diff --git a/Documentation/trace/user_events.rst b/Documentation/trace/user_events.rst index bddedabaca80..c180936f49fc 100644 --- a/Documentation/trace/user_events.rst +++ b/Documentation/trace/user_events.rst @@ -7,7 +7,7 @@ user_events: User-based Event Tracing Overview -------- User based trace events allow user processes to create events and trace data -that can be viewed via existing tools, such as ftrace, perf and eBPF. +that can be viewed via existing tools, such as ftrace and perf. To enable this feature, build your kernel with CONFIG_USER_EVENTS=y. Programs can view status of the events via @@ -67,8 +67,7 @@ The command string format is as follows:: Supported Flags ^^^^^^^^^^^^^^^ -**BPF_ITER** - EBPF programs attached to this event will get the raw iovec -struct instead of any data copies for max performance. +None yet Field Format ^^^^^^^^^^^^ @@ -160,7 +159,7 @@ The following values are defined to aid in checking what has been attached: **EVENT_STATUS_FTRACE** - Bit set if ftrace has been attached (Bit 0). -**EVENT_STATUS_PERF** - Bit set if perf/eBPF has been attached (Bit 1). +**EVENT_STATUS_PERF** - Bit set if perf has been attached (Bit 1). Writing Data ------------ @@ -204,13 +203,6 @@ It's advised for user programs to do the following:: **NOTE:** *The write_index is not emitted out into the trace being recorded.* -EBPF ----- -EBPF programs that attach to a user-based event tracepoint are given a pointer -to a struct user_bpf_context. The bpf context contains the data type (which can -be a user or kernel buffer, or can be a pointer to the iovec) and the data -length that was emitted (minus the write_index). - Example Code ------------ See sample code in samples/user_events. diff --git a/fs/proc/bootconfig.c b/fs/proc/bootconfig.c index 6d8d4bf20837..2e244ada1f97 100644 --- a/fs/proc/bootconfig.c +++ b/fs/proc/bootconfig.c @@ -32,6 +32,8 @@ static int __init copy_xbc_key_value_list(char *dst, size_t size) int ret = 0; key = kzalloc(XBC_KEYLEN_MAX, GFP_KERNEL); + if (!key) + return -ENOMEM; xbc_for_each_key_value(leaf, val) { ret = xbc_node_compose_key(leaf, key, XBC_KEYLEN_MAX); diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h index ed8cf433a46a..4816b7e11047 100644 --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -9,6 +9,7 @@ #include #include +#include #include #include #include @@ -1018,7 +1019,20 @@ unsigned long ftrace_graph_ret_addr(struct task_struct *task, int *idx, extern int register_ftrace_graph(struct fgraph_ops *ops); extern void unregister_ftrace_graph(struct fgraph_ops *ops); -extern bool ftrace_graph_is_dead(void); +/** + * ftrace_graph_is_dead - returns true if ftrace_graph_stop() was called + * + * ftrace_graph_stop() is called when a severe error is detected in + * the function graph tracing. This function is called by the critical + * paths of function graph to keep those paths from doing any more harm. + */ +DECLARE_STATIC_KEY_FALSE(kill_ftrace_graph); + +static inline bool ftrace_graph_is_dead(void) +{ + return static_branch_unlikely(&kill_ftrace_graph); +} + extern void ftrace_graph_stop(void); /* The current handlers in use */ diff --git a/include/linux/user_events.h b/include/linux/user_events.h index e570840571e1..736e05603463 100644 --- a/include/linux/user_events.h +++ b/include/linux/user_events.h @@ -32,9 +32,6 @@ /* Create dynamic location entry within a 32-bit value */ #define DYN_LOC(offset, size) ((size) << 16 | (offset)) -/* Use raw iterator for attached BPF program(s), no affect on ftrace/perf */ -#define FLAG_BPF_ITER (1 << 0) - /* * Describes an event registration and stores the results of the registration. * This structure is passed to the DIAG_IOCSREG ioctl, callers at a minimum @@ -63,54 +60,4 @@ struct user_reg { /* Requests to delete a user_event */ #define DIAG_IOCSDEL _IOW(DIAG_IOC_MAGIC, 1, char*) -/* Data type that was passed to the BPF program */ -enum { - /* Data resides in kernel space */ - USER_BPF_DATA_KERNEL, - - /* Data resides in user