X-Git-Url: http://git.lttng.org./?a=blobdiff_plain;f=lttng-syscalls.c;h=5135dfe2f88501f47c4436df3b42f878cbb6b800;hb=49c50022873702bca7c7589e82c1addee410690c;hp=09e48c4573c4727c11dba36e7f13c20366c45f41;hpb=f7bdf4db0b992946342dc845c7369e9cdca46559;p=lttng-modules.git

diff --git a/lttng-syscalls.c b/lttng-syscalls.c
index 09e48c45..5135dfe2 100644
--- a/lttng-syscalls.c
+++ b/lttng-syscalls.c
@@ -10,11 +10,19 @@
 
 #include <linux/module.h>
 #include <linux/slab.h>
+#include <linux/compat.h>
 #include <asm/ptrace.h>
 #include <asm/syscall.h>
 
 #include "ltt-events.h"
 
+#ifndef CONFIG_COMPAT
+static inline int is_compat_task(void)
+{
+	return 0;
+}
+#endif
+
 static void syscall_entry_probe(void *__data, struct pt_regs *regs, long id);
 
 /*
@@ -29,17 +37,18 @@ static void syscall_entry_probe(void *__data, struct pt_regs *regs, long id);
  */
 #define LTTNG_PACKAGE_BUILD
 #define CREATE_TRACE_POINTS
+#define TP_MODULE_OVERRIDE
+#define TRACE_INCLUDE_PATH ../instrumentation/syscalls/headers
 
 /* 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_integers.h"
+#include "instrumentation/syscalls/headers/syscalls_pointers.h"
+#undef TP_PROBE_CB
 
-#include "instrumentation/syscalls/headers/syscalls.h"
+#include "instrumentation/syscalls/headers/syscalls_unknown.h"
 
 #undef TP_MODULE_OVERRIDE
-#undef TP_PROBE_CB
 #undef LTTNG_PACKAGE_BUILD
 #undef CREATE_TRACE_POINTS
 
@@ -50,10 +59,6 @@ struct trace_syscall_entry {
 	unsigned int nrargs;
 };
 
-static int sc_table_desc_filled;
-
-#define CREATE_SYSCALL_TABLE
-
 #undef TRACE_SYSCALL_TABLE
 #define TRACE_SYSCALL_TABLE(_template, _name, _nr, _nrargs)	\
 	[ _nr ] = {						\
@@ -63,25 +68,65 @@ static int sc_table_desc_filled;
 		.desc = &__event_desc___##_name,		\
 	},
 
-static struct trace_syscall_entry sc_table[] = {
-#include "instrumentation/syscalls/headers/syscalls.h"
+#define CREATE_SYSCALL_TABLE
+
+static const struct trace_syscall_entry sc_table[] = {
+#include "instrumentation/syscalls/headers/syscalls_integers.h"
+#include "instrumentation/syscalls/headers/syscalls_pointers.h"
+};
+
+/* Create compatibility syscall table */
+static const struct trace_syscall_entry compat_sc_table[] = {
+#include "instrumentation/syscalls/headers/compat_syscalls_integers.h"
+#include "instrumentation/syscalls/headers/compat_syscalls_pointers.h"
 };
 
 #undef CREATE_SYSCALL_TABLE
 
+static void syscall_entry_unknown(struct ltt_event *event,
+	struct pt_regs *regs, unsigned int id)
+{
+	unsigned long args[UNKNOWN_SYSCALL_NRARGS];
+
+	syscall_get_arguments(current, regs, 0, UNKNOWN_SYSCALL_NRARGS, args);
+	__event_probe__sys_unknown(event, id, args);
+}
+
+/*
+ * Currently, given that the kernel syscall metadata extraction only
+ * considers native system calls (not 32-bit compability ones), we
+ * fall-back on the "unknown" system call tracing for 32-bit compat.
+ */
 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)))
+	struct ltt_event *event, *unknown_event;
+	const struct trace_syscall_entry *table, *entry;
+	size_t table_len;
+
+	if (unlikely(is_compat_task())) {
+		table = compat_sc_table;
+		table_len = ARRAY_SIZE(compat_sc_table);
+		unknown_event = chan->sc_compat_unknown;
+	} else {
+		table = sc_table;
+		table_len = ARRAY_SIZE(sc_table);
+		unknown_event = chan->sc_unknown;
+	}
+	if (unlikely(id >= table_len)) {
+		syscall_entry_unknown(unknown_event, regs, id);
 		return;
-	entry = &sc_table[id];
-	if (unlikely(!entry->func))
+	}
+	if (unlikely(is_compat_task()))
+		event = chan->compat_sc_table[id];
+	else
+		event = chan->sc_table[id];
+	if (unlikely(!event)) {
+		syscall_entry_unknown(unknown_event, regs, id);
 		return;
-	event = chan->sc_table[id];
-	WARN_ON_ONCE(!event);
+	}
+	entry = &table[id];
+	WARN_ON_ONCE(!entry);
 
 	switch (entry->nrargs) {
 	case 0:
@@ -171,41 +216,34 @@ static void syscall_entry_probe(void *__data, struct pt_regs *regs, long id)
 	}
 }
 
