x86: remove last user of get_segment_eip

is_prefetch was the last user of get_segment_eip and only on
X86_32.  This function returned the faulting instruction's
address and set the upper segment limit.

Instead, use the convert_ip_to_linear helper and rely on
probe_kernel_address to do the segment checks which was
already done everywhere the segment limit was being checked
on X86_32.

Remove get_segment_eip as well.

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 2 insertions, 13 deletions

diff --git a/arch/x86/mm/fault_64.c b/arch/x86/mm/fault_64.c
index d519b41f1962..80f8436ac8b2 100644
--- a/arch/x86/mm/fault_64.c
+++ b/arch/x86/mm/fault_64.c
@@ -84,7 +84,6 @@ static int is_prefetch(struct pt_regs *regs, unsigned long addr,
         unsigned char *max_instr;
 
 #ifdef CONFIG_X86_32
-        unsigned long limit;
         if (unlikely(boot_cpu_data.x86_vendor == X86_VENDOR_AMD &&
                      boot_cpu_data.x86 >= 6)) {
                 /* Catch an obscure case of prefetch inside an NX page. */
@@ -93,30 +92,23 @@ static int is_prefetch(struct pt_regs *regs, unsigned long addr,
         } else {
                 return 0;
         }
-        instr = (unsigned char *)get_segment_eip(regs, &limit);
 #else
         /* If it was a exec fault ignore */
         if (error_code & PF_INSTR)
                 return 0;
-        instr = (unsigned char __user *)convert_ip_to_linear(current, regs);
 #endif
 
+        instr = (unsigned char *)convert_ip_to_linear(current, regs);
         max_instr = instr + 15;
 
-#ifdef CONFIG_X86_64
         if (user_mode(regs) && instr >= (unsigned char *)TASK_SIZE)
                 return 0;
-#endif
 
         while (scan_more && instr < max_instr) {
                 unsigned char opcode;
                 unsigned char instr_hi;
                 unsigned char instr_lo;
 
-#ifdef CONFIG_X86_32
-                if (instr > (unsigned char *)limit)
-                        break;
-#endif
                 if (probe_kernel_address(instr, opcode))
                         break;
 
@@ -158,10 +150,7 @@ static int is_prefetch(struct pt_regs *regs, unsigned long addr,
                 case 0x00:
                         /* Prefetch instruction is 0x0F0D or 0x0F18 */
                         scan_more = 0;
-#ifdef CONFIG_X86_32
-                        if (instr > (unsigned char *)limit)
-                                break;
-#endif
+
                         if (probe_kernel_address(instr, opcode))
                                 break;
                         prefetch = (instr_lo == 0xF) &&