From 259b6cb38d19bbe9c039728459bc25acc0f6f8a0 Mon Sep 17 00:00:00 2001 From: Mathieu Desnoyers Date: Fri, 16 Sep 2011 19:11:44 -0400 Subject: [PATCH] detailed syscall tracing (work in progress) Buidl disabled for now. Signed-off-by: Mathieu Desnoyers --- Makefile | 2 + ltt-debugfs-abi.c | 4 +- ltt-events.c | 16 +- ltt-events.h | 3 +- lttng-syscalls.c | 266 ++++++++++++++++++++++++++++++++ probes/lttng-events.h | 15 +- probes/lttng-probe-syscalls.c | 281 +--------------------------------- 7 files changed, 290 insertions(+), 297 deletions(-) create mode 100644 lttng-syscalls.c diff --git a/Makefile b/Makefile index 07c32268..0de745f6 100644 --- a/Makefile +++ b/Makefile @@ -21,6 +21,8 @@ ltt-relay-objs := ltt-events.o ltt-debugfs-abi.o \ lttng-context-vtid.o lttng-context-ppid.o \ lttng-context-vppid.o lttng-calibrate.o +#add for testing lttng-syscalls.o + ifneq ($(CONFIG_PERF_EVENTS),) ltt-relay-objs += $(shell \ if [ $(VERSION) -ge 3 \ diff --git a/ltt-debugfs-abi.c b/ltt-debugfs-abi.c index 3d231c0d..86a17200 100644 --- a/ltt-debugfs-abi.c +++ b/ltt-debugfs-abi.c @@ -268,7 +268,7 @@ void lttng_metadata_create_events(struct file *channel_file) * We tolerate no failure path after event creation. It will stay * invariant for the rest of the session. */ - event = ltt_event_create(channel, &metadata_params, NULL); + event = ltt_event_create(channel, &metadata_params, NULL, NULL); if (!event) { goto create_error; } @@ -534,7 +534,7 @@ int lttng_abi_create_event(struct file *channel_file, * We tolerate no failure path after event creation. It * will stay invariant for the rest of the session. */ - event = ltt_event_create(channel, &event_param, NULL); + event = ltt_event_create(channel, &event_param, NULL, NULL); if (!event) { ret = -EINVAL; goto event_error; diff --git a/ltt-events.c b/ltt-events.c index f9688f54..c64c2036 100644 --- a/ltt-events.c +++ b/ltt-events.c @@ -266,7 +266,8 @@ void _ltt_channel_destroy(struct ltt_channel *chan) */ struct ltt_event *ltt_event_create(struct ltt_channel *chan, struct lttng_kernel_event *event_param, - void *filter) + void *filter, + const struct lttng_event_desc *internal_desc) { struct ltt_event *event; int ret; @@ -366,6 +367,9 @@ struct ltt_event *ltt_event_create(struct ltt_channel *chan, WARN_ON_ONCE(!ret); break; case LTTNG_KERNEL_NOOP: + event->desc = internal_desc; + if (!event->desc) + goto register_error; break; default: WARN_ON_ONCE(1); @@ -378,10 +382,7 @@ struct ltt_event *ltt_event_create(struct ltt_channel *chan, return event; statedump_error: - WARN_ON_ONCE(tracepoint_probe_unregister(event_param->name, - event->desc->probe_callback, - event)); - ltt_event_put(event->desc); + /* If a statedump error occurs, events will not be readable. */ register_error: kmem_cache_free(event_cache, event); cache_error: @@ -418,6 +419,9 @@ int _ltt_event_unregister(struct ltt_event *event) lttng_ftrace_unregister(event); ret = 0; break; + case LTTNG_KERNEL_NOOP: + ret = 0; + break; default: WARN_ON_ONCE(1); } @@ -446,6 +450,8 @@ void _ltt_event_destroy(struct ltt_event *event) module_put(event->desc->owner); lttng_ftrace_destroy_private(event); break; + case LTTNG_KERNEL_NOOP: + break; default: WARN_ON_ONCE(1); } diff --git a/ltt-events.h b/ltt-events.h index 395e410e..f3f5b8fd 100644 --- a/ltt-events.h +++ b/ltt-events.h @@ -278,7 +278,8 @@ struct ltt_channel *ltt_global_channel_create(struct ltt_session *session, struct ltt_event *ltt_event_create(struct ltt_channel *chan, struct lttng_kernel_event *event_param, - void *filter); + void *filter, + const struct lttng_event_desc *internal_desc); int ltt_channel_enable(struct ltt_channel *channel); int ltt_channel_disable(struct ltt_channel *channel); diff --git a/lttng-syscalls.c b/lttng-syscalls.c new