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| author | Jeremy Fitzhardinge <jeremy@goop.org> | 2008-07-12 13:22:00 +0400 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-07-16 13:08:27 +0400 |
| commit | 6a52e4b1cddd90fbfde8fb67021657936ee74b07 (patch) | |
| tree | c876e1fafe89169f373f6b04739242b5d646fcf7 /arch/x86/vdso/vdso32-setup.c | |
| parent | 71415c6a0877d5944d5dc3060f3b03513746158d (diff) | |
| download | linux-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.c | 19 |
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); |