From: Francis Giraldeau <francis.giraldeau@gmail.com>
Date: Wed, 17 Jul 2013 21:06:23 +0000 (-0400)
Subject: Add kernel and userspace callstack event context
X-Git-Url: http://git.efficios.com/?p=lttng-tools.git;a=commitdiff_plain;h=373148e9cedd5ec0b2302f4afe3ecd543e405f4f

Add kernel and userspace callstack event context

LTTng callstack context. The callstack context can be added to any kernel
channel. It records either the kernel or the userspace callstack, up to a
max depth. The context is a CTF sequence, such that it uses only the space
required for the number of callstack entries.

The symbol name resolution is left to the trace reader.

Signed-off-by: Francis Giraldeau <francis.giraldeau@gmail.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Francis Deslauriers <francis.deslauriers@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
---

diff --git a/configure.ac b/configure.ac
index 7c85cff4a..6a26e4998 100644
--- a/configure.ac
+++ b/configure.ac
@@ -955,6 +955,51 @@ AS_IF([test x$build_lib_relayd = xyes],
       ]
 )
 
+# Find arch type
+AS_CASE([$host_cpu],
+        [k1om], [ARCHTYPE="x86"],
+        [i386], [ARCHTYPE="x86"],
+        [i486], [ARCHTYPE="x86"],
+        [i586], [ARCHTYPE="x86"],
+        [i686], [ARCHTYPE="x86"],
+        [amd64], [ARCHTYPE="x86"],
+        [x86_64], [ARCHTYPE="x86"],
+        [powerpc], [ARCHTYPE="ppc"],
+        [ppc64], [ARCHTYPE="ppc"],
+        [powerpc64], [ARCHTYPE="ppc"],
+        [powerpc64le], [ARCHTYPE="ppc"],
+        [ppc], [ARCHTYPE="ppc"],
+        [s390], [ARCHTYPE="s390"],
+        [s390x], [ARCHTYPE="s390"],
+        [sparc], [ARCHTYPE="sparc64"],
+        [sparc64], [ARCHTYPE="sparc64"],
+        [alpha*], [ARCHTYPE="alpha"],
+        [ia64], [ARCHTYPE="ia64"],
+        [arm*], [ARCHTYPE="arm"],
+        [aarch64*], [ARCHTYPE="aarch64"],
+        [mips*], [ARCHTYPE="mips"],
+        [nios2*], [ARCHTYPE="nios2"],
+        [tile*], [ARCHTYPE="tile"],
+        [hppa*], [ARCHTYPE="hppa"],
+        [m68k], [ARCHTYPE="m68k"],
+        [riscv*], [ARCHTYPE="riscv"],
+        [ARCHTYPE="unknown"]
+)
+
+AC_SUBST(ARCHTYPE)
+
+AH_TEMPLATE([HAVE_MODULES_USERSPACE_CALLSTACK_CONTEXT], [Define if you have LTTng-modules userspace callstack tracing support])
+AC_MSG_CHECKING([for architecture support of userspace callstack tracing from the kernel])
+AS_IF([test "x$ARCHTYPE" = "xx86"],[
+        # Userspace callstack capture is only supported by the Linux kernel on x86.
+        AC_MSG_RESULT([yes])
+        have_modules_userspace_callstack_context=yes
+        AC_DEFINE([HAVE_MODULES_USERSPACE_CALLSTACK_CONTEXT], [1])
+], [
+        AC_MSG_RESULT([no])
+        have_modules_userspace_callstack_context=no
+])
+AM_CONDITIONAL([HAVE_MODULES_USERSPACE_CALLSTACK_CONTEXT], [test x$have_modules_userspace_callstack_context != xno])
 
