[lttng-dev] [PATCH lttng-modules v4 5/5] Extract the payload of epoll_wait/epoll_pwait
Julien Desfossez
jdesfossez at efficios.com
Fri Apr 15 20:37:21 UTC 2016
When epoll_wait returns, extract the content of the "events" field
(events set and data payload).
Here is an example output:
syscall_entry_epoll_wait: { epfd = 3, maxevents = 32, timeout = 100 }
syscall_exit_epoll_wait: { ret = 1, fds_length = 1,
fds = [ [0] = { raw_events = 0x1,
events = { EPOLLIN = 1, EPOLLPRI = 0, EPOLLOUT = 0, EPOLLERR = 0,
padding = 0 },
data_union = { u64 = 0x100000005, fd = 5 } } ]
}
Signed-off-by: Julien Desfossez <jdesfossez at efficios.com>
---
.../syscalls/headers/syscalls_pointers_override.h | 190 +++++++++++++++++++++
1 file changed, 190 insertions(+)
diff --git a/instrumentation/syscalls/headers/syscalls_pointers_override.h b/instrumentation/syscalls/headers/syscalls_pointers_override.h
index 9bb6a01..301b338 100644
--- a/instrumentation/syscalls/headers/syscalls_pointers_override.h
+++ b/instrumentation/syscalls/headers/syscalls_pointers_override.h
@@ -799,4 +799,194 @@ SC_LTTNG_TRACEPOINT_EVENT_CODE(epoll_ctl,
)
#endif /* defined(CONFIG_X86_32) || defined(CONFIG_X86_64) || defined(CONFIG_ARM64) || defined(CONFIG_ARM) */
+#ifndef ONCE_LTTNG_TRACE_EPOLL_H
+#define ONCE_LTTNG_TRACE_EPOLL_H
+
+static struct lttng_event_field lttng_epoll_wait_fields[] = {
+ [0] = {
+ .name = "data_union",
+ .type = {
+ .atype = atype_struct,
+ .u._struct.nr_fields = ARRAY_SIZE(lttng_epoll_data_fields),
+ .u._struct.fields = lttng_epoll_data_fields,
+ }
+ },
+ [1] = {
+ .name = "raw_events",
+ .type = __type_integer(uint32_t, 0, 0, 0, __BYTE_ORDER, 16, none),
+ },
+ [2] = {
+ .name = "events",
+ .type = {
+ .atype = atype_struct,
+ .u._struct.nr_fields = ARRAY_SIZE(lttng_epoll_ctl_events_fields),
+ .u._struct.fields = lttng_epoll_ctl_events_fields,
+ }
+ },
+};
+
+static struct lttng_type lttng_epoll_wait_elem = {
+ .atype = atype_struct,
+ .u._struct.nr_fields = ARRAY_SIZE(lttng_epoll_wait_fields),
+ .u._struct.fields = lttng_epoll_wait_fields,
+};
+
+#endif /* ONCE_LTTNG_TRACE_EPOLL_H */
+
+#if defined(CONFIG_X86_32) || defined(CONFIG_X86_64)
+#define OVERRIDE_32_epoll_wait
+#define OVERRIDE_64_epoll_wait
+SC_LTTNG_TRACEPOINT_EVENT_CODE(epoll_wait,
+ TP_PROTO(sc_exit(long ret,) int epfd, struct epoll_event __user * uevents,
+ int maxevents, int timeout),
+ TP_ARGS(sc_exit(ret,) epfd, uevents, maxevents, timeout),
+ TP_locvar(
+ sc_out(
+ int fds_length;
+ struct epoll_event *events;
+ )
+ ),
+ TP_code_pre(
+ BUILD_BUG_ON(((ARRAY_SIZE(lttng_epoll_ctl_events_fields) - 1) +
+ EPOLL_FLAGS_PADDING_SIZE) !=
+ sizeof(uint8_t) * BITS_PER_BYTE);
+ sc_out({
+ int err;
+
+ tp_locvar->fds_length = 0;
+ tp_locvar->events = NULL;
+
+ if (maxevents <= 0)
+ goto skip_code;
+
+ tp_locvar->events = kmalloc(
+ maxevents * sizeof(struct epoll_event),
+ GFP_KERNEL);
+ if (!tp_locvar->events)
+ goto skip_code;
+
+ if (ret > 0) {
+ tp_locvar->fds_length = ret;
+ err = copy_from_user(tp_locvar->events,
+ uevents, maxevents * sizeof(struct epoll_event));
+ if (err) {
+ tp_locvar->fds_length = 0;
+ }
+ }
+ }
+ skip_code:
+ )
+ ),
+ TP_FIELDS(
