From 22098763a10d9c1340827fcf6edab66f153b27f0 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sun, 13 Sep 2026 12:27:00 -0700 Subject: Merge tag 'trace-v7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull tracing fixes from Steven Rostedt: - Don't destroy user event fields when removal fails User event fields are destroyed before the event is removed from visibility. But that can fail leaving the still visible event with no fields. Move the destroying of the fields to after the event is successfully removed from visibility. - Initialize function graph state is fork before calling copy_exec_state() For non-CLONE_VM forks, copy_exec_state() allocates a new task_exec_state. If that allocation fails, ftrace_graph_exit_task() will free the tasks ret_stack pointer. Since that pointer is still using the parent's ret_stack, it mistakenly frees the parent's pointer too. Call ftrace_graph_init() on the task first which will NULL out the new tasks's ret_stack and if the copy fails, it will not free anything. - Remove FGRAPH_MAX_INDEX The macro FGRAPH_MAX_INDEX was added but never used. Remove it. - Save ent_size in function graph printing of nested functions The function graph tracer needs to look at the next event to see if the next event is the return of the current function entry. If it is, it prints a single line: ktime_get(); Otherwise it prints it like a nested function: tick_nohz_irq_exit() { ktime_get(); kcpustat_irq_exit(); } In order to look at the next event, it must save the current event so that it has the information to print from it. It saves the event in the iterator descriptor called "ent". What it doesn't save is the ent_size of the event which is now used to know if the function graph arguments are to be printed. The peek doesn't save the size so the size used happens to be that of the size of the last event that was seen. Save the entry event size in the iterator descriptor so that the correct size is used. - Fix several errors with freeing data in the histogram code The histogram code had a lot of leaked or or incorrect accounting when failures happen. Correct them. - Fix histogram regression of .percent and .graph modifiers Up until 6.3 histogram values could have "percent" or "graph" modifiers that changed how they were printed. But a change that added restricting histograms values from being strings, stack traces and other modifiers inadvertently prevented them from using the percent and graph modifiers, which were legal use cases for values. Put back the percent and graph modifiers. - Fix various typos in the comments - Set the trace_clock before initializing a histogram with clock argument The histogram API allows the user to specific which trace clock to use via a "clock=" string. The histogram is set up first before the clock is checked. If the passed in clock is not valid, it exits without fully fixing up the histogram leaving it on the list and a use-after-free can trigger. Update the clock argument first and if it fails then exit gracefully before the histogram trigger is placed on any lists. - Restore :mod: trailer after parsing in ftrace_set_clr_event The function ftrace_set_clr_event() modifies the parse string and needs to put it back to what was passed in. It searches for ":mod:" via a strsep() but fails to put back the first ':' in the string. Add back the ':' in the passed in string. - Take trace_array reference when opening a tracer options file The options files are dynamically created and some tracers add their own options. When a tracer adds their own list of options, the trace_array holding them has an array to hold the list of options for each tracer. This array increases in size via a krealloc(), and the new entry gets a newly allocated array to hold the options of the new tracer being added. The element in each entry of the tracer's option array holds a pointer back to the trace_array, a pointer to the tracer it is associated to, a pointer to the flags of the option. The issue is that these arrays are freed when the trace_array is freed when its instance it represents is removed from the instances directory. There's a race that an open of one of these options files can happen when the instance is being removed. Add a new helper function to be called by the open function of the options file to iterate all existing trace_arrays under a lock and find the one that has the given option element in one of it's tracer arrays. If found, then update the associated trace_array's reference counter to keep it from being freed. If not found, have the open call return -ENODEV. - Disable interrupts when acquiring the lock in rb_wake_up_waiters() The function rb_wake_up_waiters() assumes it will be called in interrupt context and does not disable irqs when taking cpu_buffer->reader_lock, which can be called in hard