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2022-05-11kbuild: factor out the common installation code into scripts/install.shMasahiro Yamada1-22/+0
Many architectures have similar install.sh scripts. The first half is really generic; it verifies that the kernel image and System.map exist, then executes ~/bin/${INSTALLKERNEL} or /sbin/${INSTALLKERNEL} if available. The second half is kind of arch-specific; it copies the kernel image and System.map to the destination, but the code is slightly different. Factor out the generic part into scripts/install.sh. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Nicolas Schier <n.schier@avm.de>
2022-05-03efi: x86: Set the NX-compatibility flag in the PE headerPeter Jones1-0/+4
Following Baskov Evgeniy's "Handle UEFI NX-restricted page tables" patches, it's safe to set this compatibility flag to let loaders know they don't need to make special accommodations for kernel to load if pre-boot NX is enabled. Signed-off-by: Peter Jones <pjones@redhat.com> Link: https://lore.kernel.org/all/20220329184743.798513-1-pjones@redhat.com/ Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2022-04-20x86/boot: Put globals that are accessed early into the .data sectionMichael Roth2-2/+6
The helpers in arch/x86/boot/compressed/efi.c might be used during early boot to access the EFI system/config tables, and in some cases these EFI helpers might attempt to print debug/error messages, before console_init() has been called. __putstr() checks some variables to avoid printing anything before the console has been initialized, but this isn't enough since those variables live in .bss, which may not have been cleared yet. This can lead to a triple-fault occurring, primarily when booting in legacy/CSM mode (where EFI helpers will attempt to print some debug messages). Fix this by declaring these globals in .data section instead so there is no dependency on .bss being cleared before accessing them. Fixes: c01fce9cef849 ("x86/compressed: Add SEV-SNP feature detection/setup") Reported-by: Borislav Petkov <bp@suse.de> Suggested-by: Thomas Lendacky <Thomas.Lendacky@amd.com> Signed-off-by: Michael Roth <michael.roth@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lore.kernel.org/r/20220420152613.145077-1-michael.roth@amd.com
2022-04-17x86/boot: Add an efi.h header for the decompressorBorislav Petkov6-9/+131
Copy the needed symbols only and remove the kernel proper includes. No functional changes. Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lore.kernel.org/r/YlCKWhMJEMUgJmjF@zn.tnic
2022-04-07x86/boot: Avoid #VE during boot for TDX platformsSean Christopherson2-3/+19
There are a few MSRs and control register bits that the kernel normally needs to modify during boot. But, TDX disallows modification of these registers to help provide consistent security guarantees. Fortunately, TDX ensures that these are all in the correct state before the kernel loads, which means the kernel does not need to modify them. The conditions to avoid are: * Any writes to the EFER MSR * Clearing CR4.MCE This theoretically makes the guest boot more fragile. If, for instance, EFER was set up incorrectly and a WRMSR was performed, it will trigger early exception panic or a triple fault, if it's before early exceptions are set up. However, this is likely to trip up the guest BIOS long before control reaches the kernel. In any case, these kinds of problems are unlikely to occur in production environments, and developers have good debug tools to fix them quickly. Change the common boot code to work on TDX and non-TDX systems. This should have no functional effect on non-TDX systems. Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Andi Kleen <ak@linux.intel.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20220405232939.73860-24-kirill.shutemov@linux.intel.com
2022-04-07x86/boot: Set CR0.NE early and keep it set during the bootKirill A. Shutemov1-3/+4
TDX guest requires CR0.NE to be set. Clearing the bit triggers #GP(0). If CR0.NE is 0, the MS-DOS compatibility mode for handling floating-point exceptions is selected. In this mode, the software exception handler for floating-point exceptions is invoked externally using the processor’s FERR#, INTR, and IGNNE# pins. Using FERR# and IGNNE# to handle floating-point exception is deprecated. CR0.NE=0 also limits newer processors to operate with one logical processor active. Kernel uses CR0_STATE constant to initialize CR0. It has NE bit set. But during early boot kernel has more ad-hoc approach to setting bit in the register. During some of this ad-hoc manipulation, CR0.NE is cleared. This causes a #GP in TDX guests and makes it die in early boot. Make CR0 initialization consistent, deriving the initial value of CR0 from CR0_STATE. Since CR0_STATE always has CR0.NE=1, this ensures that CR0.NE is never 0 and avoids the #GP. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20220405232939.73860-23-kirill.shutemov@linux.intel.com
2022-04-07x86/boot: Port I/O: Add decompression-time support for TDXKirill A. Shutemov3-1/+65
Port I/O instructions trigger #VE in the TDX environment. In response to the exception, kernel emulates these instructions using hypercalls. But during early boot, on the decompression stage, it is cumbersome to deal with #VE. It is cleaner to go to hypercalls directly, bypassing #VE handling. Hook up TDX-specific port I/O helpers if booting in TDX environment. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com> Link: https://lkml.kernel.org/r/20220405232939.73860-17-kirill.shutemov@linux.intel.com
2022-04-07x86/boot: Port I/O: Allow to hook up alternative helpersKirill A. Shutemov5-3/+52
Port I/O instructions trigger #VE in the TDX environment. In response to the exception, kernel emulates these instructions using hypercalls. But during early boot, on the decompression stage, it is cumbersome to deal with #VE. It is cleaner to go to hypercalls directly, bypassing #VE handling. Add a way to hook up alternative port I/O helpers in the boot stub with a new pio_ops structure. For now, set the ops structure to just call the normal I/O operation functions. out*()/in*() macros redefined to use pio_ops callbacks. It eliminates need in changing call sites. io_delay() changed to use port I/O helper instead of inline assembly. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com> Link: https://lkml.kernel.org/r/20220405232939.73860-16-kirill.shutemov@linux.intel.com
