On 2/17/2022 6:18 AM, Christian Göttsche wrote:
The struct security_hook_list member lsm is assigned in
security_add_hooks() with string literals passed from the individual
security modules. Declare the function parameter and the struct member
const to signal their immutability.
Reported by Clang [-Wwrite-strings]:
security/selinux/hooks.c:7388:63: error: passing 'const char [8]' to parameter of type 'char *' discards qualifiers [-Werror,-Wincompatible-pointer-types-discards-qualifiers]
security_add_hooks(selinux_hooks, ARRAY_SIZE(selinux_hooks), selinux);
^~~~~~~~~
./include/linux/lsm_hooks.h:1629:11: note: passing argument to parameter 'lsm' here
char *lsm);
^
Signed-off-by: Christian Göttsche <cgzones@xxxxxxxxxxxxxx>
Reviewed-by: Casey Schaufler <casey@xxxxxxxxxxxxxxxx>
---
include/linux/lsm_hooks.h | 4 ++--
security/security.c | 2 +-
2 files changed, 3 insertions(+), 3 deletions(-)
diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h
index 419b5febc3ca..47cdf3fbecef 100644
--- a/include/linux/lsm_hooks.h
+++ b/include/linux/lsm_hooks.h
@@ -1595,7 +1595,7 @@ struct security_hook_list {
struct hlist_node list;
struct hlist_head *head;
union security_list_options hook;
- char *lsm;
+ const char *lsm;
} __randomize_layout;
/*
@@ -1630,7 +1630,7 @@ extern struct security_hook_heads security_hook_heads;
extern char *lsm_names;
extern void security_add_hooks(struct security_hook_list *hooks, int count,
- char *lsm);
+ const char *lsm);
#define LSM_FLAG_LEGACY_MAJOR BIT(0)
#define LSM_FLAG_EXCLUSIVE BIT(1)
diff --git a/security/security.c b/security/security.c
index 9663ffcca4b0..a48eb3badfdd 100644
--- a/security/security.c
+++ b/security/security.c
@@ -478,7 +478,7 @@ static int lsm_append(const char *new, char **result)
* Each LSM has to register its hooks with the infrastructure.
*/
void __init security_add_hooks(struct security_hook_list *hooks, int count,
- char *lsm)
+ const char *lsm)
{
int i;