 # Export binaries build conditions.
 AM_CONDITIONAL([BUILD_BIN_LTTNG], [test x$enable_bin_lttng != xno])
diff --git a/include/lttng/event.h b/include/lttng/event.h
index 16b4d4f59..b89590dbd 100644
--- a/include/lttng/event.h
+++ b/include/lttng/event.h
@@ -142,6 +142,8 @@ enum lttng_event_context_type {
 	LTTNG_EVENT_CONTEXT_PREEMPTIBLE		= 17,
 	LTTNG_EVENT_CONTEXT_NEED_RESCHEDULE	= 18,
 	LTTNG_EVENT_CONTEXT_MIGRATABLE		= 19,
+	LTTNG_EVENT_CONTEXT_CALLSTACK_KERNEL	= 20,
+	LTTNG_EVENT_CONTEXT_CALLSTACK_USER	= 21, /* Supported on x86_32 and x86_64 only. */
 };
 
 enum lttng_event_field_type {
diff --git a/src/bin/lttng-sessiond/context.c b/src/bin/lttng-sessiond/context.c
index 3c7c34df4..6cf301dcd 100644
--- a/src/bin/lttng-sessiond/context.c
+++ b/src/bin/lttng-sessiond/context.c
@@ -259,6 +259,12 @@ int context_kernel_add(struct ltt_kernel_session *ksession,
 	case LTTNG_EVENT_CONTEXT_MIGRATABLE:
 		kctx->ctx.ctx = LTTNG_KERNEL_CONTEXT_MIGRATABLE;
 		break;
+	case LTTNG_EVENT_CONTEXT_CALLSTACK_KERNEL:
+		kctx->ctx.ctx = LTTNG_KERNEL_CONTEXT_CALLSTACK_KERNEL;
+		break;
+	case LTTNG_EVENT_CONTEXT_CALLSTACK_USER:
+		kctx->ctx.ctx = LTTNG_KERNEL_CONTEXT_CALLSTACK_USER;
+		break;
 	default:
 		ret = LTTNG_ERR_KERN_CONTEXT_FAIL;
 		goto error;
diff --git a/src/bin/lttng/commands/add_context.c b/src/bin/lttng/commands/add_context.c
index 0adaa7538..2c29a45ca 100644
--- a/src/bin/lttng/commands/add_context.c
+++ b/src/bin/lttng/commands/add_context.c
@@ -84,6 +84,8 @@ enum context_type {
 	CONTEXT_PREEMPTIBLE  = 17,
 	CONTEXT_NEED_RESCHEDULE = 18,
 	CONTEXT_MIGRATABLE   = 19,
+	CONTEXT_CALLSTACK_KERNEL = 20,
+	CONTEXT_CALLSTACK_USER = 21,
 };
 
 /*
@@ -240,6 +242,10 @@ const struct ctx_opts {
 	{ "preemptible", CONTEXT_PREEMPTIBLE },
 	{ "need_reschedule", CONTEXT_NEED_RESCHEDULE },
 	{ "migratable", CONTEXT_MIGRATABLE },
+	{ "callstack-kernel", CONTEXT_CALLSTACK_KERNEL },
+#if HAVE_MODULES_USERSPACE_CALLSTACK_CONTEXT
+	{ "callstack-user", CONTEXT_CALLSTACK_USER },
+#endif
 
 	/* Perf options */
 
diff --git a/src/common/lttng-kernel.h b/src/common/lttng-kernel.h
index 8d87539a4..9d6d60c40 100644
--- a/src/common/lttng-kernel.h
+++ b/src/common/lttng-kernel.h
@@ -58,6 +58,8 @@ enum lttng_kernel_context_type {
 	LTTNG_KERNEL_CONTEXT_PREEMPTIBLE    = 13,
 	LTTNG_KERNEL_CONTEXT_NEED_RESCHEDULE = 14,
 	LTTNG_KERNEL_CONTEXT_MIGRATABLE     = 15,
+	LTTNG_KERNEL_CONTEXT_CALLSTACK_KERNEL = 16,
+	LTTNG_KERNEL_CONTEXT_CALLSTACK_USER   = 17,
 };
 
 /* Perf counter attributes */