space */ - USER_BPF_DATA_USER, - - /* Data is a pointer to a user_bpf_iter structure */ - USER_BPF_DATA_ITER, -}; - -/* - * Describes an iovec iterator that BPF programs can use to access data for - * a given user_event write() / writev() call. - */ -struct user_bpf_iter { - - /* Offset of the data within the first iovec */ - __u32 iov_offset; - - /* Number of iovec structures */ - __u32 nr_segs; - - /* Pointer to iovec structures */ - const struct iovec *iov; -}; - -/* Context that BPF programs receive when attached to a user_event */ -struct user_bpf_context { - - /* Data type being passed (see union below) */ - __u32 data_type; - - /* Length of the data */ - __u32 data_len; - - /* Pointer to data, varies by data type */ - union { - /* Kernel data (data_type == USER_BPF_DATA_KERNEL) */ - void *kdata; - - /* User data (data_type == USER_BPF_DATA_USER) */ - void *udata; - - /* Direct iovec (data_type == USER_BPF_DATA_ITER) */ - struct user_bpf_iter *iter; - }; -}; - #endif /* _UAPI_LINUX_USER_EVENTS_H */ diff --git a/include/trace/stages/stage1_defines.h b/include/trace/stages/stage1_struct_define.h similarity index 100% rename from include/trace/stages/stage1_defines.h rename to include/trace/stages/stage1_struct_define.h diff --git a/include/trace/stages/stage2_defines.h b/include/trace/stages/stage2_data_offsets.h similarity index 100% rename from include/trace/stages/stage2_defines.h rename to include/trace/stages/stage2_data_offsets.h diff --git a/include/trace/stages/stage3_defines.h b/include/trace/stages/stage3_trace_output.h similarity index 100% rename from include/trace/stages/stage3_defines.h rename to include/trace/stages/stage3_trace_output.h diff --git a/include/trace/stages/stage4_defines.h b/include/trace/stages/stage4_event_fields.h similarity index 100% rename from include/trace/stages/stage4_defines.h rename to include/trace/stages/stage4_event_fields.h diff --git a/include/trace/stages/stage5_defines.h b/include/trace/stages/stage5_get_offsets.h similarity index 100% rename from include/trace/stages/stage5_defines.h rename to include/trace/stages/stage5_get_offsets.h diff --git a/include/trace/stages/stage6_defines.h b/include/trace/stages/stage6_event_callback.h similarity index 100% rename from include/trace/stages/stage6_defines.h rename to include/trace/stages/stage6_event_callback.h diff --git a/include/trace/stages/stage7_defines.h b/include/trace/stages/stage7_class_define.h similarity index 100% rename from include/trace/stages/stage7_defines.h rename to include/trace/stages/stage7_class_define.h diff --git a/include/trace/trace_custom_events.h b/include/trace/trace_custom_events.h index b567c7202339..6e492dba96bf 100644 --- a/include/trace/trace_custom_events.h +++ b/include/trace/trace_custom_events.h @@ -35,7 +35,7 @@ /* Stage 1 creates the structure of the recorded event layout */ -#include "stages/stage1_defines.h" +#include "stages/stage1_struct_define.h" #undef DECLARE_CUSTOM_EVENT_CLASS #define DECLARE_CUSTOM_EVENT_CLASS(name, proto, args, tstruct, assign, print) \ @@ -56,7 +56,7 @@ /* Stage 2 creates the custom class */ -#include "stages/stage2_defines.h" +#include "stages/stage2_data_offsets.h" #undef DECLARE_CUSTOM_EVENT_CLASS #define DECLARE_CUSTOM_EVENT_CLASS(call, proto, args, tstruct, assign, print) \ @@ -71,7 +71,7 @@ /* Stage 3 create the way to print the custom event */ -#include "stages/stage3_defines.h" +#include "stages/stage3_trace_output.h" #undef DECLARE_CUSTOM_EVENT_CLASS #define DECLARE_CUSTOM_EVENT_CLASS(call, proto, args, tstruct, assign, print) \ @@ -102,7 +102,7 @@ static struct trace_event_functions trace_custom_event_type_funcs_##call = { \ /* Stage 4 creates the offset layout for the fields */ -#include "stages/stage4_defines.h" +#include "stages/stage4_event_fields.h" #undef DECLARE_CUSTOM_EVENT_CLASS #define DECLARE_CUSTOM_EVENT_CLASS(call, proto, args, tstruct, func, print) \ @@ -114,7 +114,7 @@ static struct trace_event_fields trace_custom_event_fields_##call[] = { \ /* Stage 5 creates the helper function for dynamic fields */ -#include "stages/stage5_defines.h" +#include "stages/stage5_get_offsets.h" #undef DECLARE_CUSTOM_EVENT_CLASS #define DECLARE_CUSTOM_EVENT_CLASS(call, proto, args, tstruct, assign, print) \ @@ -134,7 +134,7 @@ static inline notrace int trace_custom_event_get_offsets_##call( \ /* Stage 6 creates the probe function that records the event */ -#include "stages/stage6_defines.h" +#include "stages/stage6_event_callback.h" #undef DECLARE_CUSTOM_EVENT_CLASS #define DECLARE_CUSTOM_EVENT_CLASS(call, proto, args, tstruct, assign, print) \ @@ -182,7 +182,7 @@ static inline void ftrace_test_custom_probe_##call(void) \ /* Stage 7 creates the actual class and event structure for the custom event */ -#include "stages/stage7_defines.h" +#include "stages/stage7_class_define.h" #undef DECLARE_CUSTOM_EVENT_CLASS #define DECLARE_CUSTOM_EVENT_CLASS(call, proto, args, tstruct, assign, print) \ diff --git a/include/trace/trace_events.h b/include/trace/trace_events.h index 8a8cd66cc6d5..c2f9cabf154d 100644 --- a/include/trace/trace_events.h +++ b/include/trace/trace_events.h @@ -45,7 +45,7 @@ PARAMS(print)); \ DEFINE_EVENT(name, name, PARAMS(proto), PARAMS(args)); -#include "stages/stage1_defines.h" +#include "stages/stage1_struct_define.h" #undef DECLARE_EVENT_CLASS #define DECLARE_EVENT_CLASS(name, proto, args, tstruct, assign, print) \ @@ -109,7 +109,7 @@ * The size of an array is also encoded, in the higher 16 bits of . */ -#include "stages/stage2_defines.h" +#include "stages/stage2_data_offsets.h" #undef DECLARE_EVENT_CLASS #define DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print) \ @@ -181,7 +181,7 @@ * in binary. */ -#include "stages/stage3_defines.h" +#include "stages/stage3_trace_output.h" #undef DECLARE_EVENT_CLASS #define DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print) \ @@ -236,7 +236,7 @@ static struct trace_event_functions trace_event_type_funcs_##call = { \ #include TRACE_INCLUDE(TRACE_INCLUDE_FILE) -#include "stages/stage4_defines.h" +#include "stages/stage4_event_fields.h" #undef DECLARE_EVENT_CLASS #define DECLARE_EVENT_CLASS(call, proto, args, tstruct, func, print) \ @@ -249,7 +249,7 @@ static struct trace_event_fields trace_event_fields_##call[] = { \ #include TRACE_INCLUDE(TRACE_INCLUDE_FILE) -#include "stages/stage5_defines.h" +#include "stages/stage5_get_offsets.h" #undef DECLARE_EVENT_CLASS #define DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print) \ @@ -372,7 +372,7 @@ static inline notrace int trace_event_get_offsets_##call( \ #define _TRACE_PERF_INIT(call) #endif /* CONFIG_PERF_EVENTS */ -#include "stages/stage6_defines.h" +#include "stages/stage6_event_callback.h" #undef DECLARE_EVENT_CLASS #define DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print) \ @@ -418,7 +418,7 @@ static inline void ftrace_test_probe_##call(void) \ #include TRACE_INCLUDE(TRACE_INCLUDE_FILE) -#include "stages/stage7_defines.h" +#include "stages/stage7_class_define.h" #undef DECLARE_EVENT_CLASS #define DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print) \ diff --git a/kernel/trace/fgraph.c b/kernel/trace/fgraph.c index 19028e072cdb..8f4fb328133a 100644 --- a/kernel/trace/fgraph.c +++ b/kernel/trace/fgraph.c @@ -7,6 +7,7 @@ * * Highly modified by Steven Rostedt (VMware). */ +#include #include #include #include @@ -23,24 +24,12 @@ #define ASSIGN_OPS_HASH(opsname, val) #endif -static bool kill_ftrace_graph; +DEFINE_STATIC_KEY_FALSE(kill_ftrace_graph); int ftrace_graph_active; /* Both enabled by default (can be cleared by function_graph tracer flags */ static bool fgraph_sleep_time = true; -/** - * ftrace_graph_is_dead - returns true if ftrace_graph_stop() was called - * - * ftrace_graph_stop() is called when a severe error is detected in - * the function graph tracing. This function is called by the critical - * paths of function graph to keep those paths from doing any more harm. - */ -bool ftrace_graph_is_dead(void) -{ - return kill_ftrace_graph; -} - /** * ftrace_graph_stop - set to permanently disable function graph tracing * @@ -51,7 +40,7 @@ bool ftrace_graph_is_dead(void) */ void ftrace_graph_stop(void) { - kill_ftrace_graph = true; + static_branch_enable(&kill_ftrace_graph); } /* Add a function return address to the trace stack on thread info.