[PATCH 0/3] libfdt: prepare for (U)INT32_MAX addition

[PATCH 0/3] libfdt: prepare for (U)INT32_MAX addition

[Masahiro Yamada]

As you may know, libfdt in the upstream DTC project
added referenced to (U)INT32_MAX.

The kernel code has three files to adjust:

include/linux/libfdt_env.h
arch/powerpc/boot/libfdt_env.h
arch/arm/boot/compressed/libfdt_env.h

Instead of fixing arch/arm/boot/compressed/libfdt_env.h,
it is pretty easy to refactor the ARM decompressor
to reuse <linux/lbifdt_env.h>
So, 2/3 simplifies the Makefile and deletes its own
libfdt_env.h

On the other hand, the PPC boot-wrapper is a can of worms.
I give up refactoring it.
Let's keep it closed, and just update arch/powerpc/boot/libfdt_env.h



Masahiro Yamada (3):
  libfdt: add SPDX-License-Identifier to libfdt wrappers
  ARM: decompressor: simplify libfdt builds
  libfdt: define INT32_MAX and UINT32_MAX in libfdt_env.h

 arch/arm/boot/compressed/.gitignore     |  9 -------
 arch/arm/boot/compressed/Makefile       | 33 +++++++------------------
 arch/arm/boot/compressed/atags_to_fdt.c |  1 +
 arch/arm/boot/compressed/fdt.c          |  2 ++
 arch/arm/boot/compressed/fdt_ro.c       |  2 ++
 arch/arm/boot/compressed/fdt_rw.c       |  2 ++
 arch/arm/boot/compressed/fdt_wip.c      |  2 ++
 arch/arm/boot/compressed/libfdt_env.h   | 22 -----------------
 arch/powerpc/boot/libfdt_env.h          |  2 ++
 include/linux/libfdt_env.h              |  3 +++
 lib/fdt.c                               |  1 +
 lib/fdt_empty_tree.c                    |  1 +
 lib/fdt_ro.c                            |  1 +
 lib/fdt_rw.c                            |  1 +
 lib/fdt_strerror.c                      |  1 +
 lib/fdt_sw.c                            |  1 +
 lib/fdt_wip.c                           |  1 +
 17 files changed, 30 insertions(+), 55 deletions(-)
 create mode 100644 arch/arm/boot/compressed/fdt.c
 create mode 100644 arch/arm/boot/compressed/fdt_ro.c
 create mode 100644 arch/arm/boot/compressed/fdt_rw.c
 create mode 100644 arch/arm/boot/compressed/fdt_wip.c
 delete mode 100644 arch/arm/boot/compressed/libfdt_env.h

-- 
2.17.1

[PATCH 1/3] libfdt: add SPDX-License-Identifier to libfdt wrappers

[Masahiro Yamada]

These are kernel source code even though they are just two-line wrappers.

Files without explicit license information fall back to GPL-2.0-only,
which is the project default.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---

 lib/fdt.c            | 1 +
 lib/fdt_empty_tree.c | 1 +
 lib/fdt_ro.c         | 1 +
 lib/fdt_rw.c         | 1 +
 lib/fdt_strerror.c   | 1 +
 lib/fdt_sw.c         | 1 +
 lib/fdt_wip.c        | 1 +
 7 files changed, 7 insertions(+)

