| Masami Hiramatsu | 9c5b9d3 | 2020-01-11 01:06:17 +0900 | [diff] [blame^] | 1 | // SPDX-License-Identifier: GPL-2.0 |
| 2 | /* |
| 3 | * trace_boot.c |
| 4 | * Tracing kernel boot-time |
| 5 | */ |
| 6 | |
| 7 | #define pr_fmt(fmt) "trace_boot: " fmt |
| 8 | |
| 9 | #include <linux/ftrace.h> |
| 10 | #include <linux/init.h> |
| 11 | #include <linux/bootconfig.h> |
| 12 | |
| 13 | #include "trace.h" |
| 14 | |
| 15 | #define MAX_BUF_LEN 256 |
| 16 | |
| 17 | extern int trace_set_options(struct trace_array *tr, char *option); |
| 18 | extern int tracing_set_tracer(struct trace_array *tr, const char *buf); |
| 19 | extern ssize_t tracing_resize_ring_buffer(struct trace_array *tr, |
| 20 | unsigned long size, int cpu_id); |
| 21 | |
| 22 | static void __init |
| 23 | trace_boot_set_ftrace_options(struct trace_array *tr, struct xbc_node *node) |
| 24 | { |
| 25 | struct xbc_node *anode; |
| 26 | const char *p; |
| 27 | char buf[MAX_BUF_LEN]; |
| 28 | unsigned long v = 0; |
| 29 | |
| 30 | /* Common ftrace options */ |
| 31 | xbc_node_for_each_array_value(node, "options", anode, p) { |
| 32 | if (strlcpy(buf, p, ARRAY_SIZE(buf)) >= ARRAY_SIZE(buf)) { |
| 33 | pr_err("String is too long: %s\n", p); |
| 34 | continue; |
| 35 | } |
| 36 | |
| 37 | if (trace_set_options(tr, buf) < 0) |
| 38 | pr_err("Failed to set option: %s\n", buf); |
| 39 | } |
| 40 | |
| 41 | p = xbc_node_find_value(node, "trace_clock", NULL); |
| 42 | if (p && *p != '\0') { |
| 43 | if (tracing_set_clock(tr, p) < 0) |
| 44 | pr_err("Failed to set trace clock: %s\n", p); |
| 45 | } |
| 46 | |
| 47 | p = xbc_node_find_value(node, "buffer_size", NULL); |
| 48 | if (p && *p != '\0') { |
| 49 | v = memparse(p, NULL); |
| 50 | if (v < PAGE_SIZE) |
| 51 | pr_err("Buffer size is too small: %s\n", p); |
| 52 | if (tracing_resize_ring_buffer(tr, v, RING_BUFFER_ALL_CPUS) < 0) |
| 53 | pr_err("Failed to resize trace buffer to %s\n", p); |
| 54 | } |
| 55 | } |
| 56 | |
| 57 | #ifdef CONFIG_EVENT_TRACING |
| 58 | extern int ftrace_set_clr_event(struct trace_array *tr, char *buf, int set); |
| 59 | |
| 60 | static void __init |
| 61 | trace_boot_enable_events(struct trace_array *tr, struct xbc_node *node) |
| 62 | { |
| 63 | struct xbc_node *anode; |
| 64 | char buf[MAX_BUF_LEN]; |
| 65 | const char *p; |
| 66 | |
| 67 | xbc_node_for_each_array_value(node, "events", anode, p) { |
| 68 | if (strlcpy(buf, p, ARRAY_SIZE(buf)) >= ARRAY_SIZE(buf)) { |
| 69 | pr_err("String is too long: %s\n", p); |
| 70 | continue; |
| 71 | } |
| 72 | |
| 73 | if (ftrace_set_clr_event(tr, buf, 1) < 0) |
| 74 | pr_err("Failed to enable event: %s\n", p); |
| 75 | } |
| 76 | } |
| 77 | #else |
| 78 | #define trace_boot_enable_events(tr, node) do {} while (0) |
| 79 | #endif |
| 80 | |
| 81 | static void __init |
| 82 | trace_boot_enable_tracer(struct trace_array *tr, struct xbc_node *node) |
| 83 | { |
| 84 | const char *p; |
| 85 | |
| 86 | p = xbc_node_find_value(node, "tracer", NULL); |
| 87 | if (p && *p != '\0') { |
| 88 | if (tracing_set_tracer(tr, p) < 0) |
| 89 | pr_err("Failed to set given tracer: %s\n", p); |
| 90 | } |
| 91 | } |
| 92 | |
| 93 | static int __init trace_boot_init(void) |
| 94 | { |
| 95 | struct xbc_node *trace_node; |
| 96 | struct trace_array *tr; |
| 97 | |
| 98 | trace_node = xbc_find_node("ftrace"); |
| 99 | if (!trace_node) |
| 100 | return 0; |
| 101 | |
| 102 | tr = top_trace_array(); |
| 103 | if (!tr) |
| 104 | return 0; |
| 105 | |
| 106 | trace_boot_set_ftrace_options(tr, trace_node); |
| 107 | trace_boot_enable_events(tr, trace_node); |
| 108 | trace_boot_enable_tracer(tr, trace_node); |
| 109 | |
| 110 | return 0; |
| 111 | } |
| 112 | |
| 113 | fs_initcall(trace_boot_init); |