This is a note to let you know that I've just added the patch titled x86/decompressor: Merge trampoline cleanup with switching code to the 6.1-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: x86-decompressor-merge-trampoline-cleanup-with-switching-code.patch and it can be found in the queue-6.1 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 03dda95137d3247564854ad9032c0354273a159d Mon Sep 17 00:00:00 2001 From: Ard Biesheuvel <ardb@xxxxxxxxxx> Date: Mon, 7 Aug 2023 18:27:12 +0200 Subject: x86/decompressor: Merge trampoline cleanup with switching code From: Ard Biesheuvel <ardb@xxxxxxxxxx> commit 03dda95137d3247564854ad9032c0354273a159d upstream. Now that the trampoline setup code and the actual invocation of it are all done from the C routine, the trampoline cleanup can be merged into it as well, instead of returning to asm just to call another C function. Signed-off-by: Ard Biesheuvel <ardb@xxxxxxxxxx> Signed-off-by: Borislav Petkov (AMD) <bp@xxxxxxxxx> Acked-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx> Link: https://lore.kernel.org/r/20230807162720.545787-16-ardb@xxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- arch/x86/boot/compressed/head_64.S | 14 ++++---------- arch/x86/boot/compressed/pgtable_64.c | 18 ++++-------------- 2 files changed, 8 insertions(+), 24 deletions(-) --- a/arch/x86/boot/compressed/head_64.S +++ b/arch/x86/boot/compressed/head_64.S @@ -433,20 +433,14 @@ SYM_CODE_START(startup_64) * a trampoline in 32-bit addressable memory if the current number does * not match the desired number. * - * Pass the boot_params pointer as the first argument. + * Pass the boot_params pointer as the first argument. The second + * argument is the relocated address of the page table to use instead + * of the page table in trampoline memory (if required). */ movq %r15, %rdi + leaq rva(top_pgtable)(%rbx), %rsi call configure_5level_paging - /* - * cleanup_trampoline() would restore trampoline memory. - * - * RDI is address of the page table to use instead of page table - * in trampoline memory (if required). - */ - leaq rva(top_pgtable)(%rbx), %rdi - call cleanup_trampoline - /* Zero EFLAGS */ pushq $0 popfq --- a/arch/x86/boot/compressed/pgtable_64.c +++ b/arch/x86/boot/compressed/pgtable_64.c @@ -101,7 +101,7 @@ static unsigned long find_trampoline_pla return bios_start - TRAMPOLINE_32BIT_SIZE; } -asmlinkage void configure_5level_paging(struct boot_params *bp) +asmlinkage void configure_5level_paging(struct boot_params *bp, void *pgtable) { void (*toggle_la57)(void *cr3); bool l5_required = false; @@ -191,22 +191,12 @@ asmlinkage void configure_5level_paging( } toggle_la57(trampoline_32bit); -} - -void cleanup_trampoline(void *pgtable) -{ - void *trampoline_pgtable; - - trampoline_pgtable = trampoline_32bit; /* - * Move the top level page table out of trampoline memory, - * if it's there. + * Move the top level page table out of trampoline memory. */ - if ((void *)__native_read_cr3() == trampoline_pgtable) { - memcpy(pgtable, trampoline_pgtable, PAGE_SIZE); - native_write_cr3((unsigned long)pgtable); - } + memcpy(pgtable, trampoline_32bit, PAGE_SIZE); + native_write_cr3((unsigned long)pgtable); /* Restore trampoline memory */ memcpy(trampoline_32bit, trampoline_save, TRAMPOLINE_32BIT_SIZE); Patches currently in stable-queue which might be from ardb@xxxxxxxxxx are queue-6.1/x86-boot-compressed-avoid-touching-ecx-in-startup32_set_idt_entry.patch queue-6.1/x86-boot-compressed-only-build-mem_encrypt.s-if-amd_mem_encrypt-y.patch queue-6.1/efi-capsule-loader-fix-incorrect-allocation-size.patch queue-6.1/x86-decompressor-move-global-symbol-references-to-c-code.patch queue-6.1/x86-boot-compressed-move-startup32_load_idt-into-.text-section.patch queue-6.1/x86-decompressor-only-call-the-trampoline-when-changing-paging-levels.patch queue-6.1/x86-boot-compressed-rename-efi_thunk_64.s-to-efi-mixed.s.patch queue-6.1/x86-decompressor-merge-trampoline-cleanup-with-switching-code.patch queue-6.1/x86-boot-compressed-move-efi32_pe_entry-out-of-head_64.s.patch queue-6.1/efi-verify-that-variable-services-are-supported.patch queue-6.1/x86-decompressor-call-trampoline-directly-from-c-code.patch queue-6.1/x86-boot-compressed-pull-global-variable-reference-into-startup32_load_idt.patch queue-6.1/x86-boot-compressed-simplify-idt-gdt-preserve-restore-in-the-efi-thunk.patch queue-6.1/x86-decompressor-assign-paging-related-global-variables-earlier.patch queue-6.1/x86-boot-compressed-move-32-bit-entrypoint-code-into-.text-section.patch queue-6.1/x86-boot-compressed-move-efi32_pe_entry-into-.text-section.patch queue-6.1/x86-decompressor-avoid-the-need-for-a-stack-in-the-32-bit-trampoline.patch queue-6.1/x86-boot-compressed-move-startup32_check_sev_cbit-out-of-head_64.s.patch queue-6.1/x86-boot-compressed-efi-merge-multiple-definitions-of-image_offset-into-one.patch queue-6.1/x86-boot-compressed-move-startup32_load_idt-out-of-head_64.s.patch queue-6.1/decompress-use-8-byte-alignment.patch queue-6.1/x86-boot-compressed-move-efi32_entry-out-of-head_64.s.patch queue-6.1/efi-libstub-use-efi_loader_code-region-when-moving-the-kernel-in-memory.patch queue-6.1/crypto-arm64-neonbs-fix-out-of-bounds-access-on-short-input.patch queue-6.1/x86-boot-compressed-move-bootargs-parsing-out-of-32-bit-startup-code.patch queue-6.1/efivarfs-request-at-most-512-bytes-for-variable-names.patch queue-6.1/x86-boot-compressed-adhere-to-calling-convention-in-get_sev_encryption_bit.patch queue-6.1/x86-boot-compressed-move-startup32_check_sev_cbit-into-.text.patch queue-6.1/x86-decompressor-store-boot_params-pointer-in-callee-save-register.patch queue-6.1/x86-efistub-branch-straight-to-kernel-entry-point-from-c-code.patch queue-6.1/x86-decompressor-call-trampoline-as-a-normal-function.patch queue-6.1/x86-decompressor-pass-pgtable-address-to-trampoline-directly.patch queue-6.1/x86-decompressor-use-standard-calling-convention-for-trampoline.patch queue-6.1/x86-efi-make-the-deprecated-efi-handover-protocol-optional.patch