+ sc_exit(ctf_integer(long, ret, ret))
+ sc_in(ctf_integer(int, epfd, epfd))
+ sc_in(ctf_integer(int, maxevents, maxevents))
+ sc_in(ctf_integer(int, timeout, timeout))
+ sc_out(ctf_integer(unsigned int, fds_length, tp_locvar->fds_length))
+ sc_out(
+ ctf_custom_field(
+ ctf_custom_type(
+ .atype = atype_sequence_compound,
+ .u.sequence_compound.length_name =
+ "fds_length",
+ .u.sequence_compound.elem_type =
+ <tng_epoll_wait_elem,
+ ),
+ fds,
+ ctf_custom_code(
+ uint32_t i;
+
+ ctf_align(uint64_t)
+ for (i = 0; i < tp_locvar->fds_length; i++) {
+ ctf_integer_bitfield_type(uint32_t,
+ cpu_to_le32(tp_locvar->events[i].events))
+ ctf_integer_bitfield_type(uint8_t,
+ (uint8_t) cpu_to_le32(tp_locvar->events[i].events))
+ ctf_integer_type(uint64_t, tp_locvar->events[i].data)
+ ctf_integer_type(int, tp_locvar->events[i].data)
+ }
+ )
+ )
+ )
+ ),
+ TP_code_post(
+ sc_out(
+ kfree(tp_locvar->events);
+ )
+ )
+)
+#endif /* defined(CONFIG_X86_32) || defined(CONFIG_X86_64) */
+
+#if defined(CONFIG_X86_32) || defined(CONFIG_X86_64) || defined(CONFIG_ARM64) || defined(CONFIG_ARM)
+#define OVERRIDE_32_epoll_pwait
+#define OVERRIDE_64_epoll_pwait
+SC_LTTNG_TRACEPOINT_EVENT_CODE(epoll_pwait,
+ TP_PROTO(sc_exit(long ret,) int epfd, struct epoll_event __user * uevents,
+ int maxevents, int timeout, const sigset_t * sigmask, size_t sigsetsize),
+ TP_ARGS(sc_exit(ret,) epfd, uevents, maxevents, timeout, sigmask, sigsetsize),
+ TP_locvar(
+ sc_out(
+ int fds_length;
+ struct epoll_event events[maxevents];
+ )
+ ),
+ TP_code_pre(
+ BUILD_BUG_ON(((ARRAY_SIZE(lttng_epoll_ctl_events_fields) - 1) +
+ EPOLL_FLAGS_PADDING_SIZE) !=
+ sizeof(uint8_t) * BITS_PER_BYTE);
+ sc_out({
+ int err;
+
+ if (ret > 0) {
+ tp_locvar->fds_length = ret;
+ err = copy_from_user(tp_locvar->events,
+ uevents, maxevents * sizeof(struct epoll_event));
+ if (err) {
+ tp_locvar->fds_length = 0;
+ }
+ } else {
+ tp_locvar->fds_length = 0;
+ }
+
+ })
+ ),
+ TP_FIELDS(
+ sc_exit(ctf_integer(long, ret, ret))
+ sc_in(ctf_integer(int, epfd, epfd))
+ sc_in(ctf_integer(int, maxevents, maxevents))
+ sc_in(ctf_integer(int, timeout, timeout))
+ sc_in(ctf_integer(const sigset_t *, sigmask, sigmask))
+ sc_in(ctf_integer(size_t, sigsetsize, sigsetsize))
+
+ sc_out(ctf_integer(unsigned int, fds_length, tp_locvar->fds_length))
+ sc_out(
+ ctf_custom_field(
+ ctf_custom_type(
+ .atype = atype_sequence_compound,
+ .u.sequence_compound.length_name =
+ "fds_length",
+ .u.sequence_compound.elem_type =
+ <tng_epoll_wait_elem,
+ ),
+ fds,
+ ctf_custom_code(
+ uint32_t i;
+
+ ctf_align(uint64_t)
+ for (i = 0; i < tp_locvar->fds_length; i++) {
+ ctf_integer_type(uint64_t, tp_locvar->events[i].data)
+ ctf_integer_type(int, tp_locvar->events[i].data)
+ ctf_integer_bitfield_type(uint32_t,
+ cpu_to_le32(tp_locvar->events[i].events))
+ ctf_integer_bitfield_type(uint8_t,
+ cpu_to_le32(tp_locvar->events[i].events))
+ }
+ )
+ )
+ )
+ ),
+ TP_code_post()
+)
+#endif /* defined(CONFIG_X86_32) || defined(CONFIG_X86_64) || defined(CONFIG_ARM64) || defined(CONFIG_ARM) */
+
#endif /* CREATE_SYSCALL_TABLE */
--
1.9.1
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