gcc puts literal strings lie in read-only memory. On x86_64, trying to
write to them triggers a segmentation fault.
To detect such issues at build time, variables holding a pointer to such
strings should be "const char*". "gcc -Wwrite-strings" warns when using
non-const pointers to literal strings.
Remove gcc warnings by adding const to local variables and argumens of
internal functions.
This does *not* fix this warning:
policydb_public.c:208:10: warning: passing argument 2 of 'hashtab_search' discards 'const' qualifier from pointer target type
return (hashtab_search(p->p.p_classes.table, PACKET_CLASS_NAME) ==
^
In file included from ../include/sepol/policydb/symtab.h:16:0,
from ../include/sepol/policydb/policydb.h:60,
from policydb_public.c:4:
../include/sepol/policydb/hashtab.h:98:24: note: expected 'hashtab_key_t' but argument is of type 'const char *'
extern hashtab_datum_t hashtab_search(hashtab_t h, const hashtab_key_t k);
^
Moreover the "const" word in hashtab_search prototype does not make the
second parameter "const char*" but "char* const".
---
libsepol/include/sepol/policydb/services.h | 2 +-
libsepol/src/link.c | 6 +++---
libsepol/src/policydb.c | 2 +-
libsepol/src/policydb_internal.h | 2 +-
libsepol/src/services.c | 12 ++++++------
libsepol/src/write.c | 2 +-
6 files changed, 13 insertions(+), 13 deletions(-)
diff --git a/libsepol/include/sepol/policydb/services.h b/libsepol/include/sepol/policydb/services.h
index e4e8362cdfb3..bcde47b8d618 100644
--- a/libsepol/include/sepol/policydb/services.h
+++ b/libsepol/include/sepol/policydb/services.h
@@ -223,7 +223,7 @@ extern int sepol_fs_use(const char *fstype, /* IN */
* fixed labeling behavior like transition SIDs or task SIDs.
*/
extern int sepol_genfs_sid(const char *fstype, /* IN */
- char *name, /* IN */
+ const char *name, /* IN */
sepol_security_class_t sclass, /* IN */
sepol_security_id_t * sid); /* OUT */
diff --git a/libsepol/src/link.c b/libsepol/src/link.c
index c8c510a7da9e..e0bb1988d72d 100644
--- a/libsepol/src/link.c
+++ b/libsepol/src/link.c
@@ -2089,7 +2089,7 @@ static int debug_requirements(link_state_t * state, policydb_t * p)
if (ret < 0) {
return ret;
} else if (ret == 0) {
- char *mod_name = cur->branch_list->module_name ?
+ const char *mod_name = cur->branch_list->module_name ?
cur->branch_list->module_name : "BASE";
if (req.symbol_type == SYM_CLASSES) {
struct find_perm_arg fparg;
@@ -2148,7 +2148,7 @@ static void print_missing_requirements(link_state_t * state,
missing_requirement_t * req)
{
policydb_t *p = state->base;
- char *mod_name = cur->branch_list->module_name ?
+ const char *mod_name = cur->branch_list->module_name ?
cur->branch_list->module_name : "BASE";
if (req->symbol_type == SYM_CLASSES) {
@@ -2220,7 +2220,7 @@ static int enable_avrules(link_state_t * state, policydb_t * pol)
}
decl = block->branch_list;
if (state->verbose) {
- char *mod_name = decl->module_name ?
+ const char *mod_name = decl->module_name ?
decl->module_name : "BASE";
INFO(state->handle, "check module %s decl %d\n",
mod_name, decl->decl_id);
diff --git a/libsepol/src/policydb.c b/libsepol/src/policydb.c
index 19fbfea93c5a..f077b9312dd3 100644
--- a/libsepol/src/policydb.c
+++ b/libsepol/src/policydb.c
@@ -55,7 +55,7 @@
#include "mls.h"
#define POLICYDB_TARGET_SZ ARRAY_SIZE(policydb_target_strings)
-char *policydb_target_strings[] = { POLICYDB_STRING, POLICYDB_XEN_STRING };
+const char *policydb_target_strings[] = { POLICYDB_STRING, POLICYDB_XEN_STRING };
/* These need to be updated if SYM_NUM or OCON_NUM changes */
static struct policydb_compat_info policydb_compat[] = {
diff --git a/libsepol/src/policydb_internal.h b/libsepol/src/policydb_internal.h
index 8a31506e870d..f7bcdfa3df31 100644
--- a/libsepol/src/policydb_internal.h
+++ b/libsepol/src/policydb_internal.h
@@ -6,5 +6,5 @@
hidden_proto(sepol_policydb_create)
hidden_proto(sepol_policydb_free)
-extern char *policydb_target_strings[];
+extern const char *policydb_target_strings[];
#endif
diff --git a/libsepol/src/services.c b/libsepol/src/services.c
index a1a0b98c73da..d64a8e8d7bcf 100644
--- a/libsepol/src/services.c
+++ b/libsepol/src/services.c
@@ -174,7 +174,7 @@ static char **expr_list;
static int expr_buf_used;
static int expr_buf_len;
-static void cat_expr_buf(char *e_buf, char *string)
+static void cat_expr_buf(char *e_buf, const char *string)
{
int len, new_buf_len;
char *p, *new_buf = e_buf;
@@ -209,7 +209,7 @@ static void cat_expr_buf(char *e_buf, char *string)
* POLICYDB_VERSION_CONSTRAINT_NAMES) just read the e->names list.
*/
static void get_name_list(constraint_expr_t *e, int type,
- char *src, char *op, int failed)
+ const char *src, const char *op, int failed)
{
ebitmap_t *types;
int rc = 0;
@@ -273,7 +273,7 @@ static void get_name_list(constraint_expr_t *e, int type,
return;
}
-static void msgcat(char *src, char *tgt, char *op, int failed)
+static void msgcat(const char *src, const char *tgt, const char *op, int failed)
{
char tmp_buf[128];
if (failed)
@@ -303,7 +303,7 @@ static char *get_class_info(sepol_security_class_t tclass,
}
/* Determine statement type */
- char *statements[] = {
+ const char *statements[] = {
"constrain ", /* 0 */
"mlsconstrain ", /* 1 */
"validatetrans ", /* 2 */
@@ -771,7 +771,7 @@ mls_ops:
* These contain the constraint components that are added to the
* callers reason buffer.
*/
- char *buffers[] = { class_buf, a, "); ", tmp_buf, 0 };
+ const char *buffers[] = { class_buf, a, "); ", tmp_buf, 0 };
/*
* This will add the constraints to the callers reason buffer (who is
@@ -2085,7 +2085,7 @@ int hidden sepol_get_user_sids(sepol_security_id_t fromsid,
* fixed labeling behavior like transition SIDs or task SIDs.
*/
int hidden sepol_genfs_sid(const char *fstype,
- char *path,
+ const char *path,
sepol_security_class_t sclass,
sepol_security_id_t * sid)
{
diff --git a/libsepol/src/write.c b/libsepol/src/write.c
index 6fe73e6e5a3a..2e6541da1e4d 100644
--- a/libsepol/src/write.c
+++ b/libsepol/src/write.c
@@ -1880,7 +1880,7 @@ int policydb_write(policydb_t * p, struct policy_file *fp)
size_t items, items2, len;
struct policydb_compat_info *info;
struct policy_data pd;
- char *policydb_str;
+ const char *policydb_str;
if (p->unsupported_format)
return POLICYDB_UNSUPPORTED;
--
2.1.0
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