diff --git a/lib/fdt.c b/lib/fdt.c
index 97f20069fc37..041f8922a23c 100644
--- a/lib/fdt.c
+++ b/lib/fdt.c
@@ -1,2 +1,3 @@
+// SPDX-License-Identifier: GPL-2.0-only
 #include <linux/libfdt_env.h>
 #include "../scripts/dtc/libfdt/fdt.c"
diff --git a/lib/fdt_empty_tree.c b/lib/fdt_empty_tree.c
index 5d30c58150ad..452221227bf3 100644
--- a/lib/fdt_empty_tree.c
+++ b/lib/fdt_empty_tree.c
@@ -1,2 +1,3 @@
+// SPDX-License-Identifier: GPL-2.0-only
 #include <linux/libfdt_env.h>
 #include "../scripts/dtc/libfdt/fdt_empty_tree.c"
diff --git a/lib/fdt_ro.c b/lib/fdt_ro.c
index f73c04ea7be4..9f696d19f060 100644
--- a/lib/fdt_ro.c
+++ b/lib/fdt_ro.c
@@ -1,2 +1,3 @@
+// SPDX-License-Identifier: GPL-2.0-only
 #include <linux/libfdt_env.h>
 #include "../scripts/dtc/libfdt/fdt_ro.c"
diff --git a/lib/fdt_rw.c b/lib/fdt_rw.c
index 0c1f0f4a4b13..2a61e9c6dd44 100644
--- a/lib/fdt_rw.c
+++ b/lib/fdt_rw.c
@@ -1,2 +1,3 @@
+// SPDX-License-Identifier: GPL-2.0-only
 #include <linux/libfdt_env.h>
 #include "../scripts/dtc/libfdt/fdt_rw.c"
diff --git a/lib/fdt_strerror.c b/lib/fdt_strerror.c
index 8713e3ff4707..4554e5fdac12 100644
--- a/lib/fdt_strerror.c
+++ b/lib/fdt_strerror.c
@@ -1,2 +1,3 @@
+// SPDX-License-Identifier: GPL-2.0-only
 #include <linux/libfdt_env.h>
 #include "../scripts/dtc/libfdt/fdt_strerror.c"
diff --git a/lib/fdt_sw.c b/lib/fdt_sw.c
index 9ac7e50c76ce..d3345ca399cf 100644
--- a/lib/fdt_sw.c
+++ b/lib/fdt_sw.c
@@ -1,2 +1,3 @@
+// SPDX-License-Identifier: GPL-2.0-only
 #include <linux/libfdt_env.h>
 #include "../scripts/dtc/libfdt/fdt_sw.c"
diff --git a/lib/fdt_wip.c b/lib/fdt_wip.c
index 45b3fc3d3ba1..9674d4c3b115 100644
--- a/lib/fdt_wip.c
+++ b/lib/fdt_wip.c
@@ -1,2 +1,3 @@
+// SPDX-License-Identifier: GPL-2.0-only
 #include <linux/libfdt_env.h>
 #include "../scripts/dtc/libfdt/fdt_wip.c"
-- 
2.17.1

Re: [PATCH 1/3] libfdt: add SPDX-License-Identifier to libfdt wrappers

[Rob Herring]

On Fri, Nov 1, 2019 at 1:19 AM Masahiro Yamada
<yamada.masahiro@socionext.com> wrote:
>
> These are kernel source code even though they are just two-line wrappers.
>
> Files without explicit license information fall back to GPL-2.0-only,
> which is the project default.

That is true and these are kernel only files, but given they are just
a wrapper around the .c files, maybe they should have the same
license?

Rob

Re: [PATCH 1/3] libfdt: add SPDX-License-Identifier to libfdt wrappers

[Masahiro Yamada]

Hi Rob,
(+CC: David Daney)

On Mon, Nov 4, 2019 at 11:00 PM Rob Herring <robh+dt@kernel.org> wrote:
>
> On Fri, Nov 1, 2019 at 1:19 AM Masahiro Yamada
> <yamada.masahiro@socionext.com> wrote:
> >
> > These are kernel source code even though they are just two-line wrappers.
> >
> > Files without explicit license information fall back to GPL-2.0-only,
> > which is the project default.
>
> That is true and these are kernel only files, but given they are just
> a wrapper around the .c files, maybe they should have the same
> license?


I just thought it at first
but this wraps two files, with different license.

include/linux/libfdt_env.h:  GPLv2 only
scripts/dtc/libfdt/fdt*.c :  GPLv2+ or BSD-2-Clause


Looking at the include/linux/libfdt_env.h,
I thought GPLv2 only would be preferred for
the kernel-specific code.

