summaryrefslogtreecommitdiff
path: root/arch/x86/boot/compressed
AgeCommit message (Collapse)AuthorFilesLines
2022-08-25x86: link vdso and boot with -z noexecstack --no-warn-rwx-segmentsNick Desaulniers1-0/+4
commit ffcf9c5700e49c0aee42dcba9a12ba21338e8136 upstream. Users of GNU ld (BFD) from binutils 2.39+ will observe multiple instances of a new warning when linking kernels in the form: ld: warning: arch/x86/boot/pmjump.o: missing .note.GNU-stack section implies executable stack ld: NOTE: This behaviour is deprecated and will be removed in a future version of the linker ld: warning: arch/x86/boot/compressed/vmlinux has a LOAD segment with RWX permissions Generally, we would like to avoid the stack being executable. Because there could be a need for the stack to be executable, assembler sources have to opt-in to this security feature via explicit creation of the .note.GNU-stack feature (which compilers create by default) or command line flag --noexecstack. Or we can simply tell the linker the production of such sections is irrelevant and to link the stack as --noexecstack. LLVM's LLD linker defaults to -z noexecstack, so this flag isn't strictly necessary when linking with LLD, only BFD, but it doesn't hurt to be explicit here for all linkers IMO. --no-warn-rwx-segments is currently BFD specific and only available in the current latest release, so it's wrapped in an ld-option check. While the kernel makes extensive usage of ELF sections, it doesn't use permissions from ELF segments. Link: https://lore.kernel.org/linux-block/3af4127a-f453-4cf7-f133-a181cce06f73@kernel.dk/ Link: https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=ba951afb99912da01a6e8434126b8fac7aa75107 Link: https://github.com/llvm/llvm-project/issues/57009 Reported-and-tested-by: Jens Axboe <axboe@kernel.dk> Suggested-by: Fangrui Song <maskray@google.com> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-09-26x86/boot: kbuild: allow readelf executable to be specifiedDmitry Golovin1-1/+1
commit eefb8c124fd969e9a174ff2bedff86aa305a7438 upstream. Introduce a new READELF variable to top-level Makefile, so the name of readelf binary can be specified. Before this change the name of the binary was hardcoded to "$(CROSS_COMPILE)readelf" which might not be present for every toolchain. This allows to build with LLVM Object Reader by using make parameter READELF=llvm-readelf. Link: https://github.com/ClangBuiltLinux/linux/issues/771 Signed-off-by: Dmitry Golovin <dima@golovin.in> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> [nd: conflict in exported vars list from not backporting commit e83b9f55448a ("kbuild: add ability to generate BTF type info for vmlinux")] Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-09-23x86/boot/compressed: Disable relocation relaxationArvind Sankar1-0/+2
commit 09e43968db40c33a73e9ddbfd937f46d5c334924 upstream. 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 <ndesaulniers@google.com> Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu> Signed-off-by: Ingo Molnar <mingo@kernel.org> Tested-by: Nick Desaulniers <ndesaulniers@google.com> Tested-by: Sedat Dilek <sedat.dilek@gmail.com> Acked-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20200812004308.1448603-1-nivedita@alum.mit.edu Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-06-22x86/boot: Correct relocation destination on old linkersArvind Sankar2-2/+4
[ Upstream commit 5214028dd89e49ba27007c3ee475279e584261f0 ] For the 32-bit kernel, as described in 6d92bc9d483a ("x86/build: Build compressed x86 kernels as PIE"), pre-2.26 binutils generates R_386_32 relocations in PIE mode. Since the startup code does not perform relocation, any reloc entry with R_386_32 will remain as 0 in the executing code. Commit 974f221c84b0 ("x86/boot: Move compressed kernel to the end of the decompression buffer") added a new symbol _end but did not mark it hidden, which doesn't give the correct offset on older linkers. This causes the compressed kernel to be copied beyond the end of the decompression buffer, rather than flush against it. This region of memory may be reserved or already allocated for other purposes by the bootloader. Mark _end as hidden to fix. This changes the relocation from R_386_32 to R_386_RELATIVE even on the pre-2.26 binutils. For 64-bit, this is not strictly necessary, as the 64-bit kernel is only built as PIE if the linker supports -z noreloc-overflow, which implies binutils-2.27+, but for consistency, mark _end as hidden here too. The below illustrates the before/after impact of the patch using binutils-2.25 and gcc-4.6.4 (locally compiled from source) and QEMU. Disassembly before patch: 48: 8b 86 60 02 00 00 mov 0x260(%esi),%eax 4e: 2d 00 00 00 00 sub $0x0,%eax 4f: R_386_32 _end Disassembly after patch: 48: 8b 86 60 02 00 00 mov 0x260(%esi),%eax 4e: 2d 00 f0 76 00 sub $0x76f000,%eax 4f: R_386_RELATIVE *ABS* Dump from extract_kernel before patch: early console in extract_kernel input_data: 0x0207c098 <--- this is at output + init_size input_len: 0x0074fef1 output: 0x01000000 output_len: 0x00fa63d0 kernel_total_size: 0x0107c000 needed_size: 0x0107c000 Dump from extract_kernel after patch: early console in extract_kernel input_data: 0x0190d098 <--- this is at output + init_size - _end input_len: 0x0074fef1 output: 0x01000000 output_len: 0x00fa63d0 kernel_total_size: 0x0107c000 needed_size: 0x0107c000 Fixes: 974f221c84b0 ("x86/boot: Move compressed kernel to the end of the decompression buffer") Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20200207214926.3564079-1-nivedita@alum.mit.edu Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-04-17x86/boot: Use unsigned comparison for addressesArvind Sankar2-3/+3
[ Upstream commit 81a34892c2c7c809f9c4e22c5ac936ae673fb9a2 ] 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 <nivedita@alum.mit.edu> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20200301230436.2246909-6-nivedita@alum.mit.edu Link: https://lore.kernel.org/r/20200308080859.21568-14-ardb@kernel.org Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-03-11x86/boot/compressed: Don't declare __force_order in kaslr_64.cH.J. Lu1-3/+0
[ Upstream commit df6d4f9db79c1a5d6f48b59db35ccd1e9ff9adfc ] 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 <hjl.tools@gmail.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20200124181811.4780-1-hjl.tools@gmail.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-01-23x86/efistub: Disable paging at mixed mode entryArd Biesheuvel1-0/+5
commit 4911ee401b7ceff8f38e0ac597cbf503d71e690c upstream. The EFI mixed mode entry code goes through the ordinary startup_32() routine before jumping into the kernel's EFI boot code in 64-bit mode. The 32-bit startup code must be entered with paging disabled, but this is not documented as a requirement for the EFI handover protocol, and so we should disable paging explicitly when entering the kernel from 32-bit EFI firmware. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Cc: <stable@vger.kernel.org> Cc: Arvind Sankar <nivedita@alum.mit.edu> Cc: Hans de Goede <hdegoede@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-efi@vger.kernel.org Link: https://lkml.kernel.org/r/20191224132909.102540-4-ardb@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-09-10x86/boot/compressed/64: Fix missing initialization in ↵Kirill A. Shutemov1-1/+1
