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
  ...

2 files changed, 226 insertions, 17 deletions

diff --git a/init/Kconfig b/init/Kconfig
index 24b23d843df1..cfee56c151f1 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -1224,6 +1224,20 @@ source "usr/Kconfig"
 
 endif
 
+config BOOT_CONFIG
+	bool "Boot config support"
+	depends on BLK_DEV_INITRD
+	select LIBXBC
+	default y
+	help
+	  Extra boot config allows system admin to pass a config file as
+	  complemental extension of kernel cmdline when booting.
+	  The boot config file must be attached at the end of initramfs
+	  with checksum and size.
+	  See <file:Documentation/admin-guide/bootconfig.rst> for details.
+
+	  If unsure, say Y.
+
 choice
 	prompt "Compiler optimization level"
 	default CC_OPTIMIZE_FOR_PERFORMANCE
diff --git a/init/main.c b/init/main.c
index d8c7e86c2d28..cc0ee4873419 100644
--- a/init/main.c
+++ b/init/main.c
@@ -28,6 +28,7 @@
 #include <linux/initrd.h>
 #include <linux/memblock.h>
 #include <linux/acpi.h>
+#include <linux/bootconfig.h>
 #include <linux/console.h>
 #include <linux/nmi.h>
 #include <linux/percpu.h>
@@ -136,8 +137,10 @@ char __initdata boot_command_line[COMMAND_LINE_SIZE];
 char *saved_command_line;
 /* Command line for parameter parsing */
 static char *static_command_line;
-/* Command line for per-initcall parameter parsing */
-static char *initcall_command_line;
+/* Untouched extra command line */
+static char *extra_command_line;
+/* Extra init arguments */
+static char *extra_init_args;
 
 static char *execute_command;
 static char *ramdisk_execute_command;
@@ -245,6 +248,156 @@ static int __init loglevel(char *str)
 
 early_param("loglevel", loglevel);
 
