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| * | s390/fpu: provide and use lfpc, sfpc, and stfpc inline assembliesHeiko Carstens2024-02-163-10/+32
| | | | | | | | | | | | | | | | | | | | | | | | | | | Instead of open-coding lfpc, sfpc, and stfpc inline assemblies at several locations, provide an fpu_* function for each instruction and use the function instead. Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/fpu: provide and use ld and std inline assembliesHeiko Carstens2024-02-163-72/+67
| | | | | | | | | | | | | | | | | | | | | | | | | | | Deduplicate the 64 ld and std inline assemblies. Provide an fpu inline assembly for both instructions, and use them in the new save_fp_regs() and load_fp_regs() helper functions. Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/fpu: use lfpc instead of sfpc instructionHeiko Carstens2024-02-162-9/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The only user of sfpc_safe() needs to read the new fpc register value from memory before it is set with sfpc. Avoid this indirection and use lfpc, which reads the new value from memory. Also add the "fpu_" prefix to have a common name space for fpu related inline assemblies, and provide memory access instrumentation. Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/fpu: add documentation about fpu helper functionsHeiko Carstens2024-02-161-0/+20
| | | | | | | | | | | | | | | | | | | | | | | | Add documentation which describes what the fpu helper functions are good for, and why they should be used. Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/fpu: move, rename, and merge header filesHeiko Carstens2024-02-1630-145/+129
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Move, rename, and merge the fpu and vx header files. This way fpu header files have a consistent naming scheme (fpu*.h). Also get rid of the fpu subdirectory and move header files to asm directory, so that all fpu and vx header files can be found at the same location. Merge internal.h header file into other header files, since the internal helpers are used at many locations. so those helper functions are really not internal. Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/fpu: various coding style changesHeiko Carstens2024-02-164-27/+24
| | | | | | | | | | | | | | | | | | | | | | | | | | | Address various checkpatch warnings, adjust whitespace, and try to increase readability. This is just preparation, in order to avoid that subsequent patches contain any distracting drive-by coding style changes. Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/fpu: use KERNEL_VXR_LOW instead of KERNEL_VXR_V0V7Heiko Carstens2024-02-161-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Use KERNEL_VXR_LOW instead of KERNEL_VXR_V0V7 for configurations without vector registers in order to decide if floating point registers need to be saved and restored. Kernel FPU areas which use floating point registers are supposed to use the KERNEL_FPR mask, however users may also open-code this and specify KERNEL_VXR_V0V7 and/or KERNEL_VXR_V8V15. If only KERNEL_VXR_V8V15 is specified floating point registers wouldn't be saved and restored. Improve this and check for both bits. There are currently no users where this would fix a bug. Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/nmi: remove register validation codeHeiko Carstens2024-02-162-122/+47
| | | | | | | | | | | | | | | | | | | | | | | | | | | Remove the historic machine check handler code which validates registers. Registers are automatically validated as part of the machine check handling sequence (see Principles of Operation, Machine-Check Handling chapter, Validation). Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/fpu: improve description of RXB macroHeiko Carstens2024-02-161-4/+26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The v1, v2, v3, and v4 parameters of the RXB macro are a bit misleading, since the reader can assume that the parameters always correlate with the instructions format fields V1, V2, V3, and V4 as defined in the Principles of Operation. This is not the case for a couple of instructions, therefore improve the description of the macro. Suggested by Jens Remus, who also provided the improved description. Suggested-by: Jens Remus <jremus@linux.ibm.com> Reviewed-by: Jens Remus <jremus@linux.ibm.com> Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/fpu: fix VLGV macroHeiko Carstens2024-02-161-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The VLGV macro generates the VLGV instruction and has a vr parameter which correlates to the V3 vector register field of the instruction (bits 12-15). Due to its position in the VRS-c instruction format of the VLGV instruction, this field correlates to the second bit of the RXB byte of the instruction (see Principles of Operation, Chapter "Vector Overview and Support Instructions"). Within the VLGV macro the MRXBOPC macro is used to generate the RXB field of the instruction. The usage of the MRXBOPC macro is incorrect, since the vector register number is passed as third parameter (which correlates to the first bit of the RXB byte), while it should be passed as