find_trampoline_placement() [ Upstream commit c96e8483cb2da6695c8b8d0896fe7ae272a07b54 ] Gustavo noticed that 'new' can be left uninitialized if 'bios_start' happens to be less or equal to 'entry->addr + entry->size'. Initialize the variable at the begin of the iteration to the current value of 'bios_start'. Fixes: 0a46fff2f910 ("x86/boot/compressed/64: Fix boot on machines with broken E820 table") Reported-by: "Gustavo A. R. Silva" <gustavo@embeddedor.com> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20190826133326.7cxb4vbmiawffv2r@box Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-09-10x86/boot/compressed/64: Fix boot on machines with broken E820 tableKirill A. Shutemov1-3/+10
[ Upstream commit 0a46fff2f9108c2c44218380a43a736cf4612541 ] BIOS on Samsung 500C Chromebook reports very rudimentary E820 table that consists of 2 entries: BIOS-e820: [mem 0x0000000000000000-0x0000000000000fff] usable BIOS-e820: [mem 0x00000000fffff000-0x00000000ffffffff] reserved It breaks logic in find_trampoline_placement(): bios_start lands on the end of the first 4k page and trampoline start gets placed below 0. Detect underflow and don't touch bios_start for such cases. It makes kernel ignore E820 table on machines that doesn't have two usable pages below BIOS_START_MAX. Fixes: 1b3a62643660 ("x86/boot/compressed/64: Validate trampoline placement against E820") Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: x86-ml <x86@kernel.org> Link: https://bugzilla.kernel.org/show_bug.cgi?id=203463 Link: https://lkml.kernel.org/r/20190813131654.24378-1-kirill.shutemov@linux.intel.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-08-06x86, boot: Remove multiple copy of static function sanitize_boot_params()Zhenzhong Duan2-1/+1
[ Upstream commit 8c5477e8046ca139bac250386c08453da37ec1ae ] Kernel build warns: 'sanitize_boot_params' defined but not used [-Wunused-function] at below files: arch/x86/boot/compressed/cmdline.c arch/x86/boot/compressed/error.c arch/x86/boot/compressed/early_serial_console.c arch/x86/boot/compressed/acpi.c That's becausethey each include misc.h which includes a definition of sanitize_boot_params() via bootparam_utils.h. Remove the inclusion from misc.h and have the c file including bootparam_utils.h directly. Signed-off-by: Zhenzhong Duan <zhenzhong.duan@oracle.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/1563283092-1189-1-git-send-email-zhenzhong.duan@oracle.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-07-10x86/boot/compressed/64: Do not corrupt EDX on EFER.LME=1 settingKirill A. Shutemov1-0/+2
[ Upstream commit 45b13b424faafb81c8c44541f093a682fdabdefc ] RDMSR in the trampoline code overwrites EDX but that register is used to indicate whether 5-level paging has to be enabled and if clobbered, leads to failure to boot on a 5-level paging machine. Preserve EDX on the stack while we are dealing with EFER. Fixes: b677dfae5aa1 ("x86/boot/compressed/64: Set EFER.LME=1 in 32-bit trampoline before returning to long mode") Reported-by: Kyle D Pelton <kyle.d.pelton@intel.com> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: dave.hansen@linux.intel.com Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Wei Huang <wei@redhat.com> Cc: x86-ml <x86@kernel.org> Link: https://lkml.kernel.org/r/20190206115253.1907-1-kirill.shutemov@linux.intel.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-03-14x86/boot/compressed/64: Set EFER.LME=1 in 32-bit trampoline before returning ↵Wei Huang2-1/+9
to long mode [ Upstream commit b677dfae5aa197afc5191755a76a8727ffca538a ] In some old AMD KVM implementation, guest's EFER.LME bit is cleared by KVM when the hypervsior detects that the guest sets CR0.PG to 0. This causes the guest OS to reboot when it tries to return from 32-bit trampoline code because the CPU is in incorrect state: CR4.PAE=1, CR0.PG=1, CS.L=1, but EFER.LME=0. As a precaution, set EFER.LME=1 as part of long mode activation procedure. This extra step won't cause any harm when Linux is booted on a bare-metal machine. Signed-off-by: Wei Huang <wei@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: bp@alien8.de Cc: hpa@zytor.com Link: https://lkml.kernel.org/r/20190104054411.12489-1-wei@redhat.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-03-10x86/boot/compressed/64: Do not read legacy ROM on EFI systemKirill A. Shutemov1-3/+16
commit 6f913de3231e1d70a871135b38219da7810df218 upstream. EFI systems do not necessarily provide a legacy ROM. If the ROM is missing the memory is not mapped at all. Trying to dereference values in the legacy ROM area leads to a crash on Macbook Pro. Only look for values in the legacy ROM area for non-EFI system. Fixes: 3548e131ec6a ("x86/boot/compressed/64: Find a place for 32-bit trampoline") Reported-by: Pitam Mitra <pitamm@gmail.com> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Bockjoo Kim <bockjoo@phys.ufl.edu> Cc: bp@alien8.de Cc: hpa@zytor.com Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20190219075224.35058-1-kirill.shutemov@linux.intel.com Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=202351 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-13x86/efi: Allocate e820 buffer before calling efi_exit_boot_serviceEric Snowberg1-24/+41
commit b84a64fad40637b1c9fa4f4dbf847a23e29e672b upstream. The following commit: d64934019f6c ("x86/efi: Use efi_exit_boot_services()") introduced a regression on systems with large memory maps causing them to hang on boot. The first "goto get_map" that was removed from exit_boot() ensured there was enough room for the memory map when efi_call_early(exit_boot_services) was called. This happens when (nr_desc > ARRAY_SIZE(params->e820_table). Chain of events: exit_boot() efi_exit_boot_services() efi_get_memory_map <- at this point the mm can't grow over 8 desc priv_func() exit_boot_func() allocate_e820ext() <- new mm grows over 8 desc from e820 alloc efi_call_early(exit_boot_services) <- mm key doesn't match so retry efi_call_early(get_memory_map) <- not enough room for new mm system hangs This patch allocates the e820 buffer before calling efi_exit_boot_services() and fixes the regression. [ mingo: minor cleanliness edits. ] Signed-off-by: Eric Snowberg <eric.snowberg@oracle.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: <stable@vger.kernel.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arend van Spriel <arend.vanspriel@broadcom.com> Cc: Bhupesh Sharma <bhsharma@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Hans de Goede <hdegoede@redhat.com> Cc: Joe Perches <joe@perches.com> Cc: Jon Hunter <jonathanh@nvidia.com> Cc: Julien Thierry <julien.thierry@arm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: Matt Fleming <matt@codeblueprint.co.uk> Cc: Nathan Chancellor <natechancellor@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com> Cc: Sedat Dilek <sedat.dilek@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: YiFei Zhu <zhuyifei1999@gmail.com> Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/20181129171230.18699-2-ard.biesheuvel@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-13efi/x86: Call efi_parse_options() from efi_main()Hans de Goede1-0/+10
