib/vsprintf.c: move sizeof(struct printf_spec) next to its definition

At the time of commit d048419311ff ("lib/vsprintf.c: expand field_width
to 24 bits"), there was no compiletime_assert/BUILD_BUG/....  variant
that could be used outside function scope.  Now we have static_assert(),
so move the assertion next to the definition instead of hiding it in
some arbitrary function.

Also add the appropriate #include to avoid relying on build_bug.h being
pulled in via some arbitrary chain of includes.

Link: http://lkml.kernel.org/r/20190208203015.29702-2-linux@rasmusvillemoes.dk
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Kees Cook <keescook@chromium.org>
Cc: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index 3add923..30b00de 100644 (file)
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -17,6 +17,7 @@
  */
 
 #include <stdarg.h>
+#include <linux/build_bug.h>
 #include <linux/clk.h>
 #include <linux/clk-provider.h>
 #include <linux/module.h>      /* for KSYM_SYMBOL_LEN */
@@ -405,6 +406,8 @@ struct printf_spec {
        unsigned int    base:8;         /* number base, 8, 10 or 16 only */
        signed int      precision:16;   /* # of digits/chars */
 } __packed;
+static_assert(sizeof(struct printf_spec) == 8);
+
 #define FIELD_WIDTH_MAX ((1 << 23) - 1)
 #define PRECISION_MAX ((1 << 15) - 1)
 
@@ -422,8 +425,6 @@ char *number(char *buf, char *end, unsigned long long num,
        int field_width = spec.field_width;
        int precision = spec.precision;
 
-       BUILD_BUG_ON(sizeof(struct printf_spec) != 8);
-
        /* locase = 0 or 0x20. ORing digits or letters with 'locase'
         * produces same digits or (maybe lowercased) letters */
        locase = (spec.flags & SMALL);