[Buildroot] [PATCH v1] boot/syslinux: fix gcc-10.x compile

Peter Seiderer ps.report at gmx.net
Sun Mar 7 18:14:49 UTC 2021


On Sun,  7 Mar 2021 18:47:53 +0100, Peter Seiderer <ps.report at gmx.net> wrote:

> Add two patches ([1], [2]) taken from the fedora syslinux package ([3]) to fix
> compile/linking with gcc-10.x compiler.
>
> [1] https://src.fedoraproject.org/rpms/syslinux/raw/rawhide/f/0005-Workaround-multiple-definition-of-symbol-errors.patch
> [2] https://src.fedoraproject.org/rpms/syslinux/raw/rawhide/f/0006-Replace-builtin-strlen-that-appears-to-get-optimized.patch
> [3] https://src.fedoraproject.org/rpms/syslinux/tree/rawhide
>

Fixes (part) of:

	https://bugs.busybox.net/show_bug.cgi?id=13576

Regards,
Peter


> Signed-off-by: Peter Seiderer <ps.report at gmx.net>
> ---
> Notes:
>  - possible follow-up would be a buildroot syslinux package version
>    bump to upstream syslinux-6.04-pre4 (or git master), dropping
>    all current patches and importing all current fedora patches
>    instead (and/or check for duplicates)
>  - [4] and [5] advice to use 6.04-pre1 and avoid 6.04-pre2/6.04-pre3
>    and [6] to avoid 6.04-pre4
>  - not manny updates on the official git [7], but a wiki page
>    [8] mentioning various needed patches
>
>   [4] https://www.syslinux.org/archives/2019-August/026497.html
>   [5] https://www.syslinux.org/archives/2019-August/026500.html
>   [6] https://www.syslinux.org/archives/2019-August/026509.html
>   [7] https://repo.or.cz/syslinux.git/shortlog
>   [8] https://wiki.syslinux.org/wiki/index.php?title=Building
> ---
>  ...multiple-definition-of-symbol-errors.patch | 126 ++++++++++++++++++
>  ...strlen-that-appears-to-get-optimized.patch |  42 ++++++
>  2 files changed, 168 insertions(+)
>  create mode 100644 boot/syslinux/0016-Workaround-multiple-definition-of-symbol-errors.patch
>  create mode 100644 boot/syslinux/0017-Replace-builtin-strlen-that-appears-to-get-optimized.patch
>
> diff --git a/boot/syslinux/0016-Workaround-multiple-definition-of-symbol-errors.patch b/boot/syslinux/0016-Workaround-multiple-definition-of-symbol-errors.patch
> new file mode 100644
> index 0000000000..ea91de5cb3
> --- /dev/null
> +++ b/boot/syslinux/0016-Workaround-multiple-definition-of-symbol-errors.patch
> @@ -0,0 +1,126 @@
> +From 16f293d67eace501c98494976030f4319778ebf5 Mon Sep 17 00:00:00 2001
> +From: Merlin Mathesius <mmathesi at redhat.com>
> +Date: Wed, 13 May 2020 08:02:27 -0500
> +Subject: [PATCH] Workaround multiple definition of symbol errors
> +
> +[From https://src.fedoraproject.org/rpms/syslinux/raw/rawhide/f/0005-Workaround-multiple-definition-of-symbol-errors.patch
> + plus adding '-z muldefs' for gpxe]
> +Signed-off-by: Peter Seiderer <ps.report at gmx.net>
> +---
> + com32/cmenu/Makefile           | 2 +-
> + com32/elflink/ldlinux/Makefile | 2 +-
> + com32/gpllib/Makefile          | 2 +-
> + com32/hdt/Makefile             | 2 +-
> + core/Makefile                  | 2 +-
> + dos/Makefile                   | 2 +-
