@@ -311,7 +311,7 @@ update_active (struct cpu_features *cpu_features)
/* NB: On AMX capable processors, ebx always includes AMX
states. */
unsigned int xsave_state_full_size
- = ALIGN_UP (ebx + STATE_SAVE_OFFSET, 64);
+ = ALIGN_UP (ebx + TLSDESC_CALL_REGISTER_SAVE_AREA, 64);
cpu_features->xsave_state_size
= xsave_state_full_size;
@@ -401,8 +401,10 @@ update_active (struct cpu_features *cpu_features)
unsigned int amx_size
= (xstate_amx_comp_offsets[31]
+ xstate_amx_comp_sizes[31]);
- amx_size = ALIGN_UP (amx_size + STATE_SAVE_OFFSET,
- 64);
+ amx_size
+ = ALIGN_UP ((amx_size
+ + TLSDESC_CALL_REGISTER_SAVE_AREA),
+ 64);
/* Set xsave_state_full_size to the compact AMX
state size for XSAVEC. NB: xsave_state_full_size
is only used in _dl_tlsdesc_dynamic_xsave and
@@ -410,7 +412,8 @@ update_active (struct cpu_features *cpu_features)
cpu_features->xsave_state_full_size = amx_size;
#endif
cpu_features->xsave_state_size
- = ALIGN_UP (size + STATE_SAVE_OFFSET, 64);
+ = ALIGN_UP (size + TLSDESC_CALL_REGISTER_SAVE_AREA,
+ 64);
CPU_FEATURE_SET (cpu_features, XSAVEC);
}
}
@@ -38,14 +38,60 @@
#ifdef __x86_64__
/* Offset for fxsave/xsave area used by _dl_runtime_resolve. Also need
space to preserve RCX, RDX, RSI, RDI, R8, R9 and RAX. It must be
- aligned to 16 bytes for fxsave and 64 bytes for xsave.
-
- NB: Is is non-zero because of the 128-byte red-zone. Some registers
- are saved on stack without adjusting stack pointer first. When we
- update stack pointer to allocate more space, we need to take the
- red-zone into account. */
+ aligned to 16 bytes for fxsave and 64 bytes for xsave. It is non-zero
+ because MOV, instead of PUSH, is used to save registers onto stack.
+ When we update stack pointer to allocate space
+
+ +==================+<- stack frame start aligned at 8 or 16 bytes
+ | |<- paddings from stack realignment of 64 bytes
+ |------------------|<- xsave buffer end aligned at 64 bytes
+ | |<-
+ | |<-
+ | |<-
+ |------------------|<- xsave buffer start at STATE_SAVE_OFFSET(%rsp)
+ | |<- 8-byte padding
+ | |<- R9
+ | |<- R8
+ | |<- RDI
+ | |<- RSI
+ | |<- RDX
+ | |<- RCX
+ | |<- RAX
+ +==================+<- RSP aligned at 64 bytes
+
+ */
# define STATE_SAVE_OFFSET (8 * 7 + 8)
+/* _dl_tlsdesc_dynamic preserves RDI, RSI and RBX before realigning
+ stack. After realigning stack, it saves RCX, RDX, R8, R9, R10 and
+ R11. Allocate space for RDI, RSI and RBX to avoid clobbering saved
+ RDI, RSI and RBX values on stack by xsave.
+
+ +==================+<- stack frame start aligned at 8 or 16 bytes
+ | |<- RDI saved in the red zone
+ | |<- RSI saved in the red zone
+ | |<- RBX saved in the red zone
+ | |<- paddings from stack realignment of 64 bytes
+ |------------------|<- xsave buffer end aligned at 64 bytes
+ | |<-
+ | |<-
+ | |<-
+ |------------------|<- xsave buffer start at STATE_SAVE_OFFSET(%rsp)
+ | |<- 8-byte padding for 64-byte alignment
+ | |<- 8-byte padding for 64-byte alignment
+ | |<- R11
+ | |<- R10
+ | |<- R9
+ | |<- R8
+ | |<- RDX
+ | |<- RCX
+ +==================+<- RSP aligned at 64 bytes
+
+ Define the total register save area size for all integer registers.
