glibc/sysdeps/x86_64/dl-trampoline.h
H.J. Lu 0aac205a81 x86: Update _dl_tlsdesc_dynamic to preserve caller-saved registers
Compiler generates the following instruction sequence for GNU2 dynamic
TLS access:

	leaq	tls_var@TLSDESC(%rip), %rax
	call	*tls_var@TLSCALL(%rax)

or

	leal	tls_var@TLSDESC(%ebx), %eax
	call	*tls_var@TLSCALL(%eax)

CALL instruction is transparent to compiler which assumes all registers,
except for EFLAGS and RAX/EAX, are unchanged after CALL.  When
_dl_tlsdesc_dynamic is called, it calls __tls_get_addr on the slow
path.  __tls_get_addr is a normal function which doesn't preserve any
caller-saved registers.  _dl_tlsdesc_dynamic saved and restored integer
caller-saved registers, but didn't preserve any other caller-saved
registers.  Add _dl_tlsdesc_dynamic IFUNC functions for FNSAVE, FXSAVE,
XSAVE and XSAVEC to save and restore all caller-saved registers.  This
fixes BZ #31372.

Add GLRO(dl_x86_64_runtime_resolve) with GLRO(dl_x86_tlsdesc_dynamic)
to optimize elf_machine_runtime_setup.
Reviewed-by: Noah Goldstein <goldstein.w.n@gmail.com>
2024-02-28 09:02:56 -08:00

462 lines
14 KiB
C

/* PLT trampolines. x86-64 version.
Copyright (C) 2009-2024 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
#ifndef SECTION
# define SECTION(p) p
#endif
.section SECTION(.text),"ax",@progbits
#ifdef _dl_runtime_resolve
# undef REGISTER_SAVE_AREA
# undef LOCAL_STORAGE_AREA
# undef BASE
# include "dl-trampoline-state.h"
.globl _dl_runtime_resolve
.hidden _dl_runtime_resolve
.type _dl_runtime_resolve, @function
.align 16
cfi_startproc
_dl_runtime_resolve:
cfi_adjust_cfa_offset(16) # Incorporate PLT
_CET_ENDBR
# if DL_RUNTIME_RESOLVE_REALIGN_STACK
# if LOCAL_STORAGE_AREA != 8
# error LOCAL_STORAGE_AREA must be 8
# endif
pushq %rbx # push subtracts stack by 8.
cfi_adjust_cfa_offset(8)
cfi_rel_offset(%rbx, 0)
mov %RSP_LP, %RBX_LP
cfi_def_cfa_register(%rbx)
and $-STATE_SAVE_ALIGNMENT, %RSP_LP
# endif
# ifdef REGISTER_SAVE_AREA
sub $REGISTER_SAVE_AREA, %RSP_LP
# if !DL_RUNTIME_RESOLVE_REALIGN_STACK
cfi_adjust_cfa_offset(REGISTER_SAVE_AREA)
# endif
# else
# Allocate stack space of the required size to save the state.
# if IS_IN (rtld)
sub _rtld_local_ro+RTLD_GLOBAL_RO_DL_X86_CPU_FEATURES_OFFSET+XSAVE_STATE_SIZE_OFFSET(%rip), %RSP_LP
# else
sub _dl_x86_cpu_features+XSAVE_STATE_SIZE_OFFSET(%rip), %RSP_LP
# endif
# endif
# Preserve registers otherwise clobbered.
movq %rax, REGISTER_SAVE_RAX(%rsp)
movq %rcx, REGISTER_SAVE_RCX(%rsp)
movq %rdx, REGISTER_SAVE_RDX(%rsp)
movq %rsi, REGISTER_SAVE_RSI(%rsp)
movq %rdi, REGISTER_SAVE_RDI(%rsp)
movq %r8, REGISTER_SAVE_R8(%rsp)
movq %r9, REGISTER_SAVE_R9(%rsp)
# ifdef USE_FXSAVE
fxsave STATE_SAVE_OFFSET(%rsp)
