| // Copyright 2017 The Fuchsia Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #include "asm.h" |
| #include "setjmp_impl.h" |
| #include <zircon/tls.h> |
| |
| ENTRY(setjmp) |
| |
| // Move the jmp_buf pointer to a temporary register. |
| // We'll use x0 as a scratch register since we clobber it on return anyway. |
| mov x16, x0 |
| |
| // Load the manglers into temporary registers. |
| // We'll be sure that by return these registers don't |
| // contain the raw manglers, so those values never leak. |
| adrp x0, __setjmp_manglers |
| add x0, x0, #:lo12:__setjmp_manglers |
| ldp x1, x2, [x0, #8*JB_PC] |
| ldp x3, x4, [x0, #8*JB_FP] |
| |
| // Get the thread pointer, where the unsafe SP is stored. |
| mrs x0, TPIDR_EL0 |
| ldr x0, [x0, #ZX_TLS_UNSAFE_SP_OFFSET] |
| |
| // Store all the vanilla callee-saves registers. |
| stp x19, x20, [x16, #8*JB_X(19)] |
| stp x21, x22, [x16, #8*JB_X(21)] |
| stp x23, x24, [x16, #8*JB_X(23)] |
| stp x25, x26, [x16, #8*JB_X(25)] |
| stp x27, x28, [x16, #8*JB_X(27)] |
| stp d8, d9, [x16, #8*JB_D(8)] |
| stp d10, d11, [x16, #8*JB_D(10)] |
| stp d12, d13, [x16, #8*JB_D(12)] |
| stp d14, d15, [x16, #8*JB_D(14)] |
| |
| eor x4, x4, x0 // Mangled unsafe SP. |
| eor x1, x1, x30 // Mangled PC (LR). |
| eor x3, x3, x29 // Mangled FP. |
| mov x0, sp |
| eor x2, x2, x0 // Mangled SP. |
| |
| .ifne JB_SP - JB_PC - 1 |
| .error "JB_SP expected to follow JB_PC immediately" |
| .endif |
| stp x1, x2, [x16, #8*JB_PC] |
| .ifne JB_USP - JB_FP - 1 |
| .error "JB_USP expected to follow JB_FP immediately" |
| .endif |
| stp x3, x4, [x16, #8*JB_FP] |
| |
| mov w0, wzr |
| ret |
| |
| END(setjmp) |
| |
| ALIAS(setjmp, _setjmp) |
| WEAK_ALIAS(setjmp, sigsetjmp) |
