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author | Linus Torvalds <torvalds@linux-foundation.org> | 2020-02-06 07:12:11 +0000 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-02-06 07:12:11 +0000 |
commit | e310396bb8d7db977a0e10ef7b5040e98b89c34c (patch) | |
tree | 461357ada35c637292884f0af1dc9fc41c0203ff /lib | |
parent | c1ef57a3a3f5e69e98baf89055b423da62791c13 (diff) | |
parent | a00574036c261421721fa770ccd21a1012e1fbbd (diff) | |
download | lwn-e310396bb8d7db977a0e10ef7b5040e98b89c34c.tar.gz lwn-e310396bb8d7db977a0e10ef7b5040e98b89c34c.zip |
Merge tag 'trace-v5.6-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing updates from Steven Rostedt:
- Added new "bootconfig".
This looks for a file appended to initrd to add boot config options,
and has been discussed thoroughly at Linux Plumbers.
Very useful for adding kprobes at bootup.
Only enabled if "bootconfig" is on the real kernel command line.
- Created dynamic event creation.
Merges common code between creating synthetic events and kprobe
events.
- Rename perf "ring_buffer" structure to "perf_buffer"
- Rename ftrace "ring_buffer" structure to "trace_buffer"
Had to rename existing "trace_buffer" to "array_buffer"
- Allow trace_printk() to work withing (some) tracing code.
- Sort of tracing configs to be a little better organized
- Fixed bug where ftrace_graph hash was not being protected properly
- Various other small fixes and clean ups
* tag 'trace-v5.6-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (88 commits)
bootconfig: Show the number of nodes on boot message
tools/bootconfig: Show the number of bootconfig nodes
bootconfig: Add more parse error messages
bootconfig: Use bootconfig instead of boot config
ftrace: Protect ftrace_graph_hash with ftrace_sync
ftrace: Add comment to why rcu_dereference_sched() is open coded
tracing: Annotate ftrace_graph_notrace_hash pointer with __rcu
tracing: Annotate ftrace_graph_hash pointer with __rcu
bootconfig: Only load bootconfig if "bootconfig" is on the kernel cmdline
tracing: Use seq_buf for building dynevent_cmd string
tracing: Remove useless code in dynevent_arg_pair_add()
tracing: Remove check_arg() callbacks from dynevent args
tracing: Consolidate some synth_event_trace code
tracing: Fix now invalid var_ref_vals assumption in trace action
tracing: Change trace_boot to use synth_event interface
tracing: Move tracing selftests to bottom of menu
tracing: Move mmio tracer config up with the other tracers
tracing: Move tracing test module configs together
tracing: Move all function tracing configs together
tracing: Documentation for in-kernel synthetic event API
...
Diffstat (limited to 'lib')
-rw-r--r-- | lib/Kconfig | 3 | ||||
-rw-r--r-- | lib/Makefile | 2 | ||||
-rw-r--r-- | lib/bootconfig.c | 814 |
3 files changed, 819 insertions, 0 deletions
diff --git a/lib/Kconfig b/lib/Kconfig index bc7e56370129..0cf875fd627c 100644 --- a/lib/Kconfig +++ b/lib/Kconfig @@ -573,6 +573,9 @@ config DIMLIB config LIBFDT bool +config LIBXBC + bool + config OID_REGISTRY tristate help diff --git a/lib/Makefile b/lib/Makefile index 23ca78d43d24..8bb91176c2a1 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -230,6 +230,8 @@ $(foreach file, $(libfdt_files), \ $(eval CFLAGS_$(file) = -I $(srctree)/scripts/dtc/libfdt)) lib-$(CONFIG_LIBFDT) += $(libfdt_files) +lib-$(CONFIG_LIBXBC) += bootconfig.o + obj-$(CONFIG_RBTREE_TEST) += rbtree_test.o obj-$(CONFIG_INTERVAL_TREE_TEST) += interval_tree_test.o diff --git a/lib/bootconfig.c b/lib/bootconfig.c new file mode 100644 index 000000000000..afb2e767e6fe --- /dev/null +++ b/lib/bootconfig.c @@ -0,0 +1,814 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Extra Boot Config + * Masami Hiramatsu <mhiramat@kernel.org> + */ + +#define pr_fmt(fmt) "bootconfig: " fmt + +#include <linux/bug.h> +#include <linux/ctype.h> +#include <linux/errno.h> +#include <linux/kernel.h> +#include <linux/printk.h> +#include <linux/bootconfig.h> +#include <linux/string.h> + +/* + * 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[XBC_NODE_MAX] __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 int __init xbc_parse_error(const char *msg, const char *p) +{ + int pos = p - xbc_data; + + pr_err("Parse error at pos %d: %s\n", pos, msg); + 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 initiized, 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. + */ +int __init xbc_node_index(struct xbc_node *node) +{ + return 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) +{ + int 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); + int 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_child() - Find a child node which matches given key + * @parent: An XBC node. + * @key: A key string. + * + * Search a 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_child(struct xbc_node *parent, const char *key) +{ + struct xbc_node *node; + + if (parent) + node = xbc_node_get_child(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_child(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_child(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) +{ + u16 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) +{ + if (unlikely(!xbc_data)) + return NULL; + + if (!node) { /* First try */ + node = root; + if (!node) + node = xbc_nodes; + } else { + 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 uder parent */ + if (WARN_ON(!node)) + return NULL; + } + node = xbc_node_get_next(node); + } + + 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 */ +} + +/* XBC parse and tree build */ + +static struct xbc_node * __init xbc_add_node(char *data, u32 flag) +{ + struct xbc_node *node; + unsigned long offset; + + if (xbc_node_num == XBC_NODE_MAX) + return NULL; + + node = &xbc_nodes[xbc_node_num++]; + offset = data - xbc_data; + node->data = (u16)offset; + if (WARN_ON(offset >= XBC_DATA_MAX)) + return NULL; + node->data |= flag; + node->child = 0; + node->next = 0; + + 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 struct xbc_node * __init xbc_add_sibling(char *data, u32 flag) +{ + struct xbc_node *sib, *node = xbc_add_node(data, flag); + + if (node) { + if (!last_parent) { + 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) { + 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 __init struct xbc_node *xbc_add_child(char *data, u32 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(void) +{ + /* Mark the last key as open brace */ + last_parent->next = XBC_NODE_MAX; + + return 0; +} + +static int __init __xbc_close_brace(char *p) +{ + struct xbc_node *node; + + if (!last_parent || last_parent->next != XBC_NODE_MAX) + return xbc_parse_error("Unexpected closing brace", p); + + node = last_parent; + node->next = 0; + do { + node = xbc_node_get_parent(node); + } while (node && node->next != XBC_NODE_MAX); + last_parent = node; + + 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. + */ +static int __init __xbc_parse_value(char **__v, char **__n) +{ + char *p, *v = *__v; + int c, quotes = 0; + + v = skip_spaces(v); + while (*v == '#') { + v = skip_comment(v); + v = skip_spaces(v); + } + 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)) { + v = strim(v); + *p++ = '\0'; + 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; + + do { + c = __xbc_parse_value(__v, &next); + if (c < 0) + return c; + + node = xbc_add_sibling(*__v, XBC_VALUE); + if (!node) + return -ENOMEM; + *__v = next; + } while (c == ','); + node->next = 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; + + 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 + node = find_match_node(xbc_node_get_child(last_parent), 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) +{ + struct xbc_node *prev_parent = last_parent; + struct xbc_node *node; + char *next; + int c, ret; + + ret = __xbc_parse_keys(*k); + if (ret) + return ret; + + c = __xbc_parse_value(&v, &next); + if (c < 0) + return c; + + node = xbc_add_sibling(v, XBC_VALUE); + if (!node) + return -ENOMEM; + + 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(); +} + +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, len, wlen; + struct xbc_node *n, *m; + + /* 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)); + } + } + + /* 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; +} + +/** + * xbc_destroy_all() - Clean up all parsed bootconfig + * + * 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_destroy_all(void) +{ + xbc_data = NULL; + xbc_data_size = 0; + xbc_node_num = 0; + memset(xbc_nodes, 0, sizeof(xbc_nodes)); +} + +/** + * xbc_init() - Parse given XBC file and build XBC internal tree + * @buf: boot config text + * + * This parses the boot config text in @buf. @buf must be a + * null terminated string and smaller than XBC_DATA_MAX. + * Return the number of stored nodes (>0) if succeeded, or -errno + * if there is any error. + */ +int __init xbc_init(char *buf) +{ + char *p, *q; + int ret, c; + + if (xbc_data) { + pr_err("Error: bootconfig is already initialized.\n"); + return -EBUSY; + } + + ret = strlen(buf); + if (ret > XBC_DATA_MAX - 1 || ret == 0) { + pr_err("Error: Config data is %s.\n", + ret ? "too big" : "empty"); + return -ERANGE; + } + + xbc_data = buf; + xbc_data_size = ret + 1; + last_parent = NULL; + + p = buf; + 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 '=': + ret = xbc_parse_kv(&p, q); + break; + case '{': + ret = xbc_open_brace(&p, q); + break; + case '#': + q = skip_comment(q); + /* fall through */ + case ';': + case '\n': + ret = xbc_parse_key(&p, q); + break; + case '}': + ret = xbc_close_brace(&p, q); + break; + } + } while (!ret); + + if (!ret) + ret = xbc_verify_tree(); + + if (ret < 0) + xbc_destroy_all(); + else + ret = xbc_node_num; + + return ret; +} + +/** + * xbc_debug_dump() - Dump current XBC node list + * + * Dump the current XBC node list on printk buffer for debug. + */ +void __init xbc_debug_dump(void) +{ + int i; + + for (i = 0; i < xbc_node_num; i++) { + pr_debug("[%d] %s (%s) .next=%d, .child=%d .parent=%d\n", i, + xbc_node_get_data(xbc_nodes + i), + xbc_node_is_value(xbc_nodes + i) ? "value" : "key", + xbc_nodes[i].next, xbc_nodes[i].child, + xbc_nodes[i].parent); + } +} |