summaryrefslogtreecommitdiff
path: root/arch/i386
diff options
context:
space:
mode:
Diffstat (limited to 'arch/i386')
-rw-r--r--arch/i386/kernel/entry.S9
-rw-r--r--arch/i386/kernel/process.c2
-rw-r--r--arch/i386/mm/extable.c2
-rw-r--r--arch/i386/mm/fault.c11
4 files changed, 11 insertions, 13 deletions
diff --git a/arch/i386/kernel/entry.S b/arch/i386/kernel/entry.S
index 3872fca5c74a..284f2e908ad0 100644
--- a/arch/i386/kernel/entry.S
+++ b/arch/i386/kernel/entry.S
@@ -240,8 +240,9 @@ ret_from_intr:
check_userspace:
movl EFLAGS(%esp), %eax # mix EFLAGS and CS
movb CS(%esp), %al
- testl $(VM_MASK | 3), %eax
- jz resume_kernel
+ andl $(VM_MASK | SEGMENT_RPL_MASK), %eax
+ cmpl $USER_RPL, %eax
+ jb resume_kernel # not returning to v8086 or userspace
ENTRY(resume_userspace)
DISABLE_INTERRUPTS # make sure we don't miss an interrupt
# setting need_resched or sigpending
@@ -377,8 +378,8 @@ restore_all:
# See comments in process.c:copy_thread() for details.
movb OLDSS(%esp), %ah
movb CS(%esp), %al
- andl $(VM_MASK | (4 << 8) | 3), %eax
- cmpl $((4 << 8) | 3), %eax
+ andl $(VM_MASK | (SEGMENT_TI_MASK << 8) | SEGMENT_RPL_MASK), %eax
+ cmpl $((SEGMENT_LDT << 8) | USER_RPL), %eax
CFI_REMEMBER_STATE
je ldt_ss # returning to user-space with LDT SS
restore_nocheck:
diff --git a/arch/i386/kernel/process.c b/arch/i386/kernel/process.c
index 220aeca59c3a..8c190ca7ae44 100644
--- a/arch/i386/kernel/process.c
+++ b/arch/i386/kernel/process.c
@@ -338,7 +338,7 @@ int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
regs.xes = __USER_DS;
regs.orig_eax = -1;
regs.eip = (unsigned long) kernel_thread_helper;
- regs.xcs = __KERNEL_CS;
+ regs.xcs = __KERNEL_CS | get_kernel_rpl();
regs.eflags = X86_EFLAGS_IF | X86_EFLAGS_SF | X86_EFLAGS_PF | 0x2;
/* Ok, create the new process.. */
diff --git a/arch/i386/mm/extable.c b/arch/i386/mm/extable.c
index de03c5430abc..0ce4f22a2635 100644
--- a/arch/i386/mm/extable.c
+++ b/arch/i386/mm/extable.c
@@ -11,7 +11,7 @@ int fixup_exception(struct pt_regs *regs)
const struct exception_table_entry *fixup;
#ifdef CONFIG_PNPBIOS
- if (unlikely((regs->xcs & ~15) == (GDT_ENTRY_PNPBIOS_BASE << 3)))
+ if (unlikely(SEGMENT_IS_PNP_CODE(regs->xcs)))
{
extern u32 pnp_bios_fault_eip, pnp_bios_fault_esp;
extern u32 pnp_bios_is_utter_crap;
diff --git a/arch/i386/mm/fault.c b/arch/i386/mm/fault.c
index 0ce86168a0b1..5e17a3f43b41 100644
--- a/arch/i386/mm/fault.c
+++ b/arch/i386/mm/fault.c
@@ -27,6 +27,7 @@
#include <asm/uaccess.h>
#include <asm/desc.h>
#include <asm/kdebug.h>
+#include <asm/segment.h>
extern void die(const char *,struct pt_regs *,long);
@@ -113,10 +114,10 @@ static inline unsigned long get_segment_eip(struct pt_regs *regs,
}
/* The standard kernel/user address space limit. */
- *eip_limit = (seg & 3) ? USER_DS.seg : KERNEL_DS.seg;
+ *eip_limit = user_mode(regs) ? USER_DS.seg : KERNEL_DS.seg;
/* By far the most common cases. */
- if (likely(seg == __USER_CS || seg == __KERNEL_CS))
+ if (likely(SEGMENT_IS_FLAT_CODE(seg)))
return eip;
/* Check the segment exists, is within the current LDT/GDT size,
@@ -430,11 +431,7 @@ good_area:
write = 0;
switch (error_code & 3) {
default: /* 3: write, present */
-#ifdef TEST_VERIFY_AREA
- if (regs->cs == KERNEL_CS)
- printk("WP fault at %08lx\n", regs->eip);
-#endif
- /* fall through */
+ /* fall through */
case 2: /* write, not present */
if (!(vma->vm_flags & VM_WRITE))
goto bad_area;