Changeset 0030eef in mainline for kernel/generic/src/sysinfo/sysinfo.c

Timestamp:

2012-03-02T13:55:54Z (12 years ago)

Author:

Martin Decky <martin@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

560d79f

Parents:

5869ce0

Message:

add kernel support for listing sysinfo keys from uspace

File:

• kernel/generic/src/sysinfo/sysinfo.c (modified) (5 diffs)

kernel/generic/src/sysinfo/sysinfo.c

@@ -110 +110 @@
  * @param subtree Current sysinfo (sub)tree root item.
  * @param ret     If the return value is NULL, this argument
- *                can be either also NULL (i.e. no item was
+ *                can be set either to NULL (i.e. no item was
  *                found and no data was generated) or the
  *                original pointer is used to store the value
@@ -125 +125 @@
 {
         ASSERT(subtree != NULL);
-        ASSERT(ret != NULL);
         
         sysinfo_item_t *cur = subtree;
@@ -151 +150 @@
                         case SYSINFO_SUBTREE_FUNCTION:
                                 /* Get generated data */
-                                **ret = cur->subtree.generator.fn(name + i + 1, dry_run,
-                                    cur->subtree.generator.data);
+                                if (ret != NULL)
+                                        **ret = cur->subtree.generator.fn(name + i + 1,
+                                            dry_run, cur->subtree.generator.data);
+                                
                                 return NULL;
                         default:
                                 /* Not found, no data generated */
-                                *ret = NULL;
+                                if (ret != NULL)
+                                        *ret = NULL;
+                                
                                 return NULL;
                         }
@@ -165 +168 @@
         
         /* Not found, no data generated */
-        *ret = NULL;
+        if (ret != NULL)
+                *ret = NULL;
+        
         return NULL;
 }
@@ -653 +658 @@
 }
 
