/* * Copyright (C) 2019 The Android Open Source Project * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in * the documentation and/or other materials provided with the * distribution. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #include #include .globl __tls_get_addr // These resolver functions must preserve every register except x0. They set x0 // to the offset of the TLS symbol relative to the thread pointer. ENTRY_PRIVATE(tlsdesc_resolver_static) ldr x0, [x0, #8] ret END(tlsdesc_resolver_static) ENTRY_PRIVATE(tlsdesc_resolver_dynamic) stp x19, x20, [sp, #-32]! .cfi_def_cfa_offset 32 .cfi_rel_offset x19, 0 .cfi_rel_offset x20, 8 stp x21, x22, [sp, #16] .cfi_rel_offset x21, 16 .cfi_rel_offset x22, 24 mrs x19, tpidr_el0 // __get_tls() ldr x20, [x19, #(TLS_SLOT_DTV * 8)] ldr x21, [x20] // TlsDtv::generation ldr x0, [x0, #8] // TlsDynamicResolverArg* ldr x22, [x0] // TlsDynamicResolverArg::generation cmp x21, x22 b.lo L(fallback) ldr x21, [x0, #8] // TlsIndex::module_id ldr x22, [x0, #16] // TlsIndex::offset ldr x21, [x20, x21, lsl #3] // TlsDtv::modules[module_id] cbz x21, L(fallback) add x0, x21, x22 sub x0, x0, x19 ldp x21, x22, [sp, #16] .cfi_remember_state .cfi_restore x21 .cfi_restore x22 ldp x19, x20, [sp], #32 .cfi_adjust_cfa_offset -32 .cfi_restore x19 .cfi_restore x20 ret L(fallback): .cfi_restore_state ldp x21, x22, [sp, #16] .cfi_restore x21 .cfi_restore x22 ldp x19, x20, [sp], #32 .cfi_adjust_cfa_offset -32 .cfi_restore x19 .cfi_restore x20 b tlsdesc_resolver_dynamic_slow_path END(tlsdesc_resolver_dynamic) #define SAVE_REG(x, slot) \ str x, [sp, #((slot) * 8)]; \ .cfi_rel_offset x, (slot) * 8; \ #define SAVE_GPR_PAIR(x, y, slot) \ stp x, y, [sp, #((slot) * 8)]; \ .cfi_rel_offset x, (slot) * 8; \ .cfi_rel_offset y, ((slot) + 1) * 8; \ #define SAVE_VEC_PAIR(x, y, slot) \ stp x, y, [sp, #((slot) * 8)]; \ .cfi_rel_offset x, (slot) * 8; \ .cfi_rel_offset y, ((slot) + 2) * 8; \ #define RESTORE_REG(x, slot) \ ldr x, [sp, #((slot) * 8)]; \ .cfi_restore x; \ #define RESTORE_REG_PAIR(x, y, slot) \ ldp x, y, [sp, #((slot) * 8)]; \ .cfi_restore x; \ .cfi_restore y; \ // On entry, x0 is the address of a TlsDynamicResolverArg object rather than // the TlsDescriptor address passed to the original resolver function. ENTRY_PRIVATE(tlsdesc_resolver_dynamic_slow_path) sub sp, sp, #(8 * 84) .cfi_def_cfa_offset (8 * 84) SAVE_GPR_PAIR(fp, lr, 0) mov fp, sp // Avoid leaking the contents of the shadow call stack register (x18) into // memory. x19 through x29 (fp) are callee-save registers, so we do not need // to save them. SAVE_GPR_PAIR(x1, x2, 2) SAVE_GPR_PAIR(x3, x4, 4) SAVE_GPR_PAIR(x5, x6, 6) SAVE_GPR_PAIR(x7, x8, 8) SAVE_GPR_PAIR(x9, x10, 10) SAVE_GPR_PAIR(x11, x12, 12) SAVE_GPR_PAIR(x13, x14, 14) SAVE_GPR_PAIR(x15, x16, 16) SAVE_REG(x17, 18) SAVE_VEC_PAIR(q0, q1, 20) SAVE_VEC_PAIR(q2, q3, 24) SAVE_VEC_PAIR(q4, q5, 28) SAVE_VEC_PAIR(q6, q7, 32) SAVE_VEC_PAIR(q8, q9, 36) SAVE_VEC_PAIR(q10, q11, 40) SAVE_VEC_PAIR(q12, q13, 44) SAVE_VEC_PAIR(q14, q15, 48) SAVE_VEC_PAIR(q16, q17, 52) SAVE_VEC_PAIR(q18, q19, 56) SAVE_VEC_PAIR(q20, q21, 60) SAVE_VEC_PAIR(q22, q23, 64) SAVE_VEC_PAIR(q24, q25, 68) SAVE_VEC_PAIR(q26, q27, 72) SAVE_VEC_PAIR(q28, q29, 76) SAVE_VEC_PAIR(q30, q31, 80) add x0, x0, #8 bl __tls_get_addr mrs x1, tpidr_el0 // __get_tls() sub x0, x0, x1 RESTORE_REG_PAIR(q30, q31, 80) RESTORE_REG_PAIR(q28, q29, 76) RESTORE_REG_PAIR(q26, q27, 72) RESTORE_REG_PAIR(q24, q25, 68) RESTORE_REG_PAIR(q22, q23, 64) RESTORE_REG_PAIR(q20, q21, 60) RESTORE_REG_PAIR(q18, q19, 56) RESTORE_REG_PAIR(q16, q17, 52) RESTORE_REG_PAIR(q14, q15, 48) RESTORE_REG_PAIR(q12, q13, 44) RESTORE_REG_PAIR(q10, q11, 40) RESTORE_REG_PAIR(q8, q9, 36) RESTORE_REG_PAIR(q6, q7, 32) RESTORE_REG_PAIR(q4, q5, 28) RESTORE_REG_PAIR(q2, q3, 24) RESTORE_REG_PAIR(q0, q1, 20) RESTORE_REG(x17, 18) RESTORE_REG_PAIR(x15, x16, 16) RESTORE_REG_PAIR(x13, x14, 14) RESTORE_REG_PAIR(x11, x12, 12) RESTORE_REG_PAIR(x9, x10, 10) RESTORE_REG_PAIR(x7, x8, 8) RESTORE_REG_PAIR(x5, x6, 6) RESTORE_REG_PAIR(x3, x4, 4) RESTORE_REG_PAIR(x1, x2, 2) RESTORE_REG_PAIR(fp, lr, 0) add sp, sp, #(8 * 84) .cfi_def_cfa_offset 0 ret END(tlsdesc_resolver_dynamic_slow_path) // The address of an unresolved weak TLS symbol evaluates to NULL with TLSDESC. // The value returned by this function is added to the thread pointer, so return // a negated thread pointer to cancel it out. ENTRY_PRIVATE(tlsdesc_resolver_unresolved_weak) str x19, [sp, #-16]! .cfi_def_cfa_offset 16 .cfi_rel_offset x19, 0 ldr x19, [x0, #8] mrs x0, tpidr_el0 // __get_tls() sub x0, x19, x0 ldr x19, [sp], #16 .cfi_def_cfa_offset 0 .cfi_restore x19 ret END(tlsdesc_resolver_unresolved_weak)