+#ifdef CONFIG_BOOT_CONFIG
+
+char xbc_namebuf[XBC_KEYLEN_MAX] __initdata;
+
+#define rest(dst, end) ((end) > (dst) ? (end) - (dst) : 0)
+
+static int __init xbc_snprint_cmdline(char *buf, size_t size,
+				      struct xbc_node *root)
+{
+	struct xbc_node *knode, *vnode;
+	char *end = buf + size;
+	char c = '\"';
+	const char *val;
+	int ret;
+
+	xbc_node_for_each_key_value(root, knode, val) {
+		ret = xbc_node_compose_key_after(root, knode,
+					xbc_namebuf, XBC_KEYLEN_MAX);
+		if (ret < 0)
+			return ret;
+
+		vnode = xbc_node_get_child(knode);
+		ret = snprintf(buf, rest(buf, end), "%s%c", xbc_namebuf,
+				vnode ? '=' : ' ');
+		if (ret < 0)
+			return ret;
+		buf += ret;
+		if (!vnode)
+			continue;
+
+		c = '\"';
+		xbc_array_for_each_value(vnode, val) {
+			ret = snprintf(buf, rest(buf, end), "%c%s", c, val);
+			if (ret < 0)
+				return ret;
+			buf += ret;
+			c = ',';
+		}
+		if (rest(buf, end) > 2)
+			strcpy(buf, "\" ");
+		buf += 2;
+	}
+
+	return buf - (end - size);
+}
+#undef rest
+
+/* Make an extra command line under given key word */
+static char * __init xbc_make_cmdline(const char *key)
+{
+	struct xbc_node *root;
+	char *new_cmdline;
+	int ret, len = 0;
+
+	root = xbc_find_node(key);
+	if (!root)
+		return NULL;
+
+	/* Count required buffer size */
+	len = xbc_snprint_cmdline(NULL, 0, root);
+	if (len <= 0)
+		return NULL;
+
+	new_cmdline = memblock_alloc(len + 1, SMP_CACHE_BYTES);
+	if (!new_cmdline) {
+		pr_err("Failed to allocate memory for extra kernel cmdline.\n");
+		return NULL;
+	}
+
+	ret = xbc_snprint_cmdline(new_cmdline, len + 1, root);
+	if (ret < 0 || ret > len) {
+		pr_err("Failed to print extra kernel cmdline.\n");
+		return NULL;
+	}
+
+	return new_cmdline;
+}
+
+u32 boot_config_checksum(unsigned char *p, u32 size)
+{
+	u32 ret = 0;
+
+	while (size--)
+		ret += *p++;
+
+	return ret;
+}
+
+static void __init setup_boot_config(const char *cmdline)
+{
+	u32 size, csum;
+	char *data, *copy;
+	const char *p;
+	u32 *hdr;
+	int ret;
+
+	p = strstr(cmdline, "bootconfig");
+	if (!p || (p != cmdline && !isspace(*(p-1))) ||
+	    (p[10] && !isspace(p[10])))
+		return;
+
+	if (!initrd_end)
+		goto not_found;
+
+	hdr = (u32 *)(initrd_end - 8);
+	size = hdr[0];
+	csum = hdr[1];
+
+	if (size >= XBC_DATA_MAX) {
+		pr_err("bootconfig size %d greater than max size %d\n",
+			size, XBC_DATA_MAX);
+		return;
+	}
+
+	data = ((void *)hdr) - size;
+	if ((unsigned long)data < initrd_start)
+		goto not_found;
+
+	if (boot_config_checksum((unsigned char *)data, size) != csum) {
+		pr_err("bootconfig checksum failed\n");
+		return;
+	}
+
+	copy = memblock_alloc(size + 1, SMP_CACHE_BYTES);
+	if (!copy) {
+		pr_err("Failed to allocate memory for bootconfig\n");
+		return;
+	}
+
+	memcpy(copy, data, size);
+	copy[size] = '\0';
+
+	ret = xbc_init(copy);
+	if (ret < 0)
+		pr_err("Failed to parse bootconfig\n");
+	else {
+		pr_info("Load bootconfig: %d bytes %d nodes\n", size, ret);
+		/* keys starting with "kernel." are passed via cmdline */
+		extra_command_line = xbc_make_cmdline("kernel");
+		/* Also, "init." keys are init arguments */
+		extra_init_args = xbc_make_cmdline("init");
+	}
+	return;
+not_found:
+	pr_err("'bootconfig' found on command line, but no bootconfig found\n");
+}
+#else
+#define setup_boot_config(cmdline)	do { } while (0)
+#endif
+
 /* Change NUL term back to "=", to make "param" the whole string. */
 static void __init repair_env_string(char *param, char *val)
 {
@@ -373,22 +526,50 @@ static inline void smp_prepare_cpus(unsigned int maxcpus) { }
  */
 static void __init setup_command_line(char *command_line)
 {
-	size_t len = strlen(boot_command_line) + 1;
+	size_t len, xlen = 0, ilen = 0;
 
-	saved_command_line = memblock_alloc(len, SMP_CACHE_BYTES);
-	if (!saved_command_line)
-		panic("%s: Failed to allocate %zu bytes\n", __func__, len);
+	if (extra_command_line)
+		xlen = strlen(extra_command_line);
+	if (extra_init_args)
+		ilen = strlen(extra_init_args) + 4; /* for " -- " */
 
-	initcall_command_line =	memblock_alloc(len, SMP_CACHE_BYTES);
-	if (!initcall_command_line)
-		panic("%s: Failed to allocate %zu bytes\n", __func__, len);
+	len = xlen + strlen(boot_command_line) + 1;
+
+	saved_command_line = memblock_alloc(len + ilen, SMP_CACHE_BYTES);
+	if (!saved_command_line)
+		panic("%s: Failed to allocate %zu bytes\n", __func__, len + ilen);
 
 	static_command_line = memblock_alloc(len, SMP_CACHE_BYTES);
 	if (!static_command_line)
 		panic("%s: Failed to allocate %zu bytes\n", __func__, len);
 
