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TOMOYO: Replace rw_semaphore by mutex.
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Since readers no longer use down_read(), writers no longer
need to use rw_semaphore. Replace individual rw_semaphore by
single mutex.

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>
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Tetsuo Handa authored and James Morris committed Jan 10, 2010
1 parent fdb8ebb commit f737d95
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Showing 4 changed files with 27 additions and 36 deletions.
12 changes: 7 additions & 5 deletions security/tomoyo/common.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -16,6 +16,9 @@
#include "common.h"
#include "tomoyo.h"

/* Lock for protecting policy. */
DEFINE_MUTEX(tomoyo_policy_lock);

/* Has loading policy done? */
bool tomoyo_policy_loaded;

Expand Down Expand Up @@ -1086,7 +1089,6 @@ struct tomoyo_policy_manager_entry {
* # cat /sys/kernel/security/tomoyo/manager
*/
static LIST_HEAD(tomoyo_policy_manager_list);
static DECLARE_RWSEM(tomoyo_policy_manager_list_lock);

/**
* tomoyo_update_manager_entry - Add a manager entry.
Expand Down Expand Up @@ -1118,7 +1120,7 @@ static int tomoyo_update_manager_entry(const char *manager,
saved_manager = tomoyo_save_name(manager);
if (!saved_manager)
return -ENOMEM;
down_write(&tomoyo_policy_manager_list_lock);
mutex_lock(&tomoyo_policy_lock);
list_for_each_entry_rcu(ptr, &tomoyo_policy_manager_list, list) {
if (ptr->manager != saved_manager)
continue;
Expand All @@ -1138,7 +1140,7 @@ static int tomoyo_update_manager_entry(const char *manager,
list_add_tail_rcu(&new_entry->list, &tomoyo_policy_manager_list);
error = 0;
out:
up_write(&tomoyo_policy_manager_list_lock);
mutex_unlock(&tomoyo_policy_lock);
return error;
}

Expand Down Expand Up @@ -1315,7 +1317,7 @@ static int tomoyo_delete_domain(char *domainname)

name.name = domainname;
tomoyo_fill_path_info(&name);
down_write(&tomoyo_domain_list_lock);
mutex_lock(&tomoyo_policy_lock);
/* Is there an active domain? */
list_for_each_entry_rcu(domain, &tomoyo_domain_list, list) {
/* Never delete tomoyo_kernel_domain */
Expand All @@ -1327,7 +1329,7 @@ static int tomoyo_delete_domain(char *domainname)
domain->is_deleted = true;
break;
}
up_write(&tomoyo_domain_list_lock);
mutex_unlock(&tomoyo_policy_lock);
return 0;
}

Expand Down
5 changes: 2 additions & 3 deletions security/tomoyo/common.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -431,10 +431,9 @@ static inline bool tomoyo_is_invalid(const unsigned char c)

/* The list for "struct tomoyo_domain_info". */
extern struct list_head tomoyo_domain_list;
extern struct rw_semaphore tomoyo_domain_list_lock;

/* Lock for domain->acl_info_list. */
extern struct rw_semaphore tomoyo_domain_acl_info_list_lock;
/* Lock for protecting policy. */
extern struct mutex tomoyo_policy_lock;

/* Has /sbin/init started? */
extern bool tomoyo_policy_loaded;
Expand Down
20 changes: 8 additions & 12 deletions security/tomoyo/domain.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -58,7 +58,6 @@ struct tomoyo_domain_info tomoyo_kernel_domain;
* exceptions.
*/
LIST_HEAD(tomoyo_domain_list);
DECLARE_RWSEM(tomoyo_domain_list_lock);

/*
* tomoyo_domain_initializer_entry is a structure which is used for holding
Expand Down Expand Up @@ -206,7 +205,6 @@ const char *tomoyo_get_last_name(const struct tomoyo_domain_info *domain)
* unless executed from "<kernel> /etc/rc.d/init.d/httpd" domain.
*/
static LIST_HEAD(tomoyo_domain_initializer_list);
static DECLARE_RWSEM(tomoyo_domain_initializer_list_lock);

/**
* tomoyo_update_domain_initializer_entry - Update "struct tomoyo_domain_initializer_entry" list.
Expand Down Expand Up @@ -247,7 +245,7 @@ static int tomoyo_update_domain_initializer_entry(const char *domainname,
saved_program = tomoyo_save_name(program);
if (!saved_program)
return -ENOMEM;
down_write(&tomoyo_domain_initializer_list_lock);
mutex_lock(&tomoyo_policy_lock);
list_for_each_entry_rcu(ptr, &tomoyo_domain_initializer_list, list) {
if (ptr->is_not != is_not ||
ptr->domainname != saved_domainname ||
Expand All @@ -271,7 +269,7 @@ static int tomoyo_update_domain_initializer_entry(const char *domainname,
list_add_tail_rcu(&new_entry->list, &tomoyo_domain_initializer_list);
error = 0;
out:
up_write(&tomoyo_domain_initializer_list_lock);
mutex_unlock(&tomoyo_policy_lock);
return error;
}

