diff --git a/lib/libc/gen/dlfcn.c b/lib/libc/gen/dlfcn.c --- a/lib/libc/gen/dlfcn.c +++ b/lib/libc/gen/dlfcn.c @@ -34,7 +34,9 @@ /* * Linkage to services provided by the dynamic linker. */ +#include #include +#include #include #include #include @@ -256,8 +258,30 @@ int _rtld_get_stack_prot(void) { +#ifndef IN_LIBDL + unsigned i; + int r; + static int ret; + + r = atomic_load_int(&ret); + if (r != 0) + return (r); - return (PROT_EXEC | PROT_READ | PROT_WRITE); + _once(&dl_phdr_info_once, dl_init_phdr_info); + r = PROT_EXEC | PROT_READ | PROT_WRITE; + for (i = 0; i < phdr_info.dlpi_phnum; i++) { + if (phdr_info.dlpi_phdr[i].p_type != PT_GNU_STACK) + continue; + r = PROT_READ | PROT_WRITE; + if ((phdr_info.dlpi_phdr[i].p_flags & PF_X) != 0) + r |= PROT_EXEC; + break; + } + atomic_store_int(&ret, r); + return (r); +#else + return (0); +#endif } #pragma weak _rtld_is_dlopened