X-Git-Url: http://git.liburcu.org/?a=blobdiff_plain;f=lttng-syscalls.c;h=40bf9575ddbb071dc923542803e74a9d1e88437e;hb=2a153251e0f4b17ed9b459678bff62961b825a70;hp=c0550ab0d08b692c50fa1b205b0566a96eca9575;hpb=177b36924b27f47d604bcdd8e363bb401286fbb7;p=lttng-modules.git

diff --git a/lttng-syscalls.c b/lttng-syscalls.c
index c0550ab0..40bf9575 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_unknown.h"
 
 #undef TP_MODULE_OVERRIDE
-#undef TP_PROBE_CB
 #undef LTTNG_PACKAGE_BUILD
 #undef CREATE_TRACE_POINTS
 
@@ -68,19 +77,39 @@ static struct trace_syscall_entry sc_table[] = {
 
 #undef CREATE_SYSCALL_TABLE
 
+static void syscall_entry_unknown(struct ltt_channel *chan,
+	struct pt_regs *regs, unsigned int id)
+{
+	unsigned long args[UNKNOWN_SYSCALL_NRARGS];
+	struct ltt_event *event;
+
+	event = chan->sc_unknown;
+	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)))
-		return;
-	entry = &sc_table[id];
-	if (unlikely(!entry->func))
+	if (unlikely(is_compat_task() || id >= ARRAY_SIZE(sc_table))) {
+		syscall_entry_unknown(chan, regs, id);
 		return;
+	}
 	event = chan->sc_table[id];
-	WARN_ON_ONCE(!event);
+	if (unlikely(!event)) {
+		syscall_entry_unknown(chan, regs, id);
+		return;
+	}
+	entry = &sc_table[id];
+	WARN_ON_ONCE(!entry);
 
 	switch (entry->nrargs) {
 	case 0:
@@ -185,13 +214,47 @@ int lttng_syscalls_register(struct ltt_channel *chan, void *filter)
 			return -ENOMEM;
 	}
 
+	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_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;
+		}
+	}
+
 	/* 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)
+		if (!desc) {
+			/* Unknown syscall */
 			continue;
+		}
 		/*
 		 * Skip those already populated by previous failed
 		 * register for this channel.
@@ -216,6 +279,19 @@ int lttng_syscalls_register(struct ltt_channel *chan, void *filter)
 	}
 	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;
 }
 
@@ -228,6 +304,11 @@ 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)