fourth parameter (second bit of the RXB byte). In result an incorrect instruction would be generated if the VLGV macro would be used for vector register numbers larger than 15. Fix this and pass the vector register number as fourth parameter. Currently there are no users within the kernel which use the macro in a way that broken code would be generated. Reviewed-by: Jens Remus <jremus@linux.ibm.com> Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Reviewed-by: Hendrik Brueckner <brueckner@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/setup: fix virtual vs physical address confusionGerald Schaefer2024-02-161-6/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix virtual vs physical address confusion. This does not fix a bug since virtual and physical address spaces are currently the same. /proc/iomem should report the physical address ranges, so use __pa_symbol() for resource registration, similar to other architectures. Signed-off-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390: don't allow CONFIG_COMPAT with LD=ld.lldNathan Chancellor2024-02-161-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When building 'ARCH=s390 defconfig compat.config' with GCC and LD=ld.lld, there is an error when attempting to link the compat vDSO: ld.lld: error: unknown emulation: elf_s390 make[4]: *** [arch/s390/kernel/vdso32/Makefile:48: arch/s390/kernel/vdso32/vdso32.so.dbg] Error 1 Much like clang, ld.lld only supports the 64-bit s390 emulation. Add a dependency on not using LLD to CONFIG_COMPAT to avoid breaking the build with this toolchain combination. Signed-off-by: Nathan Chancellor <nathan@kernel.org> Link: https://lore.kernel.org/r/20240214-s390-compat-lld-dep-v1-1-abf1f4b5e514@kernel.org Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/vdso: remove unused ENTRY in linker scriptsHeiko Carstens2024-02-142-2/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When linking vdso64.so.dbg with ld.lld, there is a warning about not finding _start for the starting address: ld.lld: warning: cannot find entry symbol _start; not setting start address Fix this by removing the unused ENTRY in both vdso linker scripts. See commit e247172854a5 ("powerpc/vdso: Remove unused ENTRY in linker scripts"), which solved the same problem for powerpc, for further details. Reviewed-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/bug: remove entry size from __bug_table sectionHeiko Carstens2024-02-141-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit e21f8baf8d9a ("s390/bug: add entry size to the __bug_table section") changed the __EMIT_BUG() inline assembly to emit mergeable __bug_table entries. This is at least currently not needed, but causes problems with the upcoming s390 ld.lld support: ld.lld: error: drivers/nvme/host/fc.o:(__bug_table): writable SHF_MERGE section is not supported Therefore revert the change for now. Reported-by: Nathan Chancellor <nathan@kernel.org> Closes: https://lore.kernel.org/all/20240207-s390-lld-and-orphan-warn-v1-0-8a665b3346ab@kernel.org/ Suggested-by: Nathan Chancellor <nathan@kernel.org> Reviewed-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390: link vmlinux with '-z notext'Nathan Chancellor2024-02-141-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | ld.bfd defaults to '-z notext' (although it is customizable with the '--enable-textrel-check' configure option) but ld.lld defaults to '-z text', which causes issues with building the kernel due to the presence of dynamic relocations in sections that are not writable. ld.lld: error: relocation R_390_64 cannot be used against local symbol; recompile with -fPIC Add '-z notext' to avoid these errors, as this is expected, which matches other architectures. Signed-off-by: Nathan Chancellor <nathan@kernel.org> Tested-by: Justin Stitt <justinstitt@google.com> Reviewed-by: Fangrui Song <maskray@google.com> Link: https://lore.kernel.org/r/20240207-s390-lld-and-orphan-warn-v1-11-8a665b3346ab@kernel.org Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390: select CONFIG_ARCH_WANT_LD_ORPHAN_WARNNathan Chancellor2024-02-141-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now that all sections have been properly accounted for in the s390 linker scripts, select CONFIG_ARCH_WANT_LD_ORPHAN_WARN so that '--orphan-handling' is added to LDFLAGS to catch any future sections that are added without being described in linker scripts. Signed-off-by: Nathan Chancellor <nathan@kernel.org> Tested-by: Justin Stitt <justinstitt@google.com> Link: https://lore.kernel.org/r/20240207-s390-lld-and-orphan-warn-v1-10-8a665b3346ab@kernel.org Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/boot: vmlinux.lds.S: handle commonly discarded sectionsNathan Chancellor2024-02-141-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When building with CONFIG_LD_ORPHAN_WARN after selecting CONFIG_ARCH_HAS_LD_ORPHAN_WARN, there are several series of warnings from the various discardable sections that the kernel adds for build purposes that are not needed at runtime: s390-linux-ld: warning: orphan section `.export_symbol' from `arch/s390/boot/decompressor.o' being placed in section `.export_symbol' s390-linux-ld: warning: orphan section `.discard.addressable' from `arch/s390/boot/decompressor.o' being placed in section `.discard.addressable' s390-linux-ld: warning: orphan section `.modinfo' from `arch/s390/boot/decompressor.o' being placed in section `.modinfo' include/asm-generic/vmlinux.lds.h has a macro for easily discarding these sections across the kernel named COMMON_DISCARDS, use it to clear up the warnings. Signed-off-by: Nathan Chancellor <nathan@kernel.org> Tested-by: Justin Stitt <justinstitt@google.com> Link: https://lore.kernel.org/r/20240207-s390-lld-and-orphan-warn-v1-9-8a665b3346ab@kernel.org Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/boot: vmlinux.lds.S: handle ELF required sectionsNathan Chancellor2024-02-141-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When building with CONFIG_LD_ORPHAN_WARN after selecting CONFIG_ARCH_HAS_LD_ORPHAN_WARN, there is a warning around the '.comment' section for each file in arch/s390/boot s390-linux-ld: warning: orphan section `.comment' from `arch/s390/boot/als.o' being placed in section `.comment' s390-linux-ld: warning: orphan section `.comment' from `arch/s390/boot/startup.o' being placed in section `.comment' s390-linux-ld: warning: orphan section `.comment' from `arch/s390/boot/physmem_info.o' being placed in section `.comment' include/asm-generic/vmlinux.lds.h has a macro for required ELF sections not related to debugging named ELF_DETAILS, use it to clear up the warnings. Signed-off-by: Nathan Chancellor <nathan@kernel.org> Tested-by: Justin Stitt <justinstitt@google.com> Link: https://lore.kernel.org/r/20240207-s390-lld-and-orphan-warn-v1-8-8a665b3346ab@kernel.org Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/boot: vmlinux.lds.S: handle DWARF debug sectionsNathan Chancellor2024-02-141-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When building with CONFIG_LD_ORPHAN_WARN after selecting CONFIG_ARCH_HAS_LD_ORPHAN_WARN, there are several series of warnings for each file in arch/s390/boot due to the boot linker script not handling the DWARF debug sections: s390-linux-ld: warning: orphan section `.debug_line' from `arch/s390/boot/head.o' being placed in section `.debug_line' s390-linux-ld: warning: orphan section `.debug_info' from `arch/s390/boot/head.o' being placed in section `.debug_info' s390-linux-ld: warning: orphan section `.debug_abbrev' from `arch/s390/boot/head.o' being placed in section `.debug_abbrev' s390-linux-ld: warning: orphan section `.debug_aranges' from `arch/s390/boot/head.o' being placed in section `.debug_aranges' s390-linux-ld: warning: orphan section `.debug_str' from `arch/s390/boot/head.o' being placed in section `.debug_str' include/asm-generic/vmlinux.lds.h has a macro for DWARF debug sections named DWARF_DEBUG, use it to clear up the warnings. Signed-off-by: Nathan Chancellor <nathan@kernel.org> Tested-by: Justin Stitt <justinstitt@google.com> Reviewed-by: Fangrui Song <maskray@google.com> Link: https://lore.kernel.org/r/20240207-s390-lld-and-orphan-warn-v1-7-8a665b3346ab@kernel.org Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/boot: vmlinux.lds.S: handle '.rela' sectionsNathan Chancellor2024-02-141-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When building with CONFIG_LD_ORPHAN_WARN after selecting CONFIG_ARCH_HAS_LD_ORPHAN_WARN, there are several warnings from arch/s390/boot/head.o due to the unhandled presence of '.rela' sections: s390-linux-ld: warning: orphan section `.rela.iplt' from `arch/s390/boot/head.o' being placed in section `.rela.dyn' s390-linux-ld: warning: orphan section `.rela.head.text' from `arch/s390/boot/head.o' being placed in section `.rela.dyn' s390-linux-ld: warning: orphan section `.rela.got' from `arch/s390/boot/head.o' being placed in section `.rela.dyn' s390-linux-ld: warning: orphan section `.rela.data' from `arch/s390/boot/head.o' being placed in section `.rela.dyn' s390-linux-ld: warning: orphan section `.rela.data.rel.ro' from `arch/s390/boot/head.o' being placed in section `.rela.dyn' s390-linux-ld: warning: orphan section `.rela.iplt' from `arch/s390/boot/head.o' being placed in section `.rela.dyn' s390-linux-ld: warning: orphan section `.rela.head.text' from `arch/s390/boot/head.o' being placed in section `.rela.dyn' s390-linux-ld: warning: orphan section `.rela.got' from `arch/s390/boot/head.o' being placed in section `.rela.dyn' s390-linux-ld: warning: orphan section `.rela.data' from `arch/s390/boot/head.o' being placed in section `.rela.dyn' s390-linux-ld: warning: orphan section `.rela.data.rel.ro' from `arch/s390/boot/head.o' being placed in section `.rela.dyn' These sections are unneeded for the decompressor and they are not emitted in the binary currently. In a manner similar to other architectures, coalesce the sections into '.rela.dyn' and ensure it is zero sized, which is a safe/tested approach versus full discard. Signed-off-by: Nathan Chancellor <nathan@kernel.org> Tested-by: Justin Stitt <justinstitt@google.com> Link: https://lore.kernel.org/r/20240207-s390-lld-and-orphan-warn-v1-6-8a665b3346ab@kernel.org Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/boot: vmlinux.lds.S: handle '.init.text'Nathan Chancellor2024-02-141-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When building with CONFIG_LD_ORPHAN_WARN after selecting CONFIG_ARCH_HAS_LD_ORPHAN_WARN, there is a warning about the presence of an '.init.text' section in arch/s390/boot: s390-linux-ld: warning: orphan section `.init.text' from `arch/s390/boot/sclp_early_core.o' being placed in section `.init.text' arch/s390/boot/sclp_early_core.c includes a file from the main kernel build, which picks up a usage of '__init' somewhere. For the decompressed image, this section can just be coalesced into '.text'. Signed-off-by: Nathan Chancellor <nathan@kernel.org> Tested-by: Justin Stitt <justinstitt@google.com> Link: https://lore.kernel.org/r/20240207-s390-lld-and-orphan-warn-v1-5-8a665b3346ab@kernel.org Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390: vmlinux.lds.S: explicitly keep various sectionsNathan Chancellor2024-02-141-0/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When building with CONFIG_LD_ORPHAN_WARN after selecting CONFIG_ARCH_HAS_LD_ORPHAN_WARN, there are some warnings around certain ELF sections: s390-linux-ld: warning: orphan section `.dynstr' from `arch/s390/kernel/head64.o' being placed in section `.dynstr' s390-linux-ld: warning: orphan section `.dynamic' from `arch/s390/kernel/head64.o' being placed in section `.dynamic' s390-linux-ld: warning: orphan section `.hash' from `arch/s390/kernel/head64.o' being placed in section `.hash' s390-linux-ld: warning: orphan section `.gnu.hash' from `arch/s390/kernel/head64.o' being placed in section `.gnu.hash' Explicitly keep those sections like other architectures when CONFIG_RELOCATABLE is enabled, which is always true for s390. [hca@linux.ibm.com: keep sections instead of discarding] Signed-off-by: Nathan Chancellor <nathan@kernel.org> Link: https://lore.kernel.org/r/20240207-s390-lld-and-orphan-warn-v1-4-8a665b3346ab@kernel.org Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390: vmlinux.lds.S: explicitly handle '.got' and '.plt' sectionsNathan Chancellor2024-02-142-0/+32
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When building with CONFIG_LD_ORPHAN_WARN after selecting CONFIG_ARCH_HAS_LD_ORPHAN_WARN, there are a lot of warnings around the GOT and PLT sections: s390-linux-ld: warning: orphan section `.plt' from `arch/s390/kernel/head64.o' being placed in section `.plt' s390-linux-ld: warning: orphan section `.got' from `arch/s390/kernel/head64.o' being placed in section `.got' s390-linux-ld: warning: orphan section `.got.plt' from `arch/s390/kernel/head64.o' being placed in section `.got.plt' s390-linux-ld: warning: orphan section `.iplt' from `arch/s390/kernel/head64.o' being placed in section `.iplt' s390-linux-ld: warning: orphan section `.igot.plt' from `arch/s390/kernel/head64.o' being placed in section `.igot.plt' s390-linux-ld: warning: orphan section `.iplt' from `arch/s390/boot/head.o' being placed in section `.iplt' s390-linux-ld: warning: orphan section `.igot.plt' from `arch/s390/boot/head.o' being placed in section `.igot.plt' s390-linux-ld: warning: orphan section `.got' from `arch/s390/boot/head.o' being placed in section `.got' Currently, only the '.got' section is actually emitted in the final binary. In a manner similar to other architectures, put the '.got' section near the '.data' section and coalesce the PLT sections, checking that the final section is zero sized, which is a safe/tested approach versus full discard. Signed-off-by: Nathan Chancellor <nathan@kernel.org> Tested-by: Justin Stitt <justinstitt@google.com> Link: https://lore.kernel.org/r/20240207-s390-lld-and-orphan-warn-v1-3-8a665b3346ab@kernel.org Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390: vmlinux.lds.S: handle '.data.rel' sections explicitlyNathan Chancellor2024-02-141-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When building with CONFIG_LD_ORPHAN_WARN after selecting CONFIG_ARCH_HAS_LD_ORPHAN_WARN, there are a lot of warnings around '.data.rel' sections: s390-linux-ld: warning: orphan section `.data.rel' from `kernel/sched/build_utility.o' being placed in section `.data.rel' s390-linux-ld: warning: orphan section `.data.rel.local' from `kernel/sched/build_utility.o' being placed in section `.data.rel.local' s390-linux-ld: warning: orphan section `.data.rel.ro' from `kernel/sched/build_utility.o' being placed in section `.data.rel.ro' s390-linux-ld: warning: orphan section `.data.rel.ro.local' from `kernel/sched/build_utility.o' being placed in section `.data.rel.ro.local' Describe these in vmlinux.lds.S so there is no more warning and the sections are placed consistently between linkers. Signed-off-by: Nathan Chancellor <nathan@kernel.org> Tested-by: Justin Stitt <justinstitt@google.com> Link: https://lore.kernel.org/r/20240207-s390-lld-and-orphan-warn-v1-2-8a665b3346ab@kernel.org Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/boot: add support for CONFIG_LD_ORPHAN_WARNNathan Chancellor2024-02-141-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | arch/s390/boot/vmlinux uses a different linker script and build rules than the main vmlinux, so the '--orphan-handling' flag is not applied to it. Add support for '--orphan-handling' so that all sections are properly described in the linker script, which helps eliminate bugs between linker implementations having different orphan section heuristics. Signed-off-by: Nathan Chancellor <nathan@kernel.org> Tested-by: Justin Stitt <justinstitt@google.com> Link: https://lore.kernel.org/r/20240207-s390-lld-and-orphan-warn-v1-1-8a665b3346ab@kernel.org Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/switch_to: use generic header fileHeiko Carstens2024-02-1210-47/+34