interrupt context. The issue is in PREEMPT_RT, this function is called in thread context leaving this lock open to a deadlock. Take the lock with interrupts disabled. - Use rcu_assign_pointer() for tmp_ops filter hash The tmp_ops used in update_ftrace_direct_mod() assigns its filter_hash field directly, but that field is annotated as __rcu and sparse complains. Assign it with rcu_assign_pointer() - Fix use-after-free in enable_trigger_private_data_free() The trace_event_call is accessed through the event_trigger_data's trace_event_file pointer to put the trace_event_call on freeing. The issue is that the trace_event_file data may have been freed already causing a use-after-free. Add a field to the event_trigger_data that points directly to the trace_event_call so that it can decrement its reference directly without needing to go through the trace_event_file. - Fix accounting of buffer data remote headers trace_buffer_desc_size() and trace_remote_alloc_buffer() undercount the number of pages is needed for the asked for size as it doesn't take into account the meta data on each page. Add a helper function to do the calculation properly and use that in these functions. - Catch nr_page_va overflow in ring_buffer_desc sizing The number of pages per remote ring buffer is capped by ring_buffer_desc::nr_page_va (32 bits). A buffer_size large enough to overflow that field would silently allocate a descriptor smaller than what was asked for. - Do not resize the subbuf order if any per_cpu buffer is disabled The mmapping of ring buffers disables resizing the subbuffers, but it is done per-cpu whereas the subbuf size change is done for all the per_cpu buffers under the buffer->mutex. It could change the size of some while the mapping is happening on others. Have the resize of the subbuf order check all the per_cpu buffers under the lock to see if any of them is disabled before starting and causing an inconsistency between buffers that are being mapped. * tag 'trace-v7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (25 commits) ring-buffer: Check resize_disabled before publishing the new subbuf order tracing/remotes: Catch nr_page_va overflow in ring_buffer_desc sizing tracing/remotes: Account for ring buffer page header in size calculation tracing: Don't dereference trace_event_file in deferred trigger free ftrace: Use rcu_assign_pointer() for tmp_ops filter hash ring-buffer: Acquire the lock with irqsave in rb_wake_up_waiters() tracing: Take trace_array reference when opening a tracer options file tracing: Fix ring_buffer_read_page_size() kernel-doc tracing: Restore :mod: trailer after parsing in ftrace_set_clr_event() tracing: Fix memory corruption from a "STACKTRACE" histogram key tracing: Fix memory corruption from the histogram stacktrace modifier tracing: Undo the registration when enabling the histogram trigger fails tracing: Take the reference before publishing the named histogram trigger tracing: Set the trace clock before registering the histogram trigger tracing: Fix typo "preceeded" in comment tracing: Fix typo "availabe" in comment tracing: Let histogram values keep the percent and graph modifiers tracing: Keep the entry count when the histogram stats allocation fails tracing: Free histogram the field rejected for a bad modifier tracing: Free histogram the var ref when its initialization fails ... --- lib/bootconfig.c | 1211 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 1211 insertions(+) create mode 100644 lib/bootconfig.c (limited to 'lib/bootconfig.c') diff --git a/lib/bootconfig.c b/lib/bootconfig.c new file mode 100644 index 000000000..89c88e359 --- /dev/null +++ b/lib/bootconfig.c @@ -0,0 +1,1211 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Extra Boot Config + * Masami Hiramatsu + */ + +/* + * NOTE: This is only for tools/bootconfig, because tools/bootconfig will + * run the parser sanity test. + * This does NOT mean lib/bootconfig.c is available in the user space. + * However, if you change this file, please make sure the tools/bootconfig + * has no issue on building and running. + */ +#include + +#ifdef __KERNEL__ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include /* COMMAND_LINE_SIZE */ + +#ifdef CONFIG_BOOT_CONFIG_EMBED +/* embedded_bootconfig_data is defined in bootconfig-data.S */ +extern __visible const char embedded_bootconfig_data[]; +extern __visible const char embedded_bootconfig_data_end[]; + +const char * __init xbc_get_embedded_bootconfig(size_t *size) +{ + *size = embedded_bootconfig_data_end - embedded_bootconfig_data; + return (*size) ? embedded_bootconfig_data : NULL; +} +#endif + +#ifdef CONFIG_CMDLINE_FROM_BOOTCONFIG +/* embedded_kernel_cmdline is defined in embedded-cmdline.S */ +extern __visible const char embedded_kernel_cmdline[]; +extern __visible const char embedded_kernel_cmdline_end[]; + +/* Set