The actual intention is that no dynamic relocation exists. However, some
GNU ld ports produce unneeded R_*_NONE. (If a port is not care enough to
determine the exact .rel[a].dyn size, the trailing zeros become R_*_NONE
relocations. E.g. powerpc64le ld as of 2.38 has the issue with
defconfig.) 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.)
While here, replace "egrep" with "grep" as "egrep" is deprecated in GNU
grep 3.7.
Signed-off-by: Fangrui Song <[email protected]>
---
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 8ca1c9f262a2..5ebd2e6f7d46 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 bafbf78fab77..66dc4f338a86 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 36c8f66cad25..48d713d59ef2 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 f72658b3a53f..cea97abffc03 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 096b0bf1335f..d3c5be32034d 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 f2e065671e4d..77d6bed3a700 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 12f6c4d714cd..a97f3630ca20 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 c415a685d61b..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 $@ | egrep -h "$(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
--
2.37.2.672.g94769d06f0-goog
On 2022-08-30, Fangrui Song wrote:
>The actual intention is that no dynamic relocation exists. However, some
>GNU ld ports produce unneeded R_*_NONE. (If a port is not care enough to
>determine the exact .rel[a].dyn size, the trailing zeros become R_*_NONE
>relocations. E.g. powerpc64le ld as of 2.38 has the issue with
>defconfig.) 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.)
>
>While here, replace "egrep" with "grep" as "egrep" is deprecated in GNU
>grep 3.7.
>
>Signed-off-by: Fangrui Song <[email protected]>
>---
>[...]
>
Ping.
On Sat, Sep 10, 2022 at 12:53 AM Fangrui Song <[email protected]> wrote:
>
> On 2022-08-30, Fangrui Song wrote:
> >The actual intention is that no dynamic relocation exists. However, some
> >GNU ld ports produce unneeded R_*_NONE. (If a port is not care enough to
> >determine the exact .rel[a].dyn size, the trailing zeros become R_*_NONE
> >relocations. E.g. powerpc64le ld as of 2.38 has the issue with
> >defconfig.) 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.)
> >
> >While here, replace "egrep" with "grep" as "egrep" is deprecated in GNU
> >grep 3.7.
> >
> >Signed-off-by: Fangrui Song <[email protected]>
> >---
> >[...]
> >
>
> Ping.
Ping^2 :)
Le 28/09/2022 à 07:25, Fangrui Song a écrit :
> On Sat, Sep 10, 2022 at 12:53 AM Fangrui Song <[email protected]> wrote:
>>
>> On 2022-08-30, Fangrui Song wrote:
>>> The actual intention is that no dynamic relocation exists. However, some
>>> GNU ld ports produce unneeded R_*_NONE. (If a port is not care enough to
>>> determine the exact .rel[a].dyn size, the trailing zeros become R_*_NONE
>>> relocations. E.g. powerpc64le ld as of 2.38 has the issue with
>>> defconfig.) 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.)
>>>
>>> While here, replace "egrep" with "grep" as "egrep" is deprecated in GNU
>>> grep 3.7.
>>>
>>> Signed-off-by: Fangrui Song <[email protected]>
>>> ---
>>> [...]
>>>
>>
>> Ping.
>
> Ping^2 :)
Can you explain which ARCH_REL_TYPE_ABS can be removed with this change ?
How is the verification done if ARCH_REL_TYPE_ABS is removed ?
On 2022-11-14, Christophe Leroy wrote:
>
>
>Le 28/09/2022 ? 07:25, Fangrui Song a ?crit?:
>> On Sat, Sep 10, 2022 at 12:53 AM Fangrui Song <[email protected]> wrote:
>>>
>>> On 2022-08-30, Fangrui Song wrote:
>>>> The actual intention is that no dynamic relocation exists. However, some
>>>> GNU ld ports produce unneeded R_*_NONE. (If a port is not care enough to
>>>> determine the exact .rel[a].dyn size, the trailing zeros become R_*_NONE
>>>> relocations. E.g. powerpc64le ld as of 2.38 has the issue with
>>>> defconfig.) 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.)
>>>>
>>>> While here, replace "egrep" with "grep" as "egrep" is deprecated in GNU
>>>> grep 3.7.
>>>>
>>>> Signed-off-by: Fangrui Song <[email protected]>
>>>> ---
>>>> [...]
