[PATCH v2] vdso: Improve cmd_vdso_check to check all dynamic relocations
From: Fangrui Song <hidden>
Date: 2022-12-21 23:52:00
Also in:
linux-arm-kernel, linux-mips, linux-riscv, linux-s390, lkml, loongarch
Subsystem:
arm port, arm64 port (aarch64 architecture), c-sky architecture, generic vdso library, library code, linux for powerpc (32-bit and 64-bit), loongarch, mips, risc-v architecture, s390 architecture, the rest, x86 architecture (32-bit and 64-bit), x86 entry code, x86 vdso · Maintainers:
Russell King, Catalin Marinas, Will Deacon, Guo Ren, Andy Lutomirski, Thomas Gleixner, Vincenzo Frascino, Andrew Morton, Madhavan Srinivasan, Michael Ellerman, Huacai Chen, Thomas Bogendoerfer, Paul Walmsley, Palmer Dabbelt, Albert Ou, Heiko Carstens, Vasily Gorbik, Alexander Gordeev, Linus Torvalds, Ingo Molnar, Borislav Petkov, Dave Hansen
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 <redacted> Reviewed-by: Christophe Leroy <redacted> --- 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