Messages in this thread Patch in this message | | | Date | Mon, 12 Mar 2018 05:19:14 -0700 | From | "tip-bot for Kirill A. Shutemov" <> | Subject | [tip:x86/mm] x86/boot/compressed/64: Use stack from trampoline memory |
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Commit-ID: f7ff53e4702be9ac49deacd518dd243de45c9980 Gitweb: https://git.kernel.org/tip/f7ff53e4702be9ac49deacd518dd243de45c9980 Author: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> AuthorDate: Mon, 12 Mar 2018 13:02:44 +0300 Committer: Ingo Molnar <mingo@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.shutemov@linux.intel.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Borislav Petkov <bp@suse.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Matthew Wilcox <willy@infradead.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/20180312100246.89175-3-kirill.shutemov@linux.intel.com Signed-off-by: Ingo Molnar <mingo@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
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