diff options
Diffstat (limited to 'sysdeps/unix/sysv/linux/x86_64/swapcontext.S')
| -rw-r--r-- | sysdeps/unix/sysv/linux/x86_64/swapcontext.S | 22 |
1 files changed, 4 insertions, 18 deletions
diff --git a/sysdeps/unix/sysv/linux/x86_64/swapcontext.S b/sysdeps/unix/sysv/linux/x86_64/swapcontext.S index 5925752164..2f2fe9875b 100644 --- a/sysdeps/unix/sysv/linux/x86_64/swapcontext.S +++ b/sysdeps/unix/sysv/linux/x86_64/swapcontext.S @@ -109,25 +109,11 @@ ENTRY(__swapcontext) cmpq %fs:SSP_BASE_OFFSET, %rax jnz L(shadow_stack_bound_recorded) - /* Get the base address and size of the default shadow stack - which must be the current shadow stack since nothing has - been recorded yet. */ - sub $24, %RSP_LP - mov %RSP_LP, %RSI_LP - movl $ARCH_CET_STATUS, %edi - movl $__NR_arch_prctl, %eax - syscall - testq %rax, %rax - jz L(continue_no_err) - - /* This should never happen. */ - hlt - -L(continue_no_err): - /* Record the base of the current shadow stack. */ - movq 8(%rsp), %rax + /* When the shadow stack base is unset, the default shadow + stack is in use. Use the current shadow stack pointer + as the marker for the default shadow stack. */ + rdsspq %rax movq %rax, %fs:SSP_BASE_OFFSET - add $24, %RSP_LP L(shadow_stack_bound_recorded): /* If we unwind the stack, we can't undo stack unwinding. Just |