If you prefer to align with scripts/dtc/libfdt/fdt*.c
I can change it, but I would also respect
the opinion from David Daney, the author of the
following commit:


commit ab25383983fb8d7786696f5371e75e79c3e9a405
Author: David Daney <david.daney@cavium.com>
Date:   Thu Jul 5 18:12:38 2012 +0200

    of/lib: Allow scripts/dtc/libfdt to be used from kernel code



-- 
Best Regards
Masahiro Yamada

[PATCH 2/3] ARM: decompressor: simplify libfdt builds

[Masahiro Yamada]

Copying source files during the build time may not end up with
as clean code as you expect.

lib/fdt*.c simply wrap scripts/dtc/libfdt/fdt*.c, and it works
nicely. Let's follow that approach for the arm decompressor, too.

Add four wrappers, arch/arm/boot/compressed/fdt*.c and remove the
Makefile messes.

Another nice thing is we no longer need to maintain the separate
libfdt_env.h since we can include <linux/libfdt_env.h>, and the
diff stat also looks nice.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---

 arch/arm/boot/compressed/.gitignore     |  9 -------
 arch/arm/boot/compressed/Makefile       | 33 +++++++------------------
 arch/arm/boot/compressed/atags_to_fdt.c |  1 +
 arch/arm/boot/compressed/fdt.c          |  2 ++
 arch/arm/boot/compressed/fdt_ro.c       |  2 ++
 arch/arm/boot/compressed/fdt_rw.c       |  2 ++
 arch/arm/boot/compressed/fdt_wip.c      |  2 ++
 arch/arm/boot/compressed/libfdt_env.h   | 22 -----------------
 8 files changed, 18 insertions(+), 55 deletions(-)
 create mode 100644 arch/arm/boot/compressed/fdt.c
 create mode 100644 arch/arm/boot/compressed/fdt_ro.c
 create mode 100644 arch/arm/boot/compressed/fdt_rw.c
 create mode 100644 arch/arm/boot/compressed/fdt_wip.c
 delete mode 100644 arch/arm/boot/compressed/libfdt_env.h

diff --git a/arch/arm/boot/compressed/.gitignore b/arch/arm/boot/compressed/.gitignore
index 86b2f5d28240..2fdb4885846b 100644
--- a/arch/arm/boot/compressed/.gitignore
+++ b/arch/arm/boot/compressed/.gitignore
@@ -6,12 +6,3 @@ hyp-stub.S
 piggy_data
 vmlinux
 vmlinux.lds
-
-# borrowed libfdt files
-fdt.c
-fdt.h
-fdt_ro.c
-fdt_rw.c
-fdt_wip.c
-libfdt.h
-libfdt_internal.h
diff --git a/arch/arm/boot/compressed/Makefile b/arch/arm/boot/compressed/Makefile
index 9219389bbe61..a0d645c66980 100644
--- a/arch/arm/boot/compressed/Makefile
+++ b/arch/arm/boot/compressed/Makefile
@@ -76,29 +76,23 @@ compress-$(CONFIG_KERNEL_LZMA) = lzma
 compress-$(CONFIG_KERNEL_XZ)   = xzkern
 compress-$(CONFIG_KERNEL_LZ4)  = lz4
 
-# Borrowed libfdt files for the ATAG compatibility mode
-
-libfdt		:= fdt_rw.c fdt_ro.c fdt_wip.c fdt.c
-libfdt_hdrs	:= fdt.h libfdt.h libfdt_internal.h
-
-libfdt_objs	:= $(addsuffix .o, $(basename $(libfdt)))
-
-$(addprefix $(obj)/,$(libfdt) $(libfdt_hdrs)): $(obj)/%: $(srctree)/scripts/dtc/libfdt/%
-	$(call cmd,shipped)
+ifeq ($(CONFIG_ARM_ATAG_DTB_COMPAT),y)
+libfdt_objs = fdt_rw.o fdt_ro.o fdt_wip.o fdt.o atags_to_fdt.o
 