once the embedded cmdline has actually been prepended. */ +static bool xbc_cmdline_applied __initdata; + +/* + * str_prepend() - Prepend @src in front of the string in @dst, in place + * @dst: NUL-terminated destination buffer, currently @dst_len bytes long + * @dst_len: length of the current @dst string (excluding its NUL) + * @src: bytes to prepend (not NUL-terminated) + * @src_len: number of bytes from @src to prepend + * + * The caller must guarantee @dst has room for src_len + dst_len + 1 bytes. + * Moving dst_len + 1 bytes carries @dst's NUL terminator too, so an empty + * @dst needs no special case. + */ +static void __init str_prepend(char *dst, size_t dst_len, + const char *src, size_t src_len) +{ + memmove(dst + src_len, dst, dst_len + 1); + memcpy(dst, src, src_len); +} + +/** + * xbc_prepend_embedded_cmdline() - Prepend embedded bootconfig cmdline + * @dst: cmdline buffer to prepend into (must already contain a NUL byte) + * @size: total capacity of @dst in bytes + * + * Prepend the build-time-rendered "kernel" subtree of the embedded + * bootconfig to @dst. The rendered string already ends with a single + * space (the xbc_snprint_cmdline() invariant), which serves as the + * separator between the embedded keys and any existing content of @dst. + * On overflow, log an error and leave @dst untouched rather than + * silently truncating: booting without the embedded values is better + * than refusing to boot, and the error message tells the user why + * their embedded keys are missing. + * + * Intended to be called from setup_arch() before parse_early_param() so + * that early_param() handlers see the embedded values. + */ +void __init xbc_prepend_embedded_cmdline(char *dst, size_t size) +{ + size_t embed_len = embedded_kernel_cmdline_end - embedded_kernel_cmdline; + size_t dst_len; + + if (!size || embed_len <= 1) /* trailing NUL only */ + return; + embed_len--; /* exclude trailing NUL byte */ + + dst_len = strnlen(dst, size); + if (embed_len + dst_len + 1 > size) { + pr_err("embedded bootconfig cmdline (%zu bytes) does not fit in COMMAND_LINE_SIZE with %zu bytes already used; ignoring embedded values\n", + embed_len, dst_len); + return; + } + + str_prepend(dst, dst_len, embedded_kernel_cmdline, embed_len); + xbc_cmdline_applied = true; +} + +/** + * xbc_embedded_cmdline_applied() - Did the embedded cmdline get prepended? + * + * Return true if xbc_prepend_embedded_cmdline() actually prepended the + * embedded "kernel" subtree. setup_boot_config() uses this to avoid + * rendering the same keys a second time. + */ +bool __init xbc_embedded_cmdline_applied(void) +{ + return xbc_cmdline_applied; +} +#endif /* CONFIG_CMDLINE_FROM_BOOTCONFIG */ + +/* parse_args() callback: flag when the "bootconfig" parameter is present. */ +static int __init bootconfig_optin(char *param, char *val, + const char *unused, void *arg) +{ + if (!strcmp(param, "bootconfig")) + *(bool *)arg = true; + return 0; +} + +/** + * bootconfig_cmdline_requested() - Was "bootconfig" passed on the cmdline? + * @boot_cmdline: kernel command line to inspect (not modified) + * @end_offset: if non-NULL, set to the offset of the init arguments that + * follow a "--" separator, or 0 when there is none + * + * Parse a private copy of @boot_cmdline (parse_args() is destructive) and + * report whether "bootconfig" is present before the "--" separator. + * setup_arch() uses this to gate prepending the build-time embedded cmdline; + * setup_boot_config() uses it for the runtime opt-in and to locate the init + * arguments via @end_offset. Sharing one parser keeps the early and late + * paths agreeing on what counts as opt-in. CONFIG_BOOT_CONFIG_FORCE is not + * folded in here; callers apply it where they need it. + */ +bool __init bootconfig_cmdline_requested(const char *boot_cmdline, int *end_offset) +{ + static char tmp_cmdline[COMMAND_LINE_SIZE] __initdata; + bool found = false; + char *err; + + if (end_offset) + *end_offset = 0; + + strscpy(tmp_cmdline, boot_cmdline, COMMAND_LINE_SIZE); + err = parse_args("bootconfig", tmp_cmdline, NULL, 0, 0, 0, + &found, bootconfig_optin); + if (IS_ERR(err)) + return false; + + /* parse_args() stops at "--" and returns the address of the rest. */ + if (end_offset && err) + *end_offset = err - tmp_cmdline; + + return found; +} + +#endif /* __KERNEL__ */ + +/* + * Extra Boot Config (XBC) is given as tree-structured ascii text of + * key-value pairs on memory. + * xbc_parse() parses the text to build a simple tree. Each tree node is + * simply a key word or a value. A key node may have a next key node or/and + * a child node (both key and value). A value node may have a next value + * node (for array). + */ + +static struct xbc_node *xbc_nodes __initdata; +static int xbc_node_num __initdata; +static char *xbc_data __initdata; +static size_t xbc_data_size __initdata; +static struct xbc_node *last_parent __initdata; +static const char *xbc_err_msg __initdata; +static int xbc_err_pos __initdata; +static int open_brace[XBC_DEPTH_MAX] __initdata; +static int brace_index __initdata; + +#ifdef __KERNEL__ +static inline void * __init xbc_alloc_mem(size_t size) +{ + return memblock_alloc(size, SMP_CACHE_BYTES); +} + +static inline void __init xbc_free_mem(void *addr, size_t size, bool early) +{ + if (early) + memblock_free(addr, size); + else if (addr) + memblock_free(addr, size); +} + +#else /* !