# else
movl $STATE_SAVE_MASK, %eax
xorl %edx, %edx
# Clear the XSAVE Header.
# ifdef USE_XSAVE
movq %rdx, (STATE_SAVE_OFFSET + 512)(%rsp)
movq %rdx, (STATE_SAVE_OFFSET + 512 + 8)(%rsp)
# endif
movq %rdx, (STATE_SAVE_OFFSET + 512 + 8 * 2)(%rsp)
movq %rdx, (STATE_SAVE_OFFSET + 512 + 8 * 3)(%rsp)
movq %rdx, (STATE_SAVE_OFFSET + 512 + 8 * 4)(%rsp)
movq %rdx, (STATE_SAVE_OFFSET + 512 + 8 * 5)(%rsp)
movq %rdx, (STATE_SAVE_OFFSET + 512 + 8 * 6)(%rsp)
movq %rdx, (STATE_SAVE_OFFSET + 512 + 8 * 7)(%rsp)
# ifdef USE_XSAVE
xsave STATE_SAVE_OFFSET(%rsp)
# else
xsavec STATE_SAVE_OFFSET(%rsp)
# endif
# endif
# Copy args pushed by PLT in register.
# %rdi: link_map, %rsi: reloc_index
mov (LOCAL_STORAGE_AREA + 8)(%BASE), %RSI_LP
mov LOCAL_STORAGE_AREA(%BASE), %RDI_LP
call _dl_fixup # Call resolver.
mov %RAX_LP, %R11_LP # Save return value
# Get register content back.
# ifdef USE_FXSAVE
fxrstor STATE_SAVE_OFFSET(%rsp)
# else
movl $STATE_SAVE_MASK, %eax
xorl %edx, %edx
xrstor STATE_SAVE_OFFSET(%rsp)
# endif
movq REGISTER_SAVE_R9(%rsp), %r9
movq REGISTER_SAVE_R8(%rsp), %r8
movq REGISTER_SAVE_RDI(%rsp), %rdi
movq REGISTER_SAVE_RSI(%rsp), %rsi
movq REGISTER_SAVE_RDX(%rsp), %rdx
movq REGISTER_SAVE_RCX(%rsp), %rcx
movq REGISTER_SAVE_RAX(%rsp), %rax
# if DL_RUNTIME_RESOLVE_REALIGN_STACK
mov %RBX_LP, %RSP_LP
cfi_def_cfa_register(%rsp)
movq (%rsp), %rbx
cfi_restore(%rbx)
# endif
# Adjust stack(PLT did 2 pushes)
add $(LOCAL_STORAGE_AREA + 16), %RSP_LP
cfi_adjust_cfa_offset(-(LOCAL_STORAGE_AREA + 16))
jmp *%r11 # Jump to function address.
cfi_endproc
.size _dl_runtime_resolve, .-_dl_runtime_resolve
#endif
#if !defined PROF && defined _dl_runtime_profile
# if (LR_VECTOR_OFFSET % VEC_SIZE) != 0
# error LR_VECTOR_OFFSET must be multiple of VEC_SIZE
# endif
.globl _dl_runtime_profile
.hidden _dl_runtime_profile
.type _dl_runtime_profile, @function
.align 16
_dl_runtime_profile:
cfi_startproc
cfi_adjust_cfa_offset(16) # Incorporate PLT
_CET_ENDBR
/* The La_x86_64_regs data structure pointed to by the
fourth parameter must be VEC_SIZE-byte aligned. This must
be explicitly enforced. We have the set up a dynamically
sized stack frame. %rbx points to the top half which
has a fixed size and preserves the original stack pointer. */
sub $32, %RSP_LP # Allocate the local storage.
