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/*
* 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 <platform/bionic/tls_defines.h>
#include <private/bionic_asm.h>
.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 .fallback
ldr x21, [x0, #8] // TlsIndex::module
ldr x22, [x0, #16] // TlsIndex::offset
ldr x21, [x20, x21, lsl #3] // TlsDtv::modules[module]
cbz x21, .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
.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(x29, x30, 0)
mov x29, sp
// Avoid leaking the contents of the shadow call stack register (x18) into
// memory. x19 through x29 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(x29, x30, 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)