From 3ae36655b97a03fa1decf72f04078ef945647c1a Mon Sep 17 00:00:00 2001 From: Andy Lutomirski Date: Wed, 10 Aug 2011 11:15:32 -0400 Subject: x86-64: Rework vsyscall emulation and add vsyscall= parameter There are three choices: vsyscall=native: Vsyscalls are native code that issues the corresponding syscalls. vsyscall=emulate (default): Vsyscalls are emulated by instruction fault traps, tested in the bad_area path. The actual contents of the vsyscall page is the same as the vsyscall=native case except that it's marked NX. This way programs that make assumptions about what the code in the page does will not be confused when they read that code. vsyscall=none: Trying to execute a vsyscall will segfault. Signed-off-by: Andy Lutomirski Link: http://lkml.kernel.org/r/8449fb3abf89851fd6b2260972666a6f82542284.1312988155.git.luto@mit.edu Signed-off-by: H. Peter Anvin --- arch/x86/kernel/vmlinux.lds.S | 33 --------------------------------- 1 file changed, 33 deletions(-) (limited to 'arch/x86/kernel/vmlinux.lds.S') diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S index 8f3a265476d7..0f703f10901a 100644 --- a/arch/x86/kernel/vmlinux.lds.S +++ b/arch/x86/kernel/vmlinux.lds.S @@ -71,7 +71,6 @@ PHDRS { text PT_LOAD FLAGS(5); /* R_E */ data PT_LOAD FLAGS(6); /* RW_ */ #ifdef CONFIG_X86_64 - user PT_LOAD FLAGS(5); /* R_E */ #ifdef CONFIG_SMP percpu PT_LOAD FLAGS(6); /* RW_ */ #endif @@ -174,38 +173,6 @@ SECTIONS . = ALIGN(__vvar_page + PAGE_SIZE, PAGE_SIZE); -#define VSYSCALL_ADDR (-10*1024*1024) - -#define VLOAD_OFFSET (VSYSCALL_ADDR - __vsyscall_0 + LOAD_OFFSET) -#define VLOAD(x) (ADDR(x) - VLOAD_OFFSET) - -#define VVIRT_OFFSET (VSYSCALL_ADDR - __vsyscall_0) -#define VVIRT(x) (ADDR(x) - VVIRT_OFFSET) - - __vsyscall_0 = .; - - . = VSYSCALL_ADDR; - .vsyscall : AT(VLOAD(.vsyscall)) { - /* work around gold bug 13023 */ - __vsyscall_beginning_hack = .; - *(.vsyscall_0) - - . = __vsyscall_beginning_hack + 1024; - *(.vsyscall_1) - - . = __vsyscall_beginning_hack + 2048; - *(.vsyscall_2) - - . = __vsyscall_beginning_hack + 4096; /* Pad the whole page. */ - } :user =0xcc - . = ALIGN(__vsyscall_0 + PAGE_SIZE, PAGE_SIZE); - -#undef VSYSCALL_ADDR -#undef VLOAD_OFFSET -#undef VLOAD -#undef VVIRT_OFFSET -#undef VVIRT - #endif /* CONFIG_X86_64 */ /* Init code and data - will be freed after init */ -- cgit v1.2.1