2022-04-07x86: Consolidate port I/O helpersKirill A. Shutemov2-35/+2
There are two implementations of port I/O helpers: one in the kernel and one in the boot stub. Move the helpers required for both to <asm/shared/io.h> and use the one implementation everywhere. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20220405232939.73860-15-kirill.shutemov@linux.intel.com
2022-04-07x86/tdx: Detect TDX at early kernel decompression timeKuppuswamy Sathyanarayanan7-2/+42
The early decompression code does port I/O for its console output. But, handling the decompression-time port I/O demands a different approach from normal runtime because the IDT required to support #VE based port I/O emulation is not yet set up. Paravirtualizing I/O calls during the decompression step is acceptable because the decompression code doesn't have a lot of call sites to IO instruction. To support port I/O in decompression code, TDX must be detected before the decompression code might do port I/O. Detect whether the kernel runs in a TDX guest. Add an early_is_tdx_guest() interface to query the cached TDX guest status in the decompression code. TDX is detected with CPUID. Make cpuid_count() accessible outside boot/cpuflags.c. TDX detection in the main kernel is very similar. Move common bits into <asm/shared/tdx.h>. The actual port I/O paravirtualization will come later in the series. Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Tony Luck <tony.luck@intel.com> Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com> Link: https://lkml.kernel.org/r/20220405232939.73860-13-kirill.shutemov@linux.intel.com
2022-04-07x86/sev: Use firmware-validated CPUID for SEV-SNP guestsMichael Roth1-37/+0
SEV-SNP guests will be provided the location of special 'secrets' and 'CPUID' pages via the Confidential Computing blob. This blob is provided to the run-time kernel either through a boot_params field that was initialized by the boot/compressed kernel, or via a setup_data structure as defined by the Linux Boot Protocol. Locate the Confidential Computing blob from these sources and, if found, use the provided CPUID page/table address to create a copy that the run-time kernel will use when servicing CPUID instructions via a #VC handler. Signed-off-by: Michael Roth <michael.roth@amd.com> Signed-off-by: Brijesh Singh <brijesh.singh@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lore.kernel.org/r/20220307213356.2797205-40-brijesh.singh@amd.com
2022-04-07x86/sev: Add SEV-SNP feature detection/setupMichael Roth1-27/+0
Initial/preliminary detection of SEV-SNP is done via the Confidential Computing blob. Check for it prior to the normal SEV/SME feature initialization, and add some sanity checks to confirm it agrees with SEV-SNP CPUID/MSR bits. Signed-off-by: Michael Roth <michael.roth@amd.com> Signed-off-by: Brijesh Singh <brijesh.singh@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lore.kernel.org/r/20220307213356.2797205-39-brijesh.singh@amd.com
2022-04-07x86/compressed/64: Add identity mapping for Confidential Computing blobMichael Roth3-1/+25
The run-time kernel will need to access the Confidential Computing blob very early during boot to access the CPUID table it points to. At that stage, it will be relying on the identity-mapped page table set up by the boot/compressed kernel, so make sure the blob and the CPUID table it points to are mapped in advance. [ bp: Massage. ] Signed-off-by: Michael Roth <michael.roth@amd.com> Signed-off-by: Brijesh Singh <brijesh.singh@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lore.kernel.org/r/20220307213356.2797205-38-brijesh.singh@amd.com
2022-04-07x86/compressed: Export and rename add_identity_map()Michael Roth2-9/+10
SEV-specific code will need to add some additional mappings, but doing this within ident_map_64.c requires some SEV-specific helpers to be exported and some SEV-specific struct definitions to be pulled into ident_map_64.c. Instead, export add_identity_map() so SEV-specific (and other subsystem-specific) code can be better contained outside of ident_map_64.c. While at it, rename the function to kernel_add_identity_map(), similar to the kernel_ident_mapping_init() function it relies upon. No functional changes. Suggested-by: Borislav Petkov <bp@alien8.de> Signed-off-by: Michael Roth <michael.roth@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lore.kernel.org/r/20220307213356.2797205-37-brijesh.singh@amd.com
2022-04-07x86/compressed: Use firmware-validated CPUID leaves for SEV-SNP guestsMichael Roth1-0/+46
SEV-SNP guests will be provided the location of special 'secrets' 'CPUID' pages via the Confidential Computing blob. This blob is provided to the boot kernel either through an EFI config table entry, or via a setup_data structure as defined by the Linux Boot Protocol. Locate the Confidential Computing from these sources and, if found, use the provided CPUID page/table address to create a copy that the boot kernel will use when servicing CPUID instructions via a #VC CPUID handler. [ bp: s/cpuid/CPUID/ ] Signed-off-by: Michael Roth <michael.roth@amd.com> Signed-off-by: Brijesh Singh <brijesh.singh@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lore.kernel.org/r/20220307213356.2797205-36-brijesh.singh@amd.com
2022-04-07x86/compressed: Add SEV-SNP feature detection/setupMichael Roth1-1/+111
Initial/preliminary detection of SEV-SNP is done via the Confidential Computing blob. Check for it prior to the normal SEV/SME feature initialization, and add some sanity checks to confirm it agrees with SEV-SNP CPUID/MSR bits. Signed-off-by: Michael Roth <michael.roth@amd.com> Signed-off-by: Brijesh Singh <brijesh.singh@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lore.kernel.org/r/20220307213356.2797205-35-brijesh.singh@amd.com
