From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thomas Garnier Subject: [PATCH v6 04/27] x86: relocate_kernel - Adapt assembly for PIE support Date: Thu, 31 Jan 2019 11:24:11 -0800 Message-Id: <20190131192533.34130-5-thgarnie@chromium.org> In-Reply-To: <20190131192533.34130-1-thgarnie@chromium.org> References: <20190131192533.34130-1-thgarnie@chromium.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit To: kernel-hardening@lists.openwall.com Cc: kristen@linux.intel.com, Thomas Garnier , Thomas Gleixner , Ingo Molnar , Borislav Petkov , "H. Peter Anvin" , x86@kernel.org, Thomas Garnier , linux-kernel@vger.kernel.org List-ID: Change the assembly code to use only absolute references of symbols for the kernel to be PIE compatible. Position Independent Executable (PIE) support will allow to extend the KASLR randomization range below 0xffffffff80000000. Signed-off-by: Thomas Garnier --- arch/x86/kernel/relocate_kernel_64.S | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/kernel/relocate_kernel_64.S b/arch/x86/kernel/relocate_kernel_64.S index 11eda21eb697..3320368b6ec9 100644 --- a/arch/x86/kernel/relocate_kernel_64.S +++ b/arch/x86/kernel/relocate_kernel_64.S @@ -208,7 +208,7 @@ identity_mapped: movq %rax, %cr3 lea PAGE_SIZE(%r8), %rsp call swap_pages - movq $virtual_mapped, %rax + movabsq $virtual_mapped, %rax pushq %rax ret -- 2.20.1.495.gaa96b0ce6b-goog