lttng-ust_0.12.bb: Fix compilation on uclibc

We provide alternative implementation of sched_getcpu()
when compiling for uclibc

(From OE-Core rev: 03f442250579a392b49b54648840fbeb7c0a0142)

Signed-off-by: Khem Raj <raj.khem@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/recipes-kernel/lttng/lttng-ust/uclibc-sched_getcpu.patch

@@ -0,0 +1,50 @@
+uClibc does not have sched_getcpu() implemented. So we create a wrapper
+to getcpu syscall when compiling for uclibc.
+
+So far execinfo.h does not exist on uclibc but it turns out to be that
+this header is not needed even in eglibc case so it can be removed
+
+Signed-off-by: Khem Raj <raj.khem@gmail.com>
+
+Upstream-status: Pending
+
+Index: ust-0.12/libust/tracer.h
+===================================================================
+--- ust-0.12.orig/libust/tracer.h
++++ ust-0.12/libust/tracer.h
+@@ -342,14 +342,22 @@ static __inline__ void ltt_write_trace_h
+ 	header->start_freq = trace->start_freq;
+ 	header->freq_scale = trace->freq_scale;
+ }
+-
++#ifdef __UCLIBC__
++#define sched_getcpu(cpu, node, cache) syscall(__NR_getcpu, cpu, node, cache)
++#endif
+ #ifndef UST_VALGRIND
+ 
+ static __inline__ int ust_get_cpu(void)
+ {
+ 	int cpu;
+ 
++#ifdef __UCLIBC__
++	int c, s;
++	s = syscall(__NR_getcpu, &c, NULL, NULL);
++	cpu = (s == -1) ? s : c;
++#else
+ 	cpu = sched_getcpu();
++#endif
+ 	if (likely(cpu >= 0))
+ 		return cpu;
+ 	/*
+Index: ust-0.12/libustcomm/ustcomm.c
+===================================================================
+--- ust-0.12.orig/libustcomm/ustcomm.c
++++ ust-0.12/libustcomm/ustcomm.c
+@@ -31,7 +31,6 @@
+ #include <stdio.h>
+ #include <stdlib.h>
+ #include <string.h>
+-#include <execinfo.h>
+ 
+ #include "ustcomm.h"
+ #include "usterr.h"

meta/recipes-kernel/lttng/lttng-ust_0.12.bb

@@ -12,7 +12,9 @@ DEPENDS = "liburcu"
 
 PR = "r0"
 
-SRC_URI = "http://lttng.org/files/ust/releases/ust-${PV}.tar.gz"
+SRC_URI = "http://lttng.org/files/ust/releases/ust-${PV}.tar.gz \
+           file://uclibc-sched_getcpu.patch \
+          "
 
 SRC_URI[md5sum] = "fae6e324a56016658c5b83ec14ba0043"
 SRC_URI[sha256sum] = "215b05f47d0c9e3a2934926a7d14fa9c67025db917c3a1f641df40b08314ab0c"