2022-04-07x86/sev: Move MSR-based VMGEXITs for CPUID to helperMichael Roth1-0/+1
This code will also be used later for SEV-SNP-validated CPUID code in some cases, so move it to a common helper. While here, also add a check to terminate in cases where the CPUID function/subfunction is indexed and the subfunction is non-zero, since the GHCB MSR protocol does not support non-zero subfunctions. Suggested-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Michael Roth <michael.roth@amd.com> Signed-off-by: Brijesh Singh <brijesh.singh@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lore.kernel.org/r/20220307213356.2797205-32-brijesh.singh@amd.com
2022-04-06x86/compressed/acpi: Move EFI kexec handling into common codeMichael Roth2-60/+45
Future patches for SEV-SNP-validated CPUID will also require early parsing of the EFI configuration. Incrementally move the related code into a set of helpers that can be re-used for that purpose. In this instance, the current acpi.c kexec handling is mainly used to get the alternative EFI config table address provided by kexec via a setup_data entry of type SETUP_EFI. If not present, the code then falls back to normal EFI config table address provided by EFI system table. This would need to be done by all call-sites attempting to access the EFI config table, so just have efi_get_conf_table() handle that automatically. Signed-off-by: Michael Roth <michael.roth@amd.com> Signed-off-by: Brijesh Singh <brijesh.singh@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lore.kernel.org/r/20220307213356.2797205-29-brijesh.singh@amd.com
2022-04-06x86/compressed/acpi: Move EFI vendor table lookup to helperMichael Roth3-45/+106
Future patches for SEV-SNP-validated CPUID will also require early parsing of the EFI configuration. Incrementally move the related code into a set of helpers that can be re-used for that purpose. [ bp: Unbreak unnecessarily broken lines. ] Signed-off-by: Michael Roth <michael.roth@amd.com> Signed-off-by: Brijesh Singh <brijesh.singh@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lore.kernel.org/r/20220307213356.2797205-28-brijesh.singh@amd.com
2022-04-06x86/compressed/acpi: Move EFI config table lookup to helperMichael Roth3-17/+60
Future patches for SEV-SNP-validated CPUID will also require early parsing of the EFI configuration. Incrementally move the related code into a set of helpers that can be re-used for that purpose. [ bp: Remove superfluous zeroing of a stack variable. ] Signed-off-by: Michael Roth <michael.roth@amd.com> Signed-off-by: Brijesh Singh <brijesh.singh@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lore.kernel.org/r/20220307213356.2797205-27-brijesh.singh@amd.com
2022-04-06x86/compressed/acpi: Move EFI system table lookup to helperMichael Roth3-14/+42
Future patches for SEV-SNP-validated CPUID will also require early parsing of the EFI configuration. Incrementally move the related code into a set of helpers that can be re-used for that purpose. Signed-off-by: Michael Roth <michael.roth@amd.com> Signed-off-by: Brijesh Singh <brijesh.singh@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lore.kernel.org/r/20220307213356.2797205-26-brijesh.singh@amd.com
2022-04-06x86/compressed/acpi: Move EFI detection to helperMichael Roth4-18/+77
Future patches for SEV-SNP-validated CPUID will also require early parsing of the EFI configuration. Incrementally move the related code into a set of helpers that can be re-used for that purpose. First, carve out the functionality which determines the EFI environment type the machine is booting on. [ bp: Massage commit message. ] Signed-off-by: Michael Roth <michael.roth@amd.com> Signed-off-by: Brijesh Singh <brijesh.singh@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lore.kernel.org/r/20220307213356.2797205-25-brijesh.singh@amd.com
2022-04-06x86/compressed: Register GHCB memory when SEV-SNP is activeBrijesh Singh1-0/+4
The SEV-SNP guest is required by the GHCB spec to register the GHCB's Guest Physical Address (GPA). This is because the hypervisor may prefer that a guest use a consistent and/or specific GPA for the GHCB associated with a vCPU. For more information, see the GHCB specification section "GHCB GPA Registration". If hypervisor can not work with the guest provided GPA then terminate the guest boot. Signed-off-by: Brijesh Singh <brijesh.singh@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Venu Busireddy <venu.busireddy@oracle.com> Link: https://lore.kernel.org/r/20220307213356.2797205-17-brijesh.singh@amd.com
2022-04-06x86/compressed: Add helper for validating pages in the decompression stageBrijesh Singh3-1/+67
Many of the integrity guarantees of SEV-SNP are enforced through the Reverse Map Table (RMP). Each RMP entry contains the GPA at which a particular page of DRAM should be mapped. The VMs can request the hypervisor to add pages in the RMP table via the Page State Change VMGEXIT defined in the GHCB specification. Inside each RMP entry is a Validated flag; this flag is automatically cleared to 0 by the CPU hardware when a new RMP entry is created for a guest. Each VM page can be either validated or invalidated, as indicated by the Validated flag in the RMP entry. Memory access to a private page that is not validated generates a #VC. A VM must use the PVALIDATE instruction to validate a private page before using it. To maintain the security guarantee of SEV-SNP guests, when transitioning pages from private to shared, the guest must invalidate the pages before asking the hypervisor to change the page state to shared in the RMP table. After the pages are mapped private in the page table, the guest must issue a page state change VMGEXIT to mark the pages private in the RMP table and validate them. Upon boot, BIOS should have validated the entire system memory. During the kernel decompression stage, early_setup_ghcb() uses set_page_decrypted() to make the GHCB page shared (i.e. clear encryption attribute). And while exiting from the decompression, it calls set_page_encrypted() to make the page private. Add snp_set_page_{private,shared}() helpers that are used by set_page_{decrypted,encrypted}() to change the page state in the RMP table. [ bp: Massage commit message and comments. ] Signed-off-by: Brijesh Singh <brijesh.singh@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lore.kernel.org/r/20220307213356.2797205-16-brijesh.singh@amd.com
