From 60f0f2130d30cfd008ca39743027f1e200592dff Mon Sep 17 00:00:00 2001 From: Florian Weimer Date: Wed, 4 May 2022 15:37:21 +0200 Subject: i386: Honor I386_USE_SYSENTER for 6-argument Linux system calls Introduce an int-80h-based version of __libc_do_syscall and use it if I386_USE_SYSENTER is defined as 0. Reviewed-by: H.J. Lu --- sysdeps/unix/sysv/linux/i386/Makefile | 2 +- .../unix/sysv/linux/i386/libc-do-syscall-int80.S | 25 ++++++++++++++++++++++ sysdeps/unix/sysv/linux/i386/sysdep.h | 13 +++++++++-- 3 files changed, 37 insertions(+), 3 deletions(-) create mode 100644 sysdeps/unix/sysv/linux/i386/libc-do-syscall-int80.S (limited to 'sysdeps') diff --git a/sysdeps/unix/sysv/linux/i386/Makefile b/sysdeps/unix/sysv/linux/i386/Makefile index fcab129..598e27d 100644 --- a/sysdeps/unix/sysv/linux/i386/Makefile +++ b/sysdeps/unix/sysv/linux/i386/Makefile @@ -13,7 +13,7 @@ install-bin += lddlibc4 endif ifeq ($(subdir),io) -sysdep_routines += libc-do-syscall +sysdep_routines += libc-do-syscall libc-do-syscall-int80 endif ifeq ($(subdir),stdlib) diff --git a/sysdeps/unix/sysv/linux/i386/libc-do-syscall-int80.S b/sysdeps/unix/sysv/linux/i386/libc-do-syscall-int80.S new file mode 100644 index 0000000..2c472f2 --- /dev/null +++ b/sysdeps/unix/sysv/linux/i386/libc-do-syscall-int80.S @@ -0,0 +1,25 @@ +/* Out-of-line syscall stub for six-argument syscalls from C. For static PIE. + Copyright (C) 2022 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 + . */ + +#ifndef SHARED +# define I386_USE_SYSENTER 0 +# include + +# define __libc_do_syscall __libc_do_syscall_int80 +# include "libc-do-syscall.S" +#endif diff --git a/sysdeps/unix/sysv/linux/i386/sysdep.h b/sysdeps/unix/sysv/linux/i386/sysdep.h index 4558ab6..7085f7e 100644 --- a/sysdeps/unix/sysv/linux/i386/sysdep.h +++ b/sysdeps/unix/sysv/linux/i386/sysdep.h @@ -42,6 +42,15 @@ # endif #endif +#if !I386_USE_SYSENTER && IS_IN (libc) && !defined SHARED +/* Inside static libc, we have two versions. For compilation units + with !I386_USE_SYSENTER, the vDSO entry mechanism cannot be + used. */ +# define I386_DO_SYSCALL_STRING "__libc_do_syscall_int80" +#else +# define I386_DO_SYSCALL_STRING "__libc_do_syscall" +#endif + #ifdef __ASSEMBLER__ /* Linux uses a negative return value to indicate syscall errors, @@ -301,7 +310,7 @@ struct libc_do_syscall_args }; \ asm volatile ( \ "movl %1, %%eax\n\t" \ - "call __libc_do_syscall" \ + "call " I386_DO_SYSCALL_STRING \ : "=a" (resultvar) \ : "i" (__NR_##name), "c" (arg2), "d" (arg3), "S" (arg4), "D" (&_xv) \ : "memory", "cc") @@ -315,7 +324,7 @@ struct libc_do_syscall_args }; \ asm volatile ( \ "movl %1, %%eax\n\t" \ - "call __libc_do_syscall" \ + "call " I386_DO_SYSCALL_STRING \ : "=a" (resultvar) \ : "a" (name), "c" (arg2), "d" (arg3), "S" (arg4), "D" (&_xv) \ : "memory", "cc") -- cgit v1.1