cfi_adjust_cfa_offset(32)
movq %rbx, (%rsp)
cfi_rel_offset(%rbx, 0)
/* On the stack:
56(%rbx) parameter #1
48(%rbx) return address
40(%rbx) reloc index
32(%rbx) link_map
24(%rbx) La_x86_64_regs pointer
16(%rbx) framesize
8(%rbx) rax
(%rbx) rbx
*/
movq %rax, 8(%rsp)
mov %RSP_LP, %RBX_LP
cfi_def_cfa_register(%rbx)
/* Actively align the La_x86_64_regs structure. */
and $-VEC_SIZE, %RSP_LP
/* sizeof(La_x86_64_regs). Need extra space for 8 SSE registers
to detect if any xmm0-xmm7 registers are changed by audit
module. */
sub $(LR_SIZE + XMM_SIZE*8), %RSP_LP
movq %rsp, 24(%rbx)
/* Fill the La_x86_64_regs structure. */
movq %rdx, LR_RDX_OFFSET(%rsp)
movq %r8, LR_R8_OFFSET(%rsp)
movq %r9, LR_R9_OFFSET(%rsp)
movq %rcx, LR_RCX_OFFSET(%rsp)
movq %rsi, LR_RSI_OFFSET(%rsp)
movq %rdi, LR_RDI_OFFSET(%rsp)
movq %rbp, LR_RBP_OFFSET(%rsp)
lea 48(%rbx), %RAX_LP
movq %rax, LR_RSP_OFFSET(%rsp)
/* We always store the XMM registers even if AVX is available.
This is to provide backward binary compatibility for existing
audit modules. */
VMOVA %xmm0, (LR_XMM_OFFSET + XMM_SIZE*0)(%rsp)
VMOVA %xmm1, (LR_XMM_OFFSET + XMM_SIZE*1)(%rsp)
VMOVA %xmm2, (LR_XMM_OFFSET + XMM_SIZE*2)(%rsp)
VMOVA %xmm3, (LR_XMM_OFFSET + XMM_SIZE*3)(%rsp)
VMOVA %xmm4, (LR_XMM_OFFSET + XMM_SIZE*4)(%rsp)
VMOVA %xmm5, (LR_XMM_OFFSET + XMM_SIZE*5)(%rsp)
VMOVA %xmm6, (LR_XMM_OFFSET + XMM_SIZE*6)(%rsp)
VMOVA %xmm7, (LR_XMM_OFFSET + XMM_SIZE*7)(%rsp)
# ifdef RESTORE_AVX
/* This is to support AVX audit modules. */
VMOVA %VEC(0), (LR_VECTOR_OFFSET + VECTOR_SIZE*0)(%rsp)
VMOVA %VEC(1), (LR_VECTOR_OFFSET + VECTOR_SIZE*1)(%rsp)
VMOVA %VEC(2), (LR_VECTOR_OFFSET + VECTOR_SIZE*2)(%rsp)
VMOVA %VEC(3), (LR_VECTOR_OFFSET + VECTOR_SIZE*3)(%rsp)
VMOVA %VEC(4), (LR_VECTOR_OFFSET + VECTOR_SIZE*4)(%rsp)
VMOVA %VEC(5), (LR_VECTOR_OFFSET + VECTOR_SIZE*5)(%rsp)
VMOVA %VEC(6), (LR_VECTOR_OFFSET + VECTOR_SIZE*6)(%rsp)
VMOVA %VEC(7), (LR_VECTOR_OFFSET + VECTOR_SIZE*7)(%rsp)
/* Save xmm0-xmm7 registers to detect if any of them are
changed by audit module. */
vmovdqa %xmm0, (LR_SIZE + XMM_SIZE*0)(%rsp)
vmovdqa %xmm1, (LR_SIZE + XMM_SIZE*1)(%rsp)
vmovdqa %xmm2, (LR_SIZE + XMM_SIZE*2)(%rsp)
vmovdqa %xmm3, (LR_SIZE + XMM_SIZE*3)(%rsp)
vmovdqa %xmm4, (LR_SIZE + XMM_SIZE*4)(%rsp)
vmovdqa %xmm5, (LR_SIZE + XMM_SIZE*5)(%rsp)
vmovdqa %xmm6, (LR_SIZE + XMM_SIZE*6)(%rsp)
vmovdqa %xmm7, (LR_SIZE + XMM_SIZE*7)(%rsp)
# endif
mov %RSP_LP, %RCX_LP # La_x86_64_regs pointer to %rcx.
