stat: Treat EPERM like ENOSYS for statx()

On some configurations (e.g. old Docker with the default seccomp()
profile), statx() fails with EPERM.  Consider this to mean statx() is
unsupported, as EPERM is not a documented error code in normal
operation.

Possible fix for https://github.com/alpinelinux/aports/pull/9277

1 files changed, 3 insertions, 1 deletions

diff --git a/stat.c b/stat.c
index e3d5400..a2e2c8d 100644
--- a/stat.c
+++ b/stat.c
@@ -282,7 +282,9 @@ static int bfs_stat_explicit(int at_fd, const char *at_path, int at_flags, enum
 
 	if (has_statx) {
 		int ret = bfs_statx_impl(at_fd, at_path, at_flags, flags, buf);
-		if (ret != 0 && errno == ENOSYS) {
+		// EPERM is commonly returned in a seccomp() sandbox that does
+		// not allow statx()
+		if (ret != 0 && (errno == ENOSYS || errno == EPERM)) {
 			has_statx = false;
 		} else {
 			return ret;