[ Upstream commit c33ce984435bb6142792802d75513a71e55d1969 ] Before this commit we were only calling efi_parse_options() from make_boot_params(), but make_boot_params() only gets called if the kernel gets booted directly as an EFI executable. So when booted through e.g. grub we ended up not parsing the commandline in the boot code. This makes the drivers/firmware/efi/libstub code ignore the "quiet" commandline argument resulting in the following message being printed: "EFI stub: UEFI Secure Boot is enabled." Despite the quiet request. This commits adds an extra call to efi_parse_options() to efi_main() to make sure that the options are always processed. This fixes quiet not working. This also fixes the libstub code ignoring nokaslr and efi=nochunk. Reported-by: Peter Robinson <pbrobinson@redhat.com> Signed-off-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-14x86/boot: Add -Wno-pointer-sign to KBUILD_CFLAGSNathan Chancellor1-0/+1
When compiling the kernel with Clang, this warning appears even though it is disabled for the whole kernel because this folder has its own set of KBUILD_CFLAGS. It was disabled before the beginning of git history. In file included from arch/x86/boot/compressed/kaslr.c:29: In file included from arch/x86/boot/compressed/misc.h:21: In file included from ./include/linux/elf.h:5: In file included from ./arch/x86/include/asm/elf.h:77: In file included from ./arch/x86/include/asm/vdso.h:11: In file included from ./include/linux/mm_types.h:9: In file included from ./include/linux/spinlock.h:88: In file included from ./arch/x86/include/asm/spinlock.h:43: In file included from ./arch/x86/include/asm/qrwlock.h:6: ./include/asm-generic/qrwlock.h:101:53: warning: passing 'u32 *' (aka 'unsigned int *') to parameter of type 'int *' converts between pointers to integer types with different sign [-Wpointer-sign] if (likely(atomic_try_cmpxchg_acquire(&lock->cnts, &cnts, _QW_LOCKED))) ^~~~~ ./include/linux/compiler.h:76:40: note: expanded from macro 'likely' # define likely(x) __builtin_expect(!!(x), 1) ^ ./include/asm-generic/atomic-instrumented.h:69:66: note: passing argument to parameter 'old' here static __always_inline bool atomic_try_cmpxchg(atomic_t *v, int *old, int new) ^ Signed-off-by: Nathan Chancellor <natechancellor@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Borislav Petkov <bp@alien8.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Nick Desaulniers <ndesaulniers@google.com> Link: https://lkml.kernel.org/r/20181013010713.6999-1-natechancellor@gmail.com
2018-09-27x86/boot: Fix kexec booting failure in the SEV bit detection codeKairui Song1-19/+0
Commit 1958b5fc4010 ("x86/boot: Add early boot support when running with SEV active") can occasionally cause system resets when kexec-ing a second kernel even if SEV is not active. That's because get_sev_encryption_bit() uses 32-bit rIP-relative addressing to read the value of enc_bit - a variable which caches a previously detected encryption bit position - but kexec may allocate the early boot code to a higher location, beyond the 32-bit addressing limit. In this case, garbage will be read and get_sev_encryption_bit() will return the wrong value, leading to accessing memory with the wrong encryption setting. Therefore, remove enc_bit, and thus get rid of the need to do 32-bit rIP-relative addressing in the first place. [ bp: massage commit message heavily. ] Fixes: 1958b5fc4010 ("x86/boot: Add early boot support when running with SEV active") Suggested-by: Borislav Petkov <bp@suse.de> Signed-off-by: Kairui Song <kasong@redhat.com> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com> Cc: linux-kernel@vger.kernel.org Cc: tglx@linutronix.de Cc: mingo@redhat.com Cc: hpa@zytor.com Cc: brijesh.singh@amd.com Cc: kexec@lists.infradead.org Cc: dyoung@redhat.com Cc: bhe@redhat.com Cc: ghook@redhat.com Link: https://lkml.kernel.org/r/20180927123845.32052-1-kasong@redhat.com
2018-08-25Merge tag 'kbuild-v4.19-2' of ↵Linus Torvalds1-3/+3
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull more Kbuild updates from Masahiro Yamada: - add build_{menu,n,g,x}config targets for compile-testing Kconfig - fix and improve recursive dependency detection in Kconfig - fix parallel building of menuconfig/nconfig - fix syntax error in clang-version.sh - suppress distracting log from syncconfig - remove obsolete "rpm" target - remove VMLINUX_SYMBOL(_STR) macro entirely - fix microblaze build with CONFIG_DYNAMIC_FTRACE - move compiler test for dead code/data elimination to Kconfig - rename well-known LDFLAGS variable to KBUILD_LDFLAGS - misc fixes and cleanups * tag 'kbuild-v4.19-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: kbuild: rename LDFLAGS to KBUILD_LDFLAGS kbuild: pass LDFLAGS to recordmcount.pl kbuild: test dead code/data elimination support in Kconfig initramfs: move gen_initramfs_list.sh from scripts/ to usr/ vmlinux.lds.h: remove stale <linux/export.h> include export.h: remove VMLINUX_SYMBOL() and VMLINUX_SYMBOL_STR() Coccinelle: remove pci_alloc_consistent semantic to detect in zalloc-simple.cocci kbuild: make sorting initramfs contents independent of locale kbuild: remove "rpm" target, which is alias of "rpm-pkg" kbuild: Fix LOADLIBES rename in Documentation/kbuild/makefiles.txt kconfig: suppress "configuration written to .config" for syncconfig kconfig: fix "Can't open ..." in parallel build kbuild: Add a space after `!` to prevent parsing as file pattern scripts: modpost: check memory allocation results kconfig: improve the recursive dependency report kconfig: report recursive dependency involving 'imply' kconfig: error out when seeing recursive dependency kconfig: add build-only configurator targets scripts/dtc: consolidate include path options in Makefile
2018-08-24kbuild: rename LDFLAGS to KBUILD_LDFLAGSMasahiro Yamada1-3/+3
Commit a0f97e06a43c ("kbuild: enable 'make CFLAGS=...' to add additional options to CC") renamed CFLAGS to KBUILD_CFLAGS. Commit 222d394d30e7 ("kbuild: enable 'make AFLAGS=...' to add additional options to AS") renamed AFLAGS to KBUILD_AFLAGS. Commit 06c5040cdb13 ("kbuild: enable 'make CPPFLAGS=...' to add additional options to CPP") renamed CPPFLAGS to KBUILD_CPPFLAGS. For some reason, LDFLAGS was not renamed. Using a well-known variable like LDFLAGS may result in accidental override of the variable. Kbuild generally uses KBUILD_ prefixed variables for the internally appended options, so here is one more conversion to sanitize the naming convention. I did not touch Makefiles under tools/ since the tools build system is a different world. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reviewed-by: Palmer Dabbelt <palmer@sifive.com>
2018-08-22module: allow symbol exports to be disabledArd Biesheuvel1-4/+1