*/ diff --git a/kernel/trace/trace_events_user.c b/kernel/trace/trace_events_user.c index 68d62bfac12f..706e1686b5eb 100644 --- a/kernel/trace/trace_events_user.c +++ b/kernel/trace/trace_events_user.c @@ -47,9 +47,6 @@ #define MAX_FIELD_ARRAY_SIZE 1024 #define MAX_FIELD_ARG_NAME 256 -#define MAX_BPF_COPY_SIZE PAGE_SIZE -#define MAX_STACK_BPF_DATA 512 - static char *register_page_data; static DEFINE_MUTEX(reg_mutex); @@ -410,19 +407,6 @@ static int user_event_parse_field(char *field, struct user_event *user, type[0] != 'u', FILTER_OTHER); } -static void user_event_parse_flags(struct user_event *user, char *flags) -{ - char *flag; - - if (flags == NULL) - return; - - while ((flag = strsep(&flags, ",")) != NULL) { - if (strcmp(flag, "BPF_ITER") == 0) - user->flags |= FLAG_BPF_ITER; - } -} - static int user_event_parse_fields(struct user_event *user, char *args) { char *field; @@ -718,64 +702,14 @@ static void user_event_ftrace(struct user_event *user, struct iov_iter *i, } #ifdef CONFIG_PERF_EVENTS -static void user_event_bpf(struct user_event *user, struct iov_iter *i) -{ - struct user_bpf_context context; - struct user_bpf_iter bpf_i; - char fast_data[MAX_STACK_BPF_DATA]; - void *temp = NULL; - - if ((user->flags & FLAG_BPF_ITER) && iter_is_iovec(i)) { - /* Raw iterator */ - context.data_type = USER_BPF_DATA_ITER; - context.data_len = i->count; - context.iter = &bpf_i; - - bpf_i.iov_offset = i->iov_offset; - bpf_i.iov = i->iov; - bpf_i.nr_segs = i->nr_segs; - } else if (i->nr_segs == 1 && iter_is_iovec(i)) { - /* Single buffer from user */ - context.data_type = USER_BPF_DATA_USER; - context.data_len = i->count; - context.udata = i->iov->iov_base + i->iov_offset; - } else { - /* Multi buffer from user */ - struct iov_iter copy = *i; - size_t copy_size = min_t(size_t, i->count, MAX_BPF_COPY_SIZE); - - context.data_type = USER_BPF_DATA_KERNEL; - context.kdata = fast_data; - - if (unlikely(copy_size > sizeof(fast_data))) { - temp = kmalloc(copy_size, GFP_NOWAIT); - - if (temp) - context.kdata = temp; - else - copy_size = sizeof(fast_data); - } - - context.data_len = copy_nofault(context.kdata, - copy_size, ©); - } - - trace_call_bpf(&user->call, &context); - - kfree(temp); -} - /* - * Writes the user supplied payload out to perf ring buffer or eBPF program. + * Writes the user supplied payload out to perf ring buffer. */ static void user_event_perf(struct user_event *user, struct iov_iter *i, void *tpdata, bool *faulted) { struct hlist_head *perf_head; - if (bpf_prog_array_valid(&user->call)) - user_event_bpf(user, i); - perf_head = this_cpu_ptr(user->call.perf_events); if (perf_head && !hlist_empty(perf_head)) { @@ -1141,8 +1075,6 @@ static int user_event_parse(char *name, char *args, char *flags, user->tracepoint.name = name; - user_event_parse_flags(user, flags); - ret = user_event_parse_fields(user, args); if (ret) @@ -1170,11 +1102,11 @@ static int user_event_parse(char *name, char *args, char *flags, #endif mutex_lock(&event_mutex); + ret = user_event_trace_register(user); - mutex_unlock(&event_mutex); if (ret) - goto put_user; + goto put_user_lock; user->index = index; @@ -1186,8 +1118,12 @@ static int user_event_parse(char *name, char *args, char *flags, set_bit(user->index, page_bitmap); hash_add(register_table, &user->node, key); + mutex_unlock(&event_mutex); + *newuser = user; return 0; +put_user_lock: + mutex_unlock(&event_mutex); put_user: user_event_destroy_fields(user); user_event_destroy_validators(user); @@ -1580,9 +1516,6 @@ static int user_seq_show(struct seq_file *m, void *p) busy++; } - if (flags & FLAG_BPF_ITER) - seq_puts(m, " FLAG:BPF_ITER"); - seq_puts(m, "\n"); active++; }