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Message-Id: <20170718223333.110371-11-thgarnie@google.com> Date: Tue, 18 Jul 2017 15:33:21 -0700 From: Thomas Garnier <thgarnie@...gle.com> To: Herbert Xu <herbert@...dor.apana.org.au>, "David S . Miller" <davem@...emloft.net>, Thomas Gleixner <tglx@...utronix.de>, Ingo Molnar <mingo@...hat.com>, "H . Peter Anvin" <hpa@...or.com>, Peter Zijlstra <peterz@...radead.org>, Josh Poimboeuf <jpoimboe@...hat.com>, Thomas Garnier <thgarnie@...gle.com>, Arnd Bergmann <arnd@...db.de>, Matthias Kaehlcke <mka@...omium.org>, Boris Ostrovsky <boris.ostrovsky@...cle.com>, Juergen Gross <jgross@...e.com>, Paolo Bonzini <pbonzini@...hat.com>, Radim Krčmář <rkrcmar@...hat.com>, Joerg Roedel <joro@...tes.org>, Andy Lutomirski <luto@...nel.org>, Borislav Petkov <bp@...en8.de>, "Kirill A . Shutemov" <kirill.shutemov@...ux.intel.com>, Brian Gerst <brgerst@...il.com>, Borislav Petkov <bp@...e.de>, Christian Borntraeger <borntraeger@...ibm.com>, "Rafael J . Wysocki" <rjw@...ysocki.net>, Len Brown <len.brown@...el.com>, Pavel Machek <pavel@....cz>, Tejun Heo <tj@...nel.org>, Christoph Lameter <cl@...ux.com>, Kees Cook <keescook@...omium.org>, Paul Gortmaker <paul.gortmaker@...driver.com>, Chris Metcalf <cmetcalf@...lanox.com>, "Paul E . McKenney" <paulmck@...ux.vnet.ibm.com>, Andrew Morton <akpm@...ux-foundation.org>, Christopher Li <sparse@...isli.org>, Dou Liyang <douly.fnst@...fujitsu.com>, Masahiro Yamada <yamada.masahiro@...ionext.com>, Daniel Borkmann <daniel@...earbox.net>, Markus Trippelsdorf <markus@...ppelsdorf.de>, Peter Foley <pefoley2@...oley.com>, Steven Rostedt <rostedt@...dmis.org>, Tim Chen <tim.c.chen@...ux.intel.com>, Ard Biesheuvel <ard.biesheuvel@...aro.org>, Catalin Marinas <catalin.marinas@....com>, Matthew Wilcox <mawilcox@...rosoft.com>, Michal Hocko <mhocko@...e.com>, Rob Landley <rob@...dley.net>, Jiri Kosina <jkosina@...e.cz>, "H . J . Lu" <hjl.tools@...il.com>, Paul Bolle <pebolle@...cali.nl>, Baoquan He <bhe@...hat.com>, Daniel Micay <danielmicay@...il.com> Cc: x86@...nel.org, linux-crypto@...r.kernel.org, linux-kernel@...r.kernel.org, xen-devel@...ts.xenproject.org, kvm@...r.kernel.org, linux-pm@...r.kernel.org, linux-arch@...r.kernel.org, linux-sparse@...r.kernel.org, kernel-hardening@...ts.openwall.com Subject: [RFC 10/22] x86/CPU: Adapt assembly for PIE support Change the assembly code to use only relative references of symbols for the kernel to be PIE compatible. Use the new _ASM_GET_PTR macro instead of the 'mov $symbol, %dst' construct to not have an absolute reference. Position Independent Executable (PIE) support will allow to extended the KASLR randomization range below the -2G memory limit. Signed-off-by: Thomas Garnier <thgarnie@...gle.com> --- arch/x86/include/asm/processor.h | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h index 028245e1c42b..1adea8c4436e 100644 --- a/arch/x86/include/asm/processor.h +++ b/arch/x86/include/asm/processor.h @@ -47,7 +47,7 @@ static inline void *current_text_addr(void) { void *pc; - asm volatile("mov $1f, %0; 1:":"=r" (pc)); + asm volatile(_ASM_GET_PTR(1f, %0) "; 1:":"=r" (pc)); return pc; } @@ -682,6 +682,7 @@ static inline void sync_core(void) : "+r" (__sp) : : "memory"); #else unsigned int tmp; + unsigned long tmp2; asm volatile ( "mov %%ss, %0\n\t" @@ -691,10 +692,11 @@ static inline void sync_core(void) "pushfq\n\t" "mov %%cs, %0\n\t" "pushq %q0\n\t" - "pushq $1f\n\t" + "leaq 1f(%%rip), %1\n\t" + "pushq %1\n\t" "iretq\n\t" "1:" - : "=&r" (tmp), "+r" (__sp) : : "cc", "memory"); + : "=&r" (tmp), "=&r" (tmp2), "+r" (__sp) : : "cc", "memory"); #endif } -- 2.13.2.932.g7449e964c-goog
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