__KERNEL__ */ + +static inline void *xbc_alloc_mem(size_t size) +{ + return calloc(1, size); +} + +static inline void xbc_free_mem(void *addr, size_t size, bool early) +{ + free(addr); +} +#endif + +/** + * xbc_get_info() - Get the information of loaded boot config + * @node_size: A pointer to store the number of nodes. + * @data_size: A pointer to store the size of bootconfig data. + * + * Get the number of used nodes in @node_size if it is not NULL, + * and the size of bootconfig data in @data_size if it is not NULL. + * Return 0 if the boot config is initialized, or return -ENODEV. + */ +int __init xbc_get_info(int *node_size, size_t *data_size) +{ + if (!xbc_data) + return -ENODEV; + + if (node_size) + *node_size = xbc_node_num; + if (data_size) + *data_size = xbc_data_size; + return 0; +} + +static int __init xbc_parse_error(const char *msg, const char *p) +{ + xbc_err_msg = msg; + xbc_err_pos = (int)(p - xbc_data); + + return -EINVAL; +} + +/** + * xbc_root_node() - Get the root node of extended boot config + * + * Return the address of root node of extended boot config. If the + * extended boot config is not initialized, return NULL. + */ +struct xbc_node * __init xbc_root_node(void) +{ + if (unlikely(!xbc_data)) + return NULL; + + return xbc_nodes; +} + +/** + * xbc_node_index() - Get the index of XBC node + * @node: A target node of getting index. + * + * Return the index number of @node in XBC node list. + */ +uint16_t __init xbc_node_index(struct xbc_node *node) +{ + return (uint16_t)(node - &xbc_nodes[0]); +} + +/** + * xbc_node_get_parent() - Get the parent XBC node + * @node: An XBC node. + * + * Return the parent node of @node. If the node is top node of the tree, + * return NULL. + */ +struct xbc_node * __init xbc_node_get_parent(struct xbc_node *node) +{ + return node->parent == XBC_NODE_MAX ? NULL : &xbc_nodes[node->parent]; +} + +/** + * xbc_node_get_child() - Get the child XBC node + * @node: An XBC node. + * + * Return the first child node of @node. If the node has no child, return + * NULL. + */ +struct xbc_node * __init xbc_node_get_child(struct xbc_node *node) +{ + return node->child ? &xbc_nodes[node->child] : NULL; +} + +/** + * xbc_node_get_next() - Get the next sibling XBC node + * @node: An XBC node. + * + * Return the NEXT sibling node of @node. If the node has no next sibling, + * return NULL. Note that even if this returns NULL, it doesn't mean @node + * has no siblings. (You also has to check whether the parent's child node + * is @node or not.) + */ +struct xbc_node * __init xbc_node_get_next(struct xbc_node *node) +{ + return node->next ? &xbc_nodes[node->next] : NULL; +} + +/** + * xbc_node_get_data() - Get the data of XBC node + * @node: An XBC node. + * + * Return the data (which is always a null terminated string) of @node. + * If the node has invalid data, warn and return NULL. + */ +const char * __init xbc_node_get_data(struct xbc_node *node) +{ + size_t offset = node->data & ~XBC_VALUE; + + if (WARN_ON(offset >= xbc_data_size)) + return NULL; + + return xbc_data + offset; +} + +static bool __init +xbc_node_match_prefix(struct xbc_node *node, const char **prefix) +{ + const char *p = xbc_node_get_data(node); + size_t len = strlen(p); + + if (strncmp(*prefix, p, len)) + return false; + + p = *prefix + len; + if (*p == '.') + p++; + else if (*p != '\0') + return false; + *prefix = p; + + return true; +} + +/** + * xbc_node_find_subkey() - Find a subkey node which matches given key + * @parent: An XBC node. + * @key: A key string. + * + * Search a key node under @parent which matches @key. The @key can contain + * several words jointed with '.'. If @parent is NULL, this searches the + * node from whole tree. Return NULL if no node is matched. + */ +struct xbc_node * __init +xbc_node_find_subkey(struct xbc_node *parent, const char *key) +{ + struct xbc_node *node; + + if (parent) + node = xbc_node_get_subkey(parent); + else + node = xbc_root_node(); + + while (node && xbc_node_is_key(node)) { + if (!xbc_node_match_prefix(node, &key)) + node = xbc_node_get_next(node); + else if (*key != '\0') + node = xbc_node_get_subkey(node); + else + break; + } + + return node; +} + +/** + * xbc_node_find_value() - Find a value node which matches given key + * @parent: An XBC node. + * @key: A key string. + * @vnode: A container pointer of found XBC node. + * + * Search a value node under @parent whose (parent) key node matches @key, + * store it in *@vnode, and returns the value string. + * The @key can contain several words jointed with '.'