[PATCH] selinux: introduce str_read() helper

From: Namhyung Kim
Date: Sun Jun 15 2014 - 10:03:19 EST

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There're some code duplication for reading a string value during
policydb_read(). Add str_read() helper to fix it.

Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxxx>
---
security/selinux/ss/policydb.c | 133 ++++++++++++-----------------------------
1 file changed, 37 insertions(+), 96 deletions(-)

diff --git a/security/selinux/ss/policydb.c b/security/selinux/ss/policydb.c
index 9c5cdc2caaef..26a8ea7773b7 100644
--- a/security/selinux/ss/policydb.c
+++ b/security/selinux/ss/policydb.c
@@ -1080,6 +1080,26 @@ out:
* binary representation file.
*/

+static int str_read(char **strp, gfp_t flags, void *fp, u32 len)
+{
+ int rc;
+ char *str;
+
+ str = kmalloc(len + 1, flags);
+ if (!str)
+ return -ENOMEM;
+
+ /* it's expected the caller should free the str */
+ *strp = str;
+
+ rc = next_entry(str, fp, len);
+ if (rc)
+ return rc;
+
+ str[len] = '\0';
+ return 0;
+}
+
static int perm_read(struct policydb *p, struct hashtab *h, void *fp)
{
char *key = NULL;
@@ -1100,15 +1120,9 @@ static int perm_read(struct policydb *p, struct hashtab *h, void *fp)
len = le32_to_cpu(buf[0]);
perdatum->value = le32_to_cpu(buf[1]);

- rc = -ENOMEM;
- key = kmalloc(len + 1, GFP_KERNEL);
- if (!key)
- goto bad;
-
- rc = next_entry(key, fp, len);
+ rc = str_read(&key, GFP_KERNEL, fp, len);
if (rc)
goto bad;
- key[len] = '\0';

rc = hashtab_insert(h, key, perdatum);
if (rc)
@@ -1146,15 +1160,9 @@ static int common_read(struct policydb *p, struct hashtab *h, void *fp)
comdatum->permissions.nprim = le32_to_cpu(buf[2]);
nel = le32_to_cpu(buf[3]);

- rc = -ENOMEM;
- key = kmalloc(len + 1, GFP_KERNEL);
- if (!key)
- goto bad;
-
- rc = next_entry(key, fp, len);
+ rc = str_read(&key, GFP_KERNEL, fp, len);
if (rc)
goto bad;
- key[len] = '\0';

for (i = 0; i < nel; i++) {
rc = perm_read(p, comdatum->permissions.table, fp);
@@ -1321,25 +1329,14 @@ static int class_read(struct policydb *p, struct hashtab *h, void *fp)

ncons = le32_to_cpu(buf[5]);

- rc = -ENOMEM;
- key = kmalloc(len + 1, GFP_KERNEL);
- if (!key)
- goto bad;
-
- rc = next_entry(key, fp, len);
+ rc = str_read(&key, GFP_KERNEL, fp, len);
if (rc)
goto bad;
- key[len] = '\0';

if (len2) {
- rc = -ENOMEM;
- cladatum->comkey = kmalloc(len2 + 1, GFP_KERNEL);
- if (!cladatum->comkey)
- goto bad;
- rc = next_entry(cladatum->comkey, fp, len2);
+ rc = str_read(&cladatum->comkey, GFP_KERNEL, fp, len2);
if (rc)
goto bad;
- cladatum->comkey[len2] = '\0';

rc = -EINVAL;
cladatum->comdatum = hashtab_search(p->p_commons.table, cladatum->comkey);
@@ -1422,15 +1419,9 @@ static int role_read(struct policydb *p, struct hashtab *h, void *fp)
if (p->policyvers >= POLICYDB_VERSION_BOUNDARY)
role->bounds = le32_to_cpu(buf[2]);

- rc = -ENOMEM;
- key = kmalloc(len + 1, GFP_KERNEL);
- if (!key)
- goto bad;
-
- rc = next_entry(key, fp, len);
+ rc = str_read(&key, GFP_KERNEL, fp, len);
if (rc)
goto bad;
- key[len] = '\0';

rc = ebitmap_read(&role->dominates, fp);
if (rc)
@@ -1495,14 +1486,9 @@ static int type_read(struct policydb *p, struct hashtab *h, void *fp)
typdatum->primary = le32_to_cpu(buf[2]);
}

- rc = -ENOMEM;
- key = kmalloc(len + 1, GFP_KERNEL);
- if (!key)
- goto bad;
- rc = next_entry(key, fp, len);
+ rc = str_read(&key, GFP_KERNEL, fp, len);
if (rc)
goto bad;
- key[len] = '\0';

rc = hashtab_insert(h, key, typdatum);
if (rc)
@@ -1565,14 +1551,9 @@ static int user_read(struct policydb *p, struct hashtab *h, void *fp)
if (p->policyvers >= POLICYDB_VERSION_BOUNDARY)
usrdatum->bounds = le32_to_cpu(buf[2]);

