diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/trace/trace.c | 81 | ||||
| -rw-r--r-- | kernel/trace/trace.h | 7 | ||||
| -rw-r--r-- | kernel/trace/trace_boot.c | 5 | ||||
| -rw-r--r-- | kernel/trace/trace_events.c | 76 |
4 files changed, 104 insertions, 65 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 4189ec9df6a5..c8e43675ff76 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -4022,6 +4022,11 @@ int tracing_open_generic_tr(struct inode *inode, struct file *filp) if (ret) return ret; + if ((filp->f_mode & FMODE_WRITE) && trace_array_is_readonly(tr)) { + trace_array_put(tr); + return -EACCES; + } + filp->private_data = inode->i_private; return 0; @@ -7097,6 +7102,11 @@ static int tracing_clock_open(struct inode *inode, struct file *file) if (ret) return ret; + if ((file->f_mode & FMODE_WRITE) && trace_array_is_readonly(tr)) { + trace_array_put(tr); + return -EACCES; + } + ret = single_open(file, tracing_clock_show, inode->i_private); if (ret < 0) trace_array_put(tr); @@ -9866,17 +9876,22 @@ static __init void create_trace_instances(struct dentry *d_tracer) static void init_tracer_tracefs(struct trace_array *tr, struct dentry *d_tracer) { + umode_t writable_mode = TRACE_MODE_WRITE; int cpu; + if (trace_array_is_readonly(tr)) + writable_mode = TRACE_MODE_READ; + trace_create_file("available_tracers", TRACE_MODE_READ, d_tracer, - tr, &show_traces_fops); + tr, &show_traces_fops); - trace_create_file("current_tracer", TRACE_MODE_WRITE, d_tracer, - tr, &set_tracer_fops); + trace_create_file("current_tracer", writable_mode, d_tracer, + tr, &set_tracer_fops); - trace_create_file("tracing_cpumask", TRACE_MODE_WRITE, d_tracer, + trace_create_file("tracing_cpumask", writable_mode, d_tracer, tr, &tracing_cpumask_fops); + /* Options are used for changing print-format even for readonly instance. */ trace_create_file("trace_options", TRACE_MODE_WRITE, d_tracer, tr, &tracing_iter_fops); @@ -9886,12 +9901,36 @@ init_tracer_tracefs(struct trace_array *tr, struct dentry *d_tracer) trace_create_file("trace_pipe", TRACE_MODE_READ, d_tracer, tr, &tracing_pipe_fops); - trace_create_file("buffer_size_kb", TRACE_MODE_WRITE, d_tracer, + trace_create_file("buffer_size_kb", writable_mode, d_tracer, tr, &tracing_entries_fops); trace_create_file("buffer_total_size_kb", TRACE_MODE_READ, d_tracer, tr, &tracing_total_entries_fops); + trace_create_file("trace_clock", writable_mode, d_tracer, tr, + &trace_clock_fops); + + trace_create_file("timestamp_mode", TRACE_MODE_READ, d_tracer, tr, + &trace_time_stamp_mode_fops); + + tr->buffer_percent = 50; + + trace_create_file("buffer_subbuf_size_kb", writable_mode, d_tracer, + tr, &buffer_subbuf_size_fops); + + create_trace_options_dir(tr); + + if (tr->range_addr_start) + trace_create_file("last_boot_info", TRACE_MODE_READ, d_tracer, + tr, &last_boot_fops); + + for_each_tracing_cpu(cpu) + tracing_init_tracefs_percpu(tr, cpu); + + /* Read-only instance has above files only. */ + if (trace_array_is_readonly(tr)) + return; + trace_create_file("free_buffer", 0200, d_tracer, tr, &tracing_free_buffer_fops); @@ -9903,49 +9942,29 @@ init_tracer_tracefs(struct trace_array *tr, struct dentry *d_tracer) trace_create_file("trace_marker_raw", 0220, d_tracer, tr, &tracing_mark_raw_fops); - trace_create_file("trace_clock", TRACE_MODE_WRITE, d_tracer, tr, - &trace_clock_fops); - - trace_create_file("tracing_on", TRACE_MODE_WRITE, d_tracer, - tr, &rb_simple_fops); - - trace_create_file("timestamp_mode", TRACE_MODE_READ, d_tracer, tr, - &trace_time_stamp_mode_fops); - - tr->buffer_percent = 