linux/include/trace/perf.h
Chuck Lever d07c9ad622 tracing: Introduce helpers to safely handle dynamic-sized sockaddrs
Enable a struct sockaddr to be stored in a trace record as a
dynamically-sized field. The common cases are AF_INET and AF_INET6
which are different sizes, and are vastly smaller than a struct
sockaddr_storage.

These are safer because, when used properly, the size of the
sockaddr destination field in each trace record is now guaranteed
to be the same as the source address that is being copied into it.

Link: https://lore.kernel.org/all/164182978641.8391.8277203495236105391.stgit@bazille.1015granger.net/
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-02-28 10:26:38 -05:00

115 lines
3.3 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#undef TRACE_SYSTEM_VAR
#ifdef CONFIG_PERF_EVENTS
#undef __entry
#define __entry entry
#undef __get_dynamic_array
#define __get_dynamic_array(field) \
((void *)__entry + (__entry->__data_loc_##field & 0xffff))
#undef __get_dynamic_array_len
#define __get_dynamic_array_len(field) \
((__entry->__data_loc_##field >> 16) & 0xffff)
#undef __get_str
#define __get_str(field) ((char *)__get_dynamic_array(field))
#undef __get_bitmask
#define __get_bitmask(field) (char *)__get_dynamic_array(field)
#undef __get_sockaddr
#define __get_sockaddr(field) ((struct sockaddr *)__get_dynamic_array(field))
#undef __get_rel_dynamic_array
#define __get_rel_dynamic_array(field) \
((void *)__entry + \
offsetof(typeof(*__entry), __rel_loc_##field) + \
sizeof(__entry->__rel_loc_##field) + \
(__entry->__rel_loc_##field & 0xffff))
#undef __get_rel_dynamic_array_len
#define __get_rel_dynamic_array_len(field) \
((__entry->__rel_loc_##field >> 16) & 0xffff)
#undef __get_rel_str
#define __get_rel_str(field) ((char *)__get_rel_dynamic_array(field))
#undef __get_rel_bitmask
#define __get_rel_bitmask(field) (char *)__get_rel_dynamic_array(field)
#undef __get_rel_sockaddr
#define __get_rel_sockaddr(field) ((struct sockaddr *)__get_rel_dynamic_array(field))
#undef __perf_count
#define __perf_count(c) (__count = (c))
#undef __perf_task
#define __perf_task(t) (__task = (t))
#undef DECLARE_EVENT_CLASS
#define DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print) \
static notrace void \
perf_trace_##call(void *__data, proto) \
{ \
struct trace_event_call *event_call = __data; \
struct trace_event_data_offsets_##call __maybe_unused __data_offsets;\
struct trace_event_raw_##call *entry; \
struct pt_regs *__regs; \
u64 __count = 1; \
struct task_struct *__task = NULL; \
struct hlist_head *head; \
int __entry_size; \
int __data_size; \
int rctx; \
\
__data_size = trace_event_get_offsets_##call(&__data_offsets, args); \
\
head = this_cpu_ptr(event_call->perf_events); \
if (!bpf_prog_array_valid(event_call) && \
__builtin_constant_p(!__task) && !__task && \
hlist_empty(head)) \
return; \
\
__entry_size = ALIGN(__data_size + sizeof(*entry) + sizeof(u32),\
sizeof(u64)); \
__entry_size -= sizeof(u32); \
\
entry = perf_trace_buf_alloc(__entry_size, &__regs, &rctx); \
if (!entry) \
return; \
\
perf_fetch_caller_regs(__regs); \
\
tstruct \
\
{ assign; } \
\
perf_trace_run_bpf_submit(entry, __entry_size, rctx, \
event_call, __count, __regs, \
head, __task); \
}
/*
* This part is compiled out, it is only here as a build time check
* to make sure that if the tracepoint handling changes, the
* perf probe will fail to compile unless it too is updated.
*/
#undef DEFINE_EVENT
#define DEFINE_EVENT(template, call, proto, args) \
static inline void perf_test_probe_##call(void) \
{ \
check_trace_callback_type_##call(perf_trace_##template); \
}
#undef DEFINE_EVENT_PRINT
#define DEFINE_EVENT_PRINT(template, name, proto, args, print) \
DEFINE_EVENT(template, name, PARAMS(proto), PARAMS(args))
#include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
#endif /* CONFIG_PERF_EVENTS */