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authorJeremy Fitzhardinge <jeremy@goop.org>2008-07-12 13:22:00 +0400
committerIngo Molnar <mingo@elte.hu>2008-07-16 13:08:27 +0400
commit6a52e4b1cddd90fbfde8fb67021657936ee74b07 (patch)
treec876e1fafe89169f373f6b04739242b5d646fcf7 /arch/x86/vdso/vdso32-setup.c
parent71415c6a0877d5944d5dc3060f3b03513746158d (diff)
downloadlinux-6a52e4b1cddd90fbfde8fb67021657936ee74b07.tar.xz
x86_64: further cleanup of 32-bit compat syscall mechanisms
AMD only supports "syscall" from 32-bit compat usermode. Intel and Centaur(?) only support "sysenter" from 32-bit compat usermode. Set the X86 feature bits accordingly, and set up the vdso in accordance with those bits. On the offchance we run on in a 64-bit environment which supports neither syscall nor sysenter from 32-bit mode, then fall back to the int $0x80 vdso. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Diffstat (limited to 'arch/x86/vdso/vdso32-setup.c')
-rw-r--r--arch/x86/vdso/vdso32-setup.c19
1 files changed, 9 insertions, 10 deletions
diff --git a/arch/x86/vdso/vdso32-setup.c b/arch/x86/vdso/vdso32-setup.c
index 0bce5429a515..513f330c5832 100644
--- a/arch/x86/vdso/vdso32-setup.c
+++ b/arch/x86/vdso/vdso32-setup.c
@@ -193,17 +193,12 @@ static __init void relocate_vdso(Elf32_Ehdr *ehdr)
}
}
-/*
- * These symbols are defined by vdso32.S to mark the bounds
- * of the ELF DSO images included therein.
- */
-extern const char vdso32_default_start, vdso32_default_end;
-extern const char vdso32_sysenter_start, vdso32_sysenter_end;
static struct page *vdso32_pages[1];
#ifdef CONFIG_X86_64
#define vdso32_sysenter() (boot_cpu_has(X86_FEATURE_SYSENTER32))
+#define vdso32_syscall() (boot_cpu_has(X86_FEATURE_SYSCALL32))
/* May not be __init: called during resume */
void syscall32_cpu_init(void)
@@ -226,6 +221,7 @@ static inline void map_compat_vdso(int map)
#else /* CONFIG_X86_32 */
#define vdso32_sysenter() (boot_cpu_has(X86_FEATURE_SEP))
+#define vdso32_syscall() (0)
void enable_sep_cpu(void)
{
@@ -296,12 +292,15 @@ int __init sysenter_setup(void)
gate_vma_init();
#endif
- if (!vdso32_sysenter()) {
- vsyscall = &vdso32_default_start;
- vsyscall_len = &vdso32_default_end - &vdso32_default_start;
- } else {
+ if (vdso32_syscall()) {
+ vsyscall = &vdso32_syscall_start;
+ vsyscall_len = &vdso32_syscall_end - &vdso32_syscall_start;
+ } else if (vdso32_sysenter()){
vsyscall = &vdso32_sysenter_start;
vsyscall_len = &vdso32_sysenter_end - &vdso32_sysenter_start;
+ } else {
+ vsyscall = &vdso32_int80_start;
+ vsyscall_len = &vdso32_int80_end - &vdso32_int80_start;
}
memcpy(syscall_page, vsyscall, vsyscall_len);