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(-)
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.)
Signed-off-by: Fangrui Song <maskray@google.com>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
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
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
--
2.39.0.314.g84b9a713c41-googHi 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@google.com> > Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu> > --- > 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@arm.com> # for vDSO, aarch64 Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com> # 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
On 2023-03-10, Vincenzo Frascino wrote:
>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.
Thank you! No worries.
>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?
I checked that the built vdso did not change (the patch just changes
some post-link verification).
To be more sure, I used commands like
https://github.com/ClangBuiltLinux/tc-build/blob/main/kernel/build.sh#L305
to build a kernel and commands like
~/Dev/ClangBuiltLinux/boot-utils/boot-qemu.py -a arm64 -k /tmp/linux/arm64
to run an image for a couple of architectures.
The initrd images run some init scripts along with
# buildroot/overlay-poweroff/etc/init.d/S50yolo
cat /proc/version
poweroff
I think these have exercised vdso.
>>
>> Signed-off-by: Fangrui Song <maskray@google.com>
>> Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
>> ---
>> 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@arm.com> # for vDSO, aarch64
>Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com> # for aarch64
>
Just sent v3
(https://lore.kernel.org/all/20230310190750.3323802-1-maskray@google.com/)
with the comment changes. Thanks!
>> 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
On Wed, 21 Dec 2022 15:51:47 PST (-0800), maskray@google.com 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.) > > Signed-off-by: Fangrui Song <maskray@google.com> > Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu> > --- > 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(-) [snip] > 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 Acked-by: Palmer Dabbelt <palmer@rivosinc.com> # RISC-V Thanks!
On Thu, Dec 29, 2022 at 11:22 AM Palmer Dabbelt <palmer@dabbelt.com> wrote: > > On Wed, 21 Dec 2022 15:51:47 PST (-0800), maskray@google.com 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.) > > > > Signed-off-by: Fangrui Song <maskray@google.com> > > Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu> > > --- > > 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(-) > > [snip] > > > 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 > > Acked-by: Palmer Dabbelt <palmer@rivosinc.com> # RISC-V > > Thanks! Looks like this patch hasn't been picked yet...
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