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

6 files changed, 13 insertions, 9 deletions

diff --git a/arch/x86/include/asm/elf.h b/arch/x86/include/asm/elf.h
index 5f962df30d0f..410fa6a219f6 100644
--- a/arch/x86/include/asm/elf.h
+++ b/arch/x86/include/asm/elf.h
@@ -287,7 +287,7 @@ do {									\
 #define VDSO_HIGH_BASE          0xffffe000U /* CONFIG_COMPAT_VDSO address */
 
 /* 1GB for 64bit, 8MB for 32bit */
-#define STACK_RND_MASK (test_thread_flag(TIF_IA32) ? 0x7ff : 0x3fffff)
+#define STACK_RND_MASK (test_thread_flag(TIF_ADDR32) ? 0x7ff : 0x3fffff)
 
 #define ARCH_DLINFO                                                     \
 do {                                                                    \
@@ -330,7 +330,7 @@ static inline int mmap_is_ia32(void)
         return 1;
 #endif
 #ifdef CONFIG_IA32_EMULATION
-        if (test_thread_flag(TIF_IA32))
+        if (test_thread_flag(TIF_ADDR32))
                 return 1;
 #endif
         return 0;
diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index aa9088c26931..9f748b5fb701 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -924,9 +924,9 @@ extern unsigned long thread_saved_pc(struct task_struct *tsk);
 #define IA32_PAGE_OFFSET        ((current->personality & ADDR_LIMIT_3GB) ? \
                                         0xc0000000 : 0xFFFFe000)
 
-#define TASK_SIZE               (test_thread_flag(TIF_IA32) ? \
+#define TASK_SIZE               (test_thread_flag(TIF_ADDR32) ? \
                                         IA32_PAGE_OFFSET : TASK_SIZE_MAX)
-#define TASK_SIZE_OF(child)     ((test_tsk_thread_flag(child, TIF_IA32)) ? \
+#define TASK_SIZE_OF(child)     ((test_tsk_thread_flag(child, TIF_ADDR32)) ? \
                                         IA32_PAGE_OFFSET : TASK_SIZE_MAX)
 
 #define STACK_TOP               TASK_SIZE
diff --git a/arch/x86/include/asm/thread_info.h b/arch/x86/include/asm/thread_info.h
index bc817cd8b443..d1803a495b35 100644
--- a/arch/x86/include/asm/thread_info.h
+++ b/arch/x86/include/asm/thread_info.h
@@ -86,7 +86,7 @@ struct thread_info {
 #define TIF_MCE_NOTIFY          10      /* notify userspace of an MCE */
 #define TIF_USER_RETURN_NOTIFY  11      /* notify kernel of userspace return */
 #define TIF_NOTSC               16      /* TSC is not accessible in userland */
-#define TIF_IA32                17      /* 32bit process */
+#define TIF_IA32                17      /* IA32 compatibility process */
 #define TIF_FORK                18      /* ret_from_fork */
 #define TIF_MEMDIE              20      /* is terminating due to OOM killer */
 #define TIF_DEBUG               21      /* uses debug registers */
@@ -95,6 +95,7 @@ struct thread_info {
 #define TIF_BLOCKSTEP           25      /* set when we want DEBUGCTLMSR_BTF */
 #define TIF_LAZY_MMU_UPDATES    27      /* task is updating the mmu lazily */
 #define TIF_SYSCALL_TRACEPOINT  28      /* syscall tracepoint instrumentation */
+#define TIF_ADDR32              29      /* 32-bit address space on 64 bits */
 
 #define _TIF_SYSCALL_TRACE      (1 << TIF_SYSCALL_TRACE)
 #define _TIF_NOTIFY_RESUME      (1 << TIF_NOTIFY_RESUME)
@@ -116,6 +117,7 @@ struct thread_info {
 #define _TIF_BLOCKSTEP          (1 << TIF_BLOCKSTEP)
 #define _TIF_LAZY_MMU_UPDATES   (1 << TIF_LAZY_MMU_UPDATES)
 #define _TIF_SYSCALL_TRACEPOINT (1 << TIF_SYSCALL_TRACEPOINT)
+#define _TIF_ADDR32             (1 << TIF_ADDR32)
 
 /* work to do in syscall_trace_enter() */
 #define _TIF_WORK_SYSCALL_ENTRY \
diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index 9b9fe4a85c87..0e900d09e232 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 051489082d59..f921df8c2099 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 */
diff --git a/arch/x86/oprofile/backtrace.c b/arch/x86/oprofile/backtrace.c
index bff89dfe3619..d6aa6e8315d1 100644
--- a/arch/x86/oprofile/backtrace.c
+++ b/arch/x86/oprofile/backtrace.c
@@ -67,7 +67,7 @@ x86_backtrace_32(struct pt_regs * const regs, unsigned int depth)
 {
         struct stack_frame_ia32 *head;
 
-        /* User process is 32-bit */
+        /* User process is IA32 */
         if (!current || !test_thread_flag(TIF_IA32))
                 return 0;