>>>>
>>>
>>> Ping.
>>
>> Ping^2 :)
>
>Can you explain which ARCH_REL_TYPE_ABS can be removed with this change ?
>How is the verification done if ARCH_REL_TYPE_ABS is removed ?
All ARCH_REL_TYPE_ABS relocation types can be removed. As explained, the
real intention is to check no dynamic relocation, and this is done by
the new
cmd_vdso_check = if $(READELF) -rW $@ | grep -v _NONE | grep -q "R_\w*_"; \
in this patch.
grep -v _NONE is to work around some GNU ld ports (and likely older releases
of some ports even if their latest versions are fixed) which produce
unneeded R_*_NONE dynamic relocations.
On Mon, Nov 14, 2022 at 4:46 PM Fangrui Song <[email protected]> wrote:
>
> On 2022-11-14, Christophe Leroy wrote:
> >
> >
> >Le 28/09/2022 à 07:25, Fangrui Song a écrit :
> >> On Sat, Sep 10, 2022 at 12:53 AM Fangrui Song <[email protected]> wrote:
> >>>
> >>> On 2022-08-30, Fangrui Song wrote:
> >>>> The actual intention is that no dynamic relocation exists. However, some
> >>>> GNU ld ports produce unneeded R_*_NONE. (If a port is not care enough to
> >>>> determine the exact .rel[a].dyn size, the trailing zeros become R_*_NONE
> >>>> relocations. E.g. powerpc64le ld as of 2.38 has the issue with
> >>>> defconfig.) 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.)
> >>>>
> >>>> While here, replace "egrep" with "grep" as "egrep" is deprecated in GNU
> >>>> grep 3.7.
> >>>>
> >>>> Signed-off-by: Fangrui Song <[email protected]>
> >>>> ---
> >>>> [...]
> >>>>
> >>>
> >>> Ping.
> >>
> >> Ping^2 :)
> >
> >Can you explain which ARCH_REL_TYPE_ABS can be removed with this change ?
> >How is the verification done if ARCH_REL_TYPE_ABS is removed ?
>
> All ARCH_REL_TYPE_ABS relocation types can be removed. As explained, the
> real intention is to check no dynamic relocation, and this is done by
> the new
>
> cmd_vdso_check = if $(READELF) -rW $@ | grep -v _NONE | grep -q "R_\w*_"; \
>
> in this patch.
>
> grep -v _NONE is to work around some GNU ld ports (and likely older releases
> of some ports even if their latest versions are fixed) which produce
> unneeded R_*_NONE dynamic relocations.
Ping :)
Le 04/12/2022 à 05:50, Fangrui Song a écrit :
> On Mon, Nov 14, 2022 at 4:46 PM Fangrui Song <[email protected]> wrote:
>>
>> On 2022-11-14, Christophe Leroy wrote:
>>>
>>>
>>> Le 28/09/2022 à 07:25, Fangrui Song a écrit :
>>>> On Sat, Sep 10, 2022 at 12:53 AM Fangrui Song <[email protected]> wrote:
>>>>>
>>>>> On 2022-08-30, Fangrui Song wrote:
>>>>>> The actual intention is that no dynamic relocation exists. However, some
>>>>>> GNU ld ports produce unneeded R_*_NONE. (If a port is not care enough to
>>>>>> determine the exact .rel[a].dyn size, the trailing zeros become R_*_NONE
>>>>>> relocations. E.g. powerpc64le ld as of 2.38 has the issue with
>>>>>> defconfig.) 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.)
>>>>>>
>>>>>> While here, replace "egrep" with "grep" as "egrep" is deprecated in GNU
>>>>>> grep 3.7.
>>>>>>
>>>>>> Signed-off-by: Fangrui Song <[email protected]>
>>>>>> ---
>>>>>> [...]
>>>>>>
>>>>>
>>>>> Ping.
>>>>
>>>> Ping^2 :)
>>>
>>> Can you explain which ARCH_REL_TYPE_ABS can be removed with this change ?
>>> How is the verification done if ARCH_REL_TYPE_ABS is removed ?
>>
>> All ARCH_REL_TYPE_ABS relocation types can be removed. As explained, the
>> real intention is to check no dynamic relocation, and this is done by
>> the new
Well, there was a typo in my question, I wanted to ask 'why', not 'which'.