> + efi/Makefile                   | 2 +-
> + gpxe/src/arch/i386/Makefile    | 2 +-
> + 8 files changed, 8 insertions(+), 8 deletions(-)
> +
> +diff --git a/com32/cmenu/Makefile b/com32/cmenu/Makefile
> +index 6bb52316..66cdd649 100644
> +--- a/com32/cmenu/Makefile
> ++++ b/com32/cmenu/Makefile
> +@@ -49,7 +49,7 @@ makeoutputdirs:
> + 	@mkdir -p $(OBJ)/libmenu
> +
> + libmenu/libmenu.elf: $(LIBMENU)
> +-	$(LD) -shared $(LDFLAGS) -soname $(patsubst %.elf,%.c32,$(@F)) \
> ++	$(LD) -shared $(LDFLAGS) -z muldefs -soname $(patsubst %.elf,%.c32,$(@F)) \
> + 		-o $@ $^
> +
> + tidy dist:
> +diff --git a/com32/elflink/ldlinux/Makefile b/com32/elflink/ldlinux/Makefile
> +index d948da43..67434a1f 100644
> +--- a/com32/elflink/ldlinux/Makefile
> ++++ b/com32/elflink/ldlinux/Makefile
> +@@ -33,7 +33,7 @@ endif
> + all: $(BTARGET) ldlinux_lnx.a
> +
> + ldlinux.elf : $(OBJS)
> +-	$(LD) $(LDFLAGS) -soname $(SONAME) -o $@ $^ $(LIBS)
> ++	$(LD) $(LDFLAGS) -z muldefs -soname $(SONAME) -o $@ $^ $(LIBS)
> +
> + LNXCFLAGS += -D__export='__attribute__((visibility("default")))'
> + LNXLIBOBJS = get_key.lo
> +diff --git a/com32/gpllib/Makefile b/com32/gpllib/Makefile
> +index e3e30d76..17520a1e 100644
> +--- a/com32/gpllib/Makefile
> ++++ b/com32/gpllib/Makefile
> +@@ -24,7 +24,7 @@ makeoutputdirs:
> + 		$(addprefix $(OBJ),$(sort $(dir $(LIBOBJS)))),$(b))
> +
> + libgpl.elf : $(LIBOBJS)
> +-	$(LD) -shared $(LDFLAGS) -soname $(patsubst %.elf,%.c32,$(@F)) -o $@ $^
> ++	$(LD) -shared $(LDFLAGS) -z muldefs -soname $(patsubst %.elf,%.c32,$(@F)) -o $@ $^
> +
> + tidy dist clean:
> + 	find . \( -name \*.o -o -name .\*.d -o -name \*.tmp \) -print0 | \
> +diff --git a/com32/hdt/Makefile b/com32/hdt/Makefile
> +index 80f2d0a0..8509cd96 100644
> +--- a/com32/hdt/Makefile
> ++++ b/com32/hdt/Makefile
> +@@ -52,7 +52,7 @@ QEMU			?= qemu-kvm
> + all: $(MODULES) $(TESTFILES)
> +
> + hdt.elf : $(OBJS) $(LIBS) $(C_LIBS)
> +-	$(LD) $(LDFLAGS) -o $@ $^
> ++	$(LD) $(LDFLAGS) -z muldefs -o $@ $^
> +
> + memtest:
> + 	-[ ! -f $(FLOPPY_DIR)/$(MEMTEST) ] && $(WGET) $(MEMTEST_URL) -O $(FLOPPY_DIR)/$(MEMTEST)
> +diff --git a/core/Makefile b/core/Makefile
> +index ad0acb5a..3bee4dc9 100644
> +--- a/core/Makefile
> ++++ b/core/Makefile
> +@@ -164,7 +164,7 @@ AUXLIBS = libisolinux.a libisolinux-debug.a libldlinux.a \
> + LDSCRIPT = $(SRC)/$(ARCH)/syslinux.ld
> +
> + %.elf: %.o $(LIBDEP) $(LDSCRIPT) $(AUXLIBS)
> +-	$(LD) $(LDFLAGS) -Bsymbolic $(LD_PIE) -E --hash-style=gnu -T $(LDSCRIPT) -M -o $@ $< \
> ++	$(LD) $(LDFLAGS) -z muldefs -Bsymbolic $(LD_PIE) -E --hash-style=gnu -T $(LDSCRIPT) -M -o $@ $< \
> + 		--start-group $(LIBS) $(subst $(*F).elf,lib$(*F).a,$@) --end-group \
> + 		> $(@:.elf=.map)
> + 	$(OBJDUMP) -h $@ > $(@:.elf=.sec)
> +diff --git a/dos/Makefile b/dos/Makefile
> +index b9c337d5..2af87346 100644
> +--- a/dos/Makefile
> ++++ b/dos/Makefile
> +@@ -19,7 +19,7 @@ include $(MAKEDIR)/embedded.mk
> + CFLAGS	+= -D__MSDOS__ -mregparm=3 -DREGPARM=3
> + # CFLAGS  += -DDEBUG
> +
