[PATCH v5 1/3] init/main.c: introduce function ramdisk_exec_exist()
From: <hidden>
Date: 2021-06-04 12:09:12
Also in:
lkml
Subsystem:
filesystems (vfs and infrastructure), the rest · Maintainers:
Alexander Viro, Christian Brauner, Linus Torvalds
From: Menglong Dong <redacted> Introduce the function ramdisk_exec_exist, which is used to check the exist of 'ramdisk_execute_command'. To make path lookup follow the mount on '/', use vfs_path_lookup() in init_eaccess(), and make the filesystem that mounted on '/' as root during path lookup. Signed-off-by: Menglong Dong <redacted> --- fs/init.c | 11 +++++++++-- include/linux/init.h | 1 + init/main.c | 7 ++++++- 3 files changed, 16 insertions(+), 3 deletions(-)
diff --git a/fs/init.c b/fs/init.c
index 5c36adaa9b44..166356a1f15f 100644
--- a/fs/init.c
+++ b/fs/init.c@@ -112,14 +112,21 @@ int __init init_chmod(const char *filename, umode_t mode) int __init init_eaccess(const char *filename) { - struct path path; + struct path path, root; int error; - error = kern_path(filename, LOOKUP_FOLLOW, &path); + error = kern_path("/", LOOKUP_DOWN, &root); if (error) return error; + error = vfs_path_lookup(root.dentry, root.mnt, filename, + LOOKUP_FOLLOW, &path); + if (error) + goto on_err; error = path_permission(&path, MAY_ACCESS); + path_put(&path); +on_err: + path_put(&root); return error; }
diff --git a/include/linux/init.h b/include/linux/init.h
index d82b4b2e1d25..889d538b6dfa 100644
--- a/include/linux/init.h
+++ b/include/linux/init.h@@ -149,6 +149,7 @@ extern unsigned int reset_devices; void setup_arch(char **); void prepare_namespace(void); void __init init_rootfs(void); +bool ramdisk_exec_exist(void); extern struct file_system_type rootfs_fs_type; #if defined(CONFIG_STRICT_KERNEL_RWX) || defined(CONFIG_STRICT_MODULE_RWX)
diff --git a/init/main.c b/init/main.c
index eb01e121d2f1..1153571ca977 100644
--- a/init/main.c
+++ b/init/main.c@@ -1522,6 +1522,11 @@ void __init console_on_rootfs(void) fput(file); } +bool __init ramdisk_exec_exist(void) +{ + return init_eaccess(ramdisk_execute_command) == 0; +} + static noinline void __init kernel_init_freeable(void) { /*
@@ -1568,7 +1573,7 @@ static noinline void __init kernel_init_freeable(void) * check if there is an early userspace init. If yes, let it do all * the work */ - if (init_eaccess(ramdisk_execute_command) != 0) { + if (!ramdisk_exec_exist()) { ramdisk_execute_command = NULL; prepare_namespace(); }
--
2.32.0.rc0