|
@@ -35,7 +35,7 @@
|
|
|
#include <linux/capability.h>
|
|
|
#include <linux/ptrace.h>
|
|
|
#include <linux/seq_file.h>
|
|
|
-#include <linux/mutex.h>
|
|
|
+#include <linux/rwsem.h>
|
|
|
#include <linux/nsproxy.h>
|
|
|
#include <linux/mount.h>
|
|
|
|
|
@@ -83,8 +83,8 @@ static void __shm_init_ns(struct ipc_namespace *ns, struct ipc_ids *ids)
|
|
|
}
|
|
|
|
|
|
/*
|
|
|
- * Called with shm_ids.mutex and the shp structure locked.
|
|
|
- * Only shm_ids.mutex remains locked on exit.
|
|
|
+ * Called with shm_ids.rw_mutex (writer) and the shp structure locked.
|
|
|
+ * Only shm_ids.rw_mutex remains locked on exit.
|
|
|
*/
|
|
|
static void do_shm_rmid(struct ipc_namespace *ns, struct shmid_kernel *shp)
|
|
|
{
|
|
@@ -115,7 +115,7 @@ void shm_exit_ns(struct ipc_namespace *ns)
|
|
|
int next_id;
|
|
|
int total, in_use;
|
|
|
|
|
|
- mutex_lock(&shm_ids(ns).mutex);
|
|
|
+ down_write(&shm_ids(ns).rw_mutex);
|
|
|
|
|
|
in_use = shm_ids(ns).in_use;
|
|
|
|
|
@@ -127,7 +127,7 @@ void shm_exit_ns(struct ipc_namespace *ns)
|
|
|
do_shm_rmid(ns, shp);
|
|
|
total++;
|
|
|
}
|
|
|
- mutex_unlock(&shm_ids(ns).mutex);
|
|
|
+ up_write(&shm_ids(ns).rw_mutex);
|
|
|
|
|
|
kfree(ns->ids[IPC_SHM_IDS]);
|
|
|
ns->ids[IPC_SHM_IDS] = NULL;
|
|
@@ -141,6 +141,31 @@ void __init shm_init (void)
|
|
|
IPC_SHM_IDS, sysvipc_shm_proc_show);
|
|
|
}
|
|
|
|
|
|
+/*
|
|
|
+ * shm_lock_(check_)down routines are called in the paths where the rw_mutex
|
|
|
+ * is held to protect access to the idr tree.
|
|
|
+ */
|
|
|
+static inline struct shmid_kernel *shm_lock_down(struct ipc_namespace *ns,
|
|
|
+ int id)
|
|
|
+{
|
|
|
+ struct kern_ipc_perm *ipcp = ipc_lock_down(&shm_ids(ns), id);
|
|
|
+
|
|
|
+ return container_of(ipcp, struct shmid_kernel, shm_perm);
|
|
|
+}
|
|
|
+
|
|
|
+static inline struct shmid_kernel *shm_lock_check_down(
|
|
|
+ struct ipc_namespace *ns,
|
|
|
+ int id)
|
|
|
+{
|
|
|
+ struct kern_ipc_perm *ipcp = ipc_lock_check_down(&shm_ids(ns), id);
|
|
|
+
|
|
|
+ return container_of(ipcp, struct shmid_kernel, shm_perm);
|
|
|
+}
|
|
|
+
|
|
|
+/*
|
|
|
+ * shm_lock_(check_) routines are called in the paths where the rw_mutex
|
|
|
+ * is not held.
|
|
|
+ */
|
|
|
static inline struct shmid_kernel *shm_lock(struct ipc_namespace *ns, int id)
|
|
|
{
|
|
|
struct kern_ipc_perm *ipcp = ipc_lock(&shm_ids(ns), id);
|
|
@@ -189,7 +214,7 @@ static void shm_open(struct vm_area_struct *vma)
|
|
|
* @ns: namespace
|
|
|
* @shp: struct to free
|
|
|
*
|
|
|
- * It has to be called with shp and shm_ids.mutex locked,
|
|
|
+ * It has to be called with shp and shm_ids.rw_mutex (writer) locked,
|
|
|
* but returns with shp unlocked and freed.
