| Message ID | 20240315-sysctl-const-ownership-v3-2-b86680eae02e@weissschuh.net (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | sysctl: treewide: prepare ctl_table_root for ctl_table constification | expand |
On Fri, Mar 15, 2024 at 07:11:31PM +0100, Thomas Weißschuh wrote: > The permissions callback is not supposed to modify the ctl_table. > Enforce this expectation via the typesystem. > > The patch was created with the following coccinelle script: > > @@ > identifier func, head, ctl; > @@ > > int func( > struct ctl_table_header *head, > - struct ctl_table *ctl) > + const struct ctl_table *ctl) > { ... } > > (insert_entry() from fs/proc/proc_sysctl.c is a false-positive) > > The three changed locations were validated through manually inspection > and compilation. Will remove this when I add it to constfy branch as it is unclear (for me) what "manually inspection" is and also I do not know what config you used to compile. IMO, we can just do without it. > > In addition a search for '.permissions =' was done over the full tree to > look for places that were missed by coccinelle. > None were found. > > This change also is a step to put "struct ctl_table" into .rodata > throughout the kernel. This LGTM. Will add this to the constfy testing branch with these changes in the commit message: """ sysctl: treewide: constify argument ctl_table_root::permissions(table) The permissions callback should not modify the ctl_table. Enforce this expectation via the typesystem. This is a step to put "struct ctl_table" into .rodata throughout the kernel. The patch was created with the following coccinelle script: @@ identifier func, head, ctl; @@ int func( struct ctl_table_header *head, - struct ctl_table *ctl) + const struct ctl_table *ctl) { ... } (insert_entry() from fs/proc/proc_sysctl.c is a false-positive) No additional occurances of '.permissions =' were found after a tree-wide search for places missed by the conccinelle script. """ Reviewed-by: Joel Granados <j.granados@samsung.com> > > Signed-off-by: Thomas Weißschuh <linux@weissschuh.net> > --- > include/linux/sysctl.h | 2 +- > ipc/ipc_sysctl.c | 2 +- > ipc/mq_sysctl.c | 2 +- > kernel/ucount.c | 2 +- > net/sysctl_net.c | 2 +- > 5 files changed, 5 insertions(+), 5 deletions(-) > > diff --git a/include/linux/sysctl.h b/include/linux/sysctl.h > index 60333a6b9370..f9214de0490c 100644 > --- a/include/linux/sysctl.h > +++ b/include/linux/sysctl.h > @@ -206,7 +206,7 @@ struct ctl_table_root { > struct ctl_table_set *(*lookup)(struct ctl_table_root *root); > void (*set_ownership)(struct ctl_table_header *head, > kuid_t *uid, kgid_t *gid); > - int (*permissions)(struct ctl_table_header *head, struct ctl_table *table); > + int (*permissions)(struct ctl_table_header *head, const struct ctl_table *table); > }; > > #define register_sysctl(path, table) \ > diff --git a/ipc/ipc_sysctl.c b/ipc/ipc_sysctl.c > index 1a5085e5b178..19b2a67aef40 100644 > --- a/ipc/ipc_sysctl.c > +++ b/ipc/ipc_sysctl.c > @@ -204,7 +204,7 @@ static void ipc_set_ownership(struct ctl_table_header *head, > *gid = gid_valid(ns_root_gid) ? ns_root_gid : GLOBAL_ROOT_GID; > } > > -static int ipc_permissions(struct ctl_table_header *head, struct ctl_table *table) > +static int ipc_permissions(struct ctl_table_header *head, const struct ctl_table *table) > { > int mode = table->mode; > > diff --git a/ipc/mq_sysctl.c b/ipc/mq_sysctl.c > index 6bb1c5397c69..43c0825da9e8 100644 > --- a/ipc/mq_sysctl.c > +++ b/ipc/mq_sysctl.c > @@ -90,7 +90,7 @@ static void mq_set_ownership(struct ctl_table_header *head, > *gid = gid_valid(ns_root_gid) ? ns_root_gid : GLOBAL_ROOT_GID; > } > > -static int mq_permissions(struct ctl_table_header *head, struct ctl_table *table) > +static int mq_permissions(struct ctl_table_header *head, const struct ctl_table *table) > { > int mode = table->mode; > kuid_t ns_root_uid; > diff --git a/kernel/ucount.c b/kernel/ucount.c > index 4aa6166cb856..90300840256b 100644 > --- a/kernel/ucount.c > +++ b/kernel/ucount.c > @@ -38,7 +38,7 @@ static