Expand Down Expand Up @@ -423,7 +421,6 @@ static bool tomoyo_is_domain_initializer(const struct tomoyo_path_info *
* explicitly specified by "initialize_domain".
*/
static LIST_HEAD(tomoyo_domain_keeper_list);
static DECLARE_RWSEM(tomoyo_domain_keeper_list_lock);

/**
* tomoyo_update_domain_keeper_entry - Update "struct tomoyo_domain_keeper_entry" list.
Expand Down Expand Up @@ -464,7 +461,7 @@ static int tomoyo_update_domain_keeper_entry(const char *domainname,
saved_domainname = tomoyo_save_name(domainname);
if (!saved_domainname)
return -ENOMEM;
down_write(&tomoyo_domain_keeper_list_lock);
mutex_lock(&tomoyo_policy_lock);
list_for_each_entry_rcu(ptr, &tomoyo_domain_keeper_list, list) {
if (ptr->is_not != is_not ||
ptr->domainname != saved_domainname ||
Expand All @@ -488,7 +485,7 @@ static int tomoyo_update_domain_keeper_entry(const char *domainname,
list_add_tail_rcu(&new_entry->list, &tomoyo_domain_keeper_list);
error = 0;
out:
up_write(&tomoyo_domain_keeper_list_lock);
mutex_unlock(&tomoyo_policy_lock);
return error;
}

Expand Down Expand Up @@ -624,7 +621,6 @@ static bool tomoyo_is_domain_keeper(const struct tomoyo_path_info *domainname,
* execve() succeeds is calculated using /bin/cat rather than /bin/busybox .
*/
static LIST_HEAD(tomoyo_alias_list);
static DECLARE_RWSEM(tomoyo_alias_list_lock);

/**
* tomoyo_update_alias_entry - Update "struct tomoyo_alias_entry" list.
Expand Down Expand Up @@ -654,7 +650,7 @@ static int tomoyo_update_alias_entry(const char *original_name,
saved_aliased_name = tomoyo_save_name(aliased_name);
if (!saved_original_name || !saved_aliased_name)
return -ENOMEM;
down_write(&tomoyo_alias_list_lock);
mutex_lock(&tomoyo_policy_lock);
list_for_each_entry_rcu(ptr, &tomoyo_alias_list, list) {
if (ptr->original_name != saved_original_name ||
ptr->aliased_name != saved_aliased_name)
Expand All @@ -675,7 +671,7 @@ static int tomoyo_update_alias_entry(const char *original_name,
list_add_tail_rcu(&new_entry->list, &tomoyo_alias_list);
error = 0;
out:
up_write(&tomoyo_alias_list_lock);
mutex_unlock(&tomoyo_policy_lock);
return error;
}

Expand Down Expand Up @@ -745,7 +741,7 @@ struct tomoyo_domain_info *tomoyo_find_or_assign_new_domain(const char *
struct tomoyo_domain_info *domain = NULL;
const struct tomoyo_path_info *saved_domainname;

down_write(&tomoyo_domain_list_lock);
mutex_lock(&tomoyo_policy_lock);
domain = tomoyo_find_domain(domainname);
if (domain)
goto out;
Expand Down Expand Up @@ -792,7 +788,7 @@ struct tomoyo_domain_info *tomoyo_find_or_assign_new_domain(const char *
list_add_tail_rcu(&domain->list, &tomoyo_domain_list);
}
out:
up_write(&tomoyo_domain_list_lock);
mutex_unlock(&tomoyo_policy_lock);
return domain;
}

Expand Down
26 changes: 10 additions & 16 deletions security/tomoyo/file.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -167,9 +167,6 @@ static struct tomoyo_path_info *tomoyo_get_path(struct path *path)
return NULL;
}

/* Lock for domain->acl_info_list. */
DECLARE_RWSEM(tomoyo_domain_acl_info_list_lock);

static int tomoyo_update_double_path_acl(const u8 type, const char *filename1,
const char *filename2,
struct tomoyo_domain_info *
Expand Down Expand Up @@ -204,7 +201,6 @@ static int tomoyo_update_single_path_acl(const u8 type, const char *filename,
* belongs to.
*/
static LIST_HEAD(tomoyo_globally_readable_list);
static DECLARE_RWSEM(tomoyo_globally_readable_list_lock);