2022-04-06x86/sev: Check the VMPL levelBrijesh Singh1-2/+26
The Virtual Machine Privilege Level (VMPL) feature in the SEV-SNP architecture allows a guest VM to divide its address space into four levels. The level can be used to provide hardware isolated abstraction layers within a VM. VMPL0 is the highest privilege level, and VMPL3 is the least privilege level. Certain operations must be done by the VMPL0 software, such as: * Validate or invalidate memory range (PVALIDATE instruction) * Allocate VMSA page (RMPADJUST instruction when VMSA=1) The initial SNP support requires that the guest kernel is running at VMPL0. Add such a check to verify the guest is running at level 0 before continuing the boot. There is no easy method to query the current VMPL level, so use the RMPADJUST instruction to determine whether the guest is running at the VMPL0. [ bp: Massage commit message. ] Signed-off-by: Brijesh Singh <brijesh.singh@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lore.kernel.org/r/20220307213356.2797205-15-brijesh.singh@amd.com
2022-04-06x86/sev: Check SEV-SNP features supportBrijesh Singh2-6/+32
Version 2 of the GHCB specification added the advertisement of features that are supported by the hypervisor. If the hypervisor supports SEV-SNP then it must set the SEV-SNP features bit to indicate that the base functionality is supported. Check that feature bit while establishing the GHCB; if failed, terminate the guest. Version 2 of the GHCB specification adds several new Non-Automatic Exits (NAEs), most of them are optional except the hypervisor feature. Now that the hypervisor feature NAE is implemented, bump the GHCB maximum supported protocol version. While at it, move the GHCB protocol negotiation check from the #VC exception handler to sev_enable() so that all feature detection happens before the first #VC exception. While at it, document why the GHCB page cannot be setup from load_stage2_idt(). [ bp: Massage commit message. ] Signed-off-by: Brijesh Singh <brijesh.singh@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lore.kernel.org/r/20220307213356.2797205-13-brijesh.singh@amd.com
2022-04-06x86/sev: Define the Linux-specific guest termination reasonsBrijesh Singh1-3/+3
The GHCB specification defines the reason code for reason set 0. The reason codes defined in the set 0 do not cover all possible causes for a guest to request termination. The reason sets 1 to 255 are reserved for the vendor-specific codes. Reserve the reason set 1 for the Linux guest. Define the error codes for reason set 1 so that one can have meaningful termination reasons and thus better guest failure diagnosis. While at it, change sev_es_terminate() to accept a reason set parameter. [ bp: Massage commit message. ] Signed-off-by: Brijesh Singh <brijesh.singh@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Venu Busireddy <venu.busireddy@oracle.com> Link: https://lore.kernel.org/r/20220307213356.2797205-11-brijesh.singh@amd.com
2022-04-06x86/compressed/64: Detect/setup SEV/SME features earlier during bootMichael Roth4-53/+60
With upcoming SEV-SNP support, SEV-related features need to be initialized earlier during boot, at the same point the initial #VC handler is set up, so that the SEV-SNP CPUID table can be utilized during the initial feature checks. Also, SEV-SNP feature detection will rely on EFI helper functions to scan the EFI config table for the Confidential Computing blob, and so would need to be implemented at least partially in C. Currently set_sev_encryption_mask() is used to initialize the sev_status and sme_me_mask globals that advertise what SEV/SME features are available in a guest. Rename it to sev_enable() to better reflect that (SME is only enabled in the case of SEV guests in the boot/compressed kernel), and move it to just after the stage1 #VC handler is set up so that it can be used to initialize SEV-SNP as well in future patches. While at it, re-implement it as C code so that all SEV feature detection can be better consolidated with upcoming SEV-SNP feature detection, which will also be in C. The 32-bit entry path remains unchanged, as it never relied on the set_sev_encryption_mask() initialization to begin with. [ bp: Massage commit message. ] Signed-off-by: Michael Roth <michael.roth@amd.com> Signed-off-by: Brijesh Singh <brijesh.singh@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lore.kernel.org/r/20220307213356.2797205-8-brijesh.singh@amd.com
2022-04-06x86/boot: Use MSR read/write helpers instead of inline assemblyMichael Roth2-25/+22
Update all C code to use the new boot_rdmsr()/boot_wrmsr() helpers instead of relying on inline assembly. Suggested-by: Borislav Petkov <bp@alien8.de> Signed-off-by: Michael Roth <michael.roth@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lore.kernel.org/r/20220307213356.2797205-7-brijesh.singh@amd.com
2022-04-06x86/boot: Introduce helpers for MSR reads/writesMichael Roth1-0/+26
The current set of helpers used throughout the run-time kernel have dependencies on code/facilities outside of the boot kernel, so there are a number of call-sites throughout the boot kernel where inline assembly is used instead. More will be added with subsequent patches that add support for SEV-SNP, so take the opportunity to provide a basic set of helpers that can be used by the boot kernel to reduce reliance on inline assembly. Use boot_* prefix so that it's clear these are helpers specific to the boot kernel to avoid any confusion with the various other MSR read/write helpers. [ bp: Disambiguate parameter names and trim comment. ] Suggested-by: Borislav Petkov <bp@alien8.de> Signed-off-by: Michael Roth <michael.roth@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lore.kernel.org/r/20220307213356.2797205-6-brijesh.singh@amd.com