50; - trace_create_file("buffer_percent", TRACE_MODE_WRITE, d_tracer, - tr, &buffer_percent_fops); - - trace_create_file("buffer_subbuf_size_kb", TRACE_MODE_WRITE, d_tracer, - tr, &buffer_subbuf_size_fops); + tr, &buffer_percent_fops); trace_create_file("syscall_user_buf_size", TRACE_MODE_WRITE, d_tracer, - tr, &tracing_syscall_buf_fops); + tr, &tracing_syscall_buf_fops); - create_trace_options_dir(tr); + trace_create_file("tracing_on", TRACE_MODE_WRITE, d_tracer, + tr, &rb_simple_fops); trace_create_maxlat_file(tr, d_tracer); if (ftrace_create_function_files(tr, d_tracer)) MEM_FAIL(1, "Could not allocate function filter files"); - if (tr->range_addr_start) { - trace_create_file("last_boot_info", TRACE_MODE_READ, d_tracer, - tr, &last_boot_fops); #ifdef CONFIG_TRACER_SNAPSHOT - } else { + if (!tr->range_addr_start) trace_create_file("snapshot", TRACE_MODE_WRITE, d_tracer, tr, &snapshot_fops); #endif - } trace_create_file("error_log", TRACE_MODE_WRITE, d_tracer, tr, &tracing_err_log_fops); - for_each_tracing_cpu(cpu) - tracing_init_tracefs_percpu(tr, cpu); - ftrace_init_tracefs(tr, d_tracer); } @@ -10772,7 +10791,7 @@ __init static void enable_instances(void) * Backup buffers can be freed but need vfree(). */ if (backup) - tr->flags |= TRACE_ARRAY_FL_VMALLOC; + tr->flags |= TRACE_ARRAY_FL_VMALLOC | TRACE_ARRAY_FL_RDONLY; if (start || backup) { tr->flags |= TRACE_ARRAY_FL_BOOT | TRACE_ARRAY_FL_LAST_BOOT; diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index fbbd0b2ee76f..366baa43dfab 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -462,6 +462,7 @@ enum { TRACE_ARRAY_FL_MOD_INIT = BIT(3), TRACE_ARRAY_FL_MEMMAP = BIT(4), TRACE_ARRAY_FL_VMALLOC = BIT(5), + TRACE_ARRAY_FL_RDONLY = BIT(6), }; #ifdef CONFIG_MODULES @@ -491,6 +492,12 @@ extern unsigned long trace_adjust_address(struct trace_array *tr, unsigned long extern struct trace_array *printk_trace; +static inline bool trace_array_is_readonly(struct trace_array *tr) +{ + /* backup instance is read only. */ + return tr->flags & TRACE_ARRAY_FL_RDONLY; +} + /* * The global tracer (top) should be the first trace array added, * but we check the flag anyway. diff --git a/kernel/trace/trace_boot.c b/kernel/trace/trace_boot.c index dbe29b4c6a7a..2ca2541c8a58 100644 --- a/kernel/trace/trace_boot.c +++ b/kernel/trace/trace_boot.c @@ -61,7 +61,8 @@ trace_boot_set_instance_options(struct trace_array *tr, struct xbc_node *node) v = memparse(p, NULL); if (v < PAGE_SIZE) pr_err("Buffer size is too small: %s\n", p); - if (tracing_resize_ring_buffer(tr, v, RING_BUFFER_ALL_CPUS) < 0) + if (trace_array_is_readonly(tr) || + tracing_resize_ring_buffer(tr, v, RING_BUFFER_ALL_CPUS) < 0) pr_err("Failed to resize trace buffer to %s\n", p); } @@ -597,7 +598,7 @@ trace_boot_enable_tracer(struct trace_array *tr, struct xbc_node *node) p = xbc_node_find_value(node, "tracer", NULL); if (p && *p != '\0') { - if (tracing_set_tracer(tr, p) < 0) + if (trace_array_is_readonly(tr) || tracing_set_tracer(tr, p) < 0) pr_err("Failed to set given tracer: %s\n", p); } diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index 249d1cba72c0..aa422dc80ae8 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -1401,6 +1401,9 @@ static int __ftrace_set_clr_event(struct trace_array *tr, const char *match, { int ret; + if (trace_array_is_readonly(tr)) + return -EACCES; + mutex_lock(&event_mutex); ret = __ftrace_set_clr_event_nolock(tr, match, sub, event, set, mod); mutex_unlock(&event_mutex); @@ -2973,8 +2976,8 @@ event_subsystem_dir(struct trace_array *tr, const char *name, } else __get_system(system); - /* ftrace only has directories no files */ - if (strcmp(name, "ftrace") == 0) + /* ftrace