diff options
| -rw-r--r-- | arch/i386/kernel/time.c | 10 | ||||
| -rw-r--r-- | include/asm-i386/ptrace.h | 4 | ||||
| -rw-r--r-- | include/asm-i386/segment.h | 19 |
3 files changed, 21 insertions, 12 deletions
diff --git a/arch/i386/kernel/time.c b/arch/i386/kernel/time.c index 9603ccaba997..a4f67a6e6821 100644 --- a/arch/i386/kernel/time.c +++ b/arch/i386/kernel/time.c @@ -131,15 +131,13 @@ unsigned long profile_pc(struct pt_regs *regs) unsigned long pc = instruction_pointer(regs); #ifdef CONFIG_SMP - if (!user_mode_vm(regs) && in_lock_functions(pc)) { + if (!v8086_mode(regs) && SEGMENT_IS_KERNEL_CODE(regs->xcs) && + in_lock_functions(pc)) { #ifdef CONFIG_FRAME_POINTER return *(unsigned long *)(regs->ebp + 4); #else - unsigned long *sp; - if ((regs->xcs & 3) == 0) - sp = (unsigned long *)®s->esp; - else - sp = (unsigned long *)regs->esp; + unsigned long *sp = (unsigned long *)®s->esp; + /* Return address is either directly at stack pointer or above a saved eflags. Eflags has bits 22-31 zero, kernel addresses don't. */ diff --git a/include/asm-i386/ptrace.h b/include/asm-i386/ptrace.h index 1646996c73da..6002597b9e12 100644 --- a/include/asm-i386/ptrace.h +++ b/include/asm-i386/ptrace.h @@ -49,6 +49,10 @@ static inline int user_mode_vm(struct pt_regs *regs) { return ((regs->xcs & SEGMENT_RPL_MASK) | (regs->eflags & VM_MASK)) >= USER_RPL; } +static inline int v8086_mode(struct pt_regs *regs) +{ + return (regs->eflags & VM_MASK); +} #define instruction_pointer(regs) ((regs)->eip) #define regs_return_value(regs) ((regs)->eax) diff --git a/include/asm-i386/segment.h b/include/asm-i386/segment.h index 3c796af33776..065f10bfa487 100644 --- a/include/asm-i386/segment.h +++ b/include/asm-i386/segment.h @@ -83,14 +83,8 @@ * The GDT has 32 entries */ #define GDT_ENTRIES 32 - #define GDT_SIZE (GDT_ENTRIES * 8) -/* Matches __KERNEL_CS and __USER_CS (they must be 2 entries apart) */ -#define SEGMENT_IS_FLAT_CODE(x) (((x) & 0xec) == GDT_ENTRY_KERNEL_CS * 8) -/* Matches PNP_CS32 and PNP_CS16 (they must be consecutive) */ -#define SEGMENT_IS_PNP_CODE(x) (((x) & 0xf4) == GDT_ENTRY_PNPBIOS_BASE * 8) - /* Simple and small GDT entries for booting only */ #define GDT_ENTRY_BOOT_CS 2 @@ -134,4 +128,17 @@ #ifndef CONFIG_PARAVIRT #define get_kernel_rpl() 0 #endif +/* + * Matching rules for certain types of segments. + */ + +/* Matches only __KERNEL_CS, ignoring PnP / USER / APM segments */ +#define SEGMENT_IS_KERNEL_CODE(x) (((x) & 0xfc) == GDT_ENTRY_KERNEL_CS * 8) + +/* Matches __KERNEL_CS and __USER_CS (they must be 2 entries apart) */ +#define SEGMENT_IS_FLAT_CODE(x) (((x) & 0xec) == GDT_ENTRY_KERNEL_CS * 8) + +/* Matches PNP_CS32 and PNP_CS16 (they must be consecutive) */ +#define SEGMENT_IS_PNP_CODE(x) (((x) & 0xf4) == GDT_ENTRY_PNPBIOS_BASE * 8) + #endif |