Re: [PATCH] vdso: Improve cmd_vdso_check to check all dynamic relocations
On Sun, Dec 4, 2022 at 8:58 AM Christophe Leroy wrote: > > > > Le 04/12/2022 à 05:50, Fangrui Song a écrit : > > On Mon, Nov 14, 2022 at 4:46 PM Fangrui Song 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 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 > >> --- > >> [...] > >> > > > > 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 Thanks. Can a maintainer pick up this commit?
Re: [PATCH] vdso: Improve cmd_vdso_check to check all dynamic relocations
Le 04/12/2022 à 05:50, Fangrui Song a écrit : > On Mon, Nov 14, 2022 at 4:46 PM Fangrui Song 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 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 >> --- >> [...] >> > > 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
Re: [PATCH] vdso: Improve cmd_vdso_check to check all dynamic relocations
On Mon, Nov 14, 2022 at 4:46 PM Fangrui Song 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 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 > --- > [...] > > >>> > >>> 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 :)
Re: [PATCH] vdso: Improve cmd_vdso_check to check all dynamic relocations
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 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 --- [...] 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.
Re: [PATCH] vdso: Improve cmd_vdso_check to check all dynamic relocations
Le 28/09/2022 à 07:25, Fangrui Song a écrit : > On Sat, Sep 10, 2022 at 12:53 AM Fangrui Song 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 >>> --- >>> [...] >>> >> >> 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 ?
Re: [PATCH] vdso: Improve cmd_vdso_check to check all dynamic relocations
On Sat, Sep 10, 2022 at 12:53 AM Fangrui Song 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 > >--- > >[...] > > > > Ping. Ping^2 :)
Re: [PATCH] vdso: Improve cmd_vdso_check to check all dynamic relocations
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 --- [...] Ping.
[PATCH] vdso: Improve cmd_vdso_check to check all dynamic relocations
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 --- 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
