Re: [PATCH] security: declare member holding string literal const
From: Casey Schaufler <casey@schaufler-ca.com>
Date: 2022-02-17 22:50:41
Also in:
lkml, llvm, selinux
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 <redacted>Reviewed-by: Casey Schaufler <casey@schaufler-ca.com>
quoted hunk ↗ jump to hunk
--- 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;