. If @parent is NULL, + * this searches the node from whole tree. Return the value string if a + * matched key found, return NULL if no node is matched. + * Note that this returns 0-length string and stores NULL in *@vnode if the + * key has no value. And also it will return the value of the first entry if + * the value is an array. + */ +const char * __init +xbc_node_find_value(struct xbc_node *parent, const char *key, + struct xbc_node **vnode) +{ + struct xbc_node *node = xbc_node_find_subkey(parent, key); + + if (!node || !xbc_node_is_key(node)) + return NULL; + + node = xbc_node_get_child(node); + if (node && !xbc_node_is_value(node)) + return NULL; + + if (vnode) + *vnode = node; + + return node ? xbc_node_get_data(node) : ""; +} + +/** + * xbc_node_compose_key_after() - Compose partial key string of the XBC node + * @root: Root XBC node + * @node: Target XBC node. + * @buf: A buffer to store the key. + * @size: The size of the @buf. + * + * Compose the partial key of the @node into @buf, which is starting right + * after @root (@root is not included.) If @root is NULL, this returns full + * key words of @node. + * Returns the total length of the key stored in @buf. Returns -EINVAL + * if @node is NULL or @root is not the ancestor of @node or @root is @node, + * or returns -ERANGE if the key depth is deeper than max depth. + * This is expected to be used with xbc_find_node() to list up all (child) + * keys under given key. + */ +int __init xbc_node_compose_key_after(struct xbc_node *root, + struct xbc_node *node, + char *buf, size_t size) +{ + uint16_t keys[XBC_DEPTH_MAX]; + int depth = 0, ret = 0, total = 0; + + if (!node || node == root) + return -EINVAL; + + if (xbc_node_is_value(node)) + node = xbc_node_get_parent(node); + + while (node && node != root) { + keys[depth++] = xbc_node_index(node); + if (depth == XBC_DEPTH_MAX) + return -ERANGE; + node = xbc_node_get_parent(node); + } + if (!node && root) + return -EINVAL; + + while (--depth >= 0) { + node = xbc_nodes + keys[depth]; + ret = snprintf(buf, size, "%s%s", xbc_node_get_data(node), + depth ? "." : ""); + if (ret < 0) + return ret; + if (ret >= size) { + size = 0; + } else { + size -= ret; + buf += ret; + } + total += ret; + } + + return total; +} + +/** + * xbc_node_find_next_leaf() - Find the next leaf node under given node + * @root: An XBC root node + * @node: An XBC node which starts from. + * + * Search the next leaf node (which means the terminal key node) of @node + * under @root node (including @root node itself). + * Return the next node or NULL if next leaf node is not found. + */ +struct xbc_node * __init xbc_node_find_next_leaf(struct xbc_node *root, + struct xbc_node *node) +{ + struct xbc_node *next; + + if (unlikely(!xbc_data)) + return NULL; + + if (!node) { /* First try */ + node = root; + if (!node) + node = xbc_nodes; + } else { + /* Leaf node may have a subkey */ + next = xbc_node_get_subkey(node); + if (next) { + node = next; + goto found; + } + + if (node == root) /* @root was a leaf, no child node. */ + return NULL; + + while (!node->next) { + node = xbc_node_get_parent(node); + if (node == root) + return NULL; + /* User passed a node which is not under parent */ + if (WARN_ON(!node)) + return NULL; + } + node = xbc_node_get_next(node); + } + +found: + while (node && !xbc_node_is_leaf(node)) + node = xbc_node_get_child(node); + + return node; +} + +/** + * xbc_node_find_next_key_value() - Find the next key-value pair nodes + * @root: An XBC root node + * @leaf: A container pointer of XBC node which starts from. + * + * Search the next leaf node (which means the terminal key node) of *@leaf + * under @root node. Returns the value and update *@leaf if next leaf node + * is found, or NULL if no next leaf node is found. + * Note that this returns 0-length string if the key has no value, or + * the value of the first entry if the value is an array. + */ +const char * __init xbc_node_find_next_key_value(struct xbc_node *root, + struct xbc_node **leaf) +{ + /* tip must be passed */ + if (WARN_ON(!leaf)) + return NULL; + + *leaf = xbc_node_find_next_leaf(root, *leaf); + if (!