From 03dda95137d3247564854ad9032c0354273a159d Mon Sep 17 00:00:00 2001 From: Ard Biesheuvel Date: Mon, 7 Aug 2023 18:27:12 +0200 Subject: x86/decompressor: Merge trampoline cleanup with switching code 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 Signed-off-by: Borislav Petkov (AMD) Acked-by: Kirill A. Shutemov Link: https://lore.kernel.org/r/20230807162720.545787-16-ardb@kernel.org --- arch/x86/boot/compressed/head_64.S | 14 ++++---------- arch/x86/boot/compressed/pgtable_64.c | 18 ++++-------------- 2 files changed, 8 insertions(+), 24 deletions(-) (limited to 'arch/x86/boot') diff --git a/arch/x86/boot/compressed/head_64.S b/arch/x86/boot/compressed/head_64.S index afdaf8cb8bb9..fb0e562c26f6 100644 --- a/arch/x86/boot/compressed/head_64.S +++ b/arch/x86/boot/compressed/head_64.S @@ -430,20 +430,14 @@ 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 diff --git a/arch/x86/boot/compressed/pgtable_64.c b/arch/x86/boot/compressed/pgtable_64.c index eab4e6b568ae..7939eb6e6ce9 100644 --- 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_placement(void) 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(struct boot_params *bp) } 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); -- cgit v1.2.3-58-ga151