Musl recently added a wrapper for gettid() syscall. There is no way to detect this new version in a reliable way, so rename our gettid() wrapper to a non-conflicting name. Introduce a new function which, when using a libc known to provide a wrapper for gettid(), calls it, and which, otherwise, performs the syscall directly. Anyway this function is only used on systems where /proc/thread-self does not exist, which are therefore running Linux<3.17. Fixes: https://github.com/SELinuxProject/selinux/issues/282 Signed-off-by: Nicolas Iooss <nicolas.iooss@xxxxxxx> diff --git a/libselinux/src/procattr.c b/libselinux/src/procattr.c index 1aa67ac53f39..840570525f5f 100644 --- a/libselinux/src/procattr.c +++ b/libselinux/src/procattr.c @@ -25,21 +25,23 @@ static __thread char destructor_initialized; /* Bionic and glibc >= 2.30 declare gettid() system call wrapper in unistd.h and * has a definition for it */ #ifdef __BIONIC__ - #define OVERRIDE_GETTID 0 + #define HAVE_GETTID 1 #elif !defined(__GLIBC_PREREQ) - #define OVERRIDE_GETTID 1 + #define HAVE_GETTID 0 #elif !__GLIBC_PREREQ(2,30) - #define OVERRIDE_GETTID 1 + #define HAVE_GETTID 0 #else - #define OVERRIDE_GETTID 0 + #define HAVE_GETTID 1 #endif -#if OVERRIDE_GETTID -static pid_t gettid(void) +static pid_t selinux_gettid(void) { +#if HAVE_GETTID + return gettid(); +#else return syscall(__NR_gettid); -} #endif +} static void procattr_thread_destructor(void __attribute__((unused)) *unused) { @@ -94,7 +96,7 @@ static int openattr(pid_t pid, const char *attr, int flags) if (fd >= 0 || errno != ENOENT) goto out; free(path); - tid = gettid(); + tid = selinux_gettid(); rc = asprintf(&path, "/proc/self/task/%d/attr/%s", tid, attr); } else { errno = EINVAL; -- 2.30.0