To allow existing C code to be incorporated into the decompressor or the UEFI stub, introduce a CPP macro that turns all EXPORT_SYMBOL_xxx declarations into nops, and #define it in places where such exports are undesirable. Note that this gets rid of a rather dodgy redefine of linux/export.h's header guard. Link: http://lkml.kernel.org/r/20180704083651.24360-3-ard.biesheuvel@linaro.org Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Acked-by: Nicolas Pitre <nico@linaro.org> Acked-by: Michael Ellerman <mpe@ellerman.id.au> Reviewed-by: Will Deacon <will.deacon@arm.com> Acked-by: Ingo Molnar <mingo@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: James Morris <james.morris@microsoft.com> Cc: James Morris <jmorris@namei.org> Cc: Jessica Yu <jeyu@kernel.org> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Kees Cook <keescook@chromium.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Petr Mladek <pmladek@suse.com> Cc: Russell King <linux@armlinux.org.uk> Cc: "Serge E. Hallyn" <serge@hallyn.com> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Garnier <thgarnie@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-13Merge branch 'x86-boot-for-linus' of ↵Linus Torvalds1-6/+92
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 boot updates from Thomas Gleixner: "Boot code updates for x86: - Allow to skip a given amount of huge pages for address layout randomization on the kernel command line to prevent regressions in the huge page allocation with small memory sizes - Various cleanups" * 'x86-boot-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/boot: Use CC_SET()/CC_OUT() instead of open coding it x86/boot/KASLR: Make local variable mem_limit static x86/boot/KASLR: Skip specified number of 1GB huge pages when doing physical randomization (KASLR) x86/boot/KASLR: Add two new functions for 1GB huge pages handling
2018-08-13Merge branch 'efi-core-for-linus' of ↵Linus Torvalds2-368/+189
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull EFI updates from Thomas Gleixner: "The EFI pile: - Make mixed mode UEFI runtime service invocations mutually exclusive, as mandated by the UEFI spec - Perform UEFI runtime services calls from a work queue so the calls into the firmware occur from a kernel thread - Honor the UEFI memory map attributes for live memory regions configured by UEFI as a framebuffer. This works around a coherency problem with KVM guests running on ARM. - Cleanups, improvements and fixes all over the place" * 'efi-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: efivars: Call guid_parse() against guid_t type of variable efi/cper: Use consistent types for UUIDs efi/x86: Replace references to efi_early->is64 with efi_is_64bit() efi: Deduplicate efi_open_volume() efi/x86: Add missing NULL initialization in UGA draw protocol discovery efi/x86: Merge 32-bit and 64-bit UGA draw protocol setup routines efi/x86: Align efi_uga_draw_protocol typedef names to convention efi/x86: Merge the setup_efi_pci32() and setup_efi_pci64() routines efi/x86: Prevent reentrant firmware calls in mixed mode efi/esrt: Only call efi_mem_reserve() for boot services memory fbdev/efifb: Honour UEFI memory map attributes when mapping the FB efi: Drop type and attribute checks in efi_mem_desc_lookup() efi/libstub/arm: Add opt-in Kconfig option for the DTB loader efi: Remove the declaration of efi_late_init() as the function is unused efi/cper: Avoid using get_seconds() efi: Use a work queue to invoke EFI Runtime Services efi/x86: Use non-blocking SetVariable() for efi_delete_dummy_variable() efi/x86: Clean up the eboot code
2018-08-02x86/boot/compressed/64: Validate trampoline placement against E820Kirill A. Shutemov1-18/+55
There were two report of boot failure cased by trampoline placed into a reserved memory region. It can happen on machines that don't report EBDA correctly. Fix the problem by re-validating the found address against the E820 table. If the address is in a reserved area, find the next usable region below the initial address. Fixes: 3548e131ec6a ("x86/boot/compressed/64: Find a place for 32-bit trampoline") Reported-by: Dmitry Malkin <d.malkin@real-time-systems.com> Reported-by: youling 257 <youling257@gmail.com> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Link: https://lkml.kernel.org/r/20180801133225.38121-1-kirill.shutemov@linux.intel.com
2018-07-30x86/boot/KASLR: Make local variable mem_limit staticzhong jiang1-1/+1
Fix the following sparse warning: arch/x86/boot/compressed/kaslr.c:102:20: warning: symbol 'mem_limit' was not declared. Should it be static? Signed-off-by: zhong jiang <zhongjiang@huawei.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: <gregkh@linuxfoundation.org> Link: https://lkml.kernel.org/r/1532958273-47725-1-git-send-email-zhongjiang@huawei.com
2018-07-25x86/boot: Fix if_changed build flip/flop bugKees Cook1-2/+6
Dirk Gouders reported that two consecutive "make" invocations on an already compiled tree will show alternating behaviors: $ make CALL scripts/checksyscalls.sh DESCEND objtool CHK include/generated/compile.h DATAREL arch/x86/boot/compressed/vmlinux Kernel: arch/x86/boot/bzImage is ready (#48) Building modules, stage 2. MODPOST 165 modules $ make CALL scripts/checksyscalls.sh DESCEND objtool CHK include/generated/compile.h LD arch/x86/boot/compressed/vmlinux ZOFFSET arch/x86/boot/zoffset.h AS arch/x86/boot/header.o LD arch/x86/boot/setup.elf OBJCOPY arch/x86/boot/setup.bin OBJCOPY arch/x86/boot/vmlinux.bin BUILD arch/x86/boot/bzImage Setup is 15644 bytes (padded to 15872 bytes). System is 6663 kB CRC 3eb90f40 Kernel: arch/x86/boot/bzImage is ready (#48) Building modules, stage 2. MODPOST 165 modules He bisected it back to: commit 98f78525371b ("x86/boot: Refuse to build with data relocations") The root cause was the use of the "if_changed" kbuild function multiple times for the same target. It was designed to only be used once per target, otherwise it will effectively always trigger, flipping back and forth between the two commands getting recorded by "if_changed". Instead, this patch merges the two commands into a single function to get stable build artifacts (i.e. .vmlinux.cmd), and a single build behavior. Bisected-and-Reported-by: Dirk Gouders <dirk@gouders.net> Fix-Suggested-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20180724230827.GA37823@beast Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-22efi/x86: Replace references to efi_early->is64 with efi_is_64bit()Ard Biesheuvel1-10/+6
There are a couple of places in the x86 EFI stub code where we select between 32-bit and 64-bit versions of the support routines based on the value of efi_early->is64. Referencing that field directly is a bad idea, since it prevents the compiler from inferring that this field can never be true on a 32-bit build, and can only become false on a 64-bit build if support for mixed mode is compiled in. This results in dead code to be retained in the uncompressed part of the kernel image, which is wasteful. So switch to the efi_is_64bit() helper, which will resolve to a constant boolean unless building for 64-bit with mixed mode support. Tested-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Lukas Wunner <lukas@wunner.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/20180720014726.24031-8-ard.biesheuvel@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-22efi: Deduplicate efi_open_volume()Lukas Wunner1-63/+0