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Move the switch_to() implementation to process.c and use the generic switch_to.h header file instead, like some other architectures. This addresses also the oddity that the old switch_to() implementation assigns the return value of __switch_to() to 'prev' instead of 'last', like it should. Remove also all includes of switch_to.h from C files, except process.c. Acked-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/acrs: cleanup access register handlingHeiko Carstens2024-02-1210-21/+48
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | save_access_regs() and restore_access_regs() are only available by including switch_to.h. This is done by a couple of C files, which have nothing to do with switch_to(), but only need these functions. Move both functions to a new header file and improve the implementation: - Get rid of typedef - Add memory access instrumentation support - Use long displacement instructions lamy/stamy instead of lam/stam - all current users end up with better code because of this Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/extmem: fix virtual vs physical address confusionAlexander Gordeev2024-02-091-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | Fix virtual vs physical address confusion. This does not fix a bug since virtual and physical address spaces are currently the same. Acked-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/fpu: make use of __uninitialized macroHeiko Carstens2024-02-094-3/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Code sections in s390 specific kernel code which use floating point or vector registers all come with a 520 byte stack variable to save already in use registers, if required. With INIT_STACK_ALL_PATTERN or INIT_STACK_ALL_ZERO enabled this variable will always be initialized on function entry in addition to saving register contents, which contradicts the intention (performance improvement) of such code sections. Therefore provide a DECLARE_KERNEL_FPU_ONSTACK() macro which provides struct kernel_fpu variables with an __uninitialized attribute, and convert all existing code to use this. This way only this specific type of stack variable will not be initialized, regardless of config options. Reviewed-by: Nathan Chancellor <nathan@kernel.org> Reviewed-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20240205154844.3757121-3-hca@linux.ibm.com Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/time: make stp_subsys constRicardo B. Marliere2024-02-091-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now that the driver core can properly handle constant struct bus_type, move the stp_subsys variable to be a constant structure as well, placing it into read-only memory which can not be modified at runtime. Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: "Ricardo B. Marliere" <ricardo@marliere.net> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Link: https://lore.kernel.org/r/20240204-bus_cleanup-s390_time-v1-1-d2120156982a@marliere.net Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/vdso: drop '-fPIC' from LDFLAGSNathan Chancellor2024-02-092-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | '-fPIC' as an option to the linker does not do what it seems like it should. With ld.bfd, it is treated as '-f PIC', which does not make sense based on the meaning of '-f': -f SHLIB, --auxiliary SHLIB Auxiliary filter for shared object symbol table When building with ld.lld (currently under review in a GitHub pull request), it just errors out because '-f' means nothing and neither does '-fPIC': ld.lld: error: unknown argument '-fPIC' '-fPIC' was blindly copied from CFLAGS when the vDSO stopped being linked with '$(CC)', it should not be needed. Remove it to clear up the build failure with ld.lld. Fixes: 2b2a25845d53 ("s390/vdso: Use $(LD) instead of $(CC) to link vDSO") Link: https://github.com/llvm/llvm-project/pull/75643 Signed-off-by: Nathan Chancellor <nathan@kernel.org> Reviewed-by: Fangrui Song <maskray@google.com> Link: https://lore.kernel.org/r/20240130-s390-vdso-drop-fpic-from-ldflags-v1-1-094ad104fc55@kernel.org Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/mmap: disable mmap alignment when randomize_va_space = 0Sven Schnelle2024-02-091-8/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Stefan reported a test case fail in libc. The test runs with randomize_va_space set to zero, i.e. disabled randomization. Additionally, it runs the program with the dynamic loader. Looking at the failure showed that the heap was placed right before