diff --git a/patches.suse/x86-Use-return-thunk-in-asm-code.patch b/patches.suse/x86-Use-return-thunk-in-asm-code.patch index 5ea454b..d648d53 100644 --- a/patches.suse/x86-Use-return-thunk-in-asm-code.patch +++ b/patches.suse/x86-Use-return-thunk-in-asm-code.patch @@ -33,12 +33,23 @@ Signed-off-by: Borislav Petkov arch/x86/lib/memmove_64.S | 7 ++++++- 5 files changed, 17 insertions(+), 2 deletions(-) +--- a/arch/x86/Makefile ++++ b/arch/x86/Makefile +@@ -21,7 +21,7 @@ CODE16GCC_CFLAGS := -m32 -Wa,$(srctree)/ + M16_CFLAGS := $(call cc-option, -m16, $(CODE16GCC_CFLAGS)) + + REALMODE_CFLAGS := $(M16_CFLAGS) -g -Os -D__KERNEL__ \ +- -DDISABLE_BRANCH_PROFILING \ ++ -DDISABLE_BRANCH_PROFILING -D__DISABLE_EXPORTS \ + -Wall -Wstrict-prototypes -march=i386 -mregparm=3 \ + -fno-strict-aliasing -fomit-frame-pointer -fno-pic \ + -mno-mmx -mno-sse \ --- a/arch/x86/boot/compressed/Makefile +++ b/arch/x86/boot/compressed/Makefile -@@ -34,6 +34,7 @@ KBUILD_CFLAGS += $(cflags-y) - KBUILD_CFLAGS += -mno-mmx -mno-sse - KBUILD_CFLAGS += $(call cc-option,-ffreestanding) +@@ -36,6 +36,7 @@ KBUILD_CFLAGS += $(call cc-option,-ffree KBUILD_CFLAGS += $(call cc-option,-fno-stack-protector) + # Disable relocation relaxation in case the link is not PIE. + KBUILD_CFLAGS += $(call as-option,-Wa$(comma)-mrelax-relocations=no) +KBUILD_CFLAGS += -D__DISABLE_EXPORTS KBUILD_AFLAGS := $(KBUILD_CFLAGS) -D__ASSEMBLY__ @@ -106,14 +117,3 @@ Signed-off-by: Borislav Petkov ENDPROC(__memmove) ENDPROC(memmove) EXPORT_SYMBOL(__memmove) ---- a/arch/x86/Makefile -+++ b/arch/x86/Makefile -@@ -21,7 +21,7 @@ CODE16GCC_CFLAGS := -m32 -Wa,$(srctree)/ - M16_CFLAGS := $(call cc-option, -m16, $(CODE16GCC_CFLAGS)) - - REALMODE_CFLAGS := $(M16_CFLAGS) -g -Os -D__KERNEL__ \ -- -DDISABLE_BRANCH_PROFILING \ -+ -DDISABLE_BRANCH_PROFILING -D__DISABLE_EXPORTS \ - -Wall -Wstrict-prototypes -march=i386 -mregparm=3 \ - -fno-strict-aliasing -fomit-frame-pointer -fno-pic \ - -mno-mmx -mno-sse \ diff --git a/patches.suse/x86-boot-compressed-Disable-relocation-relaxation.patch b/patches.suse/x86-boot-compressed-Disable-relocation-relaxation.patch new file mode 100644 index 0000000..d86f141 --- /dev/null +++ b/patches.suse/x86-boot-compressed-Disable-relocation-relaxation.patch @@ -0,0 +1,86 @@ +From: Arvind Sankar +Date: Tue, 11 Aug 2020 20:43:08 -0400 +Subject: x86/boot/compressed: Disable relocation relaxation +Git-commit: 09e43968db40c33a73e9ddbfd937f46d5c334924 +Patch-mainline: 5.9-rc6 +References: git-fixes + +The x86-64 psABI [0] specifies special relocation types +(R_X86_64_[REX_]GOTPCRELX) for indirection through the Global Offset +Table, semantically equivalent to R_X86_64_GOTPCREL, which the linker +can take advantage of for optimization (relaxation) at link time. This +is supported by LLD and binutils versions 2.26 onwards. + +The compressed kernel is position-independent code, however, when using +LLD or binutils versions before 2.27, it must be linked without the -pie +option. In this case, the linker may optimize certain instructions into +a non-position-independent form, by converting foo@GOTPCREL(%rip) to $foo. + +This potential issue has been present with LLD and binutils-2.26 for a +long time, but it has never manifested itself before now: + +- LLD and binutils-2.26 only relax + movq foo@GOTPCREL(%rip), %reg + to + leaq foo(%rip), %reg + which is still position-independent, rather than + mov $foo, %reg + which is permitted by the psABI when -pie is not enabled. + +- GCC happens to only generate GOTPCREL relocations on mov instructions. + +- CLang does generate GOTPCREL relocations on non-mov instructions, but + when building the compressed kernel, it uses its integrated assembler + (due to the redefinition of KBUILD_CFLAGS dropping -no-integrated-as), + which has so far defaulted to not generating the GOTPCRELX + relocations. + +Nick Desaulniers reports [1,2]: + + "A recent change [3] to a default value of configuration variable + (ENABLE_X86_RELAX_RELOCATIONS OFF -> ON) in LLVM now causes Clang's + integrated assembler to emit R_X86_64_GOTPCRELX/R_X86_64_REX_GOTPCRELX + relocations. LLD will relax instructions with these relocations based + on whether the image is being linked as position independent or not. + When not, then LLD will relax these instructions to use absolute + addressing mode (R_RELAX_GOT_PC_NOPIC). This causes kernels built with + Clang and linked with LLD to fail to boot." + +Patch series [4] is a solution to allow the compressed kernel to be +linked with -pie unconditionally, but even if merged is unlikely to be +backported. As a simple solution that can be applied to stable as well, +prevent the assembler from generating the relaxed relocation types using +the -mrelax-relocations=no option. For ease of backporting, do this +unconditionally. + +[0] https://gitlab.com/x86-psABIs/x86-64-ABI/-/blob/master/x86-64-ABI/linker-optimization.tex#L65 +[1] https://lore.kernel.org/lkml/20200807194100.3570838-1-ndesaulniers@google.com/ +[2] https://github.com/ClangBuiltLinux/linux/issues/1121 +[3] https://reviews.llvm.org/rGc41a18cf61790fc898dcda1055c3efbf442c14c0 +[4] https://lore.kernel.org/lkml/20200731202738.2577854-1-nivedita@alum.mit.edu/ + +Reported-by: Nick Desaulniers +Signed-off-by: Arvind Sankar +Signed-off-by: Ingo Molnar +Tested-by: Nick Desaulniers +Tested-by: Sedat Dilek +Acked-by: Ard Biesheuvel +Reviewed-by: Nick Desaulniers +Cc: stable@vger.kernel.org +Link: https://lore.kernel.org/r/20200812004308.1448603-1-nivedita@alum.mit.edu +Signed-off-by: Jiri Slaby +--- + arch/x86/boot/compressed/Makefile | 2 ++ + 1 file changed, 2 insertions(+) + +--- a/arch/x86/boot/compressed/Makefile ++++ b/arch/x86/boot/compressed/Makefile +@@ -34,6 +34,8 @@ KBUILD_CFLAGS += $(cflags-y) + KBUILD_CFLAGS += -mno-mmx -mno-sse + KBUILD_CFLAGS += $(call cc-option,-ffreestanding) + KBUILD_CFLAGS += $(call cc-option,-fno-stack-protector) ++# Disable relocation relaxation in case the link is not PIE. ++KBUILD_CFLAGS += $(call as-option,-Wa$(comma)-mrelax-relocations=no) + + KBUILD_AFLAGS := $(KBUILD_CFLAGS) -D__ASSEMBLY__ + GCOV_PROFILE := n diff --git a/series.conf b/series.conf index eb185c2..1b782c5 100644 --- a/series.conf +++ b/series.conf @@ -58083,6 +58083,7 @@ patches.suse/USB-UAS-fix-disconnect-by-unplugging-a-hub.patch patches.suse/USB-quirks-Add-USB_QUIRK_IGNORE_REMOTE_WAKEUP-quirk-.patch patches.suse/usblp-fix-race-between-disconnect-and-read.patch + patches.suse/x86-boot-compressed-Disable-relocation-relaxation.patch patches.suse/locking-percpu-rwsem-Use-this_cpu_-inc-dec-for-read_.patch patches.suse/ftrace-Free-the-trampoline-when-ftrace_startup-fails.patch patches.suse/s390-dasd-fix-zero-write-for-fba-devices