|
|
|
*/
|
|
|
static void shm_destroy(struct ipc_namespace *ns, struct shmid_kernel *shp)
|
|
@@ -220,9 +245,9 @@ static void shm_close(struct vm_area_struct *vma)
|
|
|
struct shmid_kernel *shp;
|
|
|
struct ipc_namespace *ns = sfd->ns;
|
|
|
|
|
|
- mutex_lock(&shm_ids(ns).mutex);
|
|
|
+ down_write(&shm_ids(ns).rw_mutex);
|
|
|
/* remove from the list of attaches of the shm segment */
|
|
|
- shp = shm_lock(ns, sfd->id);
|
|
|
+ shp = shm_lock_down(ns, sfd->id);
|
|
|
BUG_ON(IS_ERR(shp));
|
|
|
shp->shm_lprid = task_tgid_vnr(current);
|
|
|
shp->shm_dtim = get_seconds();
|
|
@@ -232,7 +257,7 @@ static void shm_close(struct vm_area_struct *vma)
|
|
|
shm_destroy(ns, shp);
|
|
|
else
|
|
|
shm_unlock(shp);
|
|
|
- mutex_unlock(&shm_ids(ns).mutex);
|
|
|
+ up_write(&shm_ids(ns).rw_mutex);
|
|
|
}
|
|
|
|
|
|
static int shm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
|
|
@@ -353,7 +378,7 @@ static struct vm_operations_struct shm_vm_ops = {
|
|
|
* @ns: namespace
|
|
|
* @params: ptr to the structure that contains key, size and shmflg
|
|
|
*
|
|
|
- * Called with shm_ids.mutex held
|
|
|
+ * Called with shm_ids.rw_mutex held as a writer.
|
|
|
*/
|
|
|
|
|
|
static int newseg(struct ipc_namespace *ns, struct ipc_params *params)
|
|
@@ -442,7 +467,7 @@ no_file:
|
|
|
}
|
|
|
|
|
|
/*
|
|
|
- * Called with shm_ids.mutex and ipcp locked.
|
|
|
+ * Called with shm_ids.rw_mutex and ipcp locked.
|
|
|
*/
|
|
|
static inline int shm_security(struct kern_ipc_perm *ipcp, int shmflg)
|
|
|
{
|
|
@@ -453,7 +478,7 @@ static inline int shm_security(struct kern_ipc_perm *ipcp, int shmflg)
|
|
|
}
|
|
|
|
|
|
/*
|
|
|
- * Called with shm_ids.mutex and ipcp locked.
|
|
|
+ * Called with shm_ids.rw_mutex and ipcp locked.
|
|
|
*/
|
|
|
static inline int shm_more_checks(struct kern_ipc_perm *ipcp,
|
|
|
struct ipc_params *params)
|
|
@@ -578,7 +603,7 @@ static inline unsigned long copy_shminfo_to_user(void __user *buf, struct shminf
|
|
|
}
|
|
|
|
|
|
/*
|
|
|
- * Called with shm_ids.mutex held
|
|
|
+ * Called with shm_ids.rw_mutex held as a reader
|
|
|
*/
|
|
|
static void shm_get_stat(struct ipc_namespace *ns, unsigned long *rss,
|
|
|
unsigned long *swp)
|
|
@@ -649,9 +674,9 @@ asmlinkage long sys_shmctl (int shmid, int cmd, struct shmid_ds __user *buf)
|
|
|
if(copy_shminfo_to_user (buf, &shminfo, version))
|
|
|
return -EFAULT;
|
|
|
|
|
|
- mutex_lock(&shm_ids(ns).mutex);
|
|
|
+ down_read(&shm_ids(ns).rw_mutex);
|
|
|
err = ipc_get_maxid(&shm_ids(ns));
|
|
|
- mutex_unlock(&shm_ids(ns).mutex);
|
|
|
+ up_read(&shm_ids(ns).rw_mutex);
|
|
|
|
|
|
if(err<0)
|
|
|
err = 0;
|
|
@@ -666,14 +691,14 @@ asmlinkage long sys_shmctl (int shmid, int cmd, struct shmid_ds __user *buf)
|
|
|
return err;
|
|
|
|
|
|
memset(&shm_info,0,sizeof(shm_info));
|
|
|
- mutex_lock(&shm_ids(ns).mutex);
|
|
|
+ down_read(&shm_ids(ns).rw_mutex);
|
|
|
shm_info.used_ids = shm_ids(ns).in_use;
|
|
|
shm_get_stat (ns, &shm_info.shm_rss, &shm_info.shm_swp);
|
|
|
shm_info.shm_tot = ns->shm_tot;
|
|
|
shm_info.swap_attempts = 0;
|
|
|
shm_info.swap_successes = 0;
|
|
|
err = ipc_get_maxid(&shm_ids(ns));
|
|
|
- mutex_unlock(&shm_ids(ns).mutex);
|
|
|
+ up_read(&shm_ids(ns).rw_mutex);
|
|
|
if(copy_to_user (buf, &shm_info, sizeof(shm_info))) {
|
|
|
err = -EFAULT;
|
|
|
goto out;
|
|
@@ -786,8 +811,8 @@ asmlinkage long sys_shmctl (int shmid, int cmd, struct shmid_ds __user *buf)
|
|
|
* Instead we set a destroyed flag, and then blow
|
|
|
* the name away when the usage hits zero.
