We allow for the fact that the guest kernel may not run in ring 0. This requires some abstraction in a few places when setting %cs or checking privilege level (user vs kernel). Signed-off-by: Ian Pratt Signed-off-by: Christian Limpach Signed-off-by: Chris Wright --- arch/i386/kernel/process.c | 2 +- arch/i386/mm/fault.c | 8 +++++--- include/asm-i386/mach-default/mach_segment.h | 8 ++++++++ include/asm-i386/mach-xen/mach_segment.h | 9 +++++++++ include/asm-i386/mach-xen/mach_system.h | 1 + include/asm-i386/ptrace.h | 6 ++++-- include/asm-i386/segment.h | 2 ++ include/asm-i386/system.h | 1 + 8 files changed, 31 insertions(+), 6 deletions(-) diff -r 0bc9790d1ce3 arch/i386/kernel/process.c --- a/arch/i386/kernel/process.c Tue Jul 18 04:04:39 2006 -0400 +++ b/arch/i386/kernel/process.c Tue Jul 18 04:33:57 2006 -0400 @@ -346,7 +346,7 @@ int kernel_thread(int (*fn)(void *), voi regs.xes = __USER_DS; regs.orig_eax = -1; regs.eip = (unsigned long) kernel_thread_helper; - regs.xcs = __KERNEL_CS; + regs.xcs = get_kernel_cs(); regs.eflags = X86_EFLAGS_IF | X86_EFLAGS_SF | X86_EFLAGS_PF | 0x2; /* Ok, create the new process.. */ diff -r 0bc9790d1ce3 arch/i386/mm/fault.c --- a/arch/i386/mm/fault.c Tue Jul 18 04:04:39 2006 -0400 +++ b/arch/i386/mm/fault.c Tue Jul 18 04:33:57 2006 -0400 @@ -28,6 +28,8 @@ #include #include +#include + extern void die(const char *,struct pt_regs *,long); #ifdef CONFIG_KPROBES @@ -119,10 +121,10 @@ static inline unsigned long get_segment_ } /* The standard kernel/user address space limit. */ - *eip_limit = (seg & 3) ? USER_DS.seg : KERNEL_DS.seg; + *eip_limit = (seg & USER_MODE_MASK) ? USER_DS.seg : KERNEL_DS.seg; /* By far the most common cases. */ - if (likely(seg == __USER_CS || seg == __KERNEL_CS)) + if (likely(seg == __USER_CS || seg == get_kernel_cs())) return eip; /* Check the segment exists, is within the current LDT/GDT size, @@ -437,7 +439,7 @@ good_area: switch (error_code & 3) { default: /* 3: write, present */ #ifdef TEST_VERIFY_AREA - if (regs->cs == KERNEL_CS) + if (regs->cs == get_kernel_cs()) printk("WP fault at %08lx\n", regs->eip); #endif /* fall through */ diff -r 0bc9790d1ce3 include/asm-i386/ptrace.h --- a/include/asm-i386/ptrace.h Tue Jul 18 04:04:39 2006 -0400 +++ b/include/asm-i386/ptrace.h Tue Jul 18 04:33:57 2006 -0400 @@ -1,5 +1,7 @@ #ifndef _I386_PTRACE_H #define _I386_PTRACE_H + +#include #define EBX 0 #define ECX 1 @@ -73,11 +75,11 @@ extern void send_sigtrap(struct task_str */ static inline int user_mode(struct pt_regs *regs) { - return (regs->xcs & 3) != 0; + return (regs->xcs & USER_MODE_MASK) != 0; } static inline int user_mode_vm(struct pt_regs *regs) { - return ((regs->xcs & 3) | (regs->eflags & VM_MASK)) != 0; + return ((regs->xcs & USER_MODE_MASK) | (regs->eflags & VM_MASK)) != 0; } #define instruction_pointer(regs) ((regs)->eip) #if defined(CONFIG_SMP) && defined(CONFIG_FRAME_POINTER) diff -r 0bc9790d1ce3 include/asm-i386/segment.h --- a/include/asm-i386/segment.h Tue Jul 18 04:04:39 2006 -0400 +++ b/include/asm-i386/segment.h Tue Jul 18 04:33:57 2006 -0400 @@ -1,5 +1,7 @@ #ifndef _ASM_SEGMENT_H #define _ASM_SEGMENT_H + +#include /* * The layout of the per-CPU GDT under Linux: diff -r 0bc9790d1ce3 include/asm-i386/system.h --- a/include/asm-i386/system.h Tue Jul 18 04:04:39 2006 -0400 +++ b/include/asm-i386/system.h Tue Jul 18 04:33:57 2006 -0400 @@ -487,6 +487,7 @@ static inline unsigned long long __cmpxc #endif #include +#include /* * disable hlt during certain critical i/o operations diff -r 0bc9790d1ce3 include/asm-i386/mach-xen/mach_system.h --- a/include/asm-i386/mach-xen/mach_system.h Tue Jul 18 04:04:39 2006 -0400 +++ b/include/asm-i386/mach-xen/mach_system.h Tue Jul 18 04:33:57 2006 -0400 @@ -1,5 +1,6 @@ #ifndef __ASM_MACH_SYSTEM_H #define __ASM_MACH_SYSTEM_H +#include #endif /* __ASM_MACH_SYSTEM_H */ diff -r 0bc9790d1ce3 include/asm-i386/mach-default/mach_segment.h --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/include/asm-i386/mach-default/mach_segment.h Tue Jul 18 04:33:57 2006 -0400 @@ -0,0 +1,8 @@ +#ifndef __ASM_MACH_SEGMENT_H +#define __ASM_MACH_SEGMENT_H + +#define USER_MODE_MASK 3 + +#define get_kernel_cs() __KERNEL_CS + +#endif /* __ASM_MACH_SEGMENT_H */ diff -r 0bc9790d1ce3 include/asm-i386/mach-xen/mach_segment.h --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/include/asm-i386/mach-xen/mach_segment.h Tue Jul 18 04:33:57 2006 -0400 @@ -0,0 +1,9 @@ +#ifndef __ASM_MACH_SEGMENT_H +#define __ASM_MACH_SEGMENT_H + +#define USER_MODE_MASK 2 + +#define get_kernel_cs() \ + (__KERNEL_CS + (xen_feature(XENFEAT_supervisor_mode_kernel) ? 0 : 1)) + +#endif /* __ASM_MACH_SEGMENT_H */ -- - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/