From 6a52e4b1cddd90fbfde8fb67021657936ee74b07 Mon Sep 17 00:00:00 2001 From: Jeremy Fitzhardinge Date: Sat, 12 Jul 2008 02:22:00 -0700 Subject: 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 Signed-off-by: H. Peter Anvin --- arch/x86/vdso/vdso32-setup.c | 19 +++++++++---------- 1 file changed, 9 insertions(+), 10 deletions(-) (limited to 'arch/x86/vdso/vdso32-setup.c') diff --git a/arch/x86/vdso/vdso32-setup.c b/arch/x86/vdso/vdso32-setup.c index 0bce5429a51..513f330c583 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); -- cgit v1.2.3