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2020-03-08x86/boot: Use unsigned comparison for addressesArvind Sankar2-3/+3
The load address is compared with LOAD_PHYSICAL_ADDR using a signed comparison currently (using jge instruction). When loading a 64-bit kernel using the new efi32_pe_entry() point added by: 97aa276579b2 ("efi/x86: Add true mixed mode entry point into .compat section") using Qemu with -m 3072, the firmware actually loads us above 2Gb, resulting in a very early crash. Use the JAE instruction to perform a unsigned comparison instead, as physical addresses should be considered unsigned. Signed-off-by: Arvind Sankar <[email protected]> Signed-off-by: Ard Biesheuvel <[email protected]> Signed-off-by: Ingo Molnar <[email protected]> Link: https://lore.kernel.org/r/[email protected] Link: https://lore.kernel.org/r/[email protected]
2020-03-08efi/x86: Avoid using code32_startArvind Sankar2-4/+3
code32_start is meant for 16-bit real-mode bootloaders to inform the kernel where the 32-bit protected mode code starts. Nothing in the protected mode kernel except the EFI stub uses it. efi_main() currently returns boot_params, with code32_start set inside it to tell efi_stub_entry() where startup_32 is located. Since it was invoked by efi_stub_entry() in the first place, boot_params is already known. Return the address of startup_32 instead. This will allow a 64-bit kernel to live above 4Gb, for example, and it's cleaner as well. Signed-off-by: Arvind Sankar <[email protected]> Signed-off-by: Ard Biesheuvel <[email protected]> Signed-off-by: Ingo Molnar <[email protected]> Link: https://lore.kernel.org/r/[email protected] Link: https://lore.kernel.org/r/[email protected]
2020-03-08efi/x86: Make efi32_pe_entry() more readableArvind Sankar1-17/+40
Set up a proper frame pointer in efi32_pe_entry() so that it's easier to calculate offsets for arguments. Signed-off-by: Arvind Sankar <[email protected]> Signed-off-by: Ard Biesheuvel <[email protected]> Signed-off-by: Ingo Molnar <[email protected]> Link: https://lore.kernel.org/r/[email protected] Link: https://lore.kernel.org/r/[email protected]
2020-03-08efi/x86: Respect 32-bit ABI in efi32_pe_entry()Arvind Sankar1-0/+4
verify_cpu() clobbers BX and DI. In case we have to return error, we need to preserve them to respect the 32-bit calling convention. Signed-off-by: Arvind Sankar <[email protected]> Signed-off-by: Ard Biesheuvel <[email protected]> Signed-off-by: Ingo Molnar <[email protected]> Link: https://lore.kernel.org/r/[email protected] Link: https://lore.kernel.org/r/[email protected]
2020-03-08efi/x86: Annotate the LOADED_IMAGE_PROTOCOL_GUID with SYM_DATAArvind Sankar1-3/+6
Use SYM_DATA*() macros to annotate this constant, and explicitly align it to 4-byte boundary. Use lower-case for hexadecimal data. Signed-off-by: Arvind Sankar <[email protected]> Signed-off-by: Ard Biesheuvel <[email protected]> Signed-off-by: Ingo Molnar <[email protected]> Link: https://lore.kernel.org/r/[email protected] Link: https://lore.kernel.org/r/[email protected]
2020-02-29x86/boot/compressed: Fix reloading of GDTR post-relocationArvind Sankar2-7/+6
The following commit: ef5a7b5eb13e ("efi/x86: Remove GDT setup from efi_main") introduced GDT setup into the 32-bit kernel's startup_32, and reloads the GDTR after relocating the kernel for paranoia's sake. A followup commit: 32d009137a56 ("x86/boot: Reload GDTR after copying to the end of the buffer") introduced a similar GDTR reload in the 64-bit kernel as well. The GDTR is adjusted by (init_size-_end), however this may not be the correct offset to apply if the kernel was loaded at a misaligned address or below LOAD_PHYSICAL_ADDR, as in that case the decompression buffer has an additional offset from the original load address. This should never happen for a conformant bootloader, but we're being paranoid anyway, so just store the new GDT address in there instead of adding any offsets, which is simpler as well. Fixes: ef5a7b5eb13e ("efi/x86: Remove GDT setup from efi_main") Fixes: 32d009137a56 ("x86/boot: Reload GDTR after copying to the end of the buffer") Signed-off-by: Arvind Sankar <[email protected]> Signed-off-by: Ingo Molnar <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Ard Biesheuvel <[email protected]> Cc: [email protected] Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Link: https://lore.kernel.org/r/[email protected]
2020-02-26Merge tag 'efi-next' of ↵Ingo Molnar6-972/+155
git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi into efi/core Pull EFI updates for v5.7 from Ard Biesheuvel: This time, the set of changes for the EFI subsystem is much larger than usual. The main reasons are: - Get things cleaned up before EFI support for RISC-V arrives, which will increase the size of the validation matrix, and therefore the threshold to making drastic changes, - After years of defunct maintainership, the GRUB project has finally started to consider changes from the distros regarding UEFI boot, some of which are highly specific to the way x86 does UEFI secure boot and measured boot, based on knowledge of both shim internals and the layout of bootparams and the x86 setup header. Having this maintenance burden on other architectures (which don't need shim in the first place) is hard to justify, so instead, we are introducing a generic Linux/UEFI boot protocol. Summary of changes: - Boot time GDT handling changes (Arvind) - Simplify handling of EFI properties table on arm64 - Generic EFI stub cleanups, to improve command line handling, file I/O, memory allocation, etc. - Introduce a generic initrd loading method based on calling back into the firmware, instead of relying on the x86 EFI handover protocol or device tree. - Introduce a mixed mode boot method that does not rely on the x86 EFI handover protocol either, and could potentially be adopted by other architectures (if another one ever surfaces where one execution mode is a superset of another) - Clean up the contents of struct efi, and move out everything that doesn't need to be stored there. - Incorporate support for UEFI spec v2.8A changes that permit firmware implementations to return EFI_UNSUPPORTED from UEFI runtime services at OS runtime, and expose a mask of which ones are supported or unsupported via a configuration table. - Various documentation updates and minor code cleanups (Heinrich) - Partial fix for the lack of by-VA cache maintenance in the decompressor on 32-bit ARM. Note that these patches were deliberately put at the beginning so they can be used as a stable branch that will be shared with a PR containing the complete fix, which I will send to the ARM tree. Signed-off-by: Ingo Molnar <[email protected]>
2020-02-25x86/vmlinux: Drop unneeded linker script discard of .eh_frameArvind Sankar1-5/+0
Now that .eh_frame sections for the files in setup.elf and realmode.elf are not generated anymore, the linker scripts don't need the special output section name /DISCARD/ any more. Remove the one in the main kernel linker script as well, since there are no .eh_frame sections already, and fix up a comment referencing .eh_frame. Update the comment in asm/dwarf2.h referring to .eh_frame so it continues to make sense, as well as being more specific. [ bp: Touch up commit message. ] Signed-off-by: Arvind Sankar <[email protected]> Signed-off-by: Borislav Petkov <[email protected]> Reviewed-by: Nathan Chancellor <[email protected]> Reviewed-by: Nick Desaulniers <[email protected]> Reviewed-by: Kees Cook <[email protected]> Tested-by: Nathan Chancellor <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-02-25x86/*/Makefile: Use -fno-asynchronous-unwind-tables to suppress .eh_frame ↵Arvind Sankar1-0/+1
sections While discussing a patch to discard .eh_frame from the compressed vmlinux using the linker script, Fangrui Song pointed out [1] that these sections shouldn't exist in the first place because arch/x86/Makefile uses -fno-asynchronous-unwind-tables. It turns out this is because the Makefiles used to build the compressed kernel redefine KBUILD_CFLAGS, dropping this flag. Add the flag to the Makefile for the compressed kernel, as well as the EFI stub Makefile to fix this. Also add the flag to boot/Makefile and realmode/rm/Makefile so that the kernel's boot code (boot/setup.elf) and realmode trampoline (realmode/rm/realmode.elf) won't be compiled with .eh_frame sections, since their linker scripts also just discard them. [1] https://lore.kernel.org/lkml/[email protected]/ Suggested-by: Fangrui Song <[email protected]> Signed-off-by: Arvind Sankar <[email protected]> Signed-off-by: Borislav Petkov <[email protected]> Reviewed-by: Nathan Chancellor <[email protected]> Reviewed-by: Nick Desaulniers <[email protected]> Reviewed-by: Kees Cook <[email protected]> Tested-by: Nathan Chancellor <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-02-24x86/boot/compressed: Remove .eh_frame section from bzImageArvind Sankar1-0/+5
Discarding unnecessary sections with "*(*)" (see thread at Link: below) works fine with the bfd linker but fails with lld: $ make -j$(nproc) -s CC=clang LD=ld.lld O=out.x86_64 distclean defconfig bzImage ld.lld: error: discarding .shstrtab section is not allowed lld tries to also discard essential sections like .shstrtab, .symtab and .strtab, which results in the link failing since .shstrtab is required by the ELF specification: the e_shstrndx field in the ELF header is the index of .shstrtab, and each section in the section table is required to have an sh_name that points into the .shstrtab. .symtab and .strtab are also necessary to generate the zoffset.h file for the bzImage header. Since the only sizeable section that can be discarded is .eh_frame, restrict the discard to only .eh_frame to be safe. [ bp: Flesh out commit message and replace offending commit with this one. ] Signed-off-by: Arvind Sankar <[email protected]> Signed-off-by: Borislav Petkov <[email protected]> Tested-by: Nathan Chancellor <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-02-23efi/x86: Implement mixed mode boot without the handover protocolArd Biesheuvel1-2/+57
Add support for booting 64-bit x86 kernels from 32-bit firmware running on 64-bit capable CPUs without requiring the bootloader to implement the EFI handover protocol or allocate the setup block, etc etc, all of which can be done by the stub itself, using code that already exists. Instead, create an ordinary EFI application entrypoint but implemented in 32-bit code [so that it can be invoked by 32-bit firmware], and stash the address of this 32-bit entrypoint in the .compat section where the bootloader can find it. Note that we use the setup block embedded in the binary to go through startup_32(), but it gets reallocated and copied in efi_pe_entry(), using the same code that runs when the x86 kernel is booted in EFI mode from native firmware. This requires the loaded image protocol to be installed on the kernel image's EFI handle, and point to the kernel image itself and not to its loader. This, in turn, requires the bootloader to use the LoadImage() boot service to load the 64-bit image from 32-bit firmware, which is in fact supported by firmware based on EDK2. (Only StartImage() will fail, and instead, the newly added entrypoint needs to be invoked) Signed-off-by: Ard Biesheuvel <[email protected]>
2020-02-23efi/libstub/x86: Incorporate eboot.c into libstubArd Biesheuvel3-812/+1
Most of the EFI stub source files of all architectures reside under drivers/firmware/efi/libstub, where they share a Makefile with special CFLAGS and an include file with declarations that are only relevant for stub code. Currently, we carry a lot of stub specific stuff in linux/efi.h only because eboot.c in arch/x86 needs them as well. So let's move eboot.c into libstub/, and move the contents of eboot.h that we still care about into efistub.h Signed-off-by: Ard Biesheuvel <[email protected]>
2020-02-22efi/libstub/x86: Avoid overflowing code32_start on PE entryArd Biesheuvel1-22/+18
When using the native PE entry point (as opposed to the EFI handover protocol entry point that is used more widely), we set code32_start, which is a 32-bit wide field, to the effective symbol address of startup_32, which could overflow given that the EFI loader may have located the running image anywhere in memory, and we haven't reached the point yet where we relocate ourselves. Since we relocate ourselves if code32_start != pref_address, this isn't likely to lead to problems in practice, given how unlikely it is that the truncated effective address of startup_32 happens to equal pref_address. But it is better to defer the assignment of code32_start to after the relocation, when it is guaranteed to fit. While at it, move the call to efi_relocate_kernel() to an earlier stage so it is more likely that our preferred offset in memory has not been occupied by other memory allocations done in the mean time. Signed-off-by: Ard Biesheuvel <[email protected]>
2020-02-22efi/libstub/x86: Remove pointless zeroing of apm_bios_infoArd Biesheuvel1-5/+0
We have some code in the EFI stub entry point that takes the address of the apm_bios_info struct in the newly allocated and zeroed out boot_params structure, only to zero it out again. This is pointless so remove it. Signed-off-by: Ard Biesheuvel <[email protected]>
2020-02-22efi/x86: Mark setup_graphics staticArvind Sankar1-1/+1
This function is only called from efi_main in the same source file. Signed-off-by: Arvind Sankar <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Ard Biesheuvel <[email protected]>
2020-02-22x86/boot: Micro-optimize GDT loading instructionsArvind Sankar1-7/+8
Rearrange the instructions a bit to use a 32-bit displacement once instead of 2/3 times. This saves 8 bytes of machine code. Signed-off-by: Arvind Sankar <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Ard Biesheuvel <[email protected]>
2020-02-22x86/boot: GDT limit value should be size - 1Arvind Sankar1-2/+2
The limit value for the GDTR should be such that adding it to the base address gives the address of the last byte of the GDT, i.e. it should be one less than the size, not the size. Signed-off-by: Arvind Sankar <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Ard Biesheuvel <[email protected]>
2020-02-22efi/x86: Remove GDT setup from efi_mainArvind Sankar2-109/+34
The 64-bit kernel will already load a GDT in startup_64, which is the next function to execute after return from efi_main. Add GDT setup code to the 32-bit kernel's startup_32 as well. Doing it in the head code has the advantage that we can avoid potentially corrupting the GDT during copy/decompression. This also removes dependence on having a specific GDT layout setup by the bootloader. Both startup_32 and startup_64 now clear interrupts on entry, so we can remove that from efi_main as well. Signed-off-by: Arvind Sankar <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Ard Biesheuvel <[email protected]>
2020-02-22x86/boot: Clear direction and interrupt flags in startup_64Arvind Sankar1-0/+3
startup_32 already clears these flags on entry, do it in startup_64 as well for consistency. The direction flag in particular is not specified to be cleared in the boot protocol documentation, and we currently call into C code (paging_prepare) without explicitly clearing it. Signed-off-by: Arvind Sankar <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Ard Biesheuvel <[email protected]>
2020-02-22x86/boot: Reload GDTR after copying to the end of the bufferArvind Sankar1-0/+10
The GDT may get overwritten during the copy or during extract_kernel, which will cause problems if any segment register is touched before the GDTR is reloaded by the decompressed kernel. For safety update the GDTR to point to the GDT within the copied kernel. Signed-off-by: Arvind Sankar <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Ard Biesheuvel <[email protected]>
2020-02-22efi/x86: Don't depend on firmware GDT layoutArvind Sankar2-17/+42
When booting in mixed mode, the firmware's GDT is still installed at handover entry in efi32_stub_entry. We save the GDTR for later use in __efi64_thunk but we are assuming that descriptor 2 (__KERNEL_CS) is a valid 32-bit code segment descriptor and that descriptor 3 (__KERNEL_DS/__BOOT_DS) is a valid data segment descriptor. This happens to be true for OVMF (it actually uses descriptor 1 for data segments, but descriptor 3 is also setup as data), but we shouldn't depend on this being the case. Fix this by saving the code and data selectors in addition to the GDTR in efi32_stub_entry, and restoring them in __efi64_thunk before calling the firmware. The UEFI specification guarantees that selectors will be flat, so using the DS selector for all the segment registers should be enough. We also need to install our own GDT before initializing segment registers in startup_32, so move the GDT load up to the beginning of the function. [ardb: mention mixed mode in the commit log] Signed-off-by: Arvind Sankar <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Ard Biesheuvel <[email protected]>
2020-02-22x86/boot: Remove KEEP_SEGMENTS supportArvind Sankar2-16/+0
Commit a24e785111a3 ("i386: paravirt boot sequence") added this flag for use by paravirtualized environments such as Xen. However, Xen never made use of this flag [1], and it was only ever used by lguest [2]. Commit ecda85e70277 ("x86/lguest: Remove lguest support") removed lguest, so KEEP_SEGMENTS has lost its last user. [1] https://lore.kernel.org/lkml/[email protected] [2] https://www.mail-archive.com/[email protected]/msg00469.html Signed-off-by: Arvind Sankar <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Ard Biesheuvel <[email protected]>
2020-02-19x86/boot/compressed/64: Remove .bss/.pgtable from bzImageArvind Sankar1-1/+1
Commit 5b11f1cee579 ("x86, boot: straighten out ranges to copy/zero in compressed/head*.S") introduced a separate .pgtable section, splitting it out from the rest of .bss. This section was added without the writeable flag, marking it as read-only. This results in the linker putting the .rela.dyn section (containing bogus dynamic relocations from head_64.o) after the .bss and .pgtable sections. When objcopy is used to convert compressed/vmlinux into a binary for the bzImage: $ objcopy -O binary -R .note -R .comment -S arch/x86/boot/compressed/vmlinux \ arch/x86/boot/vmlinux.bin the .bss and .pgtable sections get materialized as ~176KiB of zero bytes in the binary in order to place .rela.dyn at the correct location. Fix this by marking .pgtable as writeable. This moves the .rela.dyn section up in the ELF image layout so that .bss and .pgtable are the last allocated sections and so don't appear in bzImage. [ bp: Massage commit message. ] Signed-off-by: Arvind Sankar <[email protected]> Signed-off-by: Borislav Petkov <[email protected]> Acked-by: Kees Cook <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-02-19x86/boot/compressed: Don't declare __force_order in kaslr_64.cH.J. Lu1-3/+0
GCC 10 changed the default to -fno-common, which leads to LD arch/x86/boot/compressed/vmlinux ld: arch/x86/boot/compressed/pgtable_64.o:(.bss+0x0): multiple definition of `__force_order'; \ arch/x86/boot/compressed/kaslr_64.o:(.bss+0x0): first defined here make[2]: *** [arch/x86/boot/compressed/Makefile:119: arch/x86/boot/compressed/vmlinux] Error 1 Since __force_order is already provided in pgtable_64.c, there is no need to declare __force_order in kaslr_64.c. Signed-off-by: H.J. Lu <[email protected]> Signed-off-by: Borislav Petkov <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-02-12x86/boot/compressed/64: Use 32-bit (zero-extended) MOV for z_output_lenArvind Sankar1-1/+1
z_output_len is the size of the decompressed payload (i.e. vmlinux + vmlinux.relocs) and is generated as an unsigned 32-bit quantity by mkpiggy.c. The current movq $z_output_len, %r9 instruction generates a sign-extended move to %r9. Using movl $z_output_len, %r9d will instead zero-extend into %r9, which is appropriate for an unsigned 32-bit quantity. This is also what is already done for z_input_len, the size of the compressed payload. [ bp: Also, z_output_len cannot be a 64-bit quantity because it participates in: init_size: .long INIT_SIZE # kernel initialization size through INIT_SIZE which is a 32-bit quantity determined by the .long directive (vs .quad for 64-bit). Furthermore, if it really must be a 64-bit quantity, then the insn must be MOVABS which can accommodate a 64-bit immediate and which the toolchain does not generate automatically. ] Signed-off-by: Arvind Sankar <[email protected]> Signed-off-by: Borislav Petkov <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-02-12x86/boot/compressed/64: Use LEA to initialize boot stack pointerArvind Sankar1-3/+1
