6.1-stable review patch. If anyone has any objections, please let me know.
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From: Ard Biesheuvel ardb@kernel.org
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@kernel.org Signed-off-by: Borislav Petkov (AMD) bp@alien8.de Acked-by: Kirill A. Shutemov kirill.shutemov@linux.intel.com Link: https://lore.kernel.org/r/20230807162720.545787-16-ardb@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- 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);