>>
>> cmd_vdso_check = if $(READELF) -rW $@ | grep -v _NONE | grep -q "R_\w*_"; \
>>
>> in this patch.
>>
>> grep -v _NONE is to work around some GNU ld ports (and likely older releases
>> of some ports even if their latest versions are fixed) which produce
>> unneeded R_*_NONE dynamic relocations.
>
> Ping :)
Ok, that seems to work on powerpc.
Reviewed-by: Christophe Leroy <[email protected]>
On Sun, Dec 4, 2022 at 8:58 AM Christophe Leroy
<[email protected]> wrote:
>
>
>
> Le 04/12/2022 à 05:50, Fangrui Song a écrit :
> > On Mon, Nov 14, 2022 at 4:46 PM Fangrui Song <[email protected]> wrote:
> >>
> >> On 2022-11-14, Christophe Leroy wrote:
> >>>
> >>>
> >>> Le 28/09/2022 à 07:25, Fangrui Song a écrit :
> >>>> On Sat, Sep 10, 2022 at 12:53 AM Fangrui Song <[email protected]> wrote:
> >>>>>
> >>>>> On 2022-08-30, Fangrui Song wrote:
> >>>>>> The actual intention is that no dynamic relocation exists. However, some
> >>>>>> GNU ld ports produce unneeded R_*_NONE. (If a port is not care enough to
> >>>>>> determine the exact .rel[a].dyn size, the trailing zeros become R_*_NONE
> >>>>>> relocations. E.g. powerpc64le ld as of 2.38 has the issue with
> >>>>>> defconfig.) 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.)
> >>>>>>
> >>>>>> While here, replace "egrep" with "grep" as "egrep" is deprecated in GNU
> >>>>>> grep 3.7.
> >>>>>>
> >>>>>> Signed-off-by: Fangrui Song <[email protected]>
> >>>>>> ---
> >>>>>> [...]
> >>>>>>
> >>>>>
> >>>>> Ping.
> >>>>
> >>>> Ping^2 :)
> >>>
> >>> Can you explain which ARCH_REL_TYPE_ABS can be removed with this change ?
> >>> How is the verification done if ARCH_REL_TYPE_ABS is removed ?
> >>
> >> All ARCH_REL_TYPE_ABS relocation types can be removed. As explained, the
> >> real intention is to check no dynamic relocation, and this is done by
> >> the new
>
> Well, there was a typo in my question, I wanted to ask 'why', not 'which'.
>
> >>
> >> cmd_vdso_check = if $(READELF) -rW $@ | grep -v _NONE | grep -q "R_\w*_"; \
> >>
> >> in this patch.
> >>
> >> grep -v _NONE is to work around some GNU ld ports (and likely older releases
> >> of some ports even if their latest versions are fixed) which produce
> >> unneeded R_*_NONE dynamic relocations.
> >
> > Ping :)
>
> Ok, that seems to work on powerpc.
>
> Reviewed-by: Christophe Leroy <[email protected]>
Thanks. Can a maintainer pick up this commit?
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 <[email protected]>
Reviewed-by: Christophe Leroy <[email protected]>
---
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-goog
On Wed, 21 Dec 2022 15:51:47 PST (-0800), [email protected] 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 <[email protected]>
> Reviewed-by: Christophe Leroy <[email protected]>
> ---
> 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 <[email protected]> # RISC-V
Thanks!
On Thu, Dec 29, 2022 at 11:22 AM Palmer Dabbelt <[email protected]> wrote:
>
> On Wed, 21 Dec 2022 15:51:47 PST (-0800), [email protected] 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 <[email protected]>
> > Reviewed-by: Christophe Leroy <[email protected]>
> > ---
> > 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 <[email protected]> # RISC-V
>
> Thanks!
Looks like this patch hasn't been picked yet...
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 <[email protected]>
> Reviewed-by: Christophe Leroy <[email protected]>
> ---
> 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 <[email protected]> # for vDSO, aarch64
Tested-by: Vincenzo Frascino <[email protected]> # 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 <[email protected]>
>> Reviewed-by: Christophe Leroy <[email protected]>
>> ---
>> 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 <[email protected]> # for vDSO, aarch64
>Tested-by: Vincenzo Frascino <[email protected]> # for aarch64
>
Just sent v3
(https://lore.kernel.org/all/[email protected]/)
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