- rc = -ENOMEM;
- key = kmalloc(len + 1, GFP_KERNEL);
- if (!key)
- goto bad;
- rc = next_entry(key, fp, len);
+ rc = str_read(&key, GFP_KERNEL, fp, len);
if (rc)
goto bad;
- key[len] = '\0';

rc = ebitmap_read(&usrdatum->roles, fp);
if (rc)
@@ -1616,14 +1597,9 @@ static int sens_read(struct policydb *p, struct hashtab *h, void *fp)
len = le32_to_cpu(buf[0]);
levdatum->isalias = le32_to_cpu(buf[1]);

- rc = -ENOMEM;
- key = kmalloc(len + 1, GFP_ATOMIC);
- if (!key)
- goto bad;
- rc = next_entry(key, fp, len);
+ rc = str_read(&key, GFP_ATOMIC, fp, len);
if (rc)
goto bad;
- key[len] = '\0';

rc = -ENOMEM;
levdatum->level = kmalloc(sizeof(struct mls_level), GFP_ATOMIC);
@@ -1664,14 +1640,9 @@ static int cat_read(struct policydb *p, struct hashtab *h, void *fp)
catdatum->value = le32_to_cpu(buf[1]);
catdatum->isalias = le32_to_cpu(buf[2]);

- rc = -ENOMEM;
- key = kmalloc(len + 1, GFP_ATOMIC);
- if (!key)
- goto bad;
- rc = next_entry(key, fp, len);
+ rc = str_read(&key, GFP_ATOMIC, fp, len);
if (rc)
goto bad;
- key[len] = '\0';

rc = hashtab_insert(h, key, catdatum);
if (rc)
@@ -1968,18 +1939,12 @@ static int filename_trans_read(struct policydb *p, void *fp)
goto out;
len = le32_to_cpu(buf[0]);

- rc = -ENOMEM;
- name = kmalloc(len + 1, GFP_KERNEL);
- if (!name)
- goto out;
-
- ft->name = name;
-
/* path component string */
- rc = next_entry(name, fp, len);
+ rc = str_read(&name, GFP_KERNEL, fp, len);
if (rc)
goto out;
- name[len] = 0;
+
+ ft->name = name;

rc = next_entry(buf, fp, sizeof(u32) * 4);
if (rc)
@@ -2045,17 +2010,10 @@ static int genfs_read(struct policydb *p, void *fp)
if (!newgenfs)
goto out;

- rc = -ENOMEM;
- newgenfs->fstype = kmalloc(len + 1, GFP_KERNEL);
- if (!newgenfs->fstype)
- goto out;
-
- rc = next_entry(newgenfs->fstype, fp, len);
+ rc = str_read(&newgenfs->fstype, GFP_KERNEL, fp, len);
if (rc)
goto out;

- newgenfs->fstype[len] = 0;
-
for (genfs_p = NULL, genfs = p->genfs; genfs;
genfs_p = genfs, genfs = genfs->next) {
rc = -EINVAL;
@@ -2091,15 +2049,9 @@ static int genfs_read(struct policydb *p, void *fp)
if (!newc)
goto out;

- rc = -ENOMEM;
- newc->u.name = kmalloc(len + 1, GFP_KERNEL);
- if (!newc->u.name)
- goto out;
-
- rc = next_entry(newc->u.name, fp, len);
+ rc = str_read(&newc->u.name, GFP_KERNEL, fp, len);
if (rc)
goto out;
- newc->u.name[len] = 0;

rc = next_entry(buf, fp, sizeof(u32));
if (rc)
@@ -2189,16 +2141,10 @@ static int ocontext_read(struct policydb *p, struct policydb_compat_info *info,
goto out;
len = le32_to_cpu(buf[0]);

- rc = -ENOMEM;
- c->u.name = kmalloc(len + 1, GFP_KERNEL);
- if (!c->u.name)
- goto out;
-
- rc = next_entry(c->u.name, fp, len);
+ rc = str_read(&c->u.name, GFP_KERNEL, fp, len);
if (rc)
goto out;

- c->u.name[len] = 0;
rc = context_read_and_validate(&c->context[0], p, fp);
if (rc)
goto out;
@@ -2240,16 +2186,11 @@ static int ocontext_read(struct policydb *p, struct policydb_compat_info *info,
if (c->v.behavior > SECURITY_FS_USE_MAX)
goto out;

- rc = -ENOMEM;
len = le32_to_cpu(buf[1]);
- c->u.name = kmalloc(len + 1, GFP_KERNEL);
- if (!c->u.name)
- goto out;
-
- rc = next_entry(c->u.name, fp, len);
+ rc = str_read(&c->u.name, GFP_KERNEL, fp, len);
if (rc)
goto out;
- c->u.name[len] = 0;
+
rc = context_read_and_validate(&c->context[0], p, fp);
if (rc)
goto out;
--
2.0.0

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Next message: Mikael Pettersson: "Re: [RFC 0/2] __vdso_findsym"
Previous message: Peter Zijlstra: "[PATCH 07/11] qspinlock: Use a simple write to grab the lock, if applicable"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]