From c1115e1503bf955c97f4cf3b925a6a9f619764c3 Mon Sep 17 00:00:00 2001
From: Christian Brauner <brauner@kernel.org>
Date: Tue, 9 Aug 2022 16:14:25 +0200
Subject: build: detect where struct mount_attr is declared
Fixes: #4176
Signed-off-by: Christian Brauner (Microsoft) <christian.brauner@ubuntu.com>
---
meson.build | 30 ++++++++++++++++++++++++++++--
src/lxc/conf.c | 6 +++---
src/lxc/conf.h | 2 +-
src/lxc/mount_utils.c | 6 +++---
src/lxc/syscall_wrappers.h | 12 ++++++++++--
5 files changed, 45 insertions(+), 11 deletions(-)
--- a/meson.build
+++ b/meson.build
@@ -589,7 +589,6 @@ decl_headers = '''
foreach decl: [
'__aligned_u64',
'struct clone_args',
- 'struct mount_attr',
'struct open_how',
'struct rtnl_link_stats64',
]
@@ -609,7 +608,6 @@ foreach tuple: [
['struct seccomp_notif_sizes'],
['struct clone_args'],
['__aligned_u64'],
- ['struct mount_attr'],
['struct open_how'],
['struct rtnl_link_stats64'],
]
@@ -629,6 +627,34 @@ foreach tuple: [
endif
endforeach
+## Types.
+decl_headers = '''
+#include <sys/mount.h>
+'''
+
+# We get -1 if the size cannot be determined
+if cc.sizeof('struct mount_attr', prefix: decl_headers, args: '-D_GNU_SOURCE') > 0
+ srcconf.set10('HAVE_' + 'struct mount_attr'.underscorify().to_upper(), true)
+ found_types += 'struct mount_attr (sys/mount.h)'
+else
+ srcconf.set10('HAVE_' + 'struct mount_attr'.underscorify().to_upper(), false)
+ missing_types += 'struct mount_attr (sys/mount.h)'
+endif
+
+## Types.
+decl_headers = '''
+#include <linux/mount.h>
+'''
+
+# We get -1 if the size cannot be determined
+if cc.sizeof('struct mount_attr', prefix: decl_headers, args: '-D_GNU_SOURCE') > 0
+ srcconf.set10('HAVE_UAPI_' + 'struct mount_attr'.underscorify().to_upper(), true)
+ found_types += 'struct mount_attr (linux/mount.h)'
+else
+ srcconf.set10('HAVE_UAPI_' + 'struct mount_attr'.underscorify().to_upper(), false)
+ missing_types += 'struct mount_attr (linux/mount.h)'
+endif
+
## Headers.
foreach ident: [
['bpf', '''#include <sys/syscall.h>
--- a/src/lxc/conf.c
+++ b/src/lxc/conf.c
@@ -2885,7 +2885,7 @@ static int __lxc_idmapped_mounts_child(s
struct lxc_mount_options opts = {};
int dfd_from;
const char *source_relative, *target_relative;
- struct lxc_mount_attr attr = {};
+ struct mount_attr attr = {};
ret = parse_lxc_mount_attrs(&opts, mntent.mnt_opts);
if (ret < 0)
@@ -3005,7 +3005,7 @@ static int __lxc_idmapped_mounts_child(s
/* Set propagation mount options. */
if (opts.attr.propagation) {
- attr = (struct lxc_mount_attr) {
+ attr = (struct mount_attr) {
.propagation = opts.attr.propagation,
};
@@ -4109,7 +4109,7 @@ int lxc_idmapped_mounts_parent(struct lx
for (;;) {
__do_close int fd_from = -EBADF, fd_userns = -EBADF;
- struct lxc_mount_attr attr = {};
+ struct mount_attr attr = {};
struct lxc_mount_options opts = {};
ssize_t ret;
--- a/src/lxc/conf.h
+++ b/src/lxc/conf.h
@@ -223,7 +223,7 @@ struct lxc_mount_options {
unsigned long mnt_flags;
unsigned long prop_flags;
char *data;
- struct lxc_mount_attr attr;
+ struct mount_attr attr;
char *raw_options;
};
--- a/src/lxc/mount_utils.c
+++ b/src/lxc/mount_utils.c
@@ -31,7 +31,7 @@ lxc_log_define(mount_utils, lxc);
* setting in @attr_set, but must also specify MOUNT_ATTR__ATIME in the
* @attr_clr field.
*/
-static inline void set_atime(struct lxc_mount_attr *attr)
+static inline void set_atime(struct mount_attr *attr)
{
switch (attr->attr_set & MOUNT_ATTR__ATIME) {
case MOUNT_ATTR_RELATIME:
@@ -272,7 +272,7 @@ int create_detached_idmapped_mount(const
{
__do_close int fd_tree_from = -EBADF;
unsigned int open_tree_flags = OPEN_TREE_CLONE | OPEN_TREE_CLOEXEC;
- struct lxc_mount_attr attr = {
+ struct mount_attr attr = {
.attr_set = MOUNT_ATTR_IDMAP | attr_set,
.attr_clr = attr_clr,
.userns_fd = userns_fd,
@@ -335,7 +335,7 @@ int __fd_bind_mount(int dfd_from, const
__u64 attr_clr, __u64 propagation, int userns_fd,
bool recursive)
{
- struct lxc_mount_attr attr = {
+ struct mount_attr attr = {
.attr_set = attr_set,
.attr_clr = attr_clr,
.propagation = propagation,
--- a/src/lxc/syscall_wrappers.h
+++ b/src/lxc/syscall_wrappers.h
@@ -18,6 +18,12 @@
#include "macro.h"
#include "syscall_numbers.h"
+#if HAVE_STRUCT_MOUNT_ATTR
+#include <sys/mount.h>
+#elif HAVE_UAPI_STRUCT_MOUNT_ATTR
+#include <linux/mount.h>
+#endif
+
#ifdef HAVE_LINUX_MEMFD_H
#include <linux/memfd.h>
#endif
@@ -210,16 +216,18 @@ extern int fsmount(int fs_fd, unsigned i
/*
* mount_setattr()
*/
-struct lxc_mount_attr {
+#if !HAVE_STRUCT_MOUNT_ATTR && !HAVE_UAPI_STRUCT_MOUNT_ATTR
+struct mount_attr {
__u64 attr_set;
__u64 attr_clr;
__u64 propagation;
__u64 userns_fd;
};
+#endif
#if !HAVE_MOUNT_SETATTR
static inline int mount_setattr(int dfd, const char *path, unsigned int flags,
- struct lxc_mount_attr *attr, size_t size)
+ struct mount_attr *attr, size_t size)
{
return syscall(__NR_mount_setattr, dfd, path, flags, attr, size);
}