+ Add 24 to STATE_SAVE_OFFSET since RDI, RSI and RBX are saved onto
+ stack without adjusting stack pointer first, using the red-zone. */
+# define TLSDESC_CALL_REGISTER_SAVE_AREA (STATE_SAVE_OFFSET + 24)
+
/* Save SSE, AVX, AVX512, mask, bound and APX registers. Bound and APX
registers are mutually exclusive. */
# define STATE_SAVE_MASK \
@@ -66,8 +112,9 @@
(STATE_SAVE_MASK | AMX_STATE_SAVE_MASK)
#else
/* Offset for fxsave/xsave area used by _dl_tlsdesc_dynamic. Since i386
- doesn't have red-zone, use 0 here. */
+ uses PUSH to save registers onto stack, use 0 here. */
# define STATE_SAVE_OFFSET 0
+# define TLSDESC_CALL_REGISTER_SAVE_AREA 0
/* Save SSE, AVX, AXV512, mask and bound registers. */
# define STATE_SAVE_MASK \
new file mode 100644
@@ -0,0 +1,87 @@
+/* Check if TLSDESC relocation preserves %rdi, %rsi and %rbx.
+ Copyright (C) 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
+ <http://www.gnu.org/licenses/>. */
+
+#include <sysdep.h>
+
+/* On AVX512 machines, OFFSET == 104 caused _dl_tlsdesc_dynamic_xsavec
+ to clobber %rdi, %rsi and %rbx. On Intel AVX CPUs, the state size
+ is 960 bytes and this test didn't fail. It may be due to the unused
+ last 128 bytes. On AMD AVX CPUs, the state size is 832 bytes and
+ this test might fail without the fix. */
+#ifndef OFFSET
+# define OFFSET 104
+#endif
+
+ .text
+ .p2align 4
+ .globl apply_tls
+ .type apply_tls, @function
+apply_tls:
+ cfi_startproc
+ _CET_ENDBR
+ pushq %rbp
+ cfi_def_cfa_offset (16)
+ cfi_offset (6, -16)
+ movdqu (%RDI_LP), %xmm0
+ lea tls_var1@TLSDESC(%rip), %RAX_LP
+ mov %RSP_LP, %RBP_LP
+ cfi_def_cfa_register (6)
+ /* Align stack to 64 bytes. */
+ and $-64, %RSP_LP
+ sub $OFFSET, %RSP_LP
+ pushq %rbx
+ /* Set %ebx to 0xbadbeef. */
+ movl $0xbadbeef, %ebx
+ movl $0xbadbeef, %esi
+ movq %rdi, saved_rdi(%rip)
+ movq %rsi, saved_rsi(%rip)
+ call *tls_var1@TLSCALL(%RAX_LP)
+ /* Check if _dl_tlsdesc_dynamic preserves %rdi, %rsi and %rbx. */
+ cmpq saved_rdi(%rip), %rdi
+ jne L(hlt)
+ cmpq saved_rsi(%rip), %rsi
+ jne L(hlt)
+ cmpl $0xbadbeef, %ebx
+ jne L(hlt)
+ add %fs:0, %RAX_LP
+ movups %xmm0, 32(%RAX_LP)
+ movdqu 16(%RDI_LP), %xmm1
+ mov %RAX_LP, %RBX_LP
+ movups %xmm1, 48(%RAX_LP)
+ lea 32(%RBX_LP), %RAX_LP
+ pop %rbx
+ leave
+ cfi_def_cfa (7, 8)
+ ret
+L(hlt):
+ hlt
+ cfi_endproc
+ .size apply_tls, .-apply_tls
+ .hidden tls_var1
+ .globl tls_var1
+ .section .tbss,"awT",@nobits
+ .align 16
+ .type tls_var1, @object
+ .size tls_var1, 3200
+tls_var1:
+ .zero 3200
+ .local saved_rdi
+ .comm saved_rdi,8,8
+ .local saved_rsi
+ .comm saved_rsi,8,8
+ .section .note.GNU-stack,"",@progbits