From b4b31f6101433e4b8ee73779b69b935af07682f8 Mon Sep 17 00:00:00 2001 From: Andy Lutomirski <luto@amacapital.net> Date: Thu, 12 Jun 2014 17:53:11 -0700 Subject: [PATCH] x86/vdso: Add PUT_LE to store little-endian values Add PUT_LE() by analogy with GET_LE() to write littleendian values in addition to reading them. Signed-off-by: Andy Lutomirski <luto@amacapital.net> Link: http://lkml.kernel.org/r/3d9b27e92745b27b6fda1b9a98f70dc9c1246c7a.1402620737.git.luto@amacapital.net Signed-off-by: H. Peter Anvin <hpa@zytor.com> --- arch/x86/vdso/vdso2c.c | 19 ++++++++++++++++--- 1 file changed, 16 insertions(+), 3 deletions(-) diff --git a/arch/x86/vdso/vdso2c.c b/arch/x86/vdso/vdso2c.c index 450ac6eaf613cd..7a6bf50f9165fb 100644 --- a/arch/x86/vdso/vdso2c.c +++ b/arch/x86/vdso/vdso2c.c @@ -54,7 +54,7 @@ static void fail(const char *format, ...) } /* - * Evil macros to do a little-endian read. + * Evil macros for little-endian reads and writes */ #define GLE(x, bits, ifnot) \ __builtin_choose_expr( \ @@ -62,11 +62,24 @@ static void fail(const char *format, ...) (__typeof__(*(x)))get_unaligned_le##bits(x), ifnot) extern void bad_get_le(void); -#define LAST_LE(x) \ +#define LAST_GLE(x) \ __builtin_choose_expr(sizeof(*(x)) == 1, *(x), bad_get_le()) #define GET_LE(x) \ - GLE(x, 64, GLE(x, 32, GLE(x, 16, LAST_LE(x)))) + GLE(x, 64, GLE(x, 32, GLE(x, 16, LAST_GLE(x)))) + +#define PLE(x, val, bits, ifnot) \ + __builtin_choose_expr( \ + (sizeof(*(x)) == bits/8), \ + put_unaligned_le##bits((val), (x)), ifnot) + +extern void bad_put_le(void); +#define LAST_PLE(x, val) \ + __builtin_choose_expr(sizeof(*(x)) == 1, *(x) = (val), bad_put_le()) + +#define PUT_LE(x, val) \ + PLE(x, val, 64, PLE(x, val, 32, PLE(x, val, 16, LAST_PLE(x, val)))) + #define NSYMS (sizeof(required_syms) / sizeof(required_syms[0])) -- GitLab