2022-04-05Merge drm/drm-next into drm-misc-nextMaxime Ripard3-5/+4
Let's start the 5.19 development cycle. Signed-off-by: Maxime Ripard <maxime@cerno.tech>
2022-03-26Merge tag 'memcpy-v5.18-rc1' of ↵Linus Torvalds1-1/+2
git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull FORTIFY_SOURCE updates from Kees Cook: "This series consists of two halves: - strict compile-time buffer size checking under FORTIFY_SOURCE for the memcpy()-family of functions (for extensive details and rationale, see the first commit) - enabling FORTIFY_SOURCE for Clang, which has had many overlapping bugs that we've finally worked past" * tag 'memcpy-v5.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: fortify: Add Clang support fortify: Make sure strlen() may still be used as a constant expression fortify: Use __diagnose_as() for better diagnostic coverage fortify: Make pointer arguments const Compiler Attributes: Add __diagnose_as for Clang Compiler Attributes: Add __overloadable for Clang Compiler Attributes: Add __pass_object_size for Clang fortify: Replace open-coded __gnu_inline attribute fortify: Update compile-time tests for Clang 14 fortify: Detect struct member overflows in memset() at compile-time fortify: Detect struct member overflows in memmove() at compile-time fortify: Detect struct member overflows in memcpy() at compile-time
2022-03-04sysfb: Enable boot time VESA graphic mode selectionMichal Suchanek1-2/+2
Since switch to simplefb/simpledrm VESA graphic mode selection with vga= kernel parameter is no longer available with legacy BIOS. The x86 realmode boot code enables the VESA graphic modes when option FB_BOOT_VESA_SUPPORT is enabled. This option is selected by vesafb but not simplefb/simpledrm. To enable use of VESA modes with simplefb in legacy BIOS boot mode drop dependency of BOOT_VESA_SUPPORT on FB, also drop the FB_ prefix. Select the option from sysfb rather than the drivers that depend on it. The BOOT_VESA_SUPPORT is not specific to framebuffer but rather to x86 platform, move it from fbdev to x86 Kconfig. Fixes: e3263ab389a7 ("x86: provide platform-devices for boot-framebuffers") Signed-off-by: Michal Suchanek <msuchanek@suse.de> Reviewed-by: Javier Martinez Canillas <javierm@redhat.com> Acked-by: Borislav Petkov <bp@suse.de> Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de> Link: https://patchwork.freedesktop.org/patch/msgid/948c39940a4e99f5b43bdbcbe537faae71a43e1d.1645822213.git.msuchanek@suse.de
2022-02-22x86: clean up symbol aliasingMark Rutland2-4/+2
Now that we have SYM_FUNC_ALIAS() and SYM_FUNC_ALIAS_WEAK(), use those to simplify the definition of function aliases across arch/x86. For clarity, where there are multiple annotations such as EXPORT_SYMBOL(), I've tried to keep annotations grouped by symbol. For example, where a function has a name and an alias which are both exported, this is organised as: SYM_FUNC_START(func) ... asm insns ... SYM_FUNC_END(func) EXPORT_SYMBOL(func) SYM_FUNC_ALIAS(alias, func) EXPORT_SYMBOL(alias) Where there are only aliases and no exports or other annotations, I have not bothered with line spacing, e.g. SYM_FUNC_START(func) ... asm insns ... SYM_FUNC_END(func) SYM_FUNC_ALIAS(alias, func) The tools/perf/ copies of memset_64.S and memset_64.S are updated likewise to avoid the build system complaining these are mismatched: | Warning: Kernel ABI header at 'tools/arch/x86/lib/memcpy_64.S' differs from latest version at 'arch/x86/lib/memcpy_64.S' | diff -u tools/arch/x86/lib/memcpy_64.S arch/x86/lib/memcpy_64.S | Warning: Kernel ABI header at 'tools/arch/x86/lib/memset_64.S' differs from latest version at 'arch/x86/lib/memset_64.S' | diff -u tools/arch/x86/lib/memset_64.S arch/x86/lib/memset_64.S There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Ard Biesheuvel <ardb@kernel.org> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Acked-by: Mark Brown <broonie@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jiri Slaby <jslaby@suse.cz> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20220216162229.1076788-4-mark.rutland@arm.com Signed-off-by: Will Deacon <will@kernel.org>
2022-02-13fortify: Detect struct member overflows in memmove() at compile-timeKees Cook1-1/+2
As done for memcpy(), also update memmove() to use the same tightened compile-time checks under CONFIG_FORTIFY_SOURCE. Signed-off-by: Kees Cook <keescook@chromium.org>
2022-01-19Merge tag 'kbuild-v5.17' of ↵Linus Torvalds1-6/+6
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull Kbuild updates from Masahiro Yamada: - Add new kconfig target 'make mod2noconfig', which will be useful to speed up the build and test iteration. - Raise the minimum supported version of LLVM to 11.0.0 - Refactor certs/Makefile - Change the format of include/config/auto.conf to stop double-quoting string type CONFIG options. - Fix ARCH=sh builds in dash - Separate compression macros for general purposes (cmd_bzip2 etc.) and the ones for decompressors (cmd_bzip2_with_size etc.) - Misc Makefile cleanups * tag 'kbuild-v5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (34 commits) kbuild: add cmd_file_size arch: decompressor: remove useless vmlinux.bin.all-y kbuild: rename cmd_{bzip2,lzma,lzo,lz4,xzkern,zstd22} kbuild: drop $(size_append) from cmd_zstd sh: rename suffix-y to suffix_y doc: kbuild: fix default in `imply` table microblaze: use built-in function to get CPU_{MAJOR,MINOR,REV} certs: move scripts/extract-cert to certs/ kbuild: do not quote string values in include/config/auto.conf kbuild: do not include include/config/auto.conf from shell scripts certs: simplify $(srctree)/ handling and remove config_filename macro kbuild: stop using config_filename in scripts/Makefile.modsign certs: remove misleading comments about GCC PR certs: refactor file cleaning certs: remove unneeded -I$(srctree) option for system_certificates.o certs: unify duplicated cmd_extract_certs and improve the log certs: use $< and $@ to simplify the key generation rule kbuild: remove headers_check stub kbuild: move headers_check.pl to usr/include/ certs: use if_changed to re-generate the key when the key type is changed ...