some pages mapped from the binary. This made memory allocation fail after a few allocations. Normally, when address randomization is switched off and the binary is loaded from the dynamic loader, the kernel places the binary below the 128MB top gap. So the address map would look like this: 3fff7fd1000-3fff7fd2000 r--p 00000000 5e:01 1447115 /lib/ld64.so.1 3fff7fd2000-3fff7ff2000 r-xp 00001000 5e:01 1447115 /lib/ld64.so.1 3fff7ff2000-3fff7ffc000 r--p 00021000 5e:01 1447115 /lib/ld64.so.1 3fff7ffc000-3fff7ffe000 r--p 0002a000 5e:01 1447115 /lib/ld64.so.1 3fff7ffe000-3fff8000000 rw-p 0002c000 5e:01 1447115 /lib/ld64.so.1 3fff8000000-3fff8021000 rw-p 00000000 00:00 0 [heap] 3fffffda000-3ffffffb000 rw-p 00000000 00:00 0 [stack] 3ffffffc000-3ffffffe000 r--p 00000000 00:00 0 [vvar] 3ffffffe000-40000000000 r-xp 00000000 00:00 0 [vdso] However, commit 1f6b83e5e4d3 ("s390: avoid z13 cache aliasing") introduced a mmap alignment mask of 8MB. With this commit, the memory map now looks like this: 3fff7f80000-3fff7f81000 r--p 00000000 5e:01 1447115 /lib/ld64.so.1 3fff7f81000-3fff7fa1000 r-xp 00001000 5e:01 1447115 /lib/ld64.so.1 3fff7fa1000-3fff7fab000 r--p 00021000 5e:01 1447115 /lib/ld64.so.1 3fff7fab000-3fff7fad000 r--p 0002a000 5e:01 1447115 /lib/ld64.so.1 3fff7fad000-3fff7faf000 rw-p 0002c000 5e:01 1447115 /lib/ld64.so.1 3fff7faf000-3fff7fd0000 rw-p 00000000 00:00 0 [heap] 3fff7fdc000-3fff8000000 rw-p 00000000 00:00 0 3fffffda000-3ffffffb000 rw-p 00000000 00:00 0 [stack] 3ffffffc000-3ffffffe000 r--p 00000000 00:00 0 [vvar] 3ffffffe000-40000000000 r-xp 00000000 00:00 0 [vdso] The reason for this placement is that the elf loader loads the binary to end at mmap_base (0x3fff8000000 on s390). This would result in a start address of 0x3fff7fd1000, but due to the alignment requirement of 8MB, mmap chooses 0x3fff7f80000. This causes a gap between the end of the mapped binary and mmap_base. When the next non-shared and non-file pages are mapped, mmap searches from top to bottom and the first free space it finds is the gap which is now present. This leaves only a few pages for the heap. With enabled address space randomization this doesn't happen because the binary is mapped to a completely different memory area. Fix this by disabling the mmap alignment when address space randomization is disabled. This is in line with what other architectures are doing. Reported-by: Stefan Liebler <stli@linux.ibm.com> Tested-by: Stefan Liebler <stli@linux.ibm.com> Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/hypfs_sprp: remove unneeded DMA zone allocationHeiko Carstens2024-02-091-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | Remove GFP_DMA flag when allocating memory to be used for diagnose 304. Diagnose 304 can access memory beyond the DMA zone. Suggested-by: Alexander Gordeev <agordeev@linux.ibm.com> Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/diag: add missing virt_to_phys() translation to diag14()Thomas Richter2024-02-091-0/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | diag14() is currently only used by the vmur device driver. The third parameter, called subcommand, determines the type of the first parameter. For some subcommands the value of the first parameter is an address to a memory buffer and needs virtual to physical address conversion. Other subcommands interpret the first parameter is an integer. This doesn't fix a bug since virtual and physical addresses are currently the same. Suggested-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Thomas Richter <tmricht@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/time: improve steering precisionSven Schnelle2024-02-091-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The common timekeeping code steers the clock by adjusting the multiplier value of the clock. With the current value of 1000 precision is lost when the clock is steered with a userspace daemon. Increase the multiplier and the shift values to increase precision. Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Acked-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/pai_crypto: return proper error code in paicrypt_initThomas Richter2024-02-091-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | paicrypt_init() return incorrect error code in case the number of PAI crypto counters is too high. Change the return code to -E2BIG. Please merge with d0b0efedc7fe Reported-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Thomas Richter <tmricht@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/pai: export number of sysfs attribute filesThomas Richter2024-02-092-6/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The number of sysfs files to be exported by the PAI device drivers depends on the hardware version level. Use the value returned by the hardware as the maximum number of counters to be exported in the sysfs attribute tree. Without the fix, older machine generation export counter names based on paiXXXX_ctrnames static array info, which can be inaccurate, as this array could also contain newer counter names in the future. This ensures proper pai counter sysfs attributes for both newer generation and