Commit-ID: f7ff53e4702be9ac49deacd518dd243de45c9980 Gitweb: https://git.kernel.org/tip/f7ff53e4702be9ac49deacd518dd243de45c9980 Author: Kirill A. Shutemov <kirill.shute...@linux.intel.com> AuthorDate: Mon, 12 Mar 2018 13:02:44 +0300 Committer: Ingo Molnar <mi...@kernel.org> CommitDate: Mon, 12 Mar 2018 11:49:24 +0100
x86/boot/compressed/64: Use stack from trampoline memory As the first step on using trampoline memory, let's make 32-bit code use stack there. Separate stack is required to return back from trampoline and we cannot user stack from 64-bit mode as it may be above 4G. Signed-off-by: Kirill A. Shutemov <kirill.shute...@linux.intel.com> Cc: Andy Lutomirski <l...@amacapital.net> Cc: Andy Lutomirski <l...@kernel.org> Cc: Borislav Petkov <b...@alien8.de> Cc: Borislav Petkov <b...@suse.de> Cc: Brian Gerst <brge...@gmail.com> Cc: Cyrill Gorcunov <gorcu...@openvz.org> Cc: Denys Vlasenko <dvlas...@redhat.com> Cc: H. Peter Anvin <h...@zytor.com> Cc: Josh Poimboeuf <jpoim...@redhat.com> Cc: Linus Torvalds <torva...@linux-foundation.org> Cc: Matthew Wilcox <wi...@infradead.org> Cc: Peter Zijlstra <pet...@infradead.org> Cc: Thomas Gleixner <t...@linutronix.de> Cc: linux...@kvack.org Link: http://lkml.kernel.org/r/20180312100246.89175-3-kirill.shute...@linux.intel.com Signed-off-by: Ingo Molnar <mi...@kernel.org> --- arch/x86/boot/compressed/head_64.S | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/arch/x86/boot/compressed/head_64.S b/arch/x86/boot/compressed/head_64.S index f0c3a2f7e528..12915511be61 100644 --- a/arch/x86/boot/compressed/head_64.S +++ b/arch/x86/boot/compressed/head_64.S @@ -33,6 +33,7 @@ #include <asm/processor-flags.h> #include <asm/asm-offsets.h> #include <asm/bootparam.h> +#include "pgtable.h" /* * Locally defined symbols should be marked hidden: @@ -359,6 +360,8 @@ ENTRY(startup_64) pushq %rax lretq lvl5: + /* Restore the stack, the 32-bit trampoline uses its own stack */ + leaq boot_stack_end(%rbx), %rsp /* * cleanup_trampoline() would restore trampoline memory. @@ -513,6 +516,9 @@ compatible_mode: movl %eax, %ds movl %eax, %ss + /* Set up new stack */ + leal TRAMPOLINE_32BIT_STACK_END(%ecx), %esp + /* Disable paging */ movl %cr0, %eax btrl $X86_CR0_PG_BIT, %eax
