[Buildroot] [git commit branch/2021.05.x] Config.in: disable Fortify Source for microblaze

[Peter Korsgaard]

commit: https://git.buildroot.net/buildroot/commit/?id=6608f2a3c4f25a5e1fc506b19ecf74517b0b4dc8
branch: https://git.buildroot.net/buildroot/commit/?id=refs/heads/2021.05.x

As reported by Toolchain-builder project [1], the microblaze glibc
toolchain creates a system that doesn't boot when FORTIFY_SOURCE is
enabled: the init process hangs.

Also, hardening features may not be wanted or possible for such
slow soft-core cpus [2].

Note: for completeness, BR2_RELRO_PARTIAL was manually tested and it
does boot.

[1] https://gitlab.com/bootlin/toolchains-builder/-/jobs/1467624500
[2] http://lists.busybox.net/pipermail/buildroot/2021-June/312416.html

Signed-off-by: Romain Naour <romain.naour at gmail.com>
Cc: Thomas Petazzoni <thomas.petazzoni at bootlin.com>
Cc: Giulio Benetti <giulio.benetti at benettiengineering.com>
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout at mind.be>
(cherry picked from commit 2e94aeed1a97f5b66b9a8dc4f0133451b7b7b34f)
Signed-off-by: Peter Korsgaard <peter at korsgaard.com>
---
 Config.in | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/Config.in b/Config.in
index f0616098bf..2501658332 100644
--- a/Config.in
+++ b/Config.in
@@ -840,9 +840,16 @@ endchoice
 comment "RELocation Read Only (RELRO) needs shared libraries"
 	depends on !BR2_SHARED_LIBS
 
+config BR2_FORTIFY_SOURCE_ARCH_SUPPORTS
+	bool
+	default y
+	# Microblaze glibc toolchains don't work with Fortify Source enabled
+	depends on !BR2_microblaze
+
 choice
 	bool "Buffer-overflow Detection (FORTIFY_SOURCE)"
 	default BR2_FORTIFY_SOURCE_1
+	depends on BR2_FORTIFY_SOURCE_ARCH_SUPPORTS
 	depends on BR2_TOOLCHAIN_USES_GLIBC
 	depends on !BR2_OPTIMIZE_0
 	help
@@ -883,6 +890,7 @@ config BR2_FORTIFY_SOURCE_2
 endchoice
 
 comment "Fortify Source needs a glibc toolchain and optimization"
+	depends on BR2_FORTIFY_SOURCE_ARCH_SUPPORTS
 	depends on (!BR2_TOOLCHAIN_USES_GLIBC || BR2_OPTIMIZE_0)
 endmenu