Commit-ID: 32fcefa2bfc8961987e91d1daeb00624b4176d2e Gitweb: https://git.kernel.org/tip/32fcefa2bfc8961987e91d1daeb00624b4176d2e Author: Kirill A. Shutemov <kirill.shute...@linux.intel.com> AuthorDate: Mon, 26 Feb 2018 21:04:50 +0300 Committer: Ingo Molnar <mi...@kernel.org> CommitDate: Mon, 12 Mar 2018 09:37:25 +0100
x86/boot/compressed/64: Set up trampoline memory This patch clears up trampoline memory and copies trampoline code in place. It's not yet used though. Tested-by: Borislav Petkov <b...@suse.de> Signed-off-by: Kirill A. Shutemov <kirill.shute...@linux.intel.com> Cc: Andy Lutomirski <l...@amacapital.net> Cc: Andy Shevchenko <andy.shevche...@gmail.com> Cc: Cyrill Gorcunov <gorcu...@openvz.org> Cc: Eric Biederman <ebied...@xmission.com> Cc: H. Peter Anvin <h...@zytor.com> Cc: Juergen Gross <jgr...@suse.com> Cc: Kees Cook <keesc...@chromium.org> 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/20180226180451.86788-5-kirill.shute...@linux.intel.com Signed-off-by: Ingo Molnar <mi...@kernel.org> --- arch/x86/boot/compressed/head_64.S | 3 ++- arch/x86/boot/compressed/pgtable.h | 9 +++++++++ arch/x86/boot/compressed/pgtable_64.c | 7 +++++++ 3 files changed, 18 insertions(+), 1 deletion(-) diff --git a/arch/x86/boot/compressed/head_64.S b/arch/x86/boot/compressed/head_64.S index 8ba0582c65d5..c813cb004056 100644 --- a/arch/x86/boot/compressed/head_64.S +++ b/arch/x86/boot/compressed/head_64.S @@ -501,8 +501,9 @@ relocated: jmp *%rax .code32 +ENTRY(trampoline_32bit_src) compatible_mode: - /* Setup data and stack segments */ + /* Set up data and stack segments */ movl $__KERNEL_DS, %eax movl %eax, %ds movl %eax, %ss diff --git a/arch/x86/boot/compressed/pgtable.h b/arch/x86/boot/compressed/pgtable.h index 57722a2fe2a0..91f75638f6e6 100644 --- a/arch/x86/boot/compressed/pgtable.h +++ b/arch/x86/boot/compressed/pgtable.h @@ -3,9 +3,18 @@ #define TRAMPOLINE_32BIT_SIZE (2 * PAGE_SIZE) +#define TRAMPOLINE_32BIT_PGTABLE_OFFSET 0 + +#define TRAMPOLINE_32BIT_CODE_OFFSET PAGE_SIZE +#define TRAMPOLINE_32BIT_CODE_SIZE 0x60 + +#define TRAMPOLINE_32BIT_STACK_END TRAMPOLINE_32BIT_SIZE + #ifndef __ASSEMBLER__ extern unsigned long *trampoline_32bit; +extern void trampoline_32bit_src(void *return_ptr); + #endif /* __ASSEMBLER__ */ #endif /* BOOT_COMPRESSED_PAGETABLE_H */ diff --git a/arch/x86/boot/compressed/pgtable_64.c b/arch/x86/boot/compressed/pgtable_64.c index 01d08d3e3e43..810c2c32d98e 100644 --- a/arch/x86/boot/compressed/pgtable_64.c +++ b/arch/x86/boot/compressed/pgtable_64.c @@ -76,6 +76,13 @@ struct paging_config paging_prepare(void) /* Preserve trampoline memory */ memcpy(trampoline_save, trampoline_32bit, TRAMPOLINE_32BIT_SIZE); + /* Clear trampoline memory first */ + memset(trampoline_32bit, 0, TRAMPOLINE_32BIT_SIZE); + + /* Copy trampoline code in place */ + memcpy(trampoline_32bit + TRAMPOLINE_32BIT_CODE_OFFSET / sizeof(unsigned long), + &trampoline_32bit_src, TRAMPOLINE_32BIT_CODE_SIZE); + return paging_config; }
