x86: Factor out TIF_IA32 from 32-bit address space

Factor out IA32 (compatibility instruction set) from 32-bit address
space in the thread_info flags; this is a precondition patch for x32
support.

Originally-by: H. J. Lu <hjl.tools@gmail.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Link: http://lkml.kernel.org/n/tip-4pr1xnnksprt7t0h3w5fw4rv@git.kernel.org

2 files changed, 5 insertions, 3 deletions

diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index 9b9fe4a85c8..0e900d09e23 100644
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -508,6 +508,7 @@ void set_personality_64bit(void)
 
         /* Make sure to be in 64bit mode */
         clear_thread_flag(TIF_IA32);
+        clear_thread_flag(TIF_ADDR32);
 
         /* Ensure the corresponding mm is not marked. */
         if (current->mm)
@@ -526,6 +527,7 @@ void set_personality_ia32(void)
 
         /* Make sure to be in 32bit mode */
         set_thread_flag(TIF_IA32);
+        set_thread_flag(TIF_ADDR32);
         current->personality |= force_personality32;
 
         /* Mark the associated mm as containing 32-bit tasks. */
diff --git a/arch/x86/kernel/sys_x86_64.c b/arch/x86/kernel/sys_x86_64.c
index 051489082d5..f921df8c209 100644
--- a/arch/x86/kernel/sys_x86_64.c
+++ b/arch/x86/kernel/sys_x86_64.c
@@ -98,7 +98,7 @@ out:
 static void find_start_end(unsigned long flags, unsigned long *begin,
                            unsigned long *end)
 {
-        if (!test_thread_flag(TIF_IA32) && (flags & MAP_32BIT)) {
+        if (!test_thread_flag(TIF_ADDR32) && (flags & MAP_32BIT)) {
                 unsigned long new_begin;
                 /* This is usually used needed to map code in small
                    model, so it needs to be in the first 31bit. Limit
@@ -144,7 +144,7 @@ arch_get_unmapped_area(struct file *filp, unsigned long addr,
                     (!vma || addr + len <= vma->vm_start))
                         return addr;
         }
-        if (((flags & MAP_32BIT) || test_thread_flag(TIF_IA32))
+        if (((flags & MAP_32BIT) || test_thread_flag(TIF_ADDR32))
             && len <= mm->cached_hole_size) {
                 mm->cached_hole_size = 0;
                 mm->free_area_cache = begin;
@@ -205,7 +205,7 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
                 return addr;
 
         /* for MAP_32BIT mappings we force the legact mmap base */
-        if (!test_thread_flag(TIF_IA32) && (flags & MAP_32BIT))
+        if (!test_thread_flag(TIF_ADDR32) && (flags & MAP_32BIT))
                 goto bottomup;
 
         /* requesting a specific address */