Make both static maps const so they end up in rodata. Any attempt to modify them now faults instead of silently corrupting the initial idmapping.
Signed-off-by: Christian Brauner (Amutable) <[email protected]> --- fs/mnt_idmapping.c | 4 ++-- include/linux/mnt_idmapping.h | 4 ++-- 2 files changed, 4 insertions(+), 4 deletions(-) diff --git a/fs/mnt_idmapping.c b/fs/mnt_idmapping.c index 26704eeb7318..bed57094cef0 100644 --- a/fs/mnt_idmapping.c +++ b/fs/mnt_idmapping.c @@ -28,7 +28,7 @@ struct mnt_idmap { * mapping. This means that {g,u}id 0 is mapped to {g,u}id 0, {g,u}id 1 is * mapped to {g,u}id 1, [...], {g,u}id 1000 to {g,u}id 1000, [...]. */ -struct mnt_idmap nop_mnt_idmap = { +const struct mnt_idmap nop_mnt_idmap = { .count = REFCOUNT_INIT(1), }; EXPORT_SYMBOL_GPL(nop_mnt_idmap); @@ -37,7 +37,7 @@ EXPORT_SYMBOL_GPL(nop_mnt_idmap); * Carries the invalid idmapping of a full 0-4294967295 {g,u}id range. * This means that all {g,u}ids are mapped to INVALID_VFS{G,U}ID. */ -struct mnt_idmap invalid_mnt_idmap = { +const struct mnt_idmap invalid_mnt_idmap = { .count = REFCOUNT_INIT(1), }; EXPORT_SYMBOL_GPL(invalid_mnt_idmap); diff --git a/include/linux/mnt_idmapping.h b/include/linux/mnt_idmapping.h index b445c7660040..78eeef4c2996 100644 --- a/include/linux/mnt_idmapping.h +++ b/include/linux/mnt_idmapping.h @@ -8,8 +8,8 @@ struct mnt_idmap; struct user_namespace; -extern struct mnt_idmap nop_mnt_idmap; -extern struct mnt_idmap invalid_mnt_idmap; +extern const struct mnt_idmap nop_mnt_idmap; +extern const struct mnt_idmap invalid_mnt_idmap; extern struct user_namespace init_user_ns; typedef struct { -- 2.53.0
