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 7c85cff4a78df07fbce2c276a855eba63d5be395..6a26e49982ffa0286184c9131577d0ee83bef0ad 100644 (file)
--- 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 16b4d4f59437c4a982e4e6bae307d314cf341415..b89590dbde01c44d402979afc27d045ea01a0fab 100644 (file)
--- 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 3c7c34df48d6c23b62c43b14e9908d7fb0f763e3..6cf301dcd04488b1a9f02ce79584e5cf0c445dea 100644 (file)
--- 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 0adaa75385b55f3472b783a75c520e8d04c228b8..2c29a45ca3a4ce569140553480bf804020130876 100644 (file)
--- 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 8d87539a47ac25b05a8e86d239422a1af8a81dc2..9d6d60c404f885a6388969962356940c4a870319 100644 (file)
--- 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 */