-	strcpy(saved_command_line, boot_command_line);
-	strcpy(static_command_line, command_line);
+	if (xlen) {
+		/*
+		 * We have to put extra_command_line before boot command
+		 * lines because there could be dashes (separator of init
+		 * command line) in the command lines.
+		 */
+		strcpy(saved_command_line, extra_command_line);
+		strcpy(static_command_line, extra_command_line);
+	}
+	strcpy(saved_command_line + xlen, boot_command_line);
+	strcpy(static_command_line + xlen, command_line);
+
+	if (ilen) {
+		/*
+		 * Append supplemental init boot args to saved_command_line
+		 * so that user can check what command line options passed
+		 * to init.
+		 */
+		len = strlen(saved_command_line);
+		if (!strstr(boot_command_line, " -- ")) {
+			strcpy(saved_command_line + len, " -- ");
+			len += 4;
+		} else
+			saved_command_line[len++] = ' ';
+
+		strcpy(saved_command_line + len, extra_init_args);
+	}
 }
 
 /*
@@ -595,6 +776,7 @@ asmlinkage __visible void __init start_kernel(void)
 	pr_notice("%s", linux_banner);
 	early_security_init();
 	setup_arch(&command_line);
+	setup_boot_config(command_line);
 	setup_command_line(command_line);
 	setup_nr_cpu_ids();
 	setup_per_cpu_areas();
@@ -604,7 +786,7 @@ asmlinkage __visible void __init start_kernel(void)
 	build_all_zonelists(NULL);
 	page_alloc_init();
 
-	pr_notice("Kernel command line: %s\n", boot_command_line);
+	pr_notice("Kernel command line: %s\n", saved_command_line);
 	/* parameters may set static keys */
 	jump_label_init();
 	parse_early_param();
@@ -615,6 +797,9 @@ asmlinkage __visible void __init start_kernel(void)
 	if (!IS_ERR_OR_NULL(after_dashes))
 		parse_args("Setting init args", after_dashes, NULL, 0, -1, -1,
 			   NULL, set_init_arg);
+	if (extra_init_args)
+		parse_args("Setting extra init args", extra_init_args,
+			   NULL, 0, -1, -1, NULL, set_init_arg);
 
 	/*
 	 * These use large bootmem allocations and must precede
@@ -996,13 +1181,12 @@ static int __init ignore_unknown_bootoption(char *param, char *val,
 	return 0;
 }
 
-static void __init do_initcall_level(int level)
+static void __init do_initcall_level(int level, char *command_line)
 {
 	initcall_entry_t *fn;
 
-	strcpy(initcall_command_line, saved_command_line);
 	parse_args(initcall_level_names[level],
-		   initcall_command_line, __start___param,
+		   command_line, __start___param,
 		   __stop___param - __start___param,
 		   level, level,
 		   NULL, ignore_unknown_bootoption);
@@ -1015,9 +1199,20 @@ static void __init do_initcall_level(int level)
 static void __init do_initcalls(void)
 {
 	int level;
+	size_t len = strlen(saved_command_line) + 1;
+	char *command_line;
+
+	command_line = kzalloc(len, GFP_KERNEL);
+	if (!command_line)
+		panic("%s: Failed to allocate %zu bytes\n", __func__, len);
+
+	for (level = 0; level < ARRAY_SIZE(initcall_levels) - 1; level++) {
+		/* Parser modifies command_line, restore it each time */
+		strcpy(command_line, saved_command_line);
+		do_initcall_level(level, command_line);
+	}
 
-	for (level = 0; level < ARRAY_SIZE(initcall_levels) - 1; level++)
-		do_initcall_level(level);
+	kfree(command_line);
 }
 
 /*