-$(addprefix $(obj)/,$(libfdt_objs) atags_to_fdt.o): \
-	$(addprefix $(obj)/,$(libfdt_hdrs))
+OBJS	+= $(libfdt_objs)
 
-ifeq ($(CONFIG_ARM_ATAG_DTB_COMPAT),y)
-OBJS	+= $(libfdt_objs) atags_to_fdt.o
+# -fstack-protector-strong triggers protection checks in this code,
+# but it is being used too early to link to meaningful stack_chk logic.
+nossp_flags := $(call cc-option, -fno-stack-protector)
+$(foreach o, $(libfdt_objs), \
+	$(eval CFLAGS_$(o) := -I $(srctree)/scripts/dtc/libfdt) $(nossp_flags))
 endif
 
 targets       := vmlinux vmlinux.lds piggy_data piggy.o \
 		 lib1funcs.o ashldi3.o bswapsdi2.o \
 		 head.o $(OBJS)
 
-clean-files += piggy_data lib1funcs.S ashldi3.S bswapsdi2.S \
-		$(libfdt) $(libfdt_hdrs) hyp-stub.S
+clean-files += piggy_data lib1funcs.S ashldi3.S bswapsdi2.S hyp-stub.S
 
 KBUILD_CFLAGS += -DDISABLE_BRANCH_PROFILING
 KBUILD_CFLAGS += $(DISABLE_ARM_SSP_PER_TASK_PLUGIN)
@@ -108,15 +102,6 @@ ORIG_CFLAGS := $(KBUILD_CFLAGS)
 KBUILD_CFLAGS = $(subst -pg, , $(ORIG_CFLAGS))
 endif
 
-# -fstack-protector-strong triggers protection checks in this code,
-# but it is being used too early to link to meaningful stack_chk logic.
-nossp_flags := $(call cc-option, -fno-stack-protector)
-CFLAGS_atags_to_fdt.o := $(nossp_flags)
-CFLAGS_fdt.o := $(nossp_flags)
-CFLAGS_fdt_ro.o := $(nossp_flags)
-CFLAGS_fdt_rw.o := $(nossp_flags)
-CFLAGS_fdt_wip.o := $(nossp_flags)
-
 ccflags-y := -fpic $(call cc-option,-mno-single-pic-base,) -fno-builtin -I$(obj)
 asflags-y := -DZIMAGE
 
diff --git a/arch/arm/boot/compressed/atags_to_fdt.c b/arch/arm/boot/compressed/atags_to_fdt.c
index 330cd3c2eae5..53a60ba066a1 100644
--- a/arch/arm/boot/compressed/atags_to_fdt.c
+++ b/arch/arm/boot/compressed/atags_to_fdt.c
@@ -1,4 +1,5 @@
 // SPDX-License-Identifier: GPL-2.0
+#include <linux/libfdt_env.h>
 #include <asm/setup.h>
 #include <libfdt.h>
 