file mode 100644 index 00000000..28348abe --- /dev/null +++ b/lttng-syscalls.c @@ -0,0 +1,266 @@ +/* + * lttng-syscalls.c + * + * Copyright 2010 (c) - Mathieu Desnoyers + * + * LTTng sched probes. + * + * Dual LGPL v2.1/GPL v2 license. + */ + +#include +#include +#include +#include + +#include "ltt-events.h" + +static void syscall_entry_probe(void *__data, struct pt_regs *regs, long id); + +/* + * Create LTTng tracepoint probes. + */ +#define LTTNG_PACKAGE_BUILD +#define CREATE_TRACE_POINTS + +/* Hijack probe callback for system calls */ +#define TP_PROBE_CB(_template) &syscall_entry_probe +#define TP_MODULE_OVERRIDE + +#define TRACE_INCLUDE_PATH ../instrumentation/syscalls/headers + +#include "instrumentation/syscalls/headers/syscalls.h" + +#undef TP_MODULE_OVERRIDE +#undef TP_PROBE_CB +#undef LTTNG_PACKAGE_BUILD +#undef CREATE_TRACE_POINTS + +struct trace_syscall_entry { + void *func; + const struct lttng_event_desc *desc; /* Set dynamically */ + const struct lttng_event_field *fields; + unsigned int nrargs; +}; + +static int sc_table_desc_filled; + +#define CREATE_SYSCALL_TABLE + +#undef TRACE_SYSCALL_TABLE +#define TRACE_SYSCALL_TABLE(_name, _nr, _nrargs) \ + [ _nr ] = { \ + .func = __event_probe__##_name, \ + .nrargs = (_nrargs), \ + .fields = __event_fields___##_name, \ + }, + +static struct trace_syscall_entry sc_table[] = { +#include "instrumentation/syscalls/headers/syscalls.h" +}; + +#undef CREATE_SYSCALL_TABLE + +static void syscall_entry_probe(void *__data, struct pt_regs *regs, long id) +{ + struct trace_syscall_entry *entry; + struct ltt_channel *chan = __data; + struct ltt_event *event; + + if (unlikely(id >= ARRAY_SIZE(sc_table))) + return; + entry = &sc_table[id]; + if (unlikely(!entry->func)) + return; + event = chan->sc_table[id]; + WARN_ON_ONCE(!event); + + switch (entry->nrargs) { + case 0: + { + void (*fptr)(void *__data) = entry->func; + + fptr(event); + break; + } + case 1: + { + void (*fptr)(void *__data, unsigned long arg0) = entry->func; + unsigned long args[1]; + + syscall_get_arguments(current, regs, 0, entry->nrargs, args); + fptr(event, args[0]); + break; + } + case 2: + { + void (*fptr)(void *__data, + unsigned long arg0, + unsigned long arg1) = entry->func; + unsigned long args[2]; + + syscall_get_arguments(current, regs, 0, entry->nrargs, args); + fptr(event, args[0], args[1]); + break; + } + case 3: + { + void (*fptr)(void *__data, + unsigned long arg0, + unsigned long arg1, + unsigned long arg2) = entry->func; + unsigned long args[3]; + + syscall_get_arguments(current, regs, 0, entry->nrargs, args); + fptr(event, args[0], args[1], args[2]); + break; + } + case 4: + { + void (*fptr)(void *__data, + unsigned long arg0, + unsigned long arg1, + unsigned long arg2, + unsigned long arg3) = entry->func; + unsigned long args[4]; + + syscall_get_arguments(current, regs, 0, entry->nrargs, args); + fptr(event, args[0], args[1], args[2], args[3]); + break; + } + case 5: + { + void (*fptr)(void *__data, + unsigned long arg0, + unsigned long arg1, + unsigned long arg2, + unsigned long arg3, + unsigned long arg4) = entry->func; + unsigned long args[5]; + + syscall_get_arguments(current, regs, 0, entry->nrargs, args); + fptr(event, args[0], args[1], args[2], args[3], args[4]); + break; + } + case 6: + { + void (*fptr)(void *__data, + unsigned long arg0, + unsigned long arg1, + unsigned long arg2, + unsigned long arg3, + unsigned long arg4, + unsigned long arg5) = entry->func; + unsigned long args[6]; + + syscall_get_arguments(current, regs, 0, entry->nrargs, args); + fptr(event, args[0], args[1], args[2], + args[3], args[4], args[5]); + break; + } + default: + break; + } +} + +static const struct lttng_event_desc *find_syscall_desc(unsigned int id) +{ + unsigned int