+/** Return sysinfo keys determined by name
+ *
+ * Should be called with sysinfo_lock held.
+ *
+ * @param name    Sysinfo path.
+ * @param root    Root item of the sysinfo (sub)tree.
+ *                If it is NULL then consider the global
+ *                sysinfo tree.
+ * @param dry_run Do not actually get any generated
+ *                binary data, just calculate the size.
+ *
+ * @return Item value (constant or generated).
+ *
+ */
+NO_TRACE static sysinfo_return_t sysinfo_get_keys(const char *name,
+    sysinfo_item_t **root, bool dry_run)
+{
+        if (root == NULL)
+                root = &global_root;
+        
+        /* Try to find the item */
+        sysinfo_item_t *item = sysinfo_find_item(name, *root, NULL,
+            dry_run);
+        
+        sysinfo_return_t ret;
+        
+        if ((item != NULL) && (item->subtree_type == SYSINFO_SUBTREE_TABLE)) {
+                /*
+                 * Subtree found in the fixed sysinfo tree.
+                 * Calculate the size of subkeys.
+                 */
+                size_t size = 0;
+                for (sysinfo_item_t *cur = item->subtree.table; cur;
+                    cur = cur->next)
+                        size += str_size(cur->name) + 1;
+                
+                if (dry_run) {
+                        ret.tag = SYSINFO_VAL_FUNCTION_DATA;
+                        ret.data.data = NULL;
+                        ret.data.size = size;
+                } else {
+                        /* Allocate buffer for subkeys */
+                        char *names = (char *) malloc(size, FRAME_ATOMIC);
+                        if (names == NULL)
+                                return ret;
+                        
+                        size_t pos = 0;
+                        for (sysinfo_item_t *cur = item->subtree.table; cur;
+                            cur = cur->next) {
+                                str_cpy(names + pos, size - pos, cur->name);
+                                pos += str_size(cur->name) + 1;
+                        }
+                        
+                        /* Correct return value */
+                        ret.tag = SYSINFO_VAL_FUNCTION_DATA;
+                        ret.data.data = (void *) names;
+                        ret.data.size = size;
+                }
+        } else {
+                /* No item in the fixed sysinfo tree */
+                ret.tag = SYSINFO_VAL_UNDEFINED;
+        }
+        
+        return ret;
+}
+
+/** Return sysinfo keys determined by name from user space
+ *
+ * The path string passed from the user space has to be properly
+ * null-terminated (the last passed character must be null).
+ *
+ * @param ptr     Sysinfo path in the user address space.
+ * @param size    Size of the path string.
+ * @param dry_run Do not actually get any generated
+ *                binary data, just calculate the size.
+ *
+ */
+NO_TRACE static sysinfo_return_t sysinfo_get_keys_uspace(void *ptr, size_t size,
+    bool dry_run)
+{
+        sysinfo_return_t ret;
+        ret.tag = SYSINFO_VAL_UNDEFINED;
+        
+        if (size > SYSINFO_MAX_PATH)
+                return ret;
+        
+        char *path = (char *) malloc(size + 1, 0);
+        ASSERT(path);
+        
+        if ((copy_from_uspace(path, ptr, size + 1) == 0) &&
+            (path[size] == 0)) {
+                /*
+                 * Prevent other functions from messing with sysinfo while we
+                 * are reading it.
+                 */
+                mutex_lock(&sysinfo_lock);
+                ret = sysinfo_get_keys(path, NULL, dry_run);
+                mutex_unlock(&sysinfo_lock);
+        }
+        
+        free(path);
+        return ret;
+}
+
+/** Get the sysinfo keys size (syscall)
+ *
+ * The path string passed from the user space has
+ * to be properly null-terminated (the last passed
+ * character must be null).
+ *
+ * @param path_ptr  Sysinfo path in the user address space.
+ * @param path_size Size of the path string.
+ * @param size_ptr  User space pointer where to store the
+ *                  keys size.
+ *
+ * @return Error code (EOK in case of no error).
+ *
+ */
+sysarg_t sys_sysinfo_get_keys_size(void *path_ptr, size_t path_size,
+    void *size_ptr)
+{
+        int rc;
+        
+        /*
+         * Get the keys.
+         *
+         * N.B.: There is no need to free any potential keys
+         * since we request a dry run.
+         */
+        sysinfo_return_t ret =
+            sysinfo_get_keys_uspace(path_ptr, path_size, true);
+        
+        /* Check return data tag */
+        if (ret.tag == SYSINFO_VAL_DATA)
+                rc = copy_to_uspace(size_ptr, &ret.data.size,
+                    sizeof(ret.data.size));
+        else
+                rc = EINVAL;
+        
+        return (sysarg_t) rc;
+}
+
+/** Get the sysinfo keys (syscall)
+ *
+ * The path string passed from the user space has
+ * to be properly null-terminated (the last passed
+ * character must be null).
+ *
+ * If the user space buffer size does not equal
+ * the actual size of the returned data, the data
+ * is truncated.
+ *
+ * The actual size of data returned is stored to
+ * size_ptr.
+ *
+ * @param path_ptr    Sysinfo path in the user address space.
+ * @param path_size   Size of the path string.
+ * @param buffer_ptr  User space pointer to the buffer where
+ *                    to store the binary data.
+ * @param buffer_size User space buffer size.
+ * @param size_ptr    User space pointer where to store the
+ *                    binary data size.
+ *
+ * @return Error code (EOK in case of no error).
+ *
+ */
+sysarg_t sys_sysinfo_get_keys(void *path_ptr, size_t path_size,
+    void *buffer_ptr, size_t buffer_size, size_t *size_ptr)
+{
+        int rc;
+        
+        /* Get the keys */
+        sysinfo_return_t ret = sysinfo_get_keys_uspace(path_ptr, path_size,
+            false);
+        
+        /* Check return data tag */
+        if (ret.tag == SYSINFO_VAL_DATA) {
+                size_t size = min(ret.data.size, buffer_size);
+                rc = copy_to_uspace(buffer_ptr, ret.data.data, size);
+                if (rc == EOK)
+                        rc = copy_to_uspace(size_ptr, &size, sizeof(size));
+                
+                free(ret.data.data);
+        } else
+                rc = EINVAL;
+        
+        return (sysarg_t) rc;
+}
+
 /** Get the sysinfo value type (syscall)
  *