[PATCH v2] sandbox: lds: fix "ELF has a LOAD segment with RWX permissions" warning

[Ahmad Fatoum <a.fatoum@pengutronix.de>]

With binutils 2.39+, the barebox build started emitting this warning.
On platforms other than sandbox, we disable this warning by passing --no-warn-rwx
to ld as we don't care for ELF attributes as they aren't used anyway.

On sandbox, however, the ELF attributes matter, so disabling the warning
completely felt wrong. Looking more into it now, we can mark the
.barebox_rodata section in the linker file snippet we have in sandbox as
READONLY and the warning disappears, so let's do that instead.

Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
---
v1 -> v2:
  - add fallback for earlier binutils that don't know about READONLY.
---
 arch/sandbox/board/barebox.lds.S  | 2 +-
 include/asm-generic/barebox.lds.h | 5 +++++
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/arch/sandbox/board/barebox.lds.S b/arch/sandbox/board/barebox.lds.S
index ab2801f3d207..de8552dba0ac 100644
--- a/arch/sandbox/board/barebox.lds.S
+++ b/arch/sandbox/board/barebox.lds.S
@@ -5,7 +5,7 @@
 SECTIONS
 {
 	. = ALIGN(64);
-	.barebox_rodata : {
+	.barebox_rodata (READONLY) : {
 		RO_DATA_SECTION
 	}
 }
diff --git a/include/asm-generic/barebox.lds.h b/include/asm-generic/barebox.lds.h
index d3736ebaed59..9af874b2262b 100644
--- a/include/asm-generic/barebox.lds.h
+++ b/include/asm-generic/barebox.lds.h
@@ -171,3 +171,8 @@ CONFIG_ARCH_BAREBOX_MAX_PBL_SIZE < CONFIG_BAREBOX_MAX_PBL_SIZE
 	ASSERT(_barebox_pbl_size < MAX_PBL_SIZE, "Barebox pbl size > ") \
 	ASSERT(_barebox_pbl_size < MAX_PBL_SIZE, __stringify(MAX_PBL_SIZE)) \
 
+#if defined(__GNUC__) && __GNUC__ >= 11
+#define READONLY READONLY
+#else
+#define READONLY
+#endif
-- 
2.39.2