There's one ARM, one x86_32 and one x86_64 version of efi_open_volume() which can be folded into a single shared version by masking their differences with the efi_call_proto() macro introduced by commit: 3552fdf29f01 ("efi: Allow bitness-agnostic protocol calls"). To be able to dereference the device_handle attribute from the efi_loaded_image_t table in an arch- and bitness-agnostic manner, introduce the efi_table_attr() macro (which already exists for x86) to arm and arm64. No functional change intended. Signed-off-by: Lukas Wunner <lukas@wunner.de> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Hans de Goede <hdegoede@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/20180720014726.24031-7-ard.biesheuvel@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-22efi/x86: Add missing NULL initialization in UGA draw protocol discoveryArd Biesheuvel1-0/+1
The UGA draw protocol discovery routine looks for a EFI handle that has both the UGA draw protocol and the PCI I/O protocol installed. It checks for the latter by calling handle_protocol() and pass it a PCI I/O protocol pointer variable by reference, but fails to initialize it to NULL, which means the non-NULL check later on in the code could produce false positives, given that the return code of the handle_protocol() call is ignored entirely. So add the missing initialization. Tested-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Lukas Wunner <lukas@wunner.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/20180720014726.24031-6-ard.biesheuvel@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-22efi/x86: Merge 32-bit and 64-bit UGA draw protocol setup routinesArd Biesheuvel1-85/+26
The two versions of setup_uga##() are mostly identical, with the exception of the size of EFI_HANDLE. So let's merge the two, and pull the implementation into the calling function setup_uga(). Note that the 32-bit version was only mixed-mode safe by accident: it only calls the get_mode() method of the UGA draw protocol, which happens to be the first member, and so truncating the 64-bit void* at offset 0 to 32 bits happens to produce the correct value. But let's not rely on that, and use the proper API instead. Tested-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Lukas Wunner <lukas@wunner.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/20180720014726.24031-5-ard.biesheuvel@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-22efi/x86: Align efi_uga_draw_protocol typedef names to conventionArd Biesheuvel2-8/+8
The linux-efi subsystem uses typedefs with the _t suffix to declare data structures that originate in the UEFI spec. Our type mangling for mixed mode depends on this convention, so rename the UGA drawing protocols to allow efi_call_proto() to be used with them in a subsequent patch. Tested-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Lukas Wunner <lukas@wunner.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/20180720014726.24031-4-ard.biesheuvel@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-22efi/x86: Merge the setup_efi_pci32() and setup_efi_pci64() routinesArd Biesheuvel1-91/+32
After merging the 32-bit and 64-bit versions of the code that invokes the PCI I/O protocol methods to preserve PCI ROM images in commit: 2c3625cb9fa2 ("efi/x86: Fold __setup_efi_pci32() and __setup_efi_pci64() ...") there are still separate code paths for 32-bit and 64-bit, where the only difference is the size of a EFI_HANDLE. So let's parameterize a single implementation for that difference only, and get rid of the two copies of the code. While at it, rename __setup_efi_pci() to preserve_pci_rom_image() to better reflect its purpose. Tested-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Lukas Wunner <lukas@wunner.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/20180720014726.24031-3-ard.biesheuvel@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-16efi/x86: Clean up the eboot codeIngo Molnar1-120/+125
Various small cleanups: - Standardize printk messages: 'alloc' => 'allocate' 'mem' => 'memory' also put variable names in printk messages between quotes. - Align mass-assignments vertically for better readability - Break multi-line function prototypes at the name where possible, not in the middle of the parameter list - Use a newline before return statements consistently. - Use curly braces in a balanced fashion. - Remove stray newlines. No change in functionality. Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Matt Fleming <matt@codeblueprint.co.uk> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/20180711094040.12506-2-ard.biesheuvel@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-11efi/x86: Fix mixed mode reboot loop by removing pointless call to ↵Ard Biesheuvel1-9/+3
PciIo->Attributes() Hans de Goede reported that his mixed EFI mode Bay Trail tablet would not boot at all any more, but enter a reboot loop without any logs printed by the kernel. Unbreak 64-bit Linux/x86 on 32-bit UEFI: When it was first introduced, the EFI stub code that copies the contents of PCI option ROMs originally only intended to do so if the EFI_PCI_IO_ATTRIBUTE_EMBEDDED_ROM attribute was *not* set. The reason was that the UEFI spec permits PCI option ROM images to be provided by the platform directly, rather than via the ROM BAR, and in this case, the OS can only access them at runtime if they are preserved at boot time by copying them from the areas described by PciIo->RomImage and PciIo->RomSize. However, it implemented this check erroneously, as can be seen in commit: dd5fc854de5fd ("EFI: Stash ROMs if they're not in the PCI BAR") which introduced: if (!attributes & EFI_PCI_IO_ATTRIBUTE_EMBEDDED_ROM) continue; and given that the numeric value of EFI_PCI_IO_ATTRIBUTE_EMBEDDED_ROM is 0x4000, this condition never becomes true, and so the option ROMs were copied unconditionally. This was spotted and 'fixed' by commit: 886d751a2ea99a160 ("x86, efi: correct precedence of operators in setup_efi_pci") but inadvertently inverted the logic at the same time, defeating the purpose of the code, since it now only preserves option ROM images that can be read from the ROM BAR as well. Unsurprisingly, this broke some systems, and so the check was removed entirely in the following commit: 739701888f5d ("x86, efi: remove attribute check from setup_efi_pci") It is debatable whether this check should have been included in the first place, since the option ROM image provided to the UEFI driver by the firmware may be different from the one that is actually present in the card's flash ROM, and so whatever PciIo->RomImage points at should be preferred regardless of whether the attribute is set. As this was the only use of the attributes field, we can remove the call to PciIo->Attributes() entirely, which is especially nice because its prototype involves uint64_t type by-value arguments which the EFI mixed mode has trouble dealing with. Any mixed mode system with PCI is likely to be affected. Tested-by: Wilfried Klaebe <linux-kernel@lebenslange-mailadresse.de> Tested-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Matt Fleming <matt@codeblueprint.co.uk> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/20180711090235.9327-2-ard.biesheuvel@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-03x86/boot/KASLR: Skip specified number of 1GB huge pages when doing physical ↵Baoquan He1-5/+8
