[PATCH 4/9] selinux: enclose macro arguments in parenthesis

From: Christian Göttsche
Date: Tue Jan 25 2022 - 09:20:08 EST


Enclose the macro arguments in parenthesis to avoid potential evaluation
order issues.

Note the xperm and ebitmap macros are still not side-effect safe due to
double evaluation.

Reported by clang-tidy [bugprone-macro-parentheses]

Signed-off-by: Christian Göttsche <cgzones@xxxxxxxxxxxxxx>
---
security/selinux/include/security.h | 4 ++--
security/selinux/ss/ebitmap.h | 6 +++---
security/selinux/ss/sidtab.c | 4 ++--
3 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/security/selinux/include/security.h b/security/selinux/include/security.h
index 6482e0efb368..d91a5672de99 100644
--- a/security/selinux/include/security.h
+++ b/security/selinux/include/security.h
@@ -254,8 +254,8 @@ struct av_decision {
#define XPERMS_AUDITALLOW 2
#define XPERMS_DONTAUDIT 4

-#define security_xperm_set(perms, x) (perms[x >> 5] |= 1 << (x & 0x1f))
-#define security_xperm_test(perms, x) (1 & (perms[x >> 5] >> (x & 0x1f)))
+#define security_xperm_set(perms, x) ((perms)[(x) >> 5] |= 1 << ((x) & 0x1f))
+#define security_xperm_test(perms, x) (1 & ((perms)[(x) >> 5] >> ((x) & 0x1f)))
struct extended_perms_data {
u32 p[8];
};
diff --git a/security/selinux/ss/ebitmap.h b/security/selinux/ss/ebitmap.h
index 9eb2d0af2805..58eb822f11ee 100644
--- a/security/selinux/ss/ebitmap.h
+++ b/security/selinux/ss/ebitmap.h
@@ -118,9 +118,9 @@ static inline void ebitmap_node_clr_bit(struct ebitmap_node *n,
}

#define ebitmap_for_each_positive_bit(e, n, bit) \
- for (bit = ebitmap_start_positive(e, &n); \
- bit < ebitmap_length(e); \
- bit = ebitmap_next_positive(e, &n, bit)) \
+ for ((bit) = ebitmap_start_positive(e, &(n)); \
+ (bit) < ebitmap_length(e); \
+ (bit) = ebitmap_next_positive(e, &(n), bit)) \

int ebitmap_cmp(struct ebitmap *e1, struct ebitmap *e2);
int ebitmap_cpy(struct ebitmap *dst, struct ebitmap *src);
diff --git a/security/selinux/ss/sidtab.c b/security/selinux/ss/sidtab.c
index 293ec048af08..a54b8652bfb5 100644
--- a/security/selinux/ss/sidtab.c
+++ b/security/selinux/ss/sidtab.c
@@ -27,8 +27,8 @@ struct sidtab_str_cache {
char str[];
};

-#define index_to_sid(index) (index + SECINITSID_NUM + 1)
-#define sid_to_index(sid) (sid - (SECINITSID_NUM + 1))
+#define index_to_sid(index) ((index) + SECINITSID_NUM + 1)
+#define sid_to_index(sid) ((sid) - (SECINITSID_NUM + 1))

int sidtab_init(struct sidtab *s)
{
--
2.34.1