It's shorter, and it's what is used in every other place, so make it consistent. Signed-off-by: Arvind Sankar <[email protected]> Signed-off-by: Borislav Petkov <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-02-09Merge tag 'kbuild-v5.6-2' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull more Kbuild updates from Masahiro Yamada: - fix randconfig to generate a sane .config - rename hostprogs-y / always to hostprogs / always-y, which are more natual syntax. - optimize scripts/kallsyms - fix yes2modconfig and mod2yesconfig - make multiple directory targets ('make foo/ bar/') work * tag 'kbuild-v5.6-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: kbuild: make multiple directory targets work kconfig: Invalidate all symbols after changing to y or m. kallsyms: fix type of kallsyms_token_table[] scripts/kallsyms: change table to store (strcut sym_entry *) scripts/kallsyms: rename local variables in read_symbol() kbuild: rename hostprogs-y/always to hostprogs/always-y kbuild: fix the document to use extra-y for vmlinux.lds kconfig: fix broken dependency in randconfig-generated .config
2020-02-09Merge tag 'x86-urgent-2020-02-09' of ↵Linus Torvalds1-0/+6
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Thomas Gleixner: "A set of fixes for X86: - Ensure that the PIT is set up when the local APIC is disable or configured in legacy mode. This is caused by an ordering issue introduced in the recent changes which skip PIT initialization when the TSC and APIC frequencies are already known. - Handle malformed SRAT tables during early ACPI parsing which caused an infinite loop anda boot hang. - Fix a long standing race in the affinity setting code which affects PCI devices with non-maskable MSI interrupts. The problem is caused by the non-atomic writes of the MSI address (destination APIC id) and data (vector) fields which the device uses to construct the MSI message. The non-atomic writes are mandated by PCI. If both fields change and the device raises an interrupt after writing address and before writing data, then the MSI block constructs a inconsistent message which causes interrupts to be lost and subsequent malfunction of the device. The fix is to redirect the interrupt to the new vector on the current CPU first and then switch it over to the new target CPU. This allows to observe an eventually raised interrupt in the transitional stage (old CPU, new vector) to be observed in the APIC IRR and retriggered on the new target CPU and the new vector. The potential spurious interrupts caused by this are harmless and can in the worst case expose a buggy driver (all handlers have to be able to deal with spurious interrupts as they can and do happen for various reasons). - Add the missing suspend/resume mechanism for the HYPERV hypercall page which prevents resume hibernation on HYPERV guests. This change got lost before the merge window. - Mask the IOAPIC before disabling the local APIC to prevent potentially stale IOAPIC remote IRR bits which cause stale interrupt lines after resume" * tag 'x86-urgent-2020-02-09' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/apic: Mask IOAPIC entries when disabling the local APIC x86/hyperv: Suspend/resume the hypercall page for hibernation x86/apic/msi: Plug non-maskable MSI affinity race x86/boot: Handle malformed SRAT tables during early ACPI parsing x86/timer: Don't skip PIT setup when APIC is disabled or in legacy mode
2020-02-04kbuild: rename hostprogs-y/always to hostprogs/always-yMasahiro Yamada1-1/+1
In old days, the "host-progs" syntax was used for specifying host programs. It was renamed to the current "hostprogs-y" in 2004. It is typically useful in scripts/Makefile because it allows Kbuild to selectively compile host programs based on the kernel configuration. This commit renames like follows: always -> always-y hostprogs-y -> hostprogs So, scripts/Makefile will look like this: always-$(CONFIG_BUILD_BIN2C) += ... always-$(CONFIG_KALLSYMS) += ... ... hostprogs := $(always-y) $(always-m) I think this makes more sense because a host program is always a host program, irrespective of the kernel configuration. We want to specify which ones to compile by CONFIG options, so always-y will be handier. The "always", "hostprogs-y", "hostprogs-m" will be kept for backward compatibility for a while. Signed-off-by: Masahiro Yamada <[email protected]>
2020-01-31x86/boot: Handle malformed SRAT tables during early ACPI parsingSteven Clarkson1-0/+6