randomization (KASLR) When KASLR is enabled then 1GB huge pages allocations might regress sporadically. To reproduce on a KVM guest with 4GB RAM: - add the following options to the kernel command-line: 'default_hugepagesz=1G hugepagesz=1G hugepages=1' - boot the guest and check number of 1GB pages reserved: # grep HugePages_Total /proc/meminfo - sporadically, every couple of bootups the output of this command shows that when booting with "nokaslr" HugePages_Total is always 1, while booting without "nokaslr" sometimes HugePages_Total is set as 0 (that is, reserving the 1GB page failed). Note that you may need to boot a few times to trigger the issue, because it's somewhat non-deterministic. The root cause is that kernel may be put into the only good 1GB huge page in the [0x40000000, 0x7fffffff] physical range randomly. Below is the dmesg output snippet from the KVM guest. We can see that only [0x40000000, 0x7fffffff] region is good 1GB huge page, [0x100000000, 0x13fffffff] will be touched by the memblock top-down allocation: [...] e820: BIOS-provided physical RAM map: [...] BIOS-e820: [mem 0x0000000000000000-0x000000000009fbff] usable [...] BIOS-e820: [mem 0x000000000009fc00-0x000000000009ffff] reserved [...] BIOS-e820: [mem 0x00000000000f0000-0x00000000000fffff] reserved [...] BIOS-e820: [mem 0x0000000000100000-0x00000000bffdffff] usable [...] BIOS-e820: [mem 0x00000000bffe0000-0x00000000bfffffff] reserved [...] BIOS-e820: [mem 0x00000000feffc000-0x00000000feffffff] reserved [...] BIOS-e820: [mem 0x00000000fffc0000-0x00000000ffffffff] reserved [...] BIOS-e820: [mem 0x0000000100000000-0x000000013fffffff] usable Besides, on bare-metal machines with larger memory, one less 1GB huge page might be available with KASLR enabled. That too is because the kernel image might be randomized into those "good" 1GB huge pages. To fix this, firstly parse the kernel command-line to get how many 1GB huge pages are specified. Then try to skip the specified number of 1GB huge pages when decide which memory region kernel can be randomized into. Also change the name of handle_mem_memmap() as handle_mem_options() since it handles not only 'mem=' and 'memmap=', but also 'hugepagesxxx' now. Signed-off-by: Baoquan He <bhe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: douly.fnst@cn.fujitsu.com Cc: fanc.fnst@cn.fujitsu.com Cc: indou.takao@jp.fujitsu.com Cc: keescook@chromium.org Cc: lcapitulino@redhat.com Cc: yasu.isimatu@gmail.com Link: http://lkml.kernel.org/r/20180625031656.12443-3-bhe@redhat.com [ Rewrote the changelog, fixed style problems in the code. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-03x86/boot/KASLR: Add two new functions for 1GB huge pages handlingBaoquan He1-0/+83
Introduce two new functions: parse_gb_huge_pages() and process_gb_huge_pages(), which handle a conflict between KASLR and huge pages of 1GB. These two functions will be used in the next patch: - parse_gb_huge_pages() is used to parse kernel command-line to get how many 1GB huge pages have been specified. A static global variable 'max_gb_huge_pages' is added to store the number. - process_gb_huge_pages() is used to skip as many 1GB huge pages as possible from the passed in memory region according to the specified number. Signed-off-by: Baoquan He <bhe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: douly.fnst@cn.fujitsu.com Cc: fanc.fnst@cn.fujitsu.com Cc: indou.takao@jp.fujitsu.com Cc: keescook@chromium.org Cc: lcapitulino@redhat.com Cc: yasu.isimatu@gmail.com Link: http://lkml.kernel.org/r/20180625031656.12443-2-bhe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-06-24efi/x86: Fix incorrect invocation of PciIo->Attributes()Ard Biesheuvel1-1/+1
The following commit: 2c3625cb9fa2 ("efi/x86: Fold __setup_efi_pci32() and __setup_efi_pci64() into one function") ... merged the two versions of __setup_efi_pciXX(), without taking into account that the 32-bit version used a rather dodgy trick to pass an immediate 0 constant as argument for a uint64_t parameter. The issue is caused by the fact that on x86, UEFI protocol method calls are redirected via struct efi_config::call(), which is a variadic function, and so the compiler has to infer the types of the parameters from the arguments rather than from the prototype. As the 32-bit x86 calling convention passes arguments via the stack, passing the unqualified constant 0 twice is the same as passing 0ULL, which is why the 32-bit code in __setup_efi_pci32() contained the following call: status = efi_early->call(pci->attributes, pci, EfiPciIoAttributeOperationGet, 0, 0, &attributes); to invoke this UEFI protocol method: typedef EFI_STATUS (EFIAPI *EFI_PCI_IO_PROTOCOL_ATTRIBUTES) ( IN EFI_PCI_IO_PROTOCOL *This, IN EFI_PCI_IO_PROTOCOL_ATTRIBUTE_OPERATION Operation, IN UINT64 Attributes, OUT UINT64 *Result OPTIONAL ); After the merge, we inadvertently ended up with this version for both 32-bit and 64-bit builds, breaking the latter. So replace the two zeroes with the explicitly typed constant 0ULL, which works as expected on both 32-bit and 64-bit builds. Wilfried tested the 64-bit build, and I checked the generated assembly of a 32-bit build with and without this patch, and they are identical. Reported-by: Wilfried Klaebe <linux-kernel@lebenslange-mailadresse.de> Tested-by: Wilfried Klaebe <linux-kernel@lebenslange-mailadresse.de> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Matt Fleming <matt@codeblueprint.co.uk> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: hdegoede@redhat.com Cc: linux-efi@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-06-10Merge branch 'x86-urgent-for-linus' of ↵Linus Torvalds1-0/+5
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 updates and fixes from Thomas Gleixner: - Fix the (late) fallout from the vector management rework causing hlist corruption and irq descriptor reference leaks caused by a missing sanity check. The straight forward fix triggered another long standing issue to surface. The pre rework code hid the issue due to being way slower, but now the chance that user space sees an EBUSY error return when updating irq affinities is way higher, though quite a bunch of userspace tools do not handle it properly despite the fact that EBUSY could be returned for at least 10 years. It turned out that the EBUSY return can be avoided completely by utilizing the existing delayed affinity update mechanism for irq remapped scenarios as well. That's a bit more error handling in the kernel, but avoids fruitless fingerpointing discussions with tool developers. - Decouple PHYSICAL_MASK from AMD SME as its going to be required for the upcoming Intel memory encryption support as well. - Handle legacy device ACPI detection properly for newer platforms - Fix the wrong argument ordering in the vector allocation tracepoint - Simplify the IDT setup code for the APIC=n case - Use the proper string helpers in the MTRR code - Remove a stale unused VDSO source file - Convert the microcode update