musl: Create ld.so as a relative symlink

We have rootfs intercepts which fail on musl because ld.so on musl is an
absolute symlink to /usr/lib/libc.so and then it fails to load when run
with qemu user mode.

Fixes rootfs failures like

WARNING: The postinstall intercept hook 'update_pixbuf_cache' failed
(exit code: 255)! See log for details!
WARNING: The postinstalls for the following packages will be postponed
for first boot: libgdk-pixbuf-2.0-loader-jpeg li
bgdk-pixbuf-2.0-loader-png libgdk-pixbuf-2.0-loader-gif
libgdk-pixbuf-2.0-loader-xpm
WARNING: [log_check] core-image-sato: found a warning message in the
logfile (keyword 'WARNING:'):
[log_check] WARNING: The postinstall intercept hook
'update_pixbuf_cache' failed (exit code: 255)! See log for details!

WARNING: [log_check] core-image-sato: found a warning message in the
logfile (keyword 'WARNING:'):
[log_check] WARNING: The postinstalls for the following packages will be
postponed for first boot: libgdk-pixbuf-2.0-lo
ader-jpeg libgdk-pixbuf-2.0-loader-png libgdk-pixbuf-2.0-loader-gif
libgdk-pixbuf-2.0-loader-xpm

(From OE-Core rev: d48ea3354eff8244e1734fa571bb52c810431b3f)

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

2 files changed, 36 insertions, 1 deletions

diff --git a/meta/recipes-core/musl/files/0001-Make-dynamic-linker-a-relative-symlink-to-libc.patch b/meta/recipes-core/musl/files/0001-Make-dynamic-linker-a-relative-symlink-to-libc.patch
new file mode 100644
index 0000000000..5490b1cba6
--- /dev/null
+++ b/meta/recipes-core/musl/files/0001-Make-dynamic-linker-a-relative-symlink-to-libc.patch
@@ -0,0 +1,34 @@
+From 94c0b97b62125d8bbc92dce0694e387d5b2ad181 Mon Sep 17 00:00:00 2001
+From: Khem Raj <raj.khem@gmail.com>
+Date: Sun, 10 Jan 2016 12:14:02 -0800
+Subject: [PATCH] Make dynamic linker a relative symlink to libc
+
+absolute symlink into $(libdir) fails to load in a cross build
+environment, especially when executing qemu in usermode to run target
+applications, which cross build systems often do, since not everything
+can be computed during cross builds, qemu in usermode often comes to aid
+in such situations to feed into cross builds.
+
+Signed-off-by: Khem Raj <raj.khem@gmail.com>
+---
+Upstream-Status: Pending
+
+ Makefile | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/Makefile b/Makefile
+index b2226fa..0d71f7f 100644
+--- a/Makefile
++++ b/Makefile
+@@ -189,7 +189,7 @@ $(DESTDIR)$(includedir)/%: include/%
+        $(INSTALL) -D -m 644 $< $@
+ 
+ $(DESTDIR)$(LDSO_PATHNAME): $(DESTDIR)$(libdir)/libc.so
+-       $(INSTALL) -D -l $(libdir)/libc.so $@ || true
++       $(INSTALL) -D -l ..$(libdir)/libc.so $@ || true
+ 
+ install-libs: $(ALL_LIBS:lib/%=$(DESTDIR)$(libdir)/%) $(if $(SHARED_LIBS),$(DESTDIR)$(LDSO_PATHNAME),)
+ 
+-- 
+2.7.0
+
diff --git a/meta/recipes-core/musl/musl_git.bb b/meta/recipes-core/musl/musl_git.bb
index 5b94d1fe28..8970307cba 100644
--- a/meta/recipes-core/musl/musl_git.bb
+++ b/meta/recipes-core/musl/musl_git.bb
@@ -10,6 +10,7 @@ PV = "1.1.12+git${SRCPV}"
 # mirror is at git://github.com/kraj/musl.git
 
 SRC_URI = "git://git.musl-libc.org/musl \
+           file://0001-Make-dynamic-linker-a-relative-symlink-to-libc.patch \
           "
 
 S = "${WORKDIR}/git"
@@ -49,7 +50,7 @@ do_install() {
         oe_runmake install DESTDIR='${D}'
 
         install -d ${D}${bindir}
-        ln -s ${libdir}/libc.so ${D}${bindir}/ldd
+        ln -s ../../${libdir}/libc.so ${D}${bindir}/ldd
 }
 
 RDEPENDS_${PN}-dev = "linux-libc-headers-dev"