mov 48(%rbx), %RDX_LP # Load return address if needed.
mov 40(%rbx), %RSI_LP # Copy args pushed by PLT in register.
mov 32(%rbx), %RDI_LP # %rdi: link_map, %rsi: reloc_index
lea 16(%rbx), %R8_LP # Address of framesize
call _dl_profile_fixup # Call resolver.
mov %RAX_LP, %R11_LP # Save return value.
movq 8(%rbx), %rax # Get back register content.
movq LR_RDX_OFFSET(%rsp), %rdx
movq LR_R8_OFFSET(%rsp), %r8
movq LR_R9_OFFSET(%rsp), %r9
VMOVA (LR_XMM_OFFSET + XMM_SIZE*0)(%rsp), %xmm0
VMOVA (LR_XMM_OFFSET + XMM_SIZE*1)(%rsp), %xmm1
VMOVA (LR_XMM_OFFSET + XMM_SIZE*2)(%rsp), %xmm2
VMOVA (LR_XMM_OFFSET + XMM_SIZE*3)(%rsp), %xmm3
VMOVA (LR_XMM_OFFSET + XMM_SIZE*4)(%rsp), %xmm4
VMOVA (LR_XMM_OFFSET + XMM_SIZE*5)(%rsp), %xmm5
VMOVA (LR_XMM_OFFSET + XMM_SIZE*6)(%rsp), %xmm6
VMOVA (LR_XMM_OFFSET + XMM_SIZE*7)(%rsp), %xmm7
# ifdef RESTORE_AVX
/* Check if any xmm0-xmm7 registers are changed by audit
module. */
vpcmpeqb (LR_SIZE)(%rsp), %xmm0, %xmm8
vpmovmskb %xmm8, %esi
incw %si
je 2f
vmovdqa %xmm0, (LR_VECTOR_OFFSET)(%rsp)
jmp 1f
2: VMOVA (LR_VECTOR_OFFSET)(%rsp), %VEC(0)
vmovdqa %xmm0, (LR_XMM_OFFSET)(%rsp)
1: vpcmpeqb (LR_SIZE + XMM_SIZE)(%rsp), %xmm1, %xmm8
vpmovmskb %xmm8, %esi
incw %si
je 2f
vmovdqa %xmm1, (LR_VECTOR_OFFSET + VECTOR_SIZE)(%rsp)
jmp 1f
2: VMOVA (LR_VECTOR_OFFSET + VECTOR_SIZE)(%rsp), %VEC(1)
vmovdqa %xmm1, (LR_XMM_OFFSET + XMM_SIZE)(%rsp)
1: vpcmpeqb (LR_SIZE + XMM_SIZE*2)(%rsp), %xmm2, %xmm8
vpmovmskb %xmm8, %esi
incw %si
je 2f
vmovdqa %xmm2, (LR_VECTOR_OFFSET + VECTOR_SIZE*2)(%rsp)
jmp 1f
2: VMOVA (LR_VECTOR_OFFSET + VECTOR_SIZE*2)(%rsp), %VEC(2)
vmovdqa %xmm2, (LR_XMM_OFFSET + XMM_SIZE*2)(%rsp)
1: vpcmpeqb (LR_SIZE + XMM_SIZE*3)(%rsp), %xmm3, %xmm8
vpmovmskb %xmm8, %esi
incw %si
je 2f
vmovdqa %xmm3, (LR_VECTOR_OFFSET + VECTOR_SIZE*3)(%rsp)
jmp 1f
2: VMOVA (LR_VECTOR_OFFSET + VECTOR_SIZE*3)(%rsp), %VEC(3)
vmovdqa %xmm3, (LR_XMM_OFFSET + XMM_SIZE*3)(%rsp)
1: vpcmpeqb (LR_SIZE + XMM_SIZE*4)(%rsp), %xmm4, %xmm8
vpmovmskb %xmm8, %esi
incw %si