only has directories no files, readonly instance too. */ + if (strcmp(name, "ftrace") == 0 || trace_array_is_readonly(tr)) nr_entries = 0; else nr_entries = ARRAY_SIZE(system_entries); @@ -3139,28 +3142,30 @@ event_create_dir(struct eventfs_inode *parent, struct trace_event_file *file) int ret; static struct eventfs_entry event_entries[] = { { - .name = "enable", + .name = "format", .callback = event_callback, - .release = event_release, }, +#ifdef CONFIG_PERF_EVENTS { - .name = "filter", + .name = "id", .callback = event_callback, }, +#endif +#define NR_RO_EVENT_ENTRIES (1 + IS_ENABLED(CONFIG_PERF_EVENTS)) +/* Readonly files must be above this line and counted by NR_RO_EVENT_ENTRIES. */ { - .name = "trigger", + .name = "enable", .callback = event_callback, + .release = event_release, }, { - .name = "format", + .name = "filter", .callback = event_callback, }, -#ifdef CONFIG_PERF_EVENTS { - .name = "id", + .name = "trigger", .callback = event_callback, }, -#endif #ifdef CONFIG_HIST_TRIGGERS { .name = "hist", @@ -3193,7 +3198,10 @@ event_create_dir(struct eventfs_inode *parent, struct trace_event_file *file) if (!e_events) return -ENOMEM; - nr_entries = ARRAY_SIZE(event_entries); + if (trace_array_is_readonly(tr)) + nr_entries = NR_RO_EVENT_ENTRIES; + else + nr_entries = ARRAY_SIZE(event_entries); name = trace_event_name(call); ei = eventfs_create_dir(name, e_events, event_entries, nr_entries, file); @@ -4536,31 +4544,44 @@ create_event_toplevel_files(struct dentry *parent, struct trace_array *tr) int nr_entries; static struct eventfs_entry events_entries[] = { { - .name = "enable", + .name = "header_page", .callback = events_callback, }, { - .name = "header_page", + .name = "header_event", .callback = events_callback, }, +#define NR_RO_TOP_ENTRIES 2 +/* Readonly files must be above this line and counted by NR_RO_TOP_ENTRIES. */ { - .name = "header_event", + .name = "enable", .callback = events_callback, }, }; - entry = trace_create_file("set_event", TRACE_MODE_WRITE, parent, - tr, &ftrace_set_event_fops); - if (!entry) - return -ENOMEM; + if (!trace_array_is_readonly(tr)) { + entry = trace_create_file("set_event", TRACE_MODE_WRITE, parent, + tr, &ftrace_set_event_fops); + if (!entry) + return -ENOMEM; - trace_create_file("show_event_filters", TRACE_MODE_READ, parent, tr, - &ftrace_show_event_filters_fops); + /* There are not as crucial, just warn if they are not created */ + trace_create_file("show_event_filters", TRACE_MODE_READ, parent, tr, + &ftrace_show_event_filters_fops); - trace_create_file("show_event_triggers", TRACE_MODE_READ, parent, tr, - &ftrace_show_event_triggers_fops); + trace_create_file("show_event_triggers", TRACE_MODE_READ, parent, tr, + &ftrace_show_event_triggers_fops); - nr_entries = ARRAY_SIZE(events_entries); + trace_create_file("set_event_pid", TRACE_MODE_WRITE, parent, + tr, &ftrace_set_event_pid_fops); + + trace_create_file("set_event_notrace_pid", + TRACE_MODE_WRITE, parent, tr, + &ftrace_set_event_notrace_pid_fops); + nr_entries = ARRAY_SIZE(events_entries); + } else { + nr_entries = NR_RO_TOP_ENTRIES; + } e_events = eventfs_create_events_dir("events", parent, events_entries, nr_entries, tr); @@ -4569,15 +4590,6 @@ create_event_toplevel_files(struct dentry *parent, struct trace_array *tr) return -ENOMEM; } - /* There are not as crucial, just warn if they are not created */ - - trace_create_file("set_event_pid", TRACE_MODE_WRITE, parent, - tr, &ftrace_set_event_pid_fops); - - trace_create_file("set_event_notrace_pid", - TRACE_MODE_WRITE, parent, tr, - &ftrace_set_event_notrace_pid_fops); - tr->event_dir = e_events; return 0; |