Break an infinite loop when early parsing of the SRAT table is caused by a subtable with zero length. Known to affect the ASUS WS X299 SAGE motherboard with firmware version 1201 which has a large block of zeros in its SRAT table. The kernel could boot successfully on this board/firmware prior to the introduction of early parsing this table or after a BIOS update. [ bp: Fixup whitespace damage and commit message. Make it return 0 to denote that there are no immovable regions because who knows what else is broken in this BIOS. ] Fixes: 02a3e3cdb7f1 ("x86/boot: Parse SRAT table and count immovable memory regions") Signed-off-by: Steven Clarkson <[email protected]> Signed-off-by: Borislav Petkov <[email protected]> Cc: [email protected] Link: https://bugzilla.kernel.org/show_bug.cgi?id=206343 Link: https://lkml.kernel.org/r/CAHKq8taGzj0u1E_i=poHUam60Bko5BpiJ9jn0fAupFUYexvdUQ@mail.gmail.com
2020-01-28Merge branch 'x86-asm-for-linus' of ↵Linus Torvalds1-5/+3
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 asm updates from Ingo Molnar: "Misc updates: - Remove last remaining calls to exception_enter/exception_exit() and simplify the entry code some more. - Remove force_iret() - Add support for "Fast Short Rep Mov", which is available starting with Ice Lake Intel CPUs - and make the x86 assembly version of memmove() use REP MOV for all sizes when FSRM is available. - Micro-optimize/simplify the 32-bit boot code a bit. - Use a more future-proof SYSRET instruction mnemonic" * 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/boot: Simplify calculation of output address x86/entry/64: Add instruction suffix to SYSRET x86: Remove force_iret() x86/cpufeatures: Add support for fast short REP; MOVSB x86/context-tracking: Remove exception_enter/exit() from KVM_PV_REASON_PAGE_NOT_PRESENT async page fault x86/context-tracking: Remove exception_enter/exit() from do_page_fault()
2020-01-25efi/libstub/x86: Fix EFI server boot failureQian Cai1-1/+1
x86_64 EFI systems are unable to boot due to a typo in a recent commit: EFI config tables not found. -- System halted This was probably due to the absense of CONFIG_EFI_MIXED=y in testing. Fixes: 796eb8d26a57 ("efi/libstub/x86: Use const attribute for efi_is_64bit()") Signed-off-by: Qian Cai <[email protected]> Acked-by: Ard Biesheuvel <[email protected]> Signed-off-by: Ingo Molnar <[email protected]> Cc: [email protected] Cc: [email protected] Link: https://lore.kernel.org/r/[email protected]
2020-01-23x86/boot: Simplify calculation of output addressArvind Sankar1-5/+3
Condense the calculation of decompressed kernel start a little. Committer notes: before: ebp = ebx - (init_size - _end) after: eax = (ebx + _end) - init_size where in both ebx contains the temporary address the kernel is moved to for in-place decompression. The before and after difference in register state is %eax and %ebp but that is immaterial because the compressed image is not built with -mregparm, i.e., all arguments of the following extract_kernel() call are passed on the stack. Signed-off-by: Arvind Sankar <[email protected]> Signed-off-by: Borislav Petkov <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-01-20Merge tag 'v5.5-rc7' into locking/kcsan, to refresh the treeIngo Molnar1-0/+5
Signed-off-by: Ingo Molnar <[email protected]>
2020-01-20efi/libstub/x86: Fix unused-variable warningArnd Bergmann1-2/+0
The only users of these got removed, so they also need to be removed to avoid warnings: arch/x86/boot/compressed/eboot.c: In function 'setup_efi_pci': arch/x86/boot/compressed/eboot.c:117:16: error: unused variable 'nr_pci' [-Werror=unused-variable] unsigned long nr_pci; ^~~~~~ arch/x86/boot/compressed/eboot.c: In function 'setup_uga': arch/x86/boot/compressed/eboot.c:244:16: error: unused variable 'nr_ugas' [-Werror=unused-variable] unsigned long nr_ugas; ^~~~~~~ Fixes: 2732ea0d5c0a ("efi/libstub: Use a helper to iterate over a EFI handle array") Signed-off-by: Arnd Bergmann <[email protected]> Signed-off-by: Ard Biesheuvel <[email protected]> Signed-off-by: Ingo Molnar <[email protected]> Link: https://lore.kernel.org/r/[email protected]
2020-01-20efi/libstub/x86: Use mandatory 16-byte stack alignment in mixed modeArd Biesheuvel1-33/+13
Reduce the stack frame of the EFI stub's mixed mode thunk routine by 8 bytes, by moving the GDT and return addresses to EBP and EBX, which we need to preserve anyway, since their top halves will be cleared by the call into 32-bit firmware code. Doing so results in the UEFI code being entered with a 16 byte aligned stack, as mandated by the UEFI spec, fixing the last occurrence in the 64-bit kernel where we violate this requirement. Also, move the saved GDT from a global variable to an unused part of the stack frame, and touch up some other parts of the code. Signed-off-by: Ard Biesheuvel <[email protected]> Signed-off-by: Ingo Molnar <[email protected]> Link: https://lore.kernel.org/r/[email protected]
2020-01-20efi/libstub/x86: Use const attribute for efi_is_64bit()Ard Biesheuvel2-12/+9
