Hi Fangrui, Apologize for the delay, I totally missed that you had a new version of your patch since it was threaded with the old one. On 12/21/22 23:51, Fangrui Song wrote: > The actual intention is that no dynamic relocation exists. However, some > GNU ld ports produce unneeded R_*_NONE. (If a port fails to determine > the exact .rel[a].dyn size, the trailing zeros become R_*_NONE > relocations. E.g. ld's powerpc port recently fixed > https://sourceware.org/bugzilla/show_bug.cgi?id=29540) R_*_NONE are > generally no-op in the dynamic loaders. So just ignore them. > > With the change, we can remove ARCH_REL_TYPE_ABS. ARCH_REL_TYPE_ABS is a > bit misnomer as ports may check RELAVETIVE/GLOB_DAT/JUMP_SLOT which are > not called "absolute relocations". (The patch is motivated by the arm64 > port missing R_AARCH64_RELATIVE.) It makes sense to update the name, it started as "absolute relocations" but then it evolved into something else. A part that, did you perform any testing with the generated vDSO libraries? > > Signed-off-by: Fangrui Song <maskray@xxxxxxxxxx> > Reviewed-by: Christophe Leroy <christophe.leroy@xxxxxxxxxx> > --- > Change from v1: > * rebase after 8ac3b5cd3e0521d92f9755e90d140382fc292510 (lib/vdso: use "grep -E" > instead of "egrep") > * change the commit message to mention an example GNU ld bug; no longer say the > patch fixes a deprecated egrep use > --- > arch/arm/vdso/Makefile | 3 --- > arch/arm64/kernel/vdso/Makefile | 3 --- > arch/arm64/kernel/vdso32/Makefile | 3 --- > arch/csky/kernel/vdso/Makefile | 3 --- > arch/loongarch/vdso/Makefile | 3 --- > arch/mips/vdso/Makefile | 3 --- > arch/powerpc/kernel/vdso/Makefile | 1 - > arch/riscv/kernel/vdso/Makefile | 3 --- > arch/s390/kernel/vdso32/Makefile | 2 -- > arch/s390/kernel/vdso64/Makefile | 2 -- > arch/x86/entry/vdso/Makefile | 4 ---- > lib/vdso/Makefile | 13 ++++--------- > 12 files changed, 4 insertions(+), 39 deletions(-) > > diff --git a/arch/arm/vdso/Makefile b/arch/arm/vdso/Makefile > index a7ec06ce3785..e58197bba776 100644 > --- a/arch/arm/vdso/Makefile > +++ b/arch/arm/vdso/Makefile > @@ -1,8 +1,5 @@ > # SPDX-License-Identifier: GPL-2.0 > > -# Absolute relocation type $(ARCH_REL_TYPE_ABS) needs to be defined before > -# the inclusion of generic Makefile. > -ARCH_REL_TYPE_ABS := R_ARM_JUMP_SLOT|R_ARM_GLOB_DAT|R_ARM_ABS32 I would still add a comment here to say why we are including the generic Makefile to prevent that it gets accidentally removed (similar thing for every architecture touched by this patch). With that: Reviewed-by: Vincenzo Frascino <vincenzo.frascino@xxxxxxx> # for vDSO, aarch64 Tested-by: Vincenzo Frascino <vincenzo.frascino@xxxxxxx> # for aarch64 > include $(srctree)/lib/vdso/Makefile > > hostprogs := vdsomunge > diff --git a/arch/arm64/kernel/vdso/Makefile b/arch/arm64/kernel/vdso/Makefile > index beaf9586338f..1f2427b13410 100644 > --- a/arch/arm64/kernel/vdso/Makefile > +++ b/arch/arm64/kernel/vdso/Makefile > @@ -6,9 +6,6 @@ > # Heavily based on the vDSO Makefiles for other archs. > # > > -# Absolute relocation type $(ARCH_REL_TYPE_ABS) needs to be defined before > -# the inclusion of generic Makefile. > -ARCH_REL_TYPE_ABS := R_AARCH64_JUMP_SLOT|R_AARCH64_GLOB_DAT|R_AARCH64_ABS64 > include $(srctree)/lib/vdso/Makefile > > obj-vdso := vgettimeofday.o note.o sigreturn.o > diff --git a/arch/arm64/kernel/vdso32/Makefile b/arch/arm64/kernel/vdso32/Makefile > index f59bd1a4ead6..d014162c5c71 100644 > --- a/arch/arm64/kernel/vdso32/Makefile > +++ b/arch/arm64/kernel/vdso32/Makefile > @@ -3,9 +3,6 @@ > # Makefile for vdso32 > # > > -# Absolute relocation type $(ARCH_REL_TYPE_ABS) needs to be defined before > -# the inclusion of generic Makefile. > -ARCH_REL_TYPE_ABS := R_ARM_JUMP_SLOT|R_ARM_GLOB_DAT|R_ARM_ABS32 > include $(srctree)/lib/vdso/Makefile > > # Same as cc-*option, but using CC_COMPAT instead of CC > diff --git a/arch/csky/kernel/vdso/Makefile b/arch/csky/kernel/vdso/Makefile > index 0b6909f10667..86c8c4de1b0f 100644 > --- a/arch/csky/kernel/vdso/Makefile > +++ b/arch/csky/kernel/vdso/Makefile > @@ -1,8 +1,5 @@ > # SPDX-License-Identifier: GPL-2.0-only > > -# Absolute relocation type $(ARCH_REL_TYPE_ABS) needs to be defined before > -# the inclusion of generic Makefile. > -ARCH_REL_TYPE_ABS := R_CKCORE_ADDR32|R_CKCORE_JUMP_SLOT > include $(srctree)/lib/vdso/Makefile > > # Symbols present in the vdso > diff --git a/arch/loongarch/vdso/Makefile b/arch/loongarch/vdso/Makefile > index d89e2ac75f7b..1b2e0f149f55 100644 > --- a/arch/loongarch/vdso/Makefile > +++ b/arch/loongarch/vdso/Makefile > @@ -1,9 +1,6 @@ > # SPDX-License-Identifier: GPL-2.0 > # Objects to go into the VDSO. > > -# Absolute relocation type $(ARCH_REL_TYPE_ABS) needs to be defined before > -# the inclusion of generic Makefile. > -ARCH_REL_TYPE_ABS := R_LARCH_32|R_LARCH_64|R_LARCH_MARK_LA|R_LARCH_JUMP_SLOT > include $(srctree)/lib/vdso/Makefile > > obj-vdso-y := elf.o vgetcpu.o vgettimeofday.o sigreturn.o > diff --git a/arch/mips/vdso/Makefile b/arch/mips/vdso/Makefile > index 1f7d5c6c10b0..c060f3596304 100644 > --- a/arch/mips/vdso/Makefile > +++ b/arch/mips/vdso/Makefile > @@ -4,9 +4,6 @@ > # Sanitizer runtimes are unavailable and cannot be linked here. > KCSAN_SANITIZE := n > > -# Absolute relocation type $(ARCH_REL_TYPE_ABS) needs to be defined before > -# the inclusion of generic Makefile. > -ARCH_REL_TYPE_ABS := R_MIPS_JUMP_SLOT|R_MIPS_GLOB_DAT > include $(srctree)/lib/vdso/Makefile > > obj-vdso-y := elf.o vgettimeofday.o sigreturn.o > diff --git a/arch/powerpc/kernel/vdso/Makefile b/arch/powerpc/kernel/vdso/Makefile > index 6a977b0d8ffc..83c347e9136f 100644 > --- a/arch/powerpc/kernel/vdso/Makefile > +++ b/arch/powerpc/kernel/vdso/Makefile > @@ -2,7 +2,6 @@ > > # List of files in the vdso, has to be asm only for now > > -ARCH_REL_TYPE_ABS := > R_PPC_JUMP_SLOT|R_PPC_GLOB_DAT|R_PPC_ADDR32|R_PPC_ADDR24|R_PPC_ADDR16|R_PPC_ADDR16_LO|R_PPC_ADDR16_HI|R_PPC_ADDR16_HA|R_PPC_ADDR14|R_PPC_ADDR14_BRTAKEN|R_PPC_ADDR14_BRNTAKEN|R_PPC_REL24 > include $(srctree)/lib/vdso/Makefile > > obj-vdso32 = sigtramp32-32.o gettimeofday-32.o datapage-32.o cacheflush-32.o > note-32.o getcpu-32.o > diff --git a/arch/riscv/kernel/vdso/Makefile b/arch/riscv/kernel/vdso/Makefile > index 06e6b27f3bcc..d85c37e11b21 100644 > --- a/arch/riscv/kernel/vdso/Makefile > +++ b/arch/riscv/kernel/vdso/Makefile > @@ -1,9 +1,6 @@ > # SPDX-License-Identifier: GPL-2.0-only > # Copied