-int lttng_syscalls_register(struct ltt_channel *chan, void *filter)
+static
+int fill_table(const struct trace_syscall_entry *table, size_t table_len,
+	struct ltt_event **chan_table, struct ltt_channel *chan, void *filter)
 {
 	unsigned int i;
-	int ret;
-
-	wrapper_vmalloc_sync_all();
-
-	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++) {
+	for (i = 0; i < table_len; i++) {
 		struct lttng_kernel_event ev;
-		const struct lttng_event_desc *desc = sc_table[i].desc;
+		const struct lttng_event_desc *desc = table[i].desc;
 
-		if (!desc)
+		if (!desc) {
+			/* Unknown syscall */
 			continue;
+		}
 		/*
 		 * Skip those already populated by previous failed
 		 * register for this channel.
 		 */
-		if (chan->sc_table[i])
+		if (chan_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]) {
+		chan_table[i] = ltt_event_create(chan, &ev, filter,
+						desc);
+		if (!chan_table[i]) {
 			/*
 			 * If something goes wrong in event registration
 			 * after the first one, we have no choice but to
@@ -215,8 +253,105 @@ int lttng_syscalls_register(struct ltt_channel *chan, void *filter)
 			return -EINVAL;
 		}
 	}
+	return 0;
+}
+
+int lttng_syscalls_register(struct ltt_channel *chan, void *filter)
+{
+	int ret;
+
+	wrapper_vmalloc_sync_all();
+
+	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;
+	}
+
+#ifdef CONFIG_COMPAT
+	if (!chan->compat_sc_table) {
+		/* create syscall table mapping compat syscall to events */
+		chan->compat_sc_table = kzalloc(sizeof(struct ltt_event *)
+					* ARRAY_SIZE(compat_sc_table), GFP_KERNEL);
+		if (!chan->compat_sc_table)
+			return -ENOMEM;
+	}
+#endif
+	if (!chan->sc_unknown) {
+		struct lttng_kernel_event ev;
+		const struct lttng_event_desc *desc =
+			&__event_desc___sys_unknown;
+
+		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_unknown = ltt_event_create(chan, &ev, filter,
+						    desc);
+		if (!chan->sc_unknown) {
+			return -EINVAL;
+		}
+	}
+
+	if (!chan->sc_compat_unknown) {
+		struct lttng_kernel_event ev;
+		const struct lttng_event_desc *desc =
+			&__event_desc___compat_sys_unknown;
+
+		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_compat_unknown = ltt_event_create(chan, &ev, filter,
+							   desc);
+		if (!chan->sc_compat_unknown) {
+			return -EINVAL;
+		}
+	}
+
+	if (!chan->sc_exit) {
+		struct lttng_kernel_event ev;
+		const struct lttng_event_desc *desc =
+			&__event_desc___exit_syscall;
+
+		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_exit = ltt_event_create(chan, &ev, filter,
+						 desc);
+		if (!chan->sc_exit) {
+			return -EINVAL;
+		}
+	}
+
+	ret = fill_table(sc_table, ARRAY_SIZE(sc_table),
+			chan->sc_table, chan, filter);
+	if (ret)
+		return ret;
+#ifdef CONFIG_COMPAT
+	ret = fill_table(compat_sc_table, ARRAY_SIZE(compat_sc_table),
+			chan->compat_sc_table, chan, filter);
+	if (ret)
+		return ret;
+#endif
 	ret = tracepoint_probe_register("sys_enter",
 			(void *) syscall_entry_probe, chan);
+	if (ret)
+		return ret;
+	/*
+	 * We change the name of sys_exit tracepoint due to namespace
+	 * conflict with sys_exit syscall entry.
+	 */
+	ret = tracepoint_probe_register("sys_exit",
+			(void *) __event_probe__exit_syscall,
+			chan->sc_exit);
+	if (ret) {
+		WARN_ON_ONCE(tracepoint_probe_unregister("sys_enter",
+			(void *) syscall_entry_probe, chan));
+	}
 	return ret;
 }
 
@@ -229,11 +364,19 @@ int lttng_syscalls_unregister(struct ltt_channel *chan)
 
 	if (!chan->sc_table)
 		return 0;
+	ret = tracepoint_probe_unregister("sys_exit",
+			(void *) __event_probe__exit_syscall,
+			chan->sc_exit);
+	if (ret)
+		return ret;
 	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);
+#ifdef CONFIG_COMPAT
+	kfree(chan->compat_sc_table);
+#endif
 	return 0;
 }