Reshuffle the x86 stub code a bit so that we can tag the efi_is_64bit() function with the 'const' attribute, which permits the compiler to optimize away any redundant calls. Since we have two different entry points for 32 and 64 bit firmware in the startup code, this also simplifies the C code since we'll enter it with the efi_is64 variable already set. Signed-off-by: Ard Biesheuvel <[email protected]> Signed-off-by: Ingo Molnar <[email protected]> Link: https://lore.kernel.org/r/[email protected]
2020-01-10efi/x86: Allow translating 64-bit arguments for mixed mode callsArvind Sankar1-16/+0
Introduce the ability to define macros to perform argument translation for the calls that need it, and define them for the boot services that we currently use. When calling 32-bit firmware methods in mixed mode, all output parameters that are 32-bit according to the firmware, but 64-bit in the kernel (ie OUT UINTN * or OUT VOID **) must be initialized in the kernel, or the upper 32 bits may contain garbage. Define macros that zero out the upper 32 bits of the output before invoking the firmware method. When a 32-bit EFI call takes 64-bit arguments, the mixed-mode call must push the two 32-bit halves as separate arguments onto the stack. This can be achieved by splitting the argument into its two halves when calling the assembler thunk. Define a macro to do this for the free_pages boot service. Signed-off-by: Arvind Sankar <[email protected]> Signed-off-by: Ard Biesheuvel <[email protected]> Cc: Andy Lutomirski <[email protected]> Cc: Ard Biesheuvel <[email protected]> Cc: Matthew Garrett <[email protected]> Cc: [email protected] Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2020-01-10efi/x86: Check number of arguments to variadic functionsArvind Sankar1-2/+2
On x86 we need to thunk through assembler stubs to call the EFI services for mixed mode, and for runtime services in 64-bit mode. The assembler stubs have limits on how many arguments it handles. Introduce a few macros to check that we do not try to pass too many arguments to the stubs. Signed-off-by: Arvind Sankar <[email protected]> Signed-off-by: Ard Biesheuvel <[email protected]> Cc: Andy Lutomirski <[email protected]> Cc: Ard Biesheuvel <[email protected]> Cc: Matthew Garrett <[email protected]> Cc: [email protected] Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2020-01-10efi/libstub/x86: Force 'hidden' visibility for extern declarationsArd Biesheuvel1-0/+2
Commit c3710de5065d ("efi/libstub/x86: Drop __efi_early() export and efi_config struct") introduced a reference from C code in eboot.c to the startup_32 symbol defined in the .S startup code. This results in a GOT based reference to startup_32, and since GOT entries carry absolute addresses, they need to be fixed up before they can be used. On modern toolchains (binutils 2.26 or later), this reference is relaxed into a R_386_GOTOFF relocation (or the analogous X86_64 one) which never uses the absolute address in the entry, and so we get away with not fixing up the GOT table before calling the EFI entry point. However, GCC 4.6 combined with a binutils of the era (2.24) will produce a true GOT indirected reference, resulting in a wrong value to be returned for the address of startup_32() if the boot code is not running at the address it was linked at. Fortunately, we can easily override this behavior, and force GCC to emit the GOTOFF relocations explicitly, by setting the visibility pragma 'hidden'. Signed-off-by: Ard Biesheuvel <[email protected]> Cc: Andy Lutomirski <[email protected]> Cc: Ard Biesheuvel <[email protected]> Cc: Arvind Sankar <[email protected]> Cc: Matthew Garrett <[email protected]> Cc: [email protected] Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2020-01-10efi/libstub: Fix boot argument handling in mixed mode entry codeArd Biesheuvel1-7/+10
The mixed mode refactor actually broke mixed mode by failing to pass the bootparam structure to startup_32(). This went unnoticed because it apparently has a high tolerance for being passed random junk, and still boots fine in some cases. So let's fix this by populating %esi as required when entering via efi32_stub_entry, and while at it, preserve the arguments themselves instead of their address in memory (via the stack pointer) since that memory could be clobbered before we get to it. Signed-off-by: Ard Biesheuvel <[email protected]> Cc: Andy Lutomirski <[email protected]> Cc: Arvind Sankar <[email protected]> Cc: Matthew Garrett <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2019-12-30Merge tag 'v5.5-rc4' into locking/kcsan, to resolve conflictsIngo Molnar9-71/+151
Conflicts: init/main.c lib/Kconfig.debug Signed-off-by: Ingo Molnar <[email protected]>
2019-12-25efi/libstub/x86: Avoid globals to store context during mixed mode callsArd Biesheuvel1-14/+3
Instead of storing the return address in a global variable when calling a 32-bit EFI service from the 64-bit stub, avoid the indirection via efi_exit32, and take the return address from the stack. Signed-off-by: Ard Biesheuvel <[email protected]> Cc: Arvind Sankar <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: James Morse <[email protected]> Cc: Matt Fleming <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2019-12-25efi/libstub: Rename efi_call_early/_runtime macros to be more intuitiveArd Biesheuvel1-42/+35
