From faaee1f07ed25b2779bfd935ffb29f431b80d6d3 Mon Sep 17 00:00:00 2001 From: "H.J. Lu" Date: Sat, 14 Jul 2018 05:59:29 -0700 Subject: x86: Support shadow stack pointer in setjmp/longjmp Save and restore shadow stack pointer in setjmp and longjmp to support shadow stack in Intel CET. Use feature_1 in tcbhead_t to check if shadow stack is enabled before saving and restoring shadow stack pointer. Reviewed-by: Carlos O'Donell * sysdeps/i386/__longjmp.S: Include . (__longjmp): Restore shadow stack pointer if shadow stack is enabled, SHADOW_STACK_POINTER_OFFSET is defined and __longjmp isn't defined for __longjmp_cancel. * sysdeps/i386/bsd-_setjmp.S: Include . (_setjmp): Save shadow stack pointer if shadow stack is enabled and SHADOW_STACK_POINTER_OFFSET is defined. * sysdeps/i386/bsd-setjmp.S: Include . (setjmp): Save shadow stack pointer if shadow stack is enabled and SHADOW_STACK_POINTER_OFFSET is defined. * sysdeps/i386/setjmp.S: Include . (__sigsetjmp): Save shadow stack pointer if shadow stack is enabled and SHADOW_STACK_POINTER_OFFSET is defined. * sysdeps/unix/sysv/linux/i386/____longjmp_chk.S: Include . (____longjmp_chk): Restore shadow stack pointer if shadow stack is enabled and SHADOW_STACK_POINTER_OFFSET is defined. * sysdeps/unix/sysv/linux/x86/Makefile (gen-as-const-headers): Remove jmp_buf-ssp.sym. * sysdeps/unix/sysv/linux/x86_64/____longjmp_chk.S: Include . (____longjmp_chk): Restore shadow stack pointer if shadow stack is enabled and SHADOW_STACK_POINTER_OFFSET is defined. * sysdeps/x86/Makefile (gen-as-const-headers): Add jmp_buf-ssp.sym. * sysdeps/x86/jmp_buf-ssp.sym: New dummy file. * sysdeps/x86_64/__longjmp.S: Include . (__longjmp): Restore shadow stack pointer if shadow stack is enabled, SHADOW_STACK_POINTER_OFFSET is defined and __longjmp isn't defined for __longjmp_cancel. * sysdeps/x86_64/setjmp.S: Include . (__sigsetjmp): Save shadow stack pointer if shadow stack is enabled and SHADOW_STACK_POINTER_OFFSET is defined. --- sysdeps/x86_64/setjmp.S | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) (limited to 'sysdeps/x86_64/setjmp.S') diff --git a/sysdeps/x86_64/setjmp.S b/sysdeps/x86_64/setjmp.S index e0a648e3e4..78a8bf4644 100644 --- a/sysdeps/x86_64/setjmp.S +++ b/sysdeps/x86_64/setjmp.S @@ -18,9 +18,15 @@ #include #include +#include #include #include +/* Don't save shadow stack register if shadow stack isn't enabled. */ +#if !SHSTK_ENABLED +# undef SHADOW_STACK_POINTER_OFFSET +#endif + ENTRY (__sigsetjmp) /* Save registers. */ movq %rbx, (JB_RBX*8)(%rdi) @@ -54,6 +60,21 @@ ENTRY (__sigsetjmp) #endif movq %rax, (JB_PC*8)(%rdi) +#ifdef SHADOW_STACK_POINTER_OFFSET +# if IS_IN (libc) && defined SHARED && defined FEATURE_1_OFFSET + /* Check if Shadow Stack is enabled. */ + testl $X86_FEATURE_1_SHSTK, %fs:FEATURE_1_OFFSET + jz L(skip_ssp) +# else + xorl %eax, %eax +# endif + /* Get the current Shadow-Stack-Pointer and save it. */ + rdsspq %rax + movq %rax, SHADOW_STACK_POINTER_OFFSET(%rdi) +# if IS_IN (libc) && defined SHARED && defined FEATURE_1_OFFSET +L(skip_ssp): +# endif +#endif #if IS_IN (rtld) /* In ld.so we never save the signal mask. */ xorl %eax, %eax -- cgit v1.2.3