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authorJeremy Fitzhardinge <jeremy@goop.org>2008-07-12 02:22:00 -0700
committerIngo Molnar <mingo@elte.hu>2008-07-16 11:08:27 +0200
commit6a52e4b1cddd90fbfde8fb67021657936ee74b07 (patch)
treec876e1fafe89169f373f6b04739242b5d646fcf7 /arch/x86/vdso
parent71415c6a0877d5944d5dc3060f3b03513746158d (diff)
downloadlinux-6a52e4b1cddd90fbfde8fb67021657936ee74b07.tar.bz2
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')
-rw-r--r--arch/x86/vdso/Makefile2
-rw-r--r--arch/x86/vdso/vdso32-setup.c19
-rw-r--r--arch/x86/vdso/vdso32.S13
3 files changed, 18 insertions, 16 deletions
diff --git a/arch/x86/vdso/Makefile b/arch/x86/vdso/Makefile
index b7ad9f89d21f..4d6ef0a336d6 100644
--- a/arch/x86/vdso/Makefile
+++ b/arch/x86/vdso/Makefile
@@ -62,7 +62,7 @@ $(obj)/%-syms.lds: $(obj)/%.so.dbg FORCE
# Build multiple 32-bit vDSO images to choose from at boot time.
#
obj-$(VDSO32-y) += vdso32-syms.lds
-vdso32.so-$(CONFIG_X86_32) += int80
+vdso32.so-$(VDSO32-y) += int80
vdso32.so-$(CONFIG_COMPAT) += syscall
vdso32.so-$(VDSO32-y) += sysenter
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);
diff --git a/arch/x86/vdso/vdso32.S b/arch/x86/vdso/vdso32.S
index 1e36f72cab86..2ce5f82c333b 100644
--- a/arch/x86/vdso/vdso32.S
+++ b/arch/x86/vdso/vdso32.S
@@ -2,14 +2,17 @@
__INITDATA
- .globl vdso32_default_start, vdso32_default_end
-vdso32_default_start:
-#ifdef CONFIG_X86_32
+ .globl vdso32_int80_start, vdso32_int80_end
+vdso32_int80_start:
.incbin "arch/x86/vdso/vdso32-int80.so"
-#else
+vdso32_int80_end:
+
+ .globl vdso32_syscall_start, vdso32_syscall_end
+vdso32_syscall_start:
+#ifdef CONFIG_COMPAT
.incbin "arch/x86/vdso/vdso32-syscall.so"
#endif
-vdso32_default_end:
+vdso32_syscall_end:
.globl vdso32_sysenter_start, vdso32_sysenter_end
vdso32_sysenter_start: