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 <thgar...@google.com> --- arch/x86/include/asm/processor.h | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h index b446c5a082ad..b09bd50b06c7 100644 --- a/arch/x86/include/asm/processor.h +++ b/arch/x86/include/asm/processor.h @@ -49,7 +49,7 @@ 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; } @@ -695,6 +695,7 @@ static inline void sync_core(void) : ASM_CALL_CONSTRAINT : : "memory"); #else unsigned int tmp; + unsigned long tmp2; asm volatile ( UNWIND_HINT_SAVE @@ -705,11 +706,13 @@ 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" UNWIND_HINT_RESTORE "1:" - : "=&r" (tmp), ASM_CALL_CONSTRAINT : : "cc", "memory"); + : "=&r" (tmp), "=&r" (tmp2), ASM_CALL_CONSTRAINT + : : "cc", "memory"); #endif } -- 2.15.0.rc0.271.g36b669edcc-goog _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org https://lists.xen.org/xen-devel