*leaf) + return NULL; + if ((*leaf)->child) + return xbc_node_get_data(xbc_node_get_child(*leaf)); + else + return ""; /* No value key */ +} + +static char xbc_namebuf[XBC_KEYLEN_MAX] __initdata; + +#define rest(dst, end) ((end) > (dst) ? (end) - (dst) : 0) + +/** + * xbc_snprint_cmdline() - Render bootconfig keys under @root as a cmdline string + * @buf: Destination buffer (may be NULL when @size is 0 to query the length) + * @size: Size of @buf in bytes + * @root: Subtree root whose key=value pairs should be rendered + * + * Walk all key/value pairs under @root and emit them as a space-separated + * cmdline string into @buf. Values containing whitespace are quoted with + * double quotes. Returns the number of bytes that would be written if @buf + * were large enough (matching snprintf semantics), or a negative errno on + * failure. + */ +int __init xbc_snprint_cmdline(char *buf, size_t size, struct xbc_node *root) +{ + struct xbc_node *knode, *vnode; + const char *val, *q; + size_t len = 0; + int ret; + + /* + * Track the running written length rather than advancing @buf, so we + * never form "buf + size" or "buf += ret" while @buf is NULL (the + * size-probe call passes buf=NULL, size=0). NULL pointer arithmetic + * is undefined behavior and trips host UBSan / FORTIFY_SOURCE when + * this renderer runs at kernel build time. snprintf(NULL, 0, ...) + * itself is well defined and returns the would-be length. + */ + xbc_node_for_each_key_value(root, knode, val) { + /* + * An empty or value-only @root (e.g. "kernel {}" or + * "kernel = x", possibly alongside "kernel.foo = bar") + * yields @root itself here. Skip it: composing a key for it + * would fail with -EINVAL, yet any real descendant keys must + * still be rendered. An entirely empty subtree then renders + * nothing and returns 0 rather than an error. + */ + if (knode == root) + continue; + + ret = xbc_node_compose_key_after(root, knode, + xbc_namebuf, XBC_KEYLEN_MAX); + if (ret < 0) + return ret; + + vnode = xbc_node_get_child(knode); + if (!vnode) { + ret = snprintf(buf ? buf + len : NULL, rest(len, size), + "%s ", xbc_namebuf); + if (ret < 0) + return ret; + len += ret; + continue; + } + xbc_array_for_each_value(vnode, val) { + /* + * For prettier and more readable /proc/cmdline, only + * quote the value when necessary, i.e. when it contains + * whitespace. + */ + q = strpbrk(val, " \t\r\n") ? "\"" : ""; + ret = snprintf(buf ? buf + len : NULL, rest(len, size), + "%s=%s%s%s ", xbc_namebuf, q, val, q); + if (ret < 0) + return ret; + len += ret; + } + } + + return len; +} +#undef rest + +/* XBC parse and tree build */ + +static int __init xbc_init_node(struct xbc_node *node, char *data, uint16_t flag) +{ + long offset = data - xbc_data; + + if (WARN_ON(offset < 0 || offset >= XBC_DATA_MAX)) + return -EINVAL; + + node->data = (uint16_t)offset | flag; + node->child = 0; + node->next = 0; + + return 0; +} + +static struct xbc_node * __init xbc_add_node(char *data, uint16_t flag) +{ + struct xbc_node *node; + + if (xbc_node_num == XBC_NODE_MAX) + return NULL; + + node = &xbc_nodes[xbc_node_num]; + if (xbc_init_node(node, data, flag) < 0) + return NULL; + xbc_node_num++; + + return node; +} + +static inline __init struct xbc_node *xbc_last_sibling(struct xbc_node *node) +{ + while (node->next) + node = xbc_node_get_next(node); + + return node; +} + +static inline __init struct xbc_node *xbc_last_child(struct xbc_node *node) +{ + while (node->child) + node = xbc_node_get_child(node); + + return node; +} + +static struct xbc_node * __init __xbc_add_sibling(char *data, uint16_t flag, bool head) +{ + struct xbc_node *sib, *node = xbc_add_node(data, flag); + + if (node) { + if (!last_parent) { + /* Ignore @head in this case */ + node->parent = XBC_NODE_MAX; + sib = xbc_last_sibling(xbc_nodes); + sib->next = xbc_node_index(node); + } else { + node->parent = xbc_node_index(last_parent); + if (!last_parent->child || head) { + node->next = last_parent->child; + last_parent->child = xbc_node_index(node); + } else { + sib = xbc_node_get_child(last_parent); + sib = xbc_last_sibling(sib); + sib->next = xbc_node_index(node); + } + } + } else { + xbc_parse_error("Too many nodes", data); + } + + return node; +} + +static inline struct xbc_node * __init xbc_add_sibling(char *data, uint16_t flag) +{ + return __xbc_add_sibling(data, flag, false); +} + +static inline struct xbc_node * __init xbc_add_head_sibling(char *data, uint16_t flag) +{ + return __xbc_add_sibling(data, flag, true); +} + +static inline __init struct xbc_node *xbc_add_child(char *data, uint16_t flag) +{ + struct xbc_node *node = xbc_add_sibling(data, flag); + + if (node) + last_parent = node; + + return node; +} + +static inline __init bool xbc_valid_keyword(char *key) +{ + if (key[0] == '\0') + return false; + + while (isalnum(*key) || *key == '-' || *key == '_') + key++; + + return *key == '\0'; +} + +static char *skip_comment(char *p) +{ + char *ret; + + ret = strchr(p, '\n'); + if (!ret) + ret = p + strlen(p); + else + ret++; + + return ret; +} + +static char *skip_spaces_until_newline(char *p) +{ + while (isspace(*p) && *p != '\n') + p++; + return p; +} + +static int __init __xbc_open_brace(char *p) +{ + /* Push the last key as open brace */ + if (brace_index >= XBC_DEPTH_MAX) + return xbc_parse_error("Exceed max depth of braces", p); + open_brace[brace_index++] = xbc_node_index(last_parent); + + return 0; +} + +static int __init __xbc_close_brace(char *p) +{ + brace_index--; + if (!last_parent || brace_index < 0 || + (open_brace[brace_index] != xbc_node_index(last_parent))) + return xbc_parse_error("Unexpected closing brace", p); + + if (brace_index == 0) + last_parent = NULL; + else + last_parent = &xbc_nodes[open_brace[brace_index - 1]]; + + return 0; +} + +/* + * Return delimiter or error, no node added. As same as lib/cmdline.c, + * you can use " around spaces, but can't escape " for value. + * *@__v must point real value string. (not including spaces before value.) + */ +static int __init __xbc_parse_value(char **__v, char **__n) +{ + char *p, *v = *__v; + int c, quotes = 0; + + if (*v == '"' || *v == '\'') { + quotes = *v; + v++; + } + p = v - 1; + while ((c = *++p)) { + if (!isprint(c) && !isspace(c)) + return xbc_parse_error("Non printable value", p); + if (quotes) { + if (c != quotes) + continue; + quotes = 0; + *p++ = '\0'; + p = skip_spaces_until_newline(p); + c = *p; + if (c && !strchr(",;\n#}", c)) + return xbc_parse_error("No value delimiter", p); + if (*p) + p++; + break; + } + if (strchr(",;\n#}", c)) { + *p++ = '\0'; + v = strim(v); + break; + } + } + if (quotes) + return xbc_parse_error("No closing quotes", p); + if (c == '#') { + p = skip_comment(p); + c = '\n'; /* A comment must be treated as a newline */ + } + *__n = p; + *__v = v; + + return c; +} + +static int __init xbc_parse_array(char **__v) +{ + struct xbc_node *node; + char *next; + int c = 0; + + if (last_parent->child) + last_parent = xbc_node_get_child(last_parent); + + do { + /* Search the next array value beyond comments and empty lines */ + next = skip_spaces(*__v); + while (*next == '#') { + next = skip_comment(next); + next = skip_spaces(next); + } + *__v = next; + c = __xbc_parse_value(__v, &next); + if (c < 0) + return c; + + node = xbc_add_child(*__v, XBC_VALUE); + if (!node) + return -ENOMEM; + *__v = next; + } while (c == ','); + node->child = 0; + + return c; +} + +static inline __init +struct xbc_node *find_match_node(struct xbc_node *node, char *k) +{ + while (node) { + if (!strcmp(xbc_node_get_data(node), k)) + break; + node = xbc_node_get_next(node); + } + return node; +} + +static int __init __xbc_add_key(char *k) +{ + struct xbc_node *node, *child; + + if (!xbc_valid_keyword(k)) + return xbc_parse_error("Invalid keyword", k); + + if (unlikely(xbc_node_num == 0)) + goto add_node; + + if (!last_parent) { /* the first level */ + node = find_match_node(xbc_nodes, k); + } else { + child = xbc_node_get_child(last_parent); + /* Since the value node is the first child, skip it. */ + if (child && xbc_node_is_value(child)) + child = xbc_node_get_next(child); + node = find_match_node(child, k); + } + + if (node) { + last_parent = node; + } else { +add_node: + node = xbc_add_child(k, XBC_KEY); + if (!node) + return -ENOMEM; + } + return 0; +} + +static int __init __xbc_parse_keys(char *k) +{ + char *p; + int ret; + + k = strim(k); + while ((p = strchr(k, '.'))) { + *p++ = '\0'; + ret = __xbc_add_key(k); + if (ret) + return ret; + k = p; + } + + return __xbc_add_key(k); +} + +static int __init xbc_parse_kv(char **k, char *v, int op) +{ + struct xbc_node *prev_parent = last_parent; + struct xbc_node *child; + char *next; + int c, ret; + + ret = __xbc_parse_keys(*k); + if (ret) + return ret; + + v = skip_spaces_until_newline(v); + /* If there is a comment, this has an empty value. */ + if (*v == '#') { + next = skip_comment(v); + *v = '\0'; + c = '\n'; + } else { + c = __xbc_parse_value(&v, &next); + if (c < 0) + return c; + } + + child = xbc_node_get_child(last_parent); + if (child && xbc_node_is_value(child)) { + if (op == '=') + return xbc_parse_error("Value is redefined", v); + if (op == ':') { + unsigned short nidx = child->next; + + if (xbc_init_node(child, v, XBC_VALUE) < 0) + return xbc_parse_error("Failed to override value", v); + child->next = nidx; /* keep subkeys */ + goto array; + } + /* op must be '+' */ + last_parent = xbc_last_child(child); + } + /* The value node should always be the first child */ + if (!xbc_add_head_sibling(v, XBC_VALUE)) + return -ENOMEM; + +array: + if (c == ',') { /* Array */ + c = xbc_parse_array(&next); + if (c < 0) + return c; + } + + last_parent = prev_parent; + + if (c == '}') { + ret = __xbc_close_brace(next - 1); + if (ret < 0) + return ret; + } + + *k = next; + + return 0; +} + +static int __init xbc_parse_key(char **k, char *n) +{ + struct xbc_node *prev_parent = last_parent; + int ret; + + *k = strim(*k); + if (**k != '\0') { + ret = __xbc_parse_keys(*k); + if (ret) + return ret; + last_parent = prev_parent; + } + *k = n; + + return 0; +} + +static int __init