/**
* tomoyo_update_globally_readable_entry - Update "struct tomoyo_globally_readable_file_entry" list.
Expand All @@ -229,7 +225,7 @@ static int tomoyo_update_globally_readable_entry(const char *filename,
saved_filename = tomoyo_save_name(filename);
if (!saved_filename)
return -ENOMEM;
down_write(&tomoyo_globally_readable_list_lock);
mutex_lock(&tomoyo_policy_lock);
list_for_each_entry_rcu(ptr, &tomoyo_globally_readable_list, list) {
if (ptr->filename != saved_filename)
continue;
Expand All @@ -248,7 +244,7 @@ static int tomoyo_update_globally_readable_entry(const char *filename,
list_add_tail_rcu(&new_entry->list, &tomoyo_globally_readable_list);
error = 0;
out:
up_write(&tomoyo_globally_readable_list_lock);
mutex_unlock(&tomoyo_policy_lock);
return error;
}

Expand Down Expand Up @@ -352,7 +348,6 @@ bool tomoyo_read_globally_readable_policy(struct tomoyo_io_buffer *head)
* current process from accessing other process's information.
*/
static LIST_HEAD(tomoyo_pattern_list);
static DECLARE_RWSEM(tomoyo_pattern_list_lock);

/**
* tomoyo_update_file_pattern_entry - Update "struct tomoyo_pattern_entry" list.
Expand All @@ -377,7 +372,7 @@ static int tomoyo_update_file_pattern_entry(const char *pattern,
saved_pattern = tomoyo_save_name(pattern);
if (!saved_pattern)
return -ENOMEM;
down_write(&tomoyo_pattern_list_lock);
mutex_lock(&tomoyo_policy_lock);
list_for_each_entry_rcu(ptr, &tomoyo_pattern_list, list) {
if (saved_pattern != ptr->pattern)
continue;
Expand All @@ -396,7 +391,7 @@ static int tomoyo_update_file_pattern_entry(const char *pattern,
list_add_tail_rcu(&new_entry->list, &tomoyo_pattern_list);
error = 0;
out:
up_write(&tomoyo_pattern_list_lock);
mutex_unlock(&tomoyo_policy_lock);
return error;
}

Expand Down Expand Up @@ -505,7 +500,6 @@ bool tomoyo_read_file_pattern(struct tomoyo_io_buffer *head)
* need to worry whether the file is already unlink()ed or not.
*/
static LIST_HEAD(tomoyo_no_rewrite_list);
static DECLARE_RWSEM(tomoyo_no_rewrite_list_lock);

/**
* tomoyo_update_no_rewrite_entry - Update "struct tomoyo_no_rewrite_entry" list.
Expand All @@ -529,7 +523,7 @@ static int tomoyo_update_no_rewrite_entry(const char *pattern,
saved_pattern = tomoyo_save_name(pattern);
if (!saved_pattern)
return -ENOMEM;
down_write(&tomoyo_no_rewrite_list_lock);
mutex_lock(&tomoyo_policy_lock);
list_for_each_entry_rcu(ptr, &tomoyo_no_rewrite_list, list) {
if (ptr->pattern != saved_pattern)
continue;
Expand All @@ -548,7 +542,7 @@ static int tomoyo_update_no_rewrite_entry(const char *pattern,
list_add_tail_rcu(&new_entry->list, &tomoyo_no_rewrite_list);
error = 0;
out:
up_write(&tomoyo_no_rewrite_list_lock);
mutex_unlock(&tomoyo_policy_lock);
return error;
}

Expand Down Expand Up @@ -881,7 +875,7 @@ static int tomoyo_update_single_path_acl(const u8 type, const char *filename,
saved_filename = tomoyo_save_name(filename);
if (!saved_filename)
return -ENOMEM;
down_write(&tomoyo_domain_acl_info_list_lock);
mutex_lock(&tomoyo_policy_lock);
if (is_delete)
goto delete;
list_for_each_entry_rcu(ptr, &domain->acl_info_list, list) {
Expand Down Expand Up @@ -943,7 +937,7 @@ static int tomoyo_update_single_path_acl(const u8 type, const char *filename,
break;
}
out:
up_write(&tomoyo_domain_acl_info_list_lock);
mutex_unlock(&tomoyo_policy_lock);
return error;
}

Expand Down Expand Up @@ -981,7 +975,7 @@ static int tomoyo_update_double_path_acl(const u8 type, const char *filename1,
saved_filename2 = tomoyo_save_name(filename2);
if (!saved_filename1 || !saved_filename2)
return -ENOMEM;
down_write(&tomoyo_domain_acl_info_list_lock);
mutex_lock(&tomoyo_policy_lock);
if (is_delete)
goto delete;
list_for_each_entry_rcu(ptr, &domain->acl_info_list, list) {
Expand Down Expand Up @@ -1027,7 +1021,7 @@ static int tomoyo_update_double_path_acl(const u8 type, const char *filename1,
break;
}
out:
up_write(&tomoyo_domain_acl_info_list_lock);
mutex_unlock(&tomoyo_policy_lock);
return error;
}

Expand Down

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