diff --git a/arch/arm/boot/compressed/fdt.c b/arch/arm/boot/compressed/fdt.c
new file mode 100644
index 000000000000..f8ea7a201ab1
--- /dev/null
+++ b/arch/arm/boot/compressed/fdt.c
@@ -0,0 +1,2 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include "../../../../lib/fdt.c"
diff --git a/arch/arm/boot/compressed/fdt_ro.c b/arch/arm/boot/compressed/fdt_ro.c
new file mode 100644
index 000000000000..93970a4ad5ae
--- /dev/null
+++ b/arch/arm/boot/compressed/fdt_ro.c
@@ -0,0 +1,2 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include "../../../../lib/fdt_ro.c"
diff --git a/arch/arm/boot/compressed/fdt_rw.c b/arch/arm/boot/compressed/fdt_rw.c
new file mode 100644
index 000000000000..f7c6b8b7e01c
--- /dev/null
+++ b/arch/arm/boot/compressed/fdt_rw.c
@@ -0,0 +1,2 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include "../../../../lib/fdt_rw.c"
diff --git a/arch/arm/boot/compressed/fdt_wip.c b/arch/arm/boot/compressed/fdt_wip.c
new file mode 100644
index 000000000000..048d2c7a088d
--- /dev/null
+++ b/arch/arm/boot/compressed/fdt_wip.c
@@ -0,0 +1,2 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include "../../../../lib/fdt_wip.c"
diff --git a/arch/arm/boot/compressed/libfdt_env.h b/arch/arm/boot/compressed/libfdt_env.h
deleted file mode 100644
index b36c0289a308..000000000000
--- a/arch/arm/boot/compressed/libfdt_env.h
+++ /dev/null
@@ -1,22 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef _ARM_LIBFDT_ENV_H
-#define _ARM_LIBFDT_ENV_H
-
-#include <linux/types.h>
-#include <linux/string.h>
-#include <asm/byteorder.h>
-
-#define INT_MAX			((int)(~0U>>1))
-
-typedef __be16 fdt16_t;
-typedef __be32 fdt32_t;
-typedef __be64 fdt64_t;
-
-#define fdt16_to_cpu(x)		be16_to_cpu(x)
-#define cpu_to_fdt16(x)		cpu_to_be16(x)
-#define fdt32_to_cpu(x)		be32_to_cpu(x)
-#define cpu_to_fdt32(x)		cpu_to_be32(x)
-#define fdt64_to_cpu(x)		be64_to_cpu(x)
-#define cpu_to_fdt64(x)		cpu_to_be64(x)
-
-#endif
-- 
2.17.1

[PATCH 3/3] libfdt: define INT32_MAX and UINT32_MAX in libfdt_env.h

[Masahiro Yamada]

The libfdt in the upstream DTC project added references to (U)INT32_MAX
by the following commits:

  Commit 812b1956a076 ("libfdt: Tweak data handling to satisfy Coverity")
  Commit 7fcf8208b8a9 ("libfdt: add fdt_append_addrrange()")

The kernel needs to adjust libfdt_env.h before pulling in the changes.

As for the user-space programs, <stdint.h> defines (U)INT32_MAX along
with (u)int32_t.

In the kernel, on the other hand, we usually use s32 / u32 instead of
(u)int32_t for the fixed-width types.

Accordingly, we already have S32_MAX / U32_MAX for their max values.
So, we won't add (U)INT32_MAX to <linux/limits.h> any more.

Instead, add them to the in-kernel libfdt_env.h to compile fdt.c and
fdt_addresses.c

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---

 arch/powerpc/boot/libfdt_env.h | 2 ++
 include/linux/libfdt_env.h     | 3 +++
 2 files changed, 5 insertions(+)

diff --git a/arch/powerpc/boot/libfdt_env.h b/arch/powerpc/boot/libfdt_env.h
index 2abc8e83b95e..a4a386114ef5 100644
--- a/arch/powerpc/boot/libfdt_env.h
+++ b/arch/powerpc/boot/libfdt_env.h
@@ -6,6 +6,8 @@
 #include <string.h>
 
 #define INT_MAX			((int)(~0U>>1))
+#define INT32_MAX		((u32)~0U)
+#define UINT32_MAX		((s32)(INT_MAX >> 1))
 
 #include "of.h"
 
diff --git a/include/linux/libfdt_env.h b/include/linux/libfdt_env.h
index edb0f0c30904..0bd83bdb2482 100644
--- a/include/linux/libfdt_env.h
+++ b/include/linux/libfdt_env.h
@@ -11,6 +11,9 @@ typedef __be16 fdt16_t;
 typedef __be32 fdt32_t;
 typedef __be64 fdt64_t;
 
+#define INT32_MAX	S32_MAX
+#define UINT32_MAX	U32_MAX
+
 #define fdt32_to_cpu(x) be32_to_cpu(x)
 #define cpu_to_fdt32(x) cpu_to_be32(x)
 #define fdt64_to_cpu(x) be64_to_cpu(x)
-- 
2.17.1