From: Tanu Kaskinen Date: Wed, 24 Jan 2018 03:51:49 +0200 Subject: memfd-wrappers: only define memfd_create() if not already defined glibc 2.27 is to be released soon, and it will provide memfd_create(). If glibc provides the function, we must not define it ourselves, otherwise building fails due to conflict between the two implementations of the same function. BugLink: https://bugs.freedesktop.org/show_bug.cgi?id=104733 (cherry picked from commit dfb0460fb4743aec047cdf755a660a9ac2d0f3fb) --- configure.ac | 3 +++ src/pulsecore/memfd-wrappers.h | 7 ++++--- 2 files changed, 7 insertions(+), 3 deletions(-) diff --git a/configure.ac b/configure.ac index 77b5ff5..3a71fd8 100644 --- a/configure.ac +++ b/configure.ac @@ -607,6 +607,9 @@ AS_IF([test "x$enable_memfd" = "xyes" && test "x$HAVE_MEMFD" = "x0"], [AC_MSG_ERROR([*** Your Linux kernel does not support memfd shared memory. *** Use linux v3.17 or higher for such a feature.])]) +AS_IF([test "x$HAVE_MEMFD" = "x1"], + AC_CHECK_FUNCS([memfd_create])) + AC_SUBST(HAVE_MEMFD) AM_CONDITIONAL([HAVE_MEMFD], [test "x$HAVE_MEMFD" = x1]) AS_IF([test "x$HAVE_MEMFD" = "x1"], AC_DEFINE([HAVE_MEMFD], 1, [Have memfd shared memory.])) diff --git a/src/pulsecore/memfd-wrappers.h b/src/pulsecore/memfd-wrappers.h index 3bed9b2..c7aadfd 100644 --- a/src/pulsecore/memfd-wrappers.h +++ b/src/pulsecore/memfd-wrappers.h @@ -20,13 +20,14 @@ License along with PulseAudio; if not, see . ***/ -#ifdef HAVE_MEMFD +#if defined(HAVE_MEMFD) && !defined(HAVE_MEMFD_CREATE) #include #include /* - * No glibc wrappers exist for memfd_create(2), so provide our own. + * Before glibc version 2.27 there was no wrapper for memfd_create(2), + * so we have to provide our own. * * Also define memfd fcntl sealing macros. While they are already * defined in the kernel header file , that file as @@ -63,6 +64,6 @@ static inline int memfd_create(const char *name, unsigned int flags) { #define F_SEAL_WRITE 0x0008 /* prevent writes */ #endif -#endif /* HAVE_MEMFD */ +#endif /* HAVE_MEMFD && !HAVE_MEMFD_CREATE */ #endif