int set_is_seen(struct ctl_table_set *set) > } > > static int set_permissions(struct ctl_table_header *head, > - struct ctl_table *table) > + const struct ctl_table *table) > { > struct user_namespace *user_ns = > container_of(head->set, struct user_namespace, set); > diff --git a/net/sysctl_net.c b/net/sysctl_net.c > index a0a7a79991f9..f5017012a049 100644 > --- a/net/sysctl_net.c > +++ b/net/sysctl_net.c > @@ -40,7 +40,7 @@ static int is_seen(struct ctl_table_set *set) > > /* Return standard mode bits for table entry. */ > static int net_ctl_permissions(struct ctl_table_header *head, > - struct ctl_table *table) > + const struct ctl_table *table) > { > struct net *net = container_of(head->set, struct net, sysctls); > > > -- > 2.44.0 >
diff --git a/include/linux/sysctl.h b/include/linux/sysctl.h index 60333a6b9370..f9214de0490c 100644 --- a/include/linux/sysctl.h +++ b/include/linux/sysctl.h @@ -206,7 +206,7 @@ struct ctl_table_root { struct ctl_table_set *(*lookup)(struct ctl_table_root *root); void (*set_ownership)(struct ctl_table_header *head, kuid_t *uid, kgid_t *gid); - int (*permissions)(struct ctl_table_header *head, struct ctl_table *table); + int (*permissions)(struct ctl_table_header *head, const struct ctl_table *table); }; #define register_sysctl(path, table) \ diff --git a/ipc/ipc_sysctl.c b/ipc/ipc_sysctl.c index 1a5085e5b178..19b2a67aef40 100644 --- a/ipc/ipc_sysctl.c +++ b/ipc/ipc_sysctl.c @@ -204,7 +204,7 @@ static void ipc_set_ownership(struct ctl_table_header *head, *gid = gid_valid(ns_root_gid) ? ns_root_gid : GLOBAL_ROOT_GID; } -static int ipc_permissions(struct ctl_table_header *head, struct ctl_table *table) +static int ipc_permissions(struct ctl_table_header *head, const struct ctl_table *table) { int mode = table->mode; diff --git a/ipc/mq_sysctl.c b/ipc/mq_sysctl.c index 6bb1c5397c69..43c0825da9e8 100644 --- a/ipc/mq_sysctl.c +++ b/ipc/mq_sysctl.c @@ -90,7 +90,7 @@ static void mq_set_ownership(struct ctl_table_header *head, *gid = gid_valid(ns_root_gid) ? ns_root_gid : GLOBAL_ROOT_GID; } -static int mq_permissions(struct ctl_table_header *head, struct ctl_table *table) +static int mq_permissions(struct ctl_table_header *head, const struct ctl_table *table) { int mode = table->mode; kuid_t ns_root_uid; diff --git a/kernel/ucount.c b/kernel/ucount.c index 4aa6166cb856..90300840256b 100644 --- a/kernel/ucount.c +++ b/kernel/ucount.c @@ -38,7 +38,7 @@ static int set_is_seen(struct ctl_table_set *set) } static int set_permissions(struct ctl_table_header *head, - struct ctl_table *table) + const struct ctl_table *table) { struct user_namespace *user_ns = container_of(head->set, struct user_namespace, set); diff --git a/net/sysctl_net.c b/net/sysctl_net.c index a0a7a79991f9..f5017012a049 100644 --- a/net/sysctl_net.c +++ b/net/sysctl_net.c @@ -40,7 +40,7 @@ static int is_seen(struct ctl_table_set *set) /* Return standard mode bits for table entry. */ static int net_ctl_permissions(struct ctl_table_header *head, - struct ctl_table *table) + const struct ctl_table *table) { struct net *net = container_of(head->set, struct net, sysctls);
The permissions callback is not supposed to modify the ctl_table. Enforce this expectation via the typesystem. The patch was created with the following coccinelle script: @@ identifier func, head, ctl; @@ int func( struct ctl_table_header *head, - struct ctl_table *ctl) + const struct ctl_table *ctl) { ... } (insert_entry() from fs/proc/proc_sysctl.c is a false-positive) The three changed locations were validated through manually inspection and compilation. In addition a search for '.permissions =' was done over the full tree to look for places that were missed by coccinelle. None were found. This change also is a step to put "struct ctl_table" into .rodata throughout the kernel. Signed-off-by: Thomas Weißschuh <linux@weissschuh.net> --- include/linux/sysctl.h | 2 +- ipc/ipc_sysctl.c | 2 +- ipc/mq_sysctl.c | 2 +- kernel/ucount.c | 2 +- net/sysctl_net.c | 2 +- 5 files changed, 5 insertions(+), 5 deletions(-)