nss: Fix warnings generated by getcwd

getcwd() conforms to POSIX.1-2001 which leaves the behaviour when the
buf argument is NULL, undefined. This makes gcc 10+ throw the following
warning:

argument 1 is null but the corresponding size argument 2 value is 4096

Initially, this was fixed by disabling NSS_ENABLE_WERROR. This patch
re-enables NSS_ENABLE_WERROR (by leaving it to its default value) and
takes advantage of the existing functionality in nss that wraps the
getcwd call into a function making sure that the buf argument is always
properly allocated.

Signed-off-by: Andrei Gherzan <andrei.gherzan@huawei.com>
Signed-off-by: Armin Kuster <akuster808@gmail.com>

1 files changed, 5 insertions, 1 deletions

diff --git a/meta-oe/recipes-support/nss/nss_3.51.1.bb b/meta-oe/recipes-support/nss/nss_3.51.1.bb
index 3e3c3a3fdf..0e127975b4 100644
--- a/meta-oe/recipes-support/nss/nss_3.51.1.bb
+++ b/meta-oe/recipes-support/nss/nss_3.51.1.bb
@@ -62,7 +62,6 @@ do_configure_prepend_libc-musl () {
 do_compile_prepend_class-native() {
     export NSPR_INCLUDE_DIR=${STAGING_INCDIR_NATIVE}/nspr
     export NSPR_LIB_DIR=${STAGING_LIBDIR_NATIVE}
-    export NSS_ENABLE_WERROR=0
 }
 
 do_compile_prepend_class-nativesdk() {
@@ -81,6 +80,11 @@ do_compile() {
     export NATIVE_CC="${BUILD_CC}"
     # Additional defines needed on Centos 7
     export NATIVE_FLAGS="${BUILD_CFLAGS} -DLINUX -Dlinux"
+
+    # POSIX.1-2001 states that the behaviour of getcwd() when passing a null
+    # pointer as the buf argument, is unspecified.
+    export NATIVE_FLAGS="${NATIVE_FLAGS} -DGETCWD_CANT_MALLOC"
+
     export BUILD_OPT=1
 
     export FREEBL_NO_DEPEND=1