i; + + for (i = 0; i < __probe_desc___syscalls.nr_events; i++) { + if (__probe_desc___syscalls.event_desc[i].fields + == sc_table[id].fields) + return &__probe_desc___syscalls.event_desc[i]; + } + WARN_ON_ONCE(1); + return NULL; +} + +static void fill_sc_table_desc(void) +{ + unsigned int i; + + if (sc_table_desc_filled) + return; + /* + * This is O(n^2), but rare. Eventually get the TRACE_EVENT code + * to emit per-event symbols to skip this. + */ + for (i = 0; i < ARRAY_SIZE(sc_table); i++) { + const struct lttng_event_desc **desc = &sc_table[i].desc; + + if (!sc_table[i].func) + continue; + (*desc) = find_syscall_desc(i); + } + sc_table_desc_filled = 1; +} + + +int lttng_syscalls_register(struct ltt_channel *chan, void *filter) +{ + unsigned int i; + int ret; + + wrapper_vmalloc_sync_all(); + fill_sc_table_desc(); + + if (!chan->sc_table) { + /* create syscall table mapping syscall to events */ + chan->sc_table = kzalloc(sizeof(struct ltt_event *) + * ARRAY_SIZE(sc_table), GFP_KERNEL); + if (!chan->sc_table) + return -ENOMEM; + } + + /* Allocate events for each syscall, insert into table */ + for (i = 0; i < ARRAY_SIZE(sc_table); i++) { + struct lttng_kernel_event ev; + const struct lttng_event_desc *desc = sc_table[i].desc; + + if (!desc) + continue; + /* + * Skip those already populated by previous failed + * register for this channel. + */ + if (chan->sc_table[i]) + continue; + memset(&ev, 0, sizeof(ev)); + strncpy(ev.name, desc->name, LTTNG_SYM_NAME_LEN); + ev.name[LTTNG_SYM_NAME_LEN - 1] = '\0'; + ev.instrumentation = LTTNG_KERNEL_NOOP; + chan->sc_table[i] = ltt_event_create(chan, &ev, filter, + desc); + if (!chan->sc_table[i]) { + /* + * If something goes wrong in event registration + * after the first one, we have no choice but to + * leave the previous events in there, until + * deleted by session teardown. + */ + return -EINVAL; + } + } + ret = tracepoint_probe_register("sys_enter", + (void *) syscall_entry_probe, chan); + return ret; +} + +/* + * Only called at session destruction. + */ +int lttng_syscalls_unregister(struct ltt_channel *chan) +{ + int ret; + + if (!chan->sc_table) + return 0; + ret = tracepoint_probe_unregister("sys_enter", + (void *) syscall_entry_probe, chan); + if (ret) + return ret; + /* ltt_event destroy will be performed by ltt_session_destroy() */ + kfree(chan->sc_table); + return 0; +} diff --git a/probes/lttng-events.h b/probes/lttng-events.h index 39b28886..925e12da 100644 --- a/probes/lttng-events.h +++ b/probes/lttng-events.h @@ -536,15 +536,6 @@ static void __event_probe__##_name(void *__data, _proto) \ #include "lttng-events-reset.h" /* Reset all macros within TRACE_EVENT */ -/* Override for syscall tracing */ -#ifndef TP_REGISTER_OVERRIDE -#define TP_REGISTER_OVERRIDE ltt_probe_register -#endif - -#ifndef TP_UNREGISTER_OVERRIDE -#define TP_UNREGISTER_OVERRIDE ltt_probe_unregister -#endif - #define TP_ID1(_token, _system) _token##_system #define TP_ID(_token, _system) TP_ID1(_token, _system) #define module_init_eval1(_token, _system) module_init(_token##_system) @@ -552,20 +543,22 @@ static void __event_probe__##_name(void *__data, _proto) \ #define module_exit_eval1(_token, _system) module_exit(_token##_system) #define module_exit_eval(_token, _system) module_exit_eval1(_token, _system) +#ifndef TP_MODULE_OVERRIDE static int TP_ID(__lttng_events_init__, TRACE_SYSTEM)(void) { wrapper_vmalloc_sync_all(); - return TP_REGISTER_OVERRIDE(&TP_ID(__probe_desc___, TRACE_SYSTEM)); + return ltt_probe_register(&TP_ID(__probe_desc___, TRACE_SYSTEM)); } module_init_eval(__lttng_events_init__, TRACE_SYSTEM); static void TP_ID(__lttng_events_exit__, TRACE_SYSTEM)(void) { - TP_UNREGISTER_OVERRIDE(&TP_ID(__probe_desc___, TRACE_SYSTEM)); + ltt_probe_unregister(&TP_ID(__probe_desc___, TRACE_SYSTEM)); } module_exit_eval(__lttng_events_exit__, TRACE_SYSTEM); +#endif #undef module_init_eval #undef module_exit_eval diff --git a/probes/lttng-probe-syscalls.c b/probes/lttng-probe-syscalls.c index bb7217b4..8ce73dfa 100644 --- a/probes/lttng-probe-syscalls.c +++ b/probes/lttng-probe-syscalls.c @@ -1,9 +1,9 @@ /* - * probes/lttng-probe-sched.c + * probes/lttng-probe-syscalls.c * * Copyright 2010 (c) - Mathieu Desnoyers * - * LTTng sched probes. + * LTTng syscalls probes. * * Dual LGPL v2.1/GPL v2 license. */ @@ -11,8 +11,6 @@ #include #include "../ltt-events.h" -#ifndef SYSCALL_DETAIL - /* * Create the tracepoint static inlines from the kernel to validate that our * trace event macros match the kernel we run on. @@ -28,279 +26,6 @@ #include "../instrumentation/events/lttng-module/syscalls.h" -#else /* SYSCALL_DETAIL */ - -#include -#include -#include - -static void syscall_entry_probe(void *__data, struct pt_regs *regs, long id); -static int lttng_syscalls_register_probe(struct lttng_probe_desc *desc); -static void lttng_syscalls_unregister_probe(struct lttng_probe_desc *desc); - -static struct lttng_probe_desc *syscall_probe_desc; - -/* - * Create LTTng tracepoint probes. - */ -#define LTTNG_PACKAGE_BUILD -#define CREATE_TRACE_POINTS - -/* Hijack probe callback for system calls */ -#define TP_PROBE_CB(_template) &syscall_entry_probe -#define TP_REGISTER_OVERRIDE lttng_syscalls_register_probe -#define TP_UNREGISTER_OVERRIDE lttng_syscalls_unregister_probe - -#define TRACE_INCLUDE_PATH ../instrumentation/syscalls/headers - -#include "../instrumentation/syscalls/headers/syscalls.h" - -#undef TP_UNREGISTER_OVERRIDE -#undef TP_REGISTER_OVERRIDE -#undef TP_PROBE_CB -#undef LTTNG_PACKAGE_BUILD -#undef CREATE_TRACE_POINTS - -struct trace_syscall_entry { - void *func; - const struct lttng_event_desc *desc; /* Set dynamically */ - const struct lttng_event_field *fields; - unsigned int nrargs; -}; - -static int sc_table_desc_filled; - -#define CREATE_SYSCALL_TABLE - -#undef TRACE_SYSCALL_TABLE -#define TRACE_SYSCALL_TABLE(_name, _nr, _nrargs) \ - [ _nr ] = { \ - .func = __event_probe__##_name, \ - .nrargs = (_nrargs), \ - .fields = __event_fields___##_name, \ - }, - -static struct trace_syscall_entry sc_table[] = { -#include "../instrumentation/syscalls/headers/syscalls.h" -}; - -#undef CREATE_SYSCALL_TABLE - -static void syscall_entry_probe(void *__data, struct pt_regs *regs, long id) -{ - struct trace_syscall_entry *entry; - struct ltt_channel *chan = __data; - struct ltt_event *event; - - if (unlikely(id >= ARRAY_SIZE(sc_table))) - return; - entry = &sc_table[id]; - if (unlikely(!entry->func)) - return; - event = chan->sc_table[id]; - WARN_ON_ONCE(!event); - - switch (entry->nrargs) { - case 0: - { - void (*fptr)(void *__data) = entry->func; - - fptr(event); - break; - } - case 1: - { - void (*fptr)(void *__data, unsigned long arg0) = entry->func; - unsigned long args[1]; - - syscall_get_arguments(current, regs, 0, entry->nrargs, args); - fptr(event, args[0]); - break; - } - case 2: - { - void (*fptr)(void *__data, - unsigned long arg0, - unsigned long arg1) = entry->func; - unsigned long args[2]; - - syscall_get_arguments(current, regs, 0, entry->nrargs, args); - fptr(event, args[0], args[1]); - break; - } - case 3: - { - void (*fptr)(void *__data, - unsigned long arg0, - unsigned long arg1, - unsigned long arg2) = entry->func; - unsigned long args[3]; - - syscall_get_arguments(current, regs, 0, entry->nrargs, args); - fptr(event, args[0], args[1], args[2]); - break; - } - case 4: - { - void (*fptr)(void *__data, - unsigned long arg0, - unsigned long arg1, - unsigned long arg2, - unsigned long arg3) = entry->func; - unsigned long args[4]; - - syscall_get_arguments(current, regs, 