je 2f
vmovdqa %xmm4, (LR_VECTOR_OFFSET + VECTOR_SIZE*4)(%rsp)
jmp 1f
2: VMOVA (LR_VECTOR_OFFSET + VECTOR_SIZE*4)(%rsp), %VEC(4)
vmovdqa %xmm4, (LR_XMM_OFFSET + XMM_SIZE*4)(%rsp)
1: vpcmpeqb (LR_SIZE + XMM_SIZE*5)(%rsp), %xmm5, %xmm8
vpmovmskb %xmm8, %esi
incw %si
je 2f
vmovdqa %xmm5, (LR_VECTOR_OFFSET + VECTOR_SIZE*5)(%rsp)
jmp 1f
2: VMOVA (LR_VECTOR_OFFSET + VECTOR_SIZE*5)(%rsp), %VEC(5)
vmovdqa %xmm5, (LR_XMM_OFFSET + XMM_SIZE*5)(%rsp)
1: vpcmpeqb (LR_SIZE + XMM_SIZE*6)(%rsp), %xmm6, %xmm8
vpmovmskb %xmm8, %esi
incw %si
je 2f
vmovdqa %xmm6, (LR_VECTOR_OFFSET + VECTOR_SIZE*6)(%rsp)
jmp 1f
2: VMOVA (LR_VECTOR_OFFSET + VECTOR_SIZE*6)(%rsp), %VEC(6)
vmovdqa %xmm6, (LR_XMM_OFFSET + XMM_SIZE*6)(%rsp)
1: vpcmpeqb (LR_SIZE + XMM_SIZE*7)(%rsp), %xmm7, %xmm8
vpmovmskb %xmm8, %esi
incw %si
je 2f
vmovdqa %xmm7, (LR_VECTOR_OFFSET + VECTOR_SIZE*7)(%rsp)
jmp 1f
2: VMOVA (LR_VECTOR_OFFSET + VECTOR_SIZE*7)(%rsp), %VEC(7)
vmovdqa %xmm7, (LR_XMM_OFFSET + XMM_SIZE*7)(%rsp)
1:
# endif
mov 16(%rbx), %RCX_LP # Anything in framesize?
test %RCX_LP, %RCX_LP
jns 3f
/* There's nothing in the frame size, so there
will be no call to the _dl_audit_pltexit. */
/* Get back registers content. */
movq LR_RCX_OFFSET(%rsp), %rcx
movq LR_RSI_OFFSET(%rsp), %rsi
movq LR_RDI_OFFSET(%rsp), %rdi
mov %RBX_LP, %RSP_LP
movq (%rsp), %rbx
cfi_restore(%rbx)
cfi_def_cfa_register(%rsp)
add $48, %RSP_LP # Adjust the stack to the return value
# (eats the reloc index and link_map)
cfi_adjust_cfa_offset(-48)
jmp *%r11 # Jump to function address.
3:
cfi_adjust_cfa_offset(48)
cfi_rel_offset(%rbx, 0)
cfi_def_cfa_register(%rbx)
/* At this point we need to prepare new stack for the function
which has to be called. We copy the original stack to a
temporary buffer of the size specified by the 'framesize'
returned from _dl_profile_fixup */
lea LR_RSP_OFFSET(%rbx), %RSI_LP # stack
add $8, %RCX_LP
and $-16, %RCX_LP
sub %RCX_LP, %RSP_LP
mov %RSP_LP, %RDI_LP
rep movsb
movq 24(%rdi), %rcx # Get back register content.
