Merge tag 'bootconfig-v7.4' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull bootconfig updates from Masami Hiramatsu:
 "Parser robustness and validation improvements:

   - Skip printing early params to cmdline from bootconfig

     Suppress early_param keys from /proc/cmdline and warn the user,
     since bootconfig does not invoke early_param handlers and silently
     ignoring them is misleading

   - Reject unexpected data after null character

     Detect and reject non-null data following an intermediate null
     character in the bootconfig buffer, preventing silently ignored
     configuration after an early termination

  Code cleanups:

   - Merge _xbc_exit() into xbc_exit()

     Since memblock_free() now handles late freeing and NULL addresses,
     the separate _xbc_exit() helper and its early argument are
     unnecessary. Inline it into xbc_exit()

   - Remove redundant assignment in xbc_parse_array()

     The node->child = 0 assignment after the loop duplicates what
     xbc_init_node() already did

   - Skip internal tree sanity checks in kernel

     Move the node index bounds loop from xbc_verify_tree() into a
     userspace-only xbc_sanity_check_tree() to reduce boot-time
     overhead, since out-of-bounds indices cannot be produced by
     malformed input

   - Move BOOTCONFIG_FOOTER_SIZE to include/linux/bootconfig.h

     Share the footer size constant between kernel and user-space tools,
     replacing the hardcoded (BOOTCONFIG_MAGIC_LEN + 8) expression in
     init/main.c

  Tooling improvements:

   - Remove unused PAGE_SIZE macro from the bootconfig tool

   - Consolidate xbc_init() to error message wrapper

     Use init_xbc_with_error() for all bootconfig initialization paths
     in the tool for simpler and more consistent error handling"

* tag 'bootconfig-v7.4' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  bootconfig: Move BOOTCONFIG_FOOTER_SIZE to include/linux/bootconfig.h
  bootconfig: Skip internal tree sanity checks in kernel
  tools/bootconfig: Consolidate xbc_init() to error message wrapper
  bootconfig: Reject unexpected data after null character
  bootconfig: Skip printing early params to cmdline from bootconfig
  tools/bootconfig: remove unused PAGE_SIZE macro
  bootconfig: remove redundant assignment in xbc_parse_array()
  bootconfig: merge _xbc_exit() into xbc_exit()

1 files changed, 53 insertions, 31 deletions

diff --git a/lib/bootconfig.c b/lib/bootconfig.c
index 89c88e359179..819685d6c68d 100644
--- a/lib/bootconfig.c
+++ b/lib/bootconfig.c
@@ -187,12 +187,9 @@ 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)
+static inline void __init xbc_free_mem(void *addr, size_t size)
 {
-	if (early)
-		memblock_free(addr, size);
-	else if (addr)
-		memblock_free(addr, size);
+	memblock_free(addr, size);
 }
 
 #else /* !__KERNEL__ */
@@ -202,7 +199,7 @@ 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)
+static inline void xbc_free_mem(void *addr, size_t size)
 {
 	free(addr);
 }
@@ -539,18 +536,21 @@ 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
+ * xbc_snprint_cmdline_filter() - Render bootconfig keys as 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
+ * @filter: Filter callback (returns true to include, false to skip; may be NULL)
+ * @data: Private context passed to @filter
  *
  * 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.
+ * double quotes. Keys for which @filter returns false are omitted.
+ * 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)
+int __init xbc_snprint_cmdline_filter(char *buf, size_t size, struct xbc_node *root,
+				      xbc_cmdline_filter_fn filter, void *data)
 {
 	struct xbc_node *knode, *vnode;
 	const char *val, *q;
@@ -582,6 +582,9 @@ int __init xbc_snprint_cmdline(char *buf, size_t size, struct xbc_node *root)
 		if (ret < 0)
 			return ret;
 
+		if (filter && !filter(knode, xbc_namebuf, data))
+			continue;
+
 		vnode = xbc_node_get_child(knode);
 		if (!vnode) {
 			ret = snprintf(buf ? buf + len : NULL, rest(len, size),
@@ -836,7 +839,6 @@ static int __init xbc_parse_array(char **__v)
 			return -ENOMEM;
 		*__v = next;
 	} while (c == ',');
-	node->child = 0;
 
 	return c;
 }
@@ -1003,9 +1005,30 @@ static int __init xbc_close_brace(char **k, char *n)
 	return __xbc_close_brace(n - 1);
 }
 
+#ifndef __KERNEL__
+/* Sanity check for regression: node indices must be within bounds */
+static int __init xbc_sanity_check_tree(void)
+{
+	int i;
+
+	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));
+		}
+	}
+
+	return 0;
+}
+#endif
+
 static int __init xbc_verify_tree(void)
 {
-	int i, depth;
+	int depth;
 	size_t len, wlen;
 	struct xbc_node *n, *m;
 
@@ -1022,17 +1045,6 @@ static int __init xbc_verify_tree(void)
 		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;
@@ -1119,24 +1131,30 @@ static int __init xbc_parse_tree(void)
 		}
 	} while (!ret);
 
+	if (!ret) {
+		while (p < xbc_data + xbc_data_size - 1 && *p == '\0')
+			p++;
+		if (p < xbc_data + xbc_data_size - 1)
+			ret = xbc_parse_error("Unexpected data after null character", p);
+	}
+
 	return ret;
 }
 
 /**
- * _xbc_exit() - Clean up all parsed bootconfig
- * @early: Set true if this is called before budy system is initialized.
+ * xbc_exit() - 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_exit(bool early)
+void __init xbc_exit(void)
 {
-	xbc_free_mem(xbc_data, xbc_data_size, early);
+	xbc_free_mem(xbc_data, xbc_data_size);
 	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_free_mem(xbc_nodes, sizeof(struct xbc_node) * XBC_NODE_MAX);
 	xbc_nodes = NULL;
 	brace_index = 0;
 }
@@ -1189,20 +1207,24 @@ int __init xbc_init(const char *data, size_t size, const char **emsg, int *epos)
 	if (!xbc_nodes) {
 		if (emsg)
 			*emsg = "Failed to allocate bootconfig nodes";
-		_xbc_exit(true);
+		xbc_exit();
 		return -ENOMEM;
 	}
 
 	ret = xbc_parse_tree();
 	if (!ret)
 		ret = xbc_verify_tree();
+#ifndef __KERNEL__
+	if (!ret)
+		ret = xbc_sanity_check_tree();
+#endif
 
 	if (ret < 0) {
 		if (epos)
 			*epos = xbc_err_pos;
 		if (emsg)
 			*emsg = xbc_err_msg;
-		_xbc_exit(true);
+		xbc_exit();
 	} else {
 		ret = xbc_node_num;
 	}