glibc/sysdeps/x86_64/dl-trampoline-state.h

/* x86-64 PLT dl-trampoline state macros.
   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
   <https://www.gnu.org/licenses/>.  */

#if (STATE_SAVE_ALIGNMENT % 16) != 0
# error STATE_SAVE_ALIGNMENT must be multiple of 16
#endif

#if (STATE_SAVE_OFFSET % STATE_SAVE_ALIGNMENT) != 0
# error STATE_SAVE_OFFSET must be multiple of STATE_SAVE_ALIGNMENT
#endif

#if DL_RUNTIME_RESOLVE_REALIGN_STACK
/* Local stack area before jumping to function address: RBX.  */
# define LOCAL_STORAGE_AREA	8
# define BASE			rbx
# ifdef USE_FXSAVE
/* Use fxsave to save XMM registers.  */
#  define REGISTER_SAVE_AREA	(512 + STATE_SAVE_OFFSET)
#  if (REGISTER_SAVE_AREA % 16) != 0
#   error REGISTER_SAVE_AREA must be multiple of 16
#  endif
# endif
#else
# ifndef USE_FXSAVE
#  error USE_FXSAVE must be defined
# endif
/* Use fxsave to save XMM registers.  */
# define REGISTER_SAVE_AREA	(512 + STATE_SAVE_OFFSET + 8)
/* Local stack area before jumping to function address:  All saved
   registers.  */
# define LOCAL_STORAGE_AREA	REGISTER_SAVE_AREA
# define BASE			rsp
# if (REGISTER_SAVE_AREA % 16) != 8
#  error REGISTER_SAVE_AREA must be odd multiple of 8
# endif
#endif
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> 2024-02-26 14:37:03 +00:00			`/* x86-64 PLT dl-trampoline state macros.`
			`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`
			`<https://www.gnu.org/licenses/>. */`

			`#if (STATE_SAVE_ALIGNMENT % 16) != 0`
			`# error STATE_SAVE_ALIGNMENT must be multiple of 16`
			`#endif`

			`#if (STATE_SAVE_OFFSET % STATE_SAVE_ALIGNMENT) != 0`
			`# error STATE_SAVE_OFFSET must be multiple of STATE_SAVE_ALIGNMENT`
			`#endif`

			`#if DL_RUNTIME_RESOLVE_REALIGN_STACK`
			`/* Local stack area before jumping to function address: RBX. */`
			`# define LOCAL_STORAGE_AREA 8`
			`# define BASE rbx`
			`# ifdef USE_FXSAVE`
			`/* Use fxsave to save XMM registers. */`
			`# define REGISTER_SAVE_AREA (512 + STATE_SAVE_OFFSET)`
			`# if (REGISTER_SAVE_AREA % 16) != 0`
			`# error REGISTER_SAVE_AREA must be multiple of 16`
			`# endif`
			`# endif`
			`#else`
			`# ifndef USE_FXSAVE`
			`# error USE_FXSAVE must be defined`
			`# endif`
			`/* Use fxsave to save XMM registers. */`
			`# define REGISTER_SAVE_AREA (512 + STATE_SAVE_OFFSET + 8)`
			`/* Local stack area before jumping to function address: All saved`
			`registers. */`
			`# define LOCAL_STORAGE_AREA REGISTER_SAVE_AREA`
			`# define BASE rsp`
			`# if (REGISTER_SAVE_AREA % 16) != 8`
			`# error REGISTER_SAVE_AREA must be odd multiple of 8`
			`# endif`
			`#endif`