The macros efi_call_early and efi_call_runtime are used to call EFI boot services and runtime services, respectively. However, the naming is confusing, given that the early vs runtime distinction may suggest that these are used for calling the same set of services either early or late (== at runtime), while in reality, the sets of services they can be used with are completely disjoint, and efi_call_runtime is also only usable in 'early' code. So do a global sweep to replace all occurrences with efi_bs_call or efi_rt_call, respectively, where BS and RT match the idiom used by the UEFI spec to refer to boot time or runtime services. While at it, use 'func' as the macro parameter name for the function pointers, which is less likely to collide and cause weird build errors. Signed-off-by: Ard Biesheuvel <[email protected]> Cc: Arvind Sankar <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: James Morse <[email protected]> Cc: Matt Fleming <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2019-12-25efi/libstub: Drop 'table' argument from efi_table_attr() macroArd Biesheuvel1-4/+4
None of the definitions of the efi_table_attr() still refer to their 'table' argument so let's get rid of it entirely. Signed-off-by: Ard Biesheuvel <[email protected]> Cc: Arvind Sankar <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: James Morse <[email protected]> Cc: Matt Fleming <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2019-12-25efi/libstub: Drop protocol argument from efi_call_proto() macroArd Biesheuvel1-14/+9
After refactoring the mixed mode support code, efi_call_proto() no longer uses its protocol argument in any of its implementation, so let's remove it altogether. Signed-off-by: Ard Biesheuvel <[email protected]> Cc: Arvind Sankar <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: James Morse <[email protected]> Cc: Matt Fleming <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2019-12-25efi/libstub/x86: Work around page freeing issue in mixed modeArd Biesheuvel1-0/+16
Mixed mode translates calls from the 64-bit kernel into the 32-bit firmware by wrapping them in a call to a thunking routine that pushes a 32-bit word onto the stack for each argument passed to the function, regardless of the argument type. This works surprisingly well for most services and protocols, with the exception of ones that take explicit 64-bit arguments. efi_free() invokes the FreePages() EFI boot service, which takes a efi_physical_addr_t as its address argument, and this is one of those 64-bit types. This means that the 32-bit firmware will interpret the (addr, size) pair as a single 64-bit quantity, and since it is guaranteed to have the high word set (as size > 0), it will always fail due to the fact that EFI memory allocations are always < 4 GB on 32-bit firmware. So let's fix this by giving the thunking code a little hand, and pass two values for the address, and a third one for the size. Signed-off-by: Ard Biesheuvel <[email protected]> Cc: Arvind Sankar <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: James Morse <[email protected]> Cc: Matt Fleming <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2019-12-25efi/libstub: Remove 'sys_table_arg' from all function prototypesArd Biesheuvel1-22/+18
We have a helper efi_system_table() that gives us the address of the EFI system table in memory, so there is no longer point in passing it around from each function to the next. Signed-off-by: Ard Biesheuvel <[email protected]> Cc: Arvind Sankar <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: James Morse <[email protected]> Cc: Matt Fleming <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2019-12-25efi/libstub: Drop sys_table_arg from printk routinesArd Biesheuvel1-14/+14
As a first step towards getting rid of the need to pass around a function parameter 'sys_table_arg' pointing to the EFI system table, remove the references to it in the printing code, which is represents the majority of the use cases. Signed-off-by: Ard Biesheuvel <[email protected]> Cc: Arvind Sankar <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: James Morse <[email protected]> Cc: Matt Fleming <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2019-12-25efi/libstub/x86: Drop __efi_early() export and efi_config structArd Biesheuvel3-169/+45
The various pointers we stash in the efi_config struct which we retrieve using __efi_early() are simply copies of the ones in the EFI system table, which we have started accessing directly in the previous patch. So drop all the __efi_early() related plumbing, as well as all the assembly code dealing with efi_config, which allows us to move the PE/COFF entry point to C code as well. Signed-off-by: Ard Biesheuvel <[email protected]> Cc: Arvind Sankar <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: James Morse <[email protected]> Cc: Matt Fleming <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>