|
|
|
*/
|
|
|
- mutex_lock(&shm_ids(ns).mutex);
|
|
|
- shp = shm_lock_check(ns, shmid);
|
|
|
+ down_write(&shm_ids(ns).rw_mutex);
|
|
|
+ shp = shm_lock_check_down(ns, shmid);
|
|
|
if (IS_ERR(shp)) {
|
|
|
err = PTR_ERR(shp);
|
|
|
goto out_up;
|
|
@@ -809,7 +834,7 @@ asmlinkage long sys_shmctl (int shmid, int cmd, struct shmid_ds __user *buf)
|
|
|
goto out_unlock_up;
|
|
|
|
|
|
do_shm_rmid(ns, shp);
|
|
|
- mutex_unlock(&shm_ids(ns).mutex);
|
|
|
+ up_write(&shm_ids(ns).rw_mutex);
|
|
|
goto out;
|
|
|
}
|
|
|
|
|
@@ -824,8 +849,8 @@ asmlinkage long sys_shmctl (int shmid, int cmd, struct shmid_ds __user *buf)
|
|
|
err = -EFAULT;
|
|
|
goto out;
|
|
|
}
|
|
|
- mutex_lock(&shm_ids(ns).mutex);
|
|
|
- shp = shm_lock_check(ns, shmid);
|
|
|
+ down_write(&shm_ids(ns).rw_mutex);
|
|
|
+ shp = shm_lock_check_down(ns, shmid);
|
|
|
if (IS_ERR(shp)) {
|
|
|
err = PTR_ERR(shp);
|
|
|
goto out_up;
|
|
@@ -864,7 +889,7 @@ asmlinkage long sys_shmctl (int shmid, int cmd, struct shmid_ds __user *buf)
|
|
|
out_unlock_up:
|
|
|
shm_unlock(shp);
|
|
|
out_up:
|
|
|
- mutex_unlock(&shm_ids(ns).mutex);
|
|
|
+ up_write(&shm_ids(ns).rw_mutex);
|
|
|
goto out;
|
|
|
out_unlock:
|
|
|
shm_unlock(shp);
|
|
@@ -998,8 +1023,8 @@ invalid:
|
|
|
fput(file);
|
|
|
|
|
|
out_nattch:
|
|
|
- mutex_lock(&shm_ids(ns).mutex);
|
|
|
- shp = shm_lock(ns, shmid);
|
|
|
+ down_write(&shm_ids(ns).rw_mutex);
|
|
|
+ shp = shm_lock_down(ns, shmid);
|
|
|
BUG_ON(IS_ERR(shp));
|
|
|
shp->shm_nattch--;
|
|
|
if(shp->shm_nattch == 0 &&
|
|
@@ -1007,7 +1032,7 @@ out_nattch:
|
|
|
shm_destroy(ns, shp);
|
|
|
else
|
|
|
shm_unlock(shp);
|
|
|
- mutex_unlock(&shm_ids(ns).mutex);
|
|
|
+ up_write(&shm_ids(ns).rw_mutex);
|
|
|
|
|
|
out:
|
|
|
return err;
|