xbc_open_brace(char **k, char *n) +{ + int ret; + + ret = __xbc_parse_keys(*k); + if (ret) + return ret; + *k = n; + + return __xbc_open_brace(n - 1); +} + +static int __init xbc_close_brace(char **k, char *n) +{ + int ret; + + ret = xbc_parse_key(k, n); + if (ret) + return ret; + /* k is updated in xbc_parse_key() */ + + return __xbc_close_brace(n - 1); +} + +static int __init xbc_verify_tree(void) +{ + int i, depth; + size_t len, wlen; + struct xbc_node *n, *m; + + /* Brace closing */ + if (brace_index) { + n = &xbc_nodes[open_brace[brace_index - 1]]; + return xbc_parse_error("Brace is not closed", + xbc_node_get_data(n)); + } + + /* Empty tree */ + if (xbc_node_num == 0) { + xbc_parse_error("Empty config", xbc_data); + return -ENOENT; + } + + for (i = 0; i < xbc_node_num; i++) { + if (xbc_nodes[i].next >= xbc_node_num) { + return xbc_parse_error("No closing brace", + xbc_node_get_data(xbc_nodes + i)); + } + if (xbc_nodes[i].child >= xbc_node_num) { + return xbc_parse_error("Broken child node", + xbc_node_get_data(xbc_nodes + i)); + } + } + + /* Key tree limitation check */ + n = &xbc_nodes[0]; + depth = 1; + len = 0; + + while (n) { + wlen = strlen(xbc_node_get_data(n)) + 1; + len += wlen; + if (len > XBC_KEYLEN_MAX) + return xbc_parse_error("Too long key length", + xbc_node_get_data(n)); + + m = xbc_node_get_child(n); + if (m && xbc_node_is_key(m)) { + n = m; + depth++; + if (depth > XBC_DEPTH_MAX) + return xbc_parse_error("Too many key words", + xbc_node_get_data(n)); + continue; + } + len -= wlen; + m = xbc_node_get_next(n); + while (!m) { + n = xbc_node_get_parent(n); + if (!n) + break; + len -= strlen(xbc_node_get_data(n)) + 1; + depth--; + m = xbc_node_get_next(n); + } + n = m; + } + + return 0; +} + +/* Need to setup xbc_data and xbc_nodes before call this. */ +static int __init xbc_parse_tree(void) +{ + char *p, *q; + int ret = 0, c; + + last_parent = NULL; + p = xbc_data; + do { + q = strpbrk(p, "{}=+;:\n#"); + if (!q) { + p = skip_spaces(p); + if (*p != '\0') + ret = xbc_parse_error("No delimiter", p); + break; + } + + c = *q; + *q++ = '\0'; + switch (c) { + case ':': + case '+': + if (*q++ != '=') { + ret = xbc_parse_error(c == '+' ? + "Wrong '+' operator" : + "Wrong ':' operator", + q - 2); + break; + } + fallthrough; + case '=': + ret = xbc_parse_kv(&p, q, c); + break; + case '{': + ret = xbc_open_brace(&p, q); + break; + case '#': + q = skip_comment(q); + fallthrough; + case ';': + case '\n': + ret = xbc_parse_key(&p, q); + break; + case '}': + ret = xbc_close_brace(&p, q); + break; + } + } while (!ret); + + return ret; +} + +/** + * _xbc_exit() - Clean up all parsed bootconfig + * @early: Set true if this is called before budy system is initialized. + * + * This clears all data structures of parsed bootconfig on memory. + * If you need to reuse xbc_init() with new boot config, you can + * use this. + */ +void __init _xbc_exit(bool early) +{ + xbc_free_mem(xbc_data, xbc_data_size, early); + xbc_data = NULL; + xbc_data_size = 0; + xbc_node_num = 0; + xbc_free_mem(xbc_nodes, sizeof(struct xbc_node) * XBC_NODE_MAX, early); + xbc_nodes = NULL; + brace_index = 0; +} + +/** + * xbc_init() - Parse given XBC file and build XBC internal tree + * @data: The boot config text original data + * @size: The size of @data + * @emsg: A pointer of const char * to store the error message + * @epos: A pointer of int to store the error position + * + * This parses the boot config text in @data. @size must be smaller + * than XBC_DATA_MAX. + * Return the number of stored nodes (>0) if succeeded, or -errno + * if there is any error. + * In error cases, @emsg will be updated with an error message and + * @epos will be updated with the error position which is the byte offset + * of @buf. If the error is not a parser error, @epos will be -1. + */ +int __init xbc_init(const char *data, size_t size, const char **emsg, int *epos) +{ + int ret; + + if (epos) + *epos = -1; + + if (xbc_data) { + if (emsg) + *emsg = "Bootconfig is already initialized"; + return -EBUSY; + } + if (size > XBC_DATA_MAX || size == 0) { + if (emsg) + *emsg = size ? "Config data is too big" : + "Config data is empty"; + return -ERANGE; + } + + xbc_data = xbc_alloc_mem(size + 1); + if (!xbc_data) { + if (emsg) + *emsg = "Failed to allocate bootconfig data"; + return -ENOMEM; + } + memcpy(xbc_data, data, size); + xbc_data[size] = '\0'; + xbc_data_size = size + 1; + + xbc_nodes = xbc_alloc_mem(sizeof(struct xbc_node) * XBC_NODE_MAX); + if (!xbc_nodes) { + if (emsg) + *emsg = "Failed to allocate bootconfig nodes"; + _xbc_exit(true); + return -ENOMEM; + } + + ret = xbc_parse_tree(); + if (!ret) + ret = xbc_verify_tree(); + + if (ret < 0) { + if (epos) + *epos = xbc_err_pos; + if (emsg) + *emsg = xbc_err_msg; + _xbc_exit(true); + } else { + ret = xbc_node_num; + } + + return ret; +} -- cgit v1.3.1