[PATCH RFT v3] scripts: define _GNU_SOURCE for all source files

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

musl doesn't define loff_t, unless _GNU_SOURCE is defined, which
we don't do everywhere and glibc didn't mind.

This led to build errors with musl when code makes it into
scripts/ that uses loff_t. This was already fixed once e.g. in commit
c0d065fb0aa0 ("scripts: bareboximd: remove usage of loff_t").

To fix this issue for good, let's define _GNU_SOURCE globally for all files.

Link: https://lore.kernel.org/all/CAMKF1sqX7gFCEH78fHS+jkUSieL5crAU_RwAUO-daJL0u+fj0g@mail.gmail.com/
Fixes: 5171f4d0696f ("scripts: implement read_fd and pread_full for tools")
Suggested-by: Khem Raj <raj.khem@gmail.com>
Reported-by: Enrico Jörns <ejo@pengutronix.de>
Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
---
@Enrico, please give this a test. I only tested against glibc.

v2 -> v3:
  - set _GNU_SOURCE instead of defining loff_t (Khem)
v1 -> v2:
  - include <linux/types.h> from scripts/common.h (Enrico)
v2 was here:
  https://lore.barebox.org/barebox/20250127143146.2965544-1-a.fatoum@pengutronix.de/T/#u
---
 scripts/Makefile         | 4 ++++
 scripts/imx/imx-image.c  | 1 -
 scripts/imx/imx.c        | 1 -
 scripts/imx9image.c      | 1 -
 scripts/kernel-install.c | 1 -
 scripts/keytoc.c         | 1 -
 scripts/kwbimage.c       | 1 -
 7 files changed, 4 insertions(+), 6 deletions(-)

diff --git a/scripts/Makefile b/scripts/Makefile
index a780f05bd90f..c1a5b4b74775 100644
--- a/scripts/Makefile
+++ b/scripts/Makefile
@@ -60,6 +60,10 @@ rk-usb-loader-target-userldlibs += `$(CROSS_PKG_CONFIG) --libs libusb-1.0`
 
 userccflags += -I $(srctree)/$(src)/include -isystem $(srctree)/scripts/include
 
+# We need to explicitly set the macro to empty, otherwise it's defined to =1
+userccflags += -D_GNU_SOURCE=""
+KBUILD_HOSTCFLAGS += -D_GNU_SOURCE=""
+
 subdir-y			+= mod
 subdir-y			+= imx
 subdir-$(CONFIG_DTC)		+= dtc
diff --git a/scripts/imx/imx-image.c b/scripts/imx/imx-image.c
index 9ba60dbc5b4c..a8ac34091fc0 100644
--- a/scripts/imx/imx-image.c
+++ b/scripts/imx/imx-image.c
@@ -1,7 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0-or-later
 // SPDX-FileCopyrightText: 2013 Sascha Hauer, Pengutronix
 
-#define _GNU_SOURCE
 #include <stdio.h>
 #include <unistd.h>
 #include <getopt.h>
diff --git a/scripts/imx/imx.c b/scripts/imx/imx.c
index 5ccc116cfe3c..26027f0f3548 100644
--- a/scripts/imx/imx.c
+++ b/scripts/imx/imx.c
@@ -1,7 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0-or-later
 // SPDX-FileCopyrightText: 2016 Sascha Hauer, Pengutronix
 
-#define _GNU_SOURCE
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/scripts/imx9image.c b/scripts/imx9image.c
index 53fb879882e8..61b7cc943f00 100644
--- a/scripts/imx9image.c
+++ b/scripts/imx9image.c
@@ -8,7 +8,6 @@
  *
  */
 
-#define _GNU_SOURCE
 #include <stdio.h>
 #include <string.h>
 #include <stdlib.h>
diff --git a/scripts/kernel-install.c b/scripts/kernel-install.c
index d943f0288f39..240122f2d224 100644
--- a/scripts/kernel-install.c
+++ b/scripts/kernel-install.c
@@ -72,7 +72,6 @@
  *
  */
 
-#define _GNU_SOURCE
 #include <stdio.h>
 #include <string.h>
 #include <stdlib.h>
diff --git a/scripts/keytoc.c b/scripts/keytoc.c
index c60df8a5f017..2a0d7c415bf0 100644
--- a/scripts/keytoc.c
+++ b/scripts/keytoc.c
@@ -9,7 +9,6 @@
  *
  */
 #pragma GCC diagnostic ignored "-Wdeprecated-declarations"
-#define _GNU_SOURCE
 #include <stdio.h>
 #include <string.h>
 #include <time.h>
diff --git a/scripts/kwbimage.c b/scripts/kwbimage.c
index 370c54c983b5..c58c80e5415f 100644
--- a/scripts/kwbimage.c
+++ b/scripts/kwbimage.c
@@ -30,7 +30,6 @@
  * headers in v1 images
  */
 
-#define _GNU_SOURCE
 #include <stdio.h>
 #include <stdint.h>
 #include <sys/types.h>
-- 
2.39.5