2022-01-14kbuild: rename cmd_{bzip2,lzma,lzo,lz4,xzkern,zstd22}Masahiro Yamada1-6/+6
GZIP-compressed files end with 4 byte data that represents the size of the original input. The decompressors (the self-extracting kernel) exploit it to know the vmlinux size beforehand. To mimic the GZIP's trailer, Kbuild provides cmd_{bzip2,lzma,lzo,lz4,xzkern,zstd22}. Unfortunately these macros are used everywhere despite the appended size data is only useful for the decompressors. There is no guarantee that such hand-crafted trailers are safely ignored. In fact, the kernel refuses compressed initramdfs with the garbage data. That is why usr/Makefile overrides size_append to make it no-op. To limit the use of such broken compressed files, this commit renames the existing macros as follows: cmd_bzip2 --> cmd_bzip2_with_size cmd_lzma --> cmd_lzma_with_size cmd_lzo --> cmd_lzo_with_size cmd_lz4 --> cmd_lz4_with_size cmd_xzkern --> cmd_xzkern_with_size cmd_zstd22 --> cmd_zstd22_with_size To keep the decompressors working, I updated the following Makefiles accordingly: arch/arm/boot/compressed/Makefile arch/h8300/boot/compressed/Makefile arch/mips/boot/compressed/Makefile arch/parisc/boot/compressed/Makefile arch/s390/boot/compressed/Makefile arch/sh/boot/compressed/Makefile arch/x86/boot/compressed/Makefile I reused the current macro names for the normal usecases; they produce the compressed data in the proper format. I did not touch the following: arch/arc/boot/Makefile arch/arm64/boot/Makefile arch/csky/boot/Makefile arch/mips/boot/Makefile arch/riscv/boot/Makefile arch/sh/boot/Makefile kernel/Makefile This means those Makefiles will stop appending the size data. I dropped the 'override size_append' hack from usr/Makefile. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Nicolas Schier <n.schier@avm.de>
2022-01-12Merge tag 'x86_core_for_v5.17_rc1' of ↵Linus Torvalds3-8/+8
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 core updates from Borislav Petkov: - Get rid of all the .fixup sections because this generates misleading/wrong stacktraces and confuse RELIABLE_STACKTRACE and LIVEPATCH as the backtrace misses the function which is being fixed up. - Add Straight Line Speculation mitigation support which uses a new compiler switch -mharden-sls= which sticks an INT3 after a RET or an indirect branch in order to block speculation after them. Reportedly, CPUs do speculate behind such insns. - The usual set of cleanups and improvements * tag 'x86_core_for_v5.17_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (32 commits) x86/entry_32: Fix segment exceptions objtool: Remove .fixup handling x86: Remove .fixup section x86/word-at-a-time: Remove .fixup usage x86/usercopy: Remove .fixup usage x86/usercopy_32: Simplify __copy_user_intel_nocache() x86/sgx: Remove .fixup usage x86/checksum_32: Remove .fixup usage x86/vmx: Remove .fixup usage x86/kvm: Remove .fixup usage x86/segment: Remove .fixup usage x86/fpu: Remove .fixup usage x86/xen: Remove .fixup usage x86/uaccess: Remove .fixup usage x86/futex: Remove .fixup usage x86/msr: Remove .fixup usage x86/extable: Extend extable functionality x86/entry_32: Remove .fixup usage x86/entry_64: Remove .fixup usage x86/copy_mc_64: Remove .fixup usage ...