older generation processors. Signed-off-by: Thomas Richter <tmricht@linux.ibm.com> Acked-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/pai_crypto: emit error on too many countersThomas Richter2024-02-091-2/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When the device driver is initialized, it checks the number of possible counters. Should this number be too high, emit an error and return. Reported-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Signed-off-by: Thomas Richter <tmricht@linux.ibm.com> Acked-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/pai: fix attr_event_free upper limit for pai device driversThomas Richter2024-02-092-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When the device drivers are initialized, a sysfs directory is created. This contains many attributes which are allocated with kzalloc(). Should it fail, the memory for the attributes already created is freed in attr_event_free(). Its second parameter is number of attribute elements to delete. This parameter is off by one. When i. e. the 10th attribute fails to get created, attributes numbered 0 to 9 should be deleted. Currently only attributes numbered 0 to 8 are deleted. Fixes: 39d62336f5c1 ("s390/pai: add support for cryptography counters") Reported-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Signed-off-by: Thomas Richter <tmricht@linux.ibm.com> Acked-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/hypfs_diag0c: fix virtual vs physical address confusionHeiko Carstens2024-02-094-5/+20
| | | | | | | | | | | | | | | | | | | | | | | | Add missing virt_to_phys() translation to diag0c(). This doesn't fix a bug since virtual and physical addresses are currently the same. Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/hypfs_sprp: fix virtual vs physical address confusionHeiko Carstens2024-02-091-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | Add missing virt_to_phys() translation to __hypfs_sprp_diag304(). This doesn't fix a bug since virtual and physical addresses are currently the same. Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/appldata: fix virtual vs physical address confusionGerald Schaefer2024-02-091-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | Fix virtual vs physical address confusion (which currently are the same). Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/diag: fix diag26c() physical vs virtual address confusionAlexander Gordeev2024-02-092-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | Fix virtual vs physical address confusion (which currently are the same). Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
* | | Merge tag 'x86-boot-2024-03-12' of ↵Linus Torvalds2024-03-1221-329/+259
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 boot updates from Ingo Molnar: - Continuing work by Ard Biesheuvel to improve the x86 early startup code, with the long-term goal to make it position independent: - Get rid of early accesses to global objects, either by moving them to the stack, deferring the access until later, or dropping the globals entirely - Move all code that runs early via the 1:1 mapping into .head.text, and move code that does not out of it, so that build time checks can be added later to ensure that no inadvertent absolute references were emitted into code that does not tolerate them - Remove fixup_pointer() and occurrences of __pa_symbol(), which rely on the compiler emitting absolute references, which is not guaranteed - Improve the early console code - Add early console message about ignored NMIs, so that users are at least warned about their existence - even if we cannot do anything about them - Improve the kexec code's kernel load address handling - Enable more X86S (simplified x86) bits - Simplify early boot GDT handling - Micro-optimize the boot code a bit - Misc cleanups * tag 'x86-boot-2024-03-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (22 commits) x86/sev: Move early startup code into .head.text section x86/sme: Move early SME kernel encryption handling into .head.text x86/boot: Move mem_encrypt= parsing to the decompressor efi/libstub: Add generic support for parsing mem_encrypt= x86/startup_64: Simplify virtual switch on primary boot x86/startup_64: Simplify calculation of initial page table address x86/startup_64: Defer assignment of 5-level paging global variables x86/startup_64: Simplify CR4 handling in startup code x86/boot: Use 32-bit XOR to clear registers efi/x86: Set the PE/COFF header's NX compat flag unconditionally x86/boot/64: Load the final kernel GDT during early boot directly, remove startup_gdt[] x86/boot/64: Use RIP_REL_REF() to access early_top_pgt[] x86/boot/64: Use RIP_REL_REF() to access early page tables x86/boot/64: Use RIP_REL_REF() to access '__supported_pte_mask' x86/boot/64: Use RIP_REL_REF() to access early_dynamic_pgts[] x86/boot/64: Use RIP_REL_REF() to assign 'phys_base' x86/boot/64: Simplify global variable accesses in GDT/IDT programming x86/trampoline: Bypass compat mode in trampoline_start64() if not needed kexec: Allocate kernel above bzImage's pref_address x86/boot: Add a message about ignored early NMIs ...