movq 32(%rdi), %rsi
movq 40(%rdi), %rdi
call *%r11
mov 24(%rbx), %RSP_LP # Drop the copied stack content
/* Now we have to prepare the La_x86_64_retval structure for the
_dl_audit_pltexit. The La_x86_64_regs is being pointed by rsp now,
so we just need to allocate the sizeof(La_x86_64_retval) space on
the stack, since the alignment has already been taken care of. */
# ifdef RESTORE_AVX
/* sizeof(La_x86_64_retval). Need extra space for 2 SSE
registers to detect if xmm0/xmm1 registers are changed
by audit module. Since rsp is aligned to VEC_SIZE, we
need to make sure that the address of La_x86_64_retval +
LRV_VECTOR0_OFFSET is aligned to VEC_SIZE. */
# define LRV_SPACE (LRV_SIZE + XMM_SIZE*2)
# define LRV_MISALIGNED ((LRV_SIZE + LRV_VECTOR0_OFFSET) & (VEC_SIZE - 1))
# if LRV_MISALIGNED == 0
sub $LRV_SPACE, %RSP_LP
# else
sub $(LRV_SPACE + VEC_SIZE - LRV_MISALIGNED), %RSP_LP
# endif
# else
sub $LRV_SIZE, %RSP_LP # sizeof(La_x86_64_retval)
# endif
mov %RSP_LP, %RCX_LP # La_x86_64_retval argument to %rcx.
/* Fill in the La_x86_64_retval structure. */
movq %rax, LRV_RAX_OFFSET(%rcx)
movq %rdx, LRV_RDX_OFFSET(%rcx)
VMOVA %xmm0, LRV_XMM0_OFFSET(%rcx)
VMOVA %xmm1, LRV_XMM1_OFFSET(%rcx)
# ifdef RESTORE_AVX
/* This is to support AVX audit modules. */
VMOVA %VEC(0), LRV_VECTOR0_OFFSET(%rcx)
VMOVA %VEC(1), LRV_VECTOR1_OFFSET(%rcx)
/* Save xmm0/xmm1 registers to detect if they are changed
by audit module. */
vmovdqa %xmm0, (LRV_SIZE + XMM_SIZE*0)(%rcx)
vmovdqa %xmm1, (LRV_SIZE + XMM_SIZE*1)(%rcx)
# endif
fstpt LRV_ST0_OFFSET(%rcx)
fstpt LRV_ST1_OFFSET(%rcx)
movq 24(%rbx), %rdx # La_x86_64_regs argument to %rdx.
movq 40(%rbx), %rsi # Copy args pushed by PLT in register.
movq 32(%rbx), %rdi # %rdi: link_map, %rsi: reloc_index
call _dl_audit_pltexit
/* Restore return registers. */
movq LRV_RAX_OFFSET(%rsp), %rax
movq LRV_RDX_OFFSET(%rsp), %rdx
VMOVA LRV_XMM0_OFFSET(%rsp), %xmm0
VMOVA LRV_XMM1_OFFSET(%rsp), %xmm1
# ifdef RESTORE_AVX
/* Check if xmm0/xmm1 registers are changed by audit module. */
vpcmpeqb (LRV_SIZE)(%rsp), %xmm0, %xmm2
vpmovmskb %xmm2, %esi
incw %si
jne 1f
VMOVA LRV_VECTOR0_OFFSET(%rsp), %VEC(0)
1: vpcmpeqb (LRV_SIZE + XMM_SIZE)(%rsp), %xmm1, %xmm2
vpmovmskb %xmm2, %esi
incw %si
jne 1f
VMOVA LRV_VECTOR1_OFFSET(%rsp), %VEC(1)
1:
# endif
fldt LRV_ST1_OFFSET(%rsp)
fldt LRV_ST0_OFFSET(%rsp)
mov %RBX_LP, %RSP_LP
movq (%rsp), %rbx
cfi_restore(%rbx)
cfi_def_cfa_register(%rsp)
add $48, %RSP_LP # Adjust the stack to the return value
# (eats the reloc index and link_map)
cfi_adjust_cfa_offset(-48)
retq
cfi_endproc
.size _dl_runtime_profile, .-_dl_runtime_profile
#endif