From 4c2766b69c261703c62131b5e4200d0e164b5eb4 Mon Sep 17 00:00:00 2001 From: Emil Velikov Date: Sun, 7 Sep 2014 19:29:00 +0100 Subject: [PATCH] Add private mmap/munmap wrappers Unlike Linux, Android (bionic) has separate functions - mmap & mmap64. Add a local wrapper (inspired by gallium) that will be used throughout libdrm to combat this bionic feature. v2: - Drop the undefined unlikely macro. - Use macro for munmap under Android. - Wrap long lines. Signed-off-by: Emil Velikov Reviewed-by: Jakob Bornecrantz (v1) --- libdrm.h | 55 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 55 insertions(+) diff --git a/libdrm.h b/libdrm.h index 23926e6f..acfada5c 100644 --- a/libdrm.h +++ b/libdrm.h @@ -31,4 +31,59 @@ # define drm_public #endif + +/** + * Static (compile-time) assertion. + * Basically, use COND to dimension an array. If COND is false/zero the + * array size will be -1 and we'll get a compilation error. + */ +#define STATIC_ASSERT(COND) \ + do { \ + (void) sizeof(char [1 - 2*!(COND)]); \ + } while (0) + + +#include + +#if defined(ANDROID) +#include /* for EINVAL */ + +extern void *__mmap2(void *, size_t, int, int, int, size_t); + +static inline void *drm_mmap(void *addr, size_t length, int prot, int flags, + int fd, loff_t offset) +{ + /* offset must be aligned to 4096 (not necessarily the page size) */ + if (offset & 4095) { + errno = EINVAL; + return MAP_FAILED; + } + + return __mmap2(addr, length, prot, flags, fd, (size_t) (offset >> 12)); +} + +# define drm_munmap(addr, length) \ + munmap(addr, length) + + +#else + +/* assume large file support exists */ +# define drm_mmap(addr, length, prot, flags, fd, offset) \ + mmap(addr, length, prot, flags, fd, offset) + + +static inline int drm_munmap(void *addr, size_t length) +{ + /* Copied from configure code generated by AC_SYS_LARGEFILE */ +#define LARGE_OFF_T ((((off_t) 1 << 31) << 31) - 1 + \ + (((off_t) 1 << 31) << 31)) + STATIC_ASSERT(LARGE_OFF_T % 2147483629 == 721 && + LARGE_OFF_T % 2147483647 == 1); +#undef LARGE_OFF_T + + return munmap(addr, length); +} +#endif + #endif -- 2.11.0