diff --git a/base/glibc-compatibility/musl/getauxval.c b/base/glibc-compatibility/musl/getauxval.c index a429273fa1a..dad7aa938d7 100644 --- a/base/glibc-compatibility/musl/getauxval.c +++ b/base/glibc-compatibility/musl/getauxval.c @@ -1,4 +1,5 @@ #include +#include "atomic.h" #include // __environ #include @@ -17,18 +18,7 @@ static size_t __find_auxv(unsigned long type) return (size_t) -1; } -__attribute__((constructor)) static void __auxv_init() -{ - size_t i; - for (i = 0; __environ[i]; i++); - __auxv = (unsigned long *) (__environ + i + 1); - - size_t secure_idx = __find_auxv(AT_SECURE); - if (secure_idx != ((size_t) -1)) - __auxv_secure = __auxv[secure_idx]; -} - -unsigned long getauxval(unsigned long type) +unsigned long __getauxval(unsigned long type) { if (type == AT_SECURE) return __auxv_secure; @@ -43,3 +33,38 @@ unsigned long getauxval(unsigned long type) errno = ENOENT; return 0; } + +static void * volatile getauxval_func; + +static unsigned long __auxv_init(unsigned long type) +{ + if (!__environ) + { + // __environ is not initialized yet so we can't initialize __auxv right now. + // That's normally occurred only when getauxval() is called from some sanitizer's internal code. + errno = ENOENT; + return 0; + } + + // Initialize __auxv and __auxv_secure. + size_t i; + for (i = 0; __environ[i]; i++); + __auxv = (unsigned long *) (__environ + i + 1); + + size_t secure_idx = __find_auxv(AT_SECURE); + if (secure_idx != ((size_t) -1)) + __auxv_secure = __auxv[secure_idx]; + + // Now we've initialized __auxv, next time getauxval() will only call __get_auxval(). + a_cas_p(&getauxval_func, (void *)__auxv_init, (void *)__getauxval); + + return __getauxval(type); +} + +// First time getauxval() will call __auxv_init(). +static void * volatile getauxval_func = (void *)__auxv_init; + +unsigned long getauxval(unsigned long type) +{ + return ((unsigned long (*)(unsigned long))getauxval_func)(type); +}