| * \ \ Merge branch 'linus' into x86/boot, to resolve conflictIngo Molnar2024-03-12291-3368/+5286
| |\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There's a new conflict with Linus's upstream tree, because in the following merge conflict resolution in <asm/coco.h>: 38b334fc767e Merge tag 'x86_sev_for_v6.9_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Linus has resolved the conflicting placement of 'cc_mask' better than the original commit: 1c811d403afd x86/sev: Fix position dependent variable references in startup code ... which was also done by an internal merge resolution: 2e5fc4786b7a Merge branch 'x86/sev' into x86/boot, to resolve conflicts and to pick up dependent tree But Linus is right in 38b334fc767e, the 'cc_mask' declaration is sufficient within the #ifdef CONFIG_ARCH_HAS_CC_PLATFORM block. So instead of forcing Linus to do the same resolution again, merge in Linus's tree and follow his conflict resolution. Conflicts: arch/x86/include/asm/coco.h Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | x86/sev: Move early startup code into .head.text sectionArd Biesheuvel2024-03-044-24/+26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In preparation for implementing rigorous build time checks to enforce that only code that can support it will be called from the early 1:1 mapping of memory, move SEV init code that is called in this manner to the .head.text section. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Tested-by: Tom Lendacky <thomas.lendacky@amd.com> Link: https://lore.kernel.org/r/20240227151907.387873-19-ardb+git@google.com
| * | | | x86/sme: Move early SME kernel encryption handling into .head.textArd Biesheuvel2024-03-042-29/+21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The .head.text section is the initial primary entrypoint of the core kernel, and is entered with the CPU executing from a 1:1 mapping of memory. Such code must never access global variables using absolute references, as these are based on the kernel virtual mapping which is not active yet at this point. Given that the SME startup code is also called from this early execution context, move it into .head.text as well. This will allow more thorough build time checks in the future to ensure that early startup code only uses RIP-relative references to global variables. Also replace some occurrences of __pa_symbol() [which relies on the compiler generating an absolute reference, which is not guaranteed] and an open coded RIP-relative access with RIP_REL_REF(). Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Tested-by: Tom Lendacky <thomas.lendacky@amd.com> Link: https://lore.kernel.org/r/20240227151907.387873-18-ardb+git@google.com
| * | | | x86/boot: Move mem_encrypt= parsing to the decompressorArd Biesheuvel2024-03-044-42/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The early SME/SEV code parses the command line very early, in order to decide whether or not memory encryption should be enabled, which needs to occur even before the initial page tables are created. This is problematic for a number of reasons: - this early code runs from the 1:1 mapping provided by the decompressor or firmware, which uses a different translation than the one assumed by the linker, and so the code needs to be built in a special way; - parsing external input while the entire kernel image is still mapped writable is a bad idea in general, and really does not belong in security minded code; - the current code ignores the built-in command line entirely (although this appears to be the case for the entire decompressor) Given that the decompressor/EFI stub is an intrinsic part of the x86 bootable kernel image, move the command line parsing there and out of the core kernel. This removes the need to build lib/cmdline.o in a special way, or to use RIP-relative LEA instructions in inline asm blocks. This involves a new xloadflag in the setup header to indicate that mem_encrypt=on appeared on the kernel command line. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Tested-by: Tom Lendacky <thomas.lendacky@amd.com> Link: https://lore.kernel.org/r/20240227151907.387873-17-ardb+git@google.com
| * | | | x86/startup_64: Simplify virtual switch on primary bootArd Biesheuvel2024-03-041-21/+21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The secondary startup code is used on the primary boot path as well, but in this case, the initial part runs from a 1:1 mapping, until an explicit cross-jump is made to the kernel virtual mapping of the same code. On the secondary boot path, this jump is pointless as the code already executes from the mapping targeted by the jump. So combine this cross-jump with the jump from startup_64() into the common boot path. This simplifies the execution flow, and clearly separates code that runs from a 1:1 mapping from code that runs from the kernel virtual mapping. Note that this requires a page table switch, so hoist the CR3 assignment into startup_64() as well. And since absolute symbol references will no longer be permitted in .head.text once we enable the associated build time checks, a RIP-relative memory operand is used in the JMP instruction, referring to an absolute constant in the .init.rodata section. Given that the secondary startup code does not require a special placement inside the executable, move it to the .text section. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Tested-by: Tom Lendacky <thomas.lendacky@amd.com> Link: https://lore.kernel.org/r/20240227151907.387873-15-ardb+git@google.com
| * | | | x86/startup_64: Simplify calculation of initial page table addressArd Biesheuvel2024-03-041-18/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Determining the address of the initial page table to program into CR3 involves: - taking the physical address - adding the SME encryption mask On the primary entry path, the code is mapped using a 1:1 virtual to physical translation, so the physical address can be taken directly using a RIP-relative LEA instruction. On the secondary entry path, the address can be obtained by taking the offset from the virtual kernel base (__START_kernel_map) and adding the physical kernel base. This is implemented in a slightly confusing way, so clean this up. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Tested-by: Tom Lendacky <thomas.lendacky@amd.com> Link: https://lore.kernel.org/r/20240227151907.387873-14-ardb+git@google.com