0, entry->nrargs, args); - fptr(event, args[0], args[1], args[2], args[3]); - break; - } - case 5: - { - void (*fptr)(void *__data, - unsigned long arg0, - unsigned long arg1, - unsigned long arg2, - unsigned long arg3, - unsigned long arg4) = entry->func; - unsigned long args[5]; - - syscall_get_arguments(current, regs, 0, entry->nrargs, args); - fptr(event, args[0], args[1], args[2], args[3], args[4]); - break; - } - case 6: - { - void (*fptr)(void *__data, - unsigned long arg0, - unsigned long arg1, - unsigned long arg2, - unsigned long arg3, - unsigned long arg4, - unsigned long arg5) = entry->func; - unsigned long args[6]; - - syscall_get_arguments(current, regs, 0, entry->nrargs, args); - fptr(event, args[0], args[1], args[2], - args[3], args[4], args[5]); - break; - } - default: - break; - } -} - -static const struct lttng_event_desc *find_syscall_desc(unsigned int id) -{ - unsigned int i; - - for (i = 0; i < syscall_probe_desc->nr_events; i++) { - if (syscall_probe_desc->event_desc[i].fields - == sc_table[id].fields) - return &syscall_probe_desc->event_desc[i]; - } - WARN_ON_ONCE(1); - return NULL; -} - -static void fill_sc_table_desc(void) -{ - unsigned int i; - - if (sc_table_desc_filled) - return; - /* - * This is O(n^2), but rare. Eventually get the TRACE_EVENT code - * to emit per-event symbols to skip this. - */ - for (i = 0; i < ARRAY_SIZE(sc_table); i++) { - const struct lttng_event_desc **desc = &sc_table[i].desc; - - if (!sc_table[i].func) - continue; - (*desc) = find_syscall_desc(i); - } - sc_table_desc_filled = 1; -} - - -int lttng_syscalls_register(struct ltt_channel *chan, void *filter) -{ - unsigned int i; - int ret; - - fill_sc_table_desc(); - - if (!chan->sc_table) { - /* create syscall table mapping syscall to events */ - chan->sc_table = kzalloc(sizeof(struct ltt_event *) - * ARRAY_SIZE(sc_table), GFP_KERNEL); - if (!chan->sc_table) - return -ENOMEM; - } - - /* Allocate events for each syscall, insert into table */ - for (i = 0; i < ARRAY_SIZE(sc_table); i++) { - struct lttng_kernel_event ev; - const struct lttng_event_desc *desc = sc_table[i].desc; - - /* - * Skip those already populated by previous failed - * register for this channel. - */ - if (chan->sc_table[i]) - continue; - memset(&ev, 0, sizeof(ev)); - strncpy(ev.name, desc->name, LTTNG_SYM_NAME_LEN); - ev.name[LTTNG_SYM_NAME_LEN - 1] = '\0'; - ev.instrumentation = LTTNG_KERNEL_NOOP; - chan->sc_table[i] = ltt_event_create(chan, &ev, filter); - if (!chan->sc_table[i]) { - /* - * If something goes wrong in event registration - * after the first one, we have no choice but to - * leave the previous events in there, until - * deleted by session teardown. - */ - return -EINVAL; - } - } - ret = tracepoint_probe_register("syscall_entry", - (void *) syscall_entry_probe, chan); - return ret; -} - -/* - * Only called at session destruction. - */ -int lttng_syscalls_unregister(struct ltt_channel *chan) -{ - int ret; - - if (!chan->sc_table) - return 0; - ret = tracepoint_probe_unregister("syscall_entry", - (void *) syscall_entry_probe, chan); - if (ret) - return ret; - /* ltt_event destroy will be performed by ltt_session_destroy() */ - kfree(chan->sc_table); - return 0; -} - -static int lttng_syscalls_register_probe(struct lttng_probe_desc *desc) -{ - WARN_ON_ONCE(syscall_probe_desc); - syscall_probe_desc = desc; - return 0; -} - -static void lttng_syscalls_unregister_probe(struct lttng_probe_desc *desc) -{ - WARN_ON_ONCE(!syscall_probe_desc); - syscall_probe_desc = NULL; -} - -#endif /* SYSCALL_DETAIL */ - MODULE_LICENSE("GPL and additional rights"); MODULE_AUTHOR("Mathieu Desnoyers "); -MODULE_DESCRIPTION("LTTng sched probes"); +MODULE_DESCRIPTION("LTTng generic syscall probes"); -- 2.34.1