2022-01-11Merge tag 'efi-next-for-v5.17' of ↵Linus Torvalds1-3/+11
git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi Pull EFI updates from Ard Biesheuvel: - support taking the measurement of the initrd when loaded via the LoadFile2 protocol - kobject API cleanup from Greg - some header file whitespace fixes * tag 'efi-next-for-v5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi: efi: use default_groups in kobj_type efi/libstub: measure loaded initrd info into the TPM efi/libstub: consolidate initrd handling across architectures efi/libstub: x86/mixed: increase supported argument count efi/libstub: add prototype of efi_tcg2_protocol::hash_log_extend_event() include/linux/efi.h: Remove unneeded whitespaces before tabs
2022-01-10Merge tag 'x86_build_for_v5.17_rc1' of ↵Linus Torvalds1-2/+5
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 build fix from Borislav Petkov: "A fix for cross-compiling the compressed stub on arm64 with clang" * tag 'x86_build_for_v5.17_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/boot/compressed: Move CLANG_FLAGS to beginning of KBUILD_CFLAGS
2022-01-10Merge tag 'x86_cleanups_for_v5.17_rc1' of ↵Linus Torvalds1-0/+3
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 cleanups from Borislav Petkov: "The mandatory set of random minor cleanups all over tip" * tag 'x86_cleanups_for_v5.17_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/events/amd/iommu: Remove redundant assignment to variable shift x86/boot/string: Add missing function prototypes x86/fpu: Remove duplicate copy_fpstate_to_sigframe() prototype x86/uaccess: Move variable into switch case statement
2021-12-23x86/boot/compressed: Move CLANG_FLAGS to beginning of KBUILD_CFLAGSNathan Chancellor1-2/+5
When cross compiling i386_defconfig on an arm64 host with clang, there are a few instances of '-Waddress-of-packed-member' and '-Wgnu-variable-sized-type-not-at-end' in arch/x86/boot/compressed/, which should both be disabled with the cc-disable-warning calls in that directory's Makefile, which indicates that cc-disable-warning is failing at the point of testing these flags. The cc-disable-warning calls fail because at the point that the flags are tested, KBUILD_CFLAGS has '-march=i386' without $(CLANG_FLAGS), which has the '--target=' flag to tell clang what architecture it is targeting. Without the '--target=' flag, the host architecture (arm64) is used and i386 is not a valid value for '-march=' in that case. This error can be seen by adding some logging to try-run: clang-14: error: the clang compiler does not support '-march=i386' Invoking the compiler has to succeed prior to calling cc-option or cc-disable-warning in order to accurately test whether or not the flag is supported; if it doesn't, the requested flag can never be added to the compiler flags. Move $(CLANG_FLAGS) to the beginning of KBUILD_FLAGS so that any new flags that might be added in the future can be accurately tested. Fixes: d5cbd80e302d ("x86/boot: Add $(CLANG_FLAGS) to compressed KBUILD_CFLAGS") Signed-off-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lore.kernel.org/r/20211222163040.1961481-1-nathan@kernel.org
2021-12-10x86/boot/string: Add missing function prototypesKees Cook1-0/+3
Silence "warning: no previous prototype for ... [-Wmissing-prototypes]" warnings from string.h when building under W=1. [ bp: Clarify commit message. ] Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lore.kernel.org/r/20211119175325.3668419-1-keescook@chromium.org
2021-12-08x86: Prepare asm files for straight-line-speculationPeter Zijlstra3-8/+8
Replace all ret/retq instructions with RET in preparation of making RET a macro. Since AS is case insensitive it's a big no-op without RET defined. find arch/x86/ -name \*.S | while read file do sed -i 's/\<ret[q]*\>/RET/' $file done Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lore.kernel.org/r/20211204134907.905503893@infradead.org
2021-11-21efi/libstub: x86/mixed: increase supported argument countArd Biesheuvel1-3/+11
Increase the number of arguments supported by mixed mode calls, so that we will be able to call into the TCG2 protocol to measure the initrd and extend the associated PCR. This involves the TCG2 protocol's hash_log_extend_event() method, which takes five arguments, three of which are u64 and need to be split, producing a total of 8 outgoing Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org> Link: https://lore.kernel.org/r/20211119114745.1560453-3-ilias.apalodimas@linaro.org Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2021-11-15x86/sev: Shorten GHCB terminate macro namesBrijesh Singh1-3/+3
Shorten macro names for improved readability. Suggested-by: Borislav Petkov <bp@suse.de> Signed-off-by: Brijesh Singh <brijesh.singh@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Venu Busireddy <venu.busireddy@oracle.com> Link: https://lkml.kernel.org/r/20211110220731.2396491-5-brijesh.singh@amd.com
2021-11-02Merge tag 'x86_core_for_v5.16_rc1' of ↵Linus Torvalds3-4/+5
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 core updates from Borislav Petkov: - Do not #GP on userspace use of CLI/STI but pretend it was a NOP to keep old userspace from breaking. Adjust the corresponding iopl selftest to that. - Improve stack overflow warnings to say which stack got overflowed and raise the exception stack sizes to 2 pages since overflowing the single page of exception stack is very easy to do nowadays with all the tracing machinery enabled. With that, rip out the custom mapping of AMD SEV's too. - A bunch of changes in preparation for FGKASLR like supporting more than 64K section headers in the relocs tool, correct ORC lookup table size to cover the whole kernel .text and other adjustments. * tag 'x86_core_for_v5.16_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: selftests/x86/iopl: Adjust to the faked iopl CLI/STI usage vmlinux.lds.h: Have ORC lookup cover entire _etext - _stext x86/boot/compressed: Avoid duplicate malloc() implementations x86/boot: Allow a "silent" kaslr random byte fetch x86/tools/relocs: Support >64K section headers x86/sev: Make the #VC exception stacks part of the default stacks storage x86: Increase exception stack sizes x86/mm/64: Improve stack overflow warnings x86/iopl: Fake iopl(3) CLI/STI usage
2021-11-01Merge tag 'overflow-v5.16-rc1' of ↵Linus Torvalds2-0/+4