from arch/tile/kernel/vdso/Makefile > > -# Absolute relocation type $(ARCH_REL_TYPE_ABS) needs to be defined before > -# the inclusion of generic Makefile. > -ARCH_REL_TYPE_ABS := R_RISCV_32|R_RISCV_64|R_RISCV_JUMP_SLOT > include $(srctree)/lib/vdso/Makefile > # Symbols present in the vdso > vdso-syms = rt_sigreturn > diff --git a/arch/s390/kernel/vdso32/Makefile b/arch/s390/kernel/vdso32/Makefile > index 245bddfe9bc0..e795fdbbf484 100644 > --- a/arch/s390/kernel/vdso32/Makefile > +++ b/arch/s390/kernel/vdso32/Makefile > @@ -2,8 +2,6 @@ > # List of files in the vdso > > KCOV_INSTRUMENT := n > -ARCH_REL_TYPE_ABS := R_390_COPY|R_390_GLOB_DAT|R_390_JMP_SLOT|R_390_RELATIVE > -ARCH_REL_TYPE_ABS += R_390_GOT|R_390_PLT > > include $(srctree)/lib/vdso/Makefile > obj-vdso32 = vdso_user_wrapper-32.o note-32.o > diff --git a/arch/s390/kernel/vdso64/Makefile b/arch/s390/kernel/vdso64/Makefile > index 9e2b95a222a9..47dbbfdfad68 100644 > --- a/arch/s390/kernel/vdso64/Makefile > +++ b/arch/s390/kernel/vdso64/Makefile > @@ -2,8 +2,6 @@ > # List of files in the vdso > > KCOV_INSTRUMENT := n > -ARCH_REL_TYPE_ABS := R_390_COPY|R_390_GLOB_DAT|R_390_JMP_SLOT|R_390_RELATIVE > -ARCH_REL_TYPE_ABS += R_390_GOT|R_390_PLT > > include $(srctree)/lib/vdso/Makefile > obj-vdso64 = vdso_user_wrapper.o note.o > diff --git a/arch/x86/entry/vdso/Makefile b/arch/x86/entry/vdso/Makefile > index 838613ac15b8..b292c24acb8e 100644 > --- a/arch/x86/entry/vdso/Makefile > +++ b/arch/x86/entry/vdso/Makefile > @@ -3,10 +3,6 @@ > # Building vDSO images for x86. > # > > -# Absolute relocation type $(ARCH_REL_TYPE_ABS) needs to be defined before > -# the inclusion of generic Makefile. > -ARCH_REL_TYPE_ABS := R_X86_64_JUMP_SLOT|R_X86_64_GLOB_DAT|R_X86_64_RELATIVE| > -ARCH_REL_TYPE_ABS += R_386_GLOB_DAT|R_386_JMP_SLOT|R_386_RELATIVE > include $(srctree)/lib/vdso/Makefile > > # Sanitizer runtimes are unavailable and cannot be linked here. > diff --git a/lib/vdso/Makefile b/lib/vdso/Makefile > index e814061d6aa0..9f031eafc465 100644 > --- a/lib/vdso/Makefile > +++ b/lib/vdso/Makefile > @@ -5,18 +5,13 @@ GENERIC_VDSO_DIR := $(dir $(GENERIC_VDSO_MK_PATH)) > > c-gettimeofday-$(CONFIG_GENERIC_GETTIMEOFDAY) := $(addprefix > $(GENERIC_VDSO_DIR), gettimeofday.c) > > -# This cmd checks that the vdso library does not contain absolute relocation > +# This cmd checks that the vdso library does not contain dynamic relocations. > # It has to be called after the linking of the vdso library and requires it > # as a parameter. > # > -# $(ARCH_REL_TYPE_ABS) is defined in the arch specific makefile and corresponds > -# to the absolute relocation types printed by "objdump -R" and accepted by the > -# dynamic linker. > -ifndef ARCH_REL_TYPE_ABS > -$(error ARCH_REL_TYPE_ABS is not set) > -endif > - > +# As a workaround for some GNU ld ports which produce unneeded R_*_NONE > +# dynamic relocations, ignore R_*_NONE. > quiet_cmd_vdso_check = VDSOCHK $@ > - cmd_vdso_check = if $(OBJDUMP) -R $@ | grep -E -h "$(ARCH_REL_TYPE_ABS)"; \ > + cmd_vdso_check = if $(READELF) -rW $@ | grep -v _NONE | grep -q " R_\w*_"; \ > then (echo >&2 "$@: dynamic relocations are not supported"; \ > rm -f $@; /bin/false); fi -- Regards, Vincenzo