lock to a raw spinlock as its used in atomic context. * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/intel_rdt: Enable CMT and MBM on new Skylake stepping x86/apic/vector: Print APIC control bits in debugfs genirq/affinity: Defer affinity setting if irq chip is busy x86/platform/uv: Use apic_ack_irq() x86/ioapic: Use apic_ack_irq() irq_remapping: Use apic_ack_irq() x86/apic: Provide apic_ack_irq() genirq/migration: Avoid out of line call if pending is not set genirq/generic_pending: Do not lose pending affinity update x86/apic/vector: Prevent hlist corruption and leaks x86/vector: Fix the args of vector_alloc tracepoint x86/idt: Simplify the idt_setup_apic_and_irq_gates() x86/platform/uv: Remove extra parentheses x86/mm: Decouple dynamic __PHYSICAL_MASK from AMD SME x86: Mark native_set_p4d() as __always_inline x86/microcode: Make the late update update_lock a raw lock for RT x86/mtrr: Convert to use strncpy_from_user() helper x86/mtrr: Convert to use match_string() helper x86/vdso: Remove unused file x86/i8237: Register device based on FADT legacy boot flag
2018-06-06x86/mm: Decouple dynamic __PHYSICAL_MASK from AMD SMEKirill A. Shutemov1-0/+5
AMD SME claims one bit from physical address to indicate whether the page is encrypted or not. To achieve that we clear out the bit from __PHYSICAL_MASK. The capability to adjust __PHYSICAL_MASK is required beyond AMD SME. For instance for upcoming Intel Multi-Key Total Memory Encryption. Factor it out into a separate feature with own Kconfig handle. It also helps with overhead of AMD SME. It saves more than 3k in .text on defconfig + AMD_MEM_ENCRYPT: add/remove: 3/2 grow/shrink: 5/110 up/down: 189/-3753 (-3564) We would need to return to this once we have infrastructure to patch constants in code. That's good candidate for it. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com> Cc: linux-mm@kvack.org Cc: "H. Peter Anvin" <hpa@zytor.com> Link: https://lkml.kernel.org/r/20180518113028.79825-1-kirill.shutemov@linux.intel.com
2018-06-05Merge branch 'x86-boot-for-linus' of ↵Linus Torvalds5-10/+17
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 boot updates from Ingo Molnar: - Centaur CPU updates (David Wang) - AMD and other CPU topology enumeration improvements and fixes (Borislav Petkov, Thomas Gleixner, Suravee Suthikulpanit) - Continued 5-level paging work (Kirill A. Shutemov) * 'x86-boot-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/mm: Mark __pgtable_l5_enabled __initdata x86/mm: Mark p4d_offset() __always_inline x86/mm: Introduce the 'no5lvl' kernel parameter x86/mm: Stop pretending pgtable_l5_enabled is a variable x86/mm: Unify pgtable_l5_enabled usage in early boot code x86/boot/compressed/64: Fix trampoline page table address calculation x86/CPU: Move x86_cpuinfo::x86_max_cores assignment to detect_num_cpu_cores() x86/Centaur: Report correct CPU/cache topology x86/CPU: Move cpu_detect_cache_sizes() into init_intel_cacheinfo() x86/CPU: Make intel_num_cpu_cores() generic x86/CPU: Move cpu local function declarations to local header x86/CPU/AMD: Derive CPU topology from CPUID function 0xB when available x86/CPU: Modify detect_extended_topology() to return result x86/CPU/AMD: Calculate last level cache ID from number of sharing threads x86/CPU: Rename intel_cacheinfo.c to cacheinfo.c perf/events/amd/uncore: Fix amd_uncore_llc ID to use pre-defined cpu_llc_id x86/CPU/AMD: Have smp_num_siblings and cpu_llc_id always be present x86/Centaur: Initialize supported CPU features properly
2018-06-05Merge branch 'efi-core-for-linus' of ↵Linus Torvalds1-82/+32
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull EFI updates from Ingo Molnar: - decode x86 CPER data (Yazen Ghannam) - ignore unrealistically large option ROMs (Hans de Goede) - initialize UEFI secure boot state during Xen dom0 boot (Daniel Kiper) - additional minor tweaks and fixes. * 'efi-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: efi/capsule-loader: Don't output reset log when reset flags are not set efi/x86: Ignore unrealistically large option ROMs efi/x86: Fold __setup_efi_pci32() and __setup_efi_pci64() into one function efi: Align efi_pci_io_protocol typedefs to type naming convention efi/libstub/tpm: Make function efi_retrieve_tpm2_eventlog_1_2() static efi: Decode IA32/X64 Context Info structure efi: Decode IA32/X64 MS Check structure efi: Decode additional IA32/X64 Bus Check fields efi: Decode IA32/X64 Cache, TLB, and Bus Check structures efi: Decode UEFI-defined IA32/X64 Error Structure GUIDs efi: Decode IA32/X64 Processor Error Info Structure efi: Decode IA32/X64 Processor Error Section efi: Fix IA32/X64 Processor Error Record definition efi/cper: Remove the INDENT_SP silliness x86/xen/efi: Initialize UEFI secure boot state during dom0 boot
2018-05-20Merge branch 'x86-urgent-for-linus' of ↵Linus Torvalds2-24/+69
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Thomas Gleixner: "An unfortunately larger set of fixes, but a large portion is selftests: - Fix the missing clusterid initializaiton for x2apic cluster management which caused boot failures due to IPIs being sent to the wrong cluster - Drop TX_COMPAT when a 64bit executable is exec()'ed from a compat task - Wrap access to __supported_pte_mask in __startup_64() where clang compile fails due to a non PC relative access being generated. - Two fixes for 5 level paging fallout in the decompressor: - Handle GOT correctly for paging_prepare() and cleanup_trampoline() - Fix the page table handling in cleanup_trampoline() to avoid page table corruption. - Stop special casing protection key 0 as this is inconsistent with the manpage and also inconsistent with the allocation map handling. - Override the protection key wen moving away from PROT_EXEC to prevent inaccessible memory. - Fix and update the protection key selftests to address breakage and to cover the above issue - Add a MOV SS self test" [ Part of the x86 fixes were in the earlier core pull due to dependencies ] * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (21 commits) x86/mm: Drop TS_COMPAT on 64-bit exec() syscall x86/apic/x2apic: Initialize cluster ID properly x86/boot/compressed/64: Fix moving page table out of trampoline memory x86/boot/compressed/64: Set up GOT for paging_prepare() and cleanup_trampoline() x86/pkeys: Do not special case protection key 0 x86/pkeys/selftests: Add a test for pkey 0 x86/pkeys/selftests: Save off 'prot' for allocations x86/pkeys/selftests: Fix pointer math x86/pkeys: Override pkey when moving away from PROT_EXEC x86/pkeys/selftests: Fix pkey exhaustion test off-by-one x86/pkeys/selftests: Add PROT_EXEC test x86/pkeys/selftests: Factor out "instruction page" x86/pkeys/selftests: Allow faults on unknown keys x86/pkeys/selftests: Avoid printf-in-signal deadlocks x86/pkeys/selftests: Remove dead debugging code, fix dprint_in_signal x86/pkeys/selftests: Stop using assert() x86/pkeys/selftests: Give better unexpected fault error messages x86/selftests: Add mov_to_ss test x86/mpx/selftests: Adjust the self-test to fresh distros that export the MPX ABI x86/pkeys/selftests: Adjust the self-test to fresh distros that export the pkeys ABI ...