git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull overflow updates from Kees Cook: "The end goal of the current buffer overflow detection work[0] is to gain full compile-time and run-time coverage of all detectable buffer overflows seen via array indexing or memcpy(), memmove(), and memset(). The str*() family of functions already have full coverage. While much of the work for these changes have been on-going for many releases (i.e. 0-element and 1-element array replacements, as well as avoiding false positives and fixing discovered overflows[1]), this series contains the foundational elements of several related buffer overflow detection improvements by providing new common helpers and FORTIFY_SOURCE changes needed to gain the introspection required for compiler visibility into array sizes. Also included are a handful of already Acked instances using the helpers (or related clean-ups), with many more waiting at the ready to be taken via subsystem-specific trees[2]. The new helpers are: - struct_group() for gaining struct member range introspection - memset_after() and memset_startat() for clearing to the end of structures - DECLARE_FLEX_ARRAY() for using flex arrays in unions or alone in structs Also included is the beginning of the refactoring of FORTIFY_SOURCE to support memcpy() introspection, fix missing and regressed coverage under GCC, and to prepare to fix the currently broken Clang support. Finishing this work is part of the larger series[0], but depends on all the false positives and buffer overflow bug fixes to have landed already and those that depend on this series to land. As part of the FORTIFY_SOURCE refactoring, a set of both a compile-time and run-time tests are added for FORTIFY_SOURCE and the mem*()-family functions respectively. The compile time tests have found a legitimate (though corner-case) bug[6] already. Please note that the appearance of "panic" and "BUG" in the FORTIFY_SOURCE refactoring are the result of relocating existing code, and no new use of those code-paths are expected nor desired. Finally, there are two tree-wide conversions for 0-element arrays and flexible array unions to gain sane compiler introspection coverage that result in no known object code differences. After this series (and the changes that have now landed via netdev and usb), we are very close to finally being able to build with -Warray-bounds and -Wzero-length-bounds. However, due corner cases in GCC[3] and Clang[4], I have not included the last two patches that turn on these options, as I don't want to introduce any known warnings to the build. Hopefully these can be solved soon" Link: https://lore.kernel.org/lkml/20210818060533.3569517-1-keescook@chromium.org/ [0] Link: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/log/?qt=grep&q=FORTIFY_SOURCE [1] Link: https://lore.kernel.org/lkml/202108220107.3E26FE6C9C@keescook/ [2] Link: https://lore.kernel.org/lkml/3ab153ec-2798-da4c-f7b1-81b0ac8b0c5b@roeck-us.net/ [3] Link: https://bugs.llvm.org/show_bug.cgi?id=51682 [4] Link: https://lore.kernel.org/lkml/202109051257.29B29745C0@keescook/ [5] Link: https://lore.kernel.org/lkml/20211020200039.170424-1-keescook@chromium.org/ [6] * tag 'overflow-v5.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: (30 commits) fortify: strlen: Avoid shadowing previous locals compiler-gcc.h: Define __SANITIZE_ADDRESS__ under hwaddress sanitizer treewide: Replace 0-element memcpy() destinations with flexible arrays treewide: Replace open-coded flex arrays in unions stddef: Introduce DECLARE_FLEX_ARRAY() helper btrfs: Use memset_startat() to clear end of struct string.h: Introduce memset_startat() for wiping trailing members and padding xfrm: Use memset_after() to clear padding string.h: Introduce memset_after() for wiping trailing members/padding lib: Introduce CONFIG_MEMCPY_KUNIT_TEST fortify: Add compile-time FORTIFY_SOURCE tests fortify: Allow strlen() and strnlen() to pass compile-time known lengths fortify: Prepare to improve strnlen() and strlen() warnings fortify: Fix dropped strcpy() compile-time write overflow check fortify: Explicitly disable Clang support fortify: Move remaining fortify helpers into fortify-string.h lib/string: Move helper functions out of string.c compiler_types.h: Remove __compiletime_object_size() cm4000_cs: Use struct_group() to zero struct cm4000_dev region can: flexcan: Use struct_group() to zero struct flexcan_regs regions ...
2021-10-27x86/boot/compressed: Avoid duplicate malloc() implementationsKees Cook3-4/+5
The early malloc() and free() implementation in include/linux/decompress/mm.h (which is also included by the static decompressors) is static. This is fine when the only thing interested in using malloc() is the decompression code, but the x86 early boot environment may use malloc() in a couple places, leading to a potential collision when the static copies of the available memory region ("malloc_ptr") gets reset to the global "free_mem_ptr" value. As it happened, the existing usage pattern was accidentally safe because each user did 1 malloc() and 1 free() before returning and were not nested: extract_kernel() (misc.c) choose_random_location() (kaslr.c) mem_avoid_init() handle_mem_options() malloc() ... free() ... parse_elf() (misc.c) malloc() ... free() Once the future FGKASLR series is added, however, it will insert additional malloc() calls local to fgkaslr.c in the middle of parse_elf()'s malloc()/free() pair: parse_elf() (misc.c) malloc() if (...) { layout_randomized_image(output, &ehdr, phdrs); malloc() <- boom ... else layout_image(output, &ehdr, phdrs); free() To avoid collisions, there must be a single implementation of malloc(). Adjust include/linux/decompress/mm.h so that visibility can be controlled, provide prototypes in misc.h, and implement the functions in misc.c. This also results in a small size savings: $ size vmlinux.before vmlinux.after text data bss dec hex filename 8842314 468 178320 9021102 89a6ae vmlinux.before 8842240 468 178320 9021028 89a664 vmlinux.after Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20211013175742.1197608-4-keescook@chromium.org
2021-09-29x86/boot: Fix make hdimage with older versions of mtoolsH. Peter Anvin (Intel)2-9/+11
Some versions of mtools (fixed somewhere between 4.0.31 and 4.0.35) generate bad output for mformat when used with the partition= option. Use the offset= option instead. An mtools.conf entry is *also* needed with partition= to support mpartition; combining them in one entry does not work either. Don't specify the -t option to mpartition; it is unnecessary and seems to confuse mpartition under some circumstances. Also do a few minor optimizations: Use a larger cluster size; there is no reason for the typical 4K clusters when we are dealing mainly with comparatively huge files. Start the partition at 32K. There is no reason to align it more than that, since the internal FAT filesystem structures will at best be cluster-aligned, and 32K is the maximum FAT cluster size. [ bp: Remove "we". ] Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20210911003906.2700218-1-hpa@zytor.com