> +-LDFLAGS	 = -T $(SRC)/dosexe.ld
> ++LDFLAGS	 = -T $(SRC)/dosexe.ld -z muldefs
> + OPTFLAGS = -g
> + INCLUDES = -include code16.h -nostdinc -iwithprefix include \
> + 	   -I$(SRC) -I$(SRC)/.. -I$(SRC)/../libfat \
> +diff --git a/efi/Makefile b/efi/Makefile
> +index d24d16db..7c714ebf 100644
> +--- a/efi/Makefile
> ++++ b/efi/Makefile
> +@@ -70,7 +70,7 @@ $(OBJS): subdirs
> + BTARGET  = syslinux.efi
> +
> + syslinux.so: $(OBJS) $(CORE_OBJS) $(LIB_OBJS)
> +-	$(LD) $(LDFLAGS) --strip-debug -o $@ $^ -lgnuefi -lefi
> ++	$(LD) $(LDFLAGS) -z muldefs --strip-debug -o $@ $^ -lgnuefi -lefi
> +
> + # We need to rename the .hash section because the EFI firmware
> + # linker really doesn't like it.
> +diff --git a/gpxe/src/arch/i386/Makefile b/gpxe/src/arch/i386/Makefile
> +index dd8da802..be1d00ff 100644
> +--- a/gpxe/src/arch/i386/Makefile
> ++++ b/gpxe/src/arch/i386/Makefile
> +@@ -55,7 +55,7 @@ ASFLAGS		+= --32
> + ifeq ($(HOST_OS),FreeBSD)
> + LDFLAGS		+= -m elf_i386_fbsd
> + else
> +-LDFLAGS		+= -m elf_i386
> ++LDFLAGS		+= -z muldefs -m elf_i386
> + endif
> +
> + # EFI requires -fshort-wchar, and nothing else currently uses wchar_t
> +--
> +2.30.1
> +
> diff --git a/boot/syslinux/0017-Replace-builtin-strlen-that-appears-to-get-optimized.patch b/boot/syslinux/0017-Replace-builtin-strlen-that-appears-to-get-optimized.patch
> new file mode 100644
> index 0000000000..69a7e87d85
> --- /dev/null
> +++ b/boot/syslinux/0017-Replace-builtin-strlen-that-appears-to-get-optimized.patch
> @@ -0,0 +1,42 @@
> +From 698a6ce88524b727d265b204d648e78d8acb485c Mon Sep 17 00:00:00 2001
> +From: Merlin Mathesius <mmathesi at redhat.com>
> +Date: Wed, 13 May 2020 11:58:37 -0500
> +Subject: [PATCH] Replace builtin strlen that appears to get optimized away
> +
> +[From https://src.fedoraproject.org/rpms/syslinux/raw/rawhide/f/0006-Replace-builtin-strlen-that-appears-to-get-optimized.patch]
> +Signed-off-by: Peter Seiderer <ps.report at gmx.net>
> +---
> + dos/string.h | 12 +++++++++++-
> + 1 file changed, 11 insertions(+), 1 deletion(-)
> +
> +diff --git a/dos/string.h b/dos/string.h
> +index f648de2d..407d0233 100644
> +--- a/dos/string.h
> ++++ b/dos/string.h
> +@@ -5,12 +5,22 @@
> + #ifndef _STRING_H
> + #define _STRING_H
> +
> ++#include <stddef.h>
> ++
> + /* Standard routines */
> + #define memcpy(a,b,c)	__builtin_memcpy(a,b,c)
> + #define memmove(a,b,c)	__builtin_memmove(a,b,c)
> + #define memset(a,b,c)	__builtin_memset(a,b,c)
> + #define strcpy(a,b)	__builtin_strcpy(a,b)
> +-#define strlen(a)	__builtin_strlen(a)
> ++#define strlen(a)	inline_strlen(a)
> ++
> ++/* replacement for builtin strlen that appears to get optimized away */
> ++static inline size_t inline_strlen(const char *str)
> ++{
> ++    size_t l;
> ++    for (l = 0; *str++; l++);
> ++    return l;
> ++}
> +
> + /* This only returns true or false */
> + static inline int memcmp(const void *__m1, const void *__m2, unsigned int __n)
> +--
> +2.30.1
> +



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