mirror of
https://github.com/torvalds/linux.git
synced 2024-12-28 05:41:55 +00:00
Updates to Tracing:
- Rename the staging files to give them some meaning. Just stage1,stag2,etc, does not show what they are for - Check for NULL from allocation in bootconfig - Hold event mutex for dyn_event call in user events - Mark user events to broken (to work on the API) - Remove eBPF updates from user events - Remove user events from uapi header to keep it from being installed. - Move ftrace_graph_is_dead() into inline as it is called from hot paths and also convert it into a static branch. -----BEGIN PGP SIGNATURE----- iIoEABYIADIWIQRRSw7ePDh/lE+zeZMp5XQQmuv6qgUCYkmyIBQccm9zdGVkdEBn b29kbWlzLm9yZwAKCRAp5XQQmuv6qutfAQD90gbUgFMFe2akF5sKhonF5T6mm0+w BsWqNlBEKBxmfwD+Krfpxql/PKp/gCufcIUUkYC4E6Wl9akf3eO1qQel1Ao= =ZTn1 -----END PGP SIGNATURE----- Merge tag 'trace-v5.18-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull more tracing updates from Steven Rostedt: - Rename the staging files to give them some meaning. Just stage1,stag2,etc, does not show what they are for - Check for NULL from allocation in bootconfig - Hold event mutex for dyn_event call in user events - Mark user events to broken (to work on the API) - Remove eBPF updates from user events - Remove user events from uapi header to keep it from being installed. - Move ftrace_graph_is_dead() into inline as it is called from hot paths and also convert it into a static branch. * tag 'trace-v5.18-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: tracing: Move user_events.h temporarily out of include/uapi ftrace: Make ftrace_graph_is_dead() a static branch tracing: Set user_events to BROKEN tracing/user_events: Remove eBPF interfaces tracing/user_events: Hold event_mutex during dyn_event_add proc: bootconfig: Add null pointer check tracing: Rename the staging files for trace_events
This commit is contained in:
Linus Torvalds
commit
09bb8856d4
@ -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.
|
||||
|
||||
@ -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);
|
||||
|
||||
@ -9,6 +9,7 @@
|
||||
|
||||
#include <linux/trace_recursion.h>
|
||||
#include <linux/trace_clock.h>
|
||||
#include <linux/jump_label.h>
|
||||
#include <linux/kallsyms.h>
|
||||
#include <linux/linkage.h>
|
||||
#include <linux/bitops.h>
|
||||
@ -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 */
|
||||
|
||||
@ -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 */
|
||||
|
||||
@ -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) \
|
||||
|
||||
@ -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 <item>.
|
||||
*/
|
||||
|
||||
#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) \
|
||||
|
||||
@ -7,6 +7,7 @@
|
||||
*
|
||||
* Highly modified by Steven Rostedt (VMware).
|
||||
*/
|
||||
#include <linux/jump_label.h>
|
||||
#include <linux/suspend.h>
|
||||
#include <linux/ftrace.h>
|
||||
#include <linux/slab.h>
|
||||
@ -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.*/
|
||||
|
||||
@ -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 @@ parse:
|
||||
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 @@ discard:
|
||||
}
|
||||
|
||||
#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++;
|
||||
}
|
||||
|
||||
Loading…
Reference in New Issue
Block a user