[PATCH] drop gfp_mask in audit_log_exit()
Al Viro [Thu, 30 Mar 2006 01:17:10 +0000 (20:17 -0500)]
now we can do that - all callers are process-synchronous and do not hold
any locks.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

kernel/auditsc.c

index 8ec52ff..ba0ec1b 100644 (file)
@@ -506,7 +506,7 @@ static inline void audit_free_context(struct audit_context *context)
                printk(KERN_ERR "audit: freed %d contexts\n", count);
 }
 
-static void audit_log_task_context(struct audit_buffer *ab, gfp_t gfp_mask)
+static void audit_log_task_context(struct audit_buffer *ab)
 {
        char *ctx = NULL;
        ssize_t len = 0;
@@ -518,7 +518,7 @@ static void audit_log_task_context(struct audit_buffer *ab, gfp_t gfp_mask)
                return;
        }
 
-       ctx = kmalloc(len, gfp_mask);
+       ctx = kmalloc(len, GFP_KERNEL);
        if (!ctx)
                goto error_path;
 
@@ -536,47 +536,46 @@ error_path:
        return;
 }
 
-static void audit_log_task_info(struct audit_buffer *ab, struct task_struct *tsk, gfp_t gfp_mask)
+static void audit_log_task_info(struct audit_buffer *ab, struct task_struct *tsk)
 {
        char name[sizeof(tsk->comm)];
        struct mm_struct *mm = tsk->mm;
        struct vm_area_struct *vma;
 
+       /* tsk == current */
+
        get_task_comm(name, tsk);
        audit_log_format(ab, " comm=");
        audit_log_untrustedstring(ab, name);
 
-       if (!mm)
-               return;
-
-       /*
-        * this is brittle; all callers that pass GFP_ATOMIC will have
-        * NULL tsk->mm and we won't get here.
-        */
-       down_read(&mm->mmap_sem);
-       vma = mm->mmap;
-       while (vma) {
-               if ((vma->vm_flags & VM_EXECUTABLE) &&
-                   vma->vm_file) {
-                       audit_log_d_path(ab, "exe=",
-                                        vma->vm_file->f_dentry,
-                                        vma->vm_file->f_vfsmnt);
-                       break;
+       if (mm) {
+               down_read(&mm->mmap_sem);
+               vma = mm->mmap;
+               while (vma) {
+                       if ((vma->vm_flags & VM_EXECUTABLE) &&
+                           vma->vm_file) {
+                               audit_log_d_path(ab, "exe=",
+                                                vma->vm_file->f_dentry,
+                                                vma->vm_file->f_vfsmnt);
+                               break;
+                       }
+                       vma = vma->vm_next;
                }
-               vma = vma->vm_next;
+               up_read(&mm->mmap_sem);
        }
-       up_read(&mm->mmap_sem);
-       audit_log_task_context(ab, gfp_mask);
+       audit_log_task_context(ab);
 }
 
-static void audit_log_exit(struct audit_context *context, struct task_struct *tsk, gfp_t gfp_mask)
+static void audit_log_exit(struct audit_context *context, struct task_struct *tsk)
 {
        int i;
        struct audit_buffer *ab;
        struct audit_aux_data *aux;
        const char *tty;
 
-       ab = audit_log_start(context, gfp_mask, AUDIT_SYSCALL);
+       /* tsk == current */
+
+       ab = audit_log_start(context, GFP_KERNEL, AUDIT_SYSCALL);
        if (!ab)
                return;         /* audit_panic has been called */
        audit_log_format(ab, "arch=%x syscall=%d",
@@ -607,12 +606,12 @@ static void audit_log_exit(struct audit_context *context, struct task_struct *ts
                  context->gid,
                  context->euid, context->suid, context->fsuid,
                  context->egid, context->sgid, context->fsgid, tty);
-       audit_log_task_info(ab, gfp_mask);
+       audit_log_task_info(ab, tsk);
        audit_log_end(ab);
 
        for (aux = context->aux; aux; aux = aux->next) {
 
-               ab = audit_log_start(context, gfp_mask, aux->type);
+               ab = audit_log_start(context, GFP_KERNEL, aux->type);
                if (!ab)
                        continue; /* audit_panic has been called */
 
@@ -649,7 +648,7 @@ static void audit_log_exit(struct audit_context *context, struct task_struct *ts
        }
 
        if (context->pwd && context->pwdmnt) {
-               ab = audit_log_start(context, gfp_mask, AUDIT_CWD);
+               ab = audit_log_start(context, GFP_KERNEL, AUDIT_CWD);
                if (ab) {
                        audit_log_d_path(ab, "cwd=", context->pwd, context->pwdmnt);
                        audit_log_end(ab);
@@ -659,7 +658,7 @@ static void audit_log_exit(struct audit_context *context, struct task_struct *ts
                unsigned long ino  = context->names[i].ino;
                unsigned long pino = context->names[i].pino;
 
-               ab = audit_log_start(context, gfp_mask, AUDIT_PATH);
+               ab = audit_log_start(context, GFP_KERNEL, AUDIT_PATH);
                if (!ab)
                        continue; /* audit_panic has been called */
 
@@ -712,8 +711,9 @@ void audit_free(struct task_struct *tsk)
         * function (e.g., exit_group), then free context block. 
         * We use GFP_ATOMIC here because we might be doing this 
         * in the context of the idle thread */
+       /* that can happen only if we are called from do_exit() */
        if (context->in_syscall && context->auditable)
-               audit_log_exit(context, tsk, GFP_ATOMIC);
+               audit_log_exit(context, tsk);
 
        audit_free_context(context);
 }
@@ -821,6 +821,8 @@ void audit_syscall_exit(struct task_struct *tsk, int valid, long return_code)
 {
        struct audit_context *context;
 
+       /* tsk == current */
+
        get_task_struct(tsk);
        task_lock(tsk);
        context = audit_get_context(tsk, valid, return_code);
@@ -832,7 +834,7 @@ void audit_syscall_exit(struct task_struct *tsk, int valid, long return_code)
                goto out;
 
        if (context->in_syscall && context->auditable)
-               audit_log_exit(context, tsk, GFP_KERNEL);
+               audit_log_exit(context, tsk);
 
        context->in_syscall = 0;
        context->auditable  = 0;