2018-05-19x86/mm: Introduce the 'no5lvl' kernel parameterKirill A. Shutemov3-3/+12
This kernel parameter allows to force kernel to use 4-level paging even if hardware and kernel support 5-level paging. The option may be useful to work around regressions related to 5-level paging. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Hugh Dickins <hughd@google.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20180518103528.59260-5-kirill.shutemov@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-05-19x86/mm: Unify pgtable_l5_enabled usage in early boot codeKirill A. Shutemov2-6/+4
Usually pgtable_l5_enabled is defined using cpu_feature_enabled(). cpu_feature_enabled() is not available in early boot code. We use several different preprocessor tricks to get around it. It's messy. Unify them all. If cpu_feature_enabled() is not yet available, USE_EARLY_PGTABLE_L5 can be defined before all includes. It makes pgtable_l5_enabled rely on __pgtable_l5_enabled variable instead. This approach fits all early users. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Hugh Dickins <hughd@google.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20180518103528.59260-3-kirill.shutemov@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-05-19x86/boot/compressed/64: Fix trampoline page table address calculationKirill A. Shutemov1-1/+1
Hugh noticied that we calculate the address of the trampoline page table incorrectly in cleanup_trampoline(). TRAMPOLINE_32BIT_PGTABLE_OFFSET has to be divided by sizeof(unsigned long), since trampoline_32bit is an 'unsigned long' pointer. TRAMPOLINE_32BIT_PGTABLE_OFFSET is zero so the bug doesn't have a visible effect. Reported-by: Hugh Dickins <hughd@google.com> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Fixes: e9d0e6330eb8 ("x86/boot/compressed/64: Prepare new top-level page table for trampoline") Link: http://lkml.kernel.org/r/20180518103528.59260-2-kirill.shutemov@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-05-16x86/boot/compressed/64: Fix moving page table out of trampoline memoryKirill A. Shutemov2-11/+14
cleanup_trampoline() relocates the top-level page table out of trampoline memory. We use 'top_pgtable' as our new top-level page table. But if the 'top_pgtable' would be referenced from C in a usual way, the address of the table will be calculated relative to RIP. After kernel gets relocated, the address will be in the middle of decompression buffer and the page table may get overwritten. This leads to a crash. We calculate the address of other page tables relative to the relocation address. It makes them safe. We should do the same for 'top_pgtable'. Calculate the address of 'top_pgtable' in assembly and pass down to cleanup_trampoline(). Move the page table to .pgtable section where the rest of page tables are. The section is @nobits so we save 4k in kernel image. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Hugh Dickins <hughd@google.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Fixes: e9d0e6330eb8 ("x86/boot/compressed/64: Prepare new top-level page table for trampoline") Link: http://lkml.kernel.org/r/20180516080131.27913-3-kirill.shutemov@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-05-16x86/boot/compressed/64: Set up GOT for paging_prepare() and cleanup_trampoline()Kirill A. Shutemov1-13/+55
Eric and Hugh have reported instant reboot due to my recent changes in decompression code. The root cause is that I didn't realize that we need to adjust GOT to be able to run C code that early. The problem is only visible with an older toolchain. Binutils >= 2.24 is able to eliminate GOT references by replacing them with RIP-relative address loads: https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;a=commitdiff;h=80d873266dec We need to adjust GOT two times: - before calling paging_prepare() using the initial load address - before calling C code from the relocated kernel Reported-by: Eric Dumazet <eric.dumazet@gmail.com> Reported-by: Hugh Dickins <hughd@google.com> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Fixes: 194a9749c73d ("x86/boot/compressed/64: Handle 5-level paging boot if kernel is above 4G") Link: http://lkml.kernel.org/r/20180516080131.27913-2-kirill.shutemov@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-05-14efi/x86: Ignore unrealistically large option ROMsHans de Goede1-1/+8
setup_efi_pci() tries to save a copy of each PCI option ROM as this may be necessary for the device driver for the PCI device to have access too. On some systems the efi_pci_io_protocol's romimage and romsize fields contain invalid data, which looks a bit like pointers pointing back into other EFI code or data. Interpreting these pointers as romsize leads to a very large value and if we then try to alloc this amount of memory to save a copy the alloc call fails. This leads to a "Failed to alloc mem for rom" error being printed on the EFI console for each PCI device. This commit avoids the printing of these errors, by checking romsize before doing the alloc and if it is larger then the EFI spec limit of 16 MiB silently ignore the ROM fields instead of trying to alloc mem and fail. Tested-by: Hans de Goede <hdegoede@redhat.com> [ardb: deduplicate 32/64 bit changes, use SZ_16M symbolic constant] Signed-off-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Matt Fleming <matt@codeblueprint.co.uk> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/20180504060003.19618-16-ard.biesheuvel@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-05-14efi/x86: Fold __setup_efi_pci32() and __setup_efi_pci64() into one functionArd Biesheuvel1-82/+25
As suggested by Lukas, use his efi_call_proto() and efi_table_attr() macros to merge __setup_efi_pci32() and __setup_efi_pci64() into a single function, removing the need to duplicate changes made in subsequent patches across both. Tested-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Lukas Wunner <lukas@wunner.de> Cc: Matt Fleming <matt@codeblueprint.co.uk> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/20180504060003.19618-15-ard.biesheuvel@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-05-14efi: Align efi_pci_io_protocol typedefs to type naming conventionArd Biesheuvel1-4/+4
In order to use the helper macros that perform type mangling with the EFI PCI I/O protocol struct typedefs, align their Linux typenames with the convention we use for definitionns that originate in the UEFI spec, and add the trailing _t to each. Tested-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Matt Fleming <matt@codeblueprint.co.uk> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/20180504060003.19618-14-ard.biesheuvel@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-05-14efi: Avoid potential crashes, fix the 'struct efi_pci_io_protocol_32' ↵Ard Biesheuvel1-2/+4
definition for mixed mode Mixed mode allows a kernel built for x86_64 to interact with 32-bit EFI firmware, but requires us to define all struct definitions carefully when it comes to pointer sizes. 'struct efi_pci_io_protocol_32' currently uses a 'void *' for the 'romimage' field, which will be interpreted as a 64-bit field on such kernels, potentially resulting in bogus memory references and subsequent crashes. Tested-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: <stable@vger.kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Matt Fleming <matt@codeblueprint.co.uk> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/20180504060003.19618-13-ard.biesheuvel@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>