[PATCH] x86_64: Use a common function to find code segment bases
To avoid some code duplication.
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/arch/x86_64/mm/fault.c b/arch/x86_64/mm/fault.c
index d4676ca..e033092 100644
--- a/arch/x86_64/mm/fault.c
+++ b/arch/x86_64/mm/fault.c
@@ -62,21 +62,19 @@
static noinline int is_prefetch(struct pt_regs *regs, unsigned long addr,
unsigned long error_code)
{
- unsigned char *instr = (unsigned char *)(regs->rip);
+ unsigned char *instr;
int scan_more = 1;
int prefetch = 0;
- unsigned char *max_instr = instr + 15;
+ unsigned char *max_instr;
/* If it was a exec fault ignore */
if (error_code & (1<<4))
return 0;
- /* Code segments in LDT could have a non zero base. Don't check
- when that's possible */
- if (regs->cs & (1<<2))
- return 0;
+ instr = (unsigned char *)convert_rip_to_linear(current, regs);
+ max_instr = instr + 15;
- if ((regs->cs & 3) != 0 && regs->rip >= TASK_SIZE)
+ if ((regs->cs & 3) != 0 && instr >= (unsigned char *)TASK_SIZE)
return 0;
while (scan_more && instr < max_instr) {
diff --git a/include/asm-x86_64/ptrace.h b/include/asm-x86_64/ptrace.h
index c7865cf..5bbc8d3 100644
--- a/include/asm-x86_64/ptrace.h
+++ b/include/asm-x86_64/ptrace.h
@@ -86,6 +86,11 @@
extern unsigned long profile_pc(struct pt_regs *regs);
void signal_fault(struct pt_regs *regs, void __user *frame, char *where);
+struct task_struct;
+
+extern unsigned long
+convert_rip_to_linear(struct task_struct *child, struct pt_regs *regs);
+
enum {
EF_CF = 0x00000001,
EF_PF = 0x00000004,
