x86: get rid of the insane TIF_ABI_PENDING bit

commit 05d43ed8a89c159ff641d472f970e3f1baa66318 upstream.

Now that the previous commit made it possible to do the personality
setting at the point of no return, we do just that for ELF binaries.
And suddenly all the reasons for that insane TIF_ABI_PENDING bit go
away, and we can just make SET_PERSONALITY() just do the obvious thing
for a 32-bit compat process.

Everything becomes much more straightforward this way.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>

diff --git a/arch/x86/ia32/ia32_aout.c b/arch/x86/ia32/ia32_aout.c
index a59b0946c432993be49f0647c78a032c4e913974..14531abdd0ced75cc2f5a60e9ff29fe0308a91b8 100644 (file)
--- a/arch/x86/ia32/ia32_aout.c
+++ b/arch/x86/ia32/ia32_aout.c
@@ -311,7 +311,6 @@ static int load_aout_binary(struct linux_binprm *bprm, struct pt_regs *regs)
        /* OK, This is the point of no return */
        set_personality(PER_LINUX);
        set_thread_flag(TIF_IA32);
-       clear_thread_flag(TIF_ABI_PENDING);
 
        setup_new_exec(bprm);
 

diff --git a/arch/x86/include/asm/elf.h b/arch/x86/include/asm/elf.h
index 456a304b817266320ad59d6f6b49419ea4e1aa15..8ac9d9ae129e787d99979472880c1ba53f2fd830 100644 (file)
--- a/arch/x86/include/asm/elf.h
+++ b/arch/x86/include/asm/elf.h
@@ -197,14 +197,8 @@ do {                                                       \
        set_fs(USER_DS);                                \
 } while (0)
 
-#define COMPAT_SET_PERSONALITY(ex)                     \
-do {                                                   \
-       if (test_thread_flag(TIF_IA32))                 \
-               clear_thread_flag(TIF_ABI_PENDING);     \
-       else                                            \
-               set_thread_flag(TIF_ABI_PENDING);       \
-       current->personality |= force_personality32;    \
-} while (0)
+void set_personality_ia32(void);
+#define COMPAT_SET_PERSONALITY(ex) set_personality_ia32()
 
 #define COMPAT_ELF_PLATFORM                    ("i686")
 

diff --git a/arch/x86/include/asm/thread_info.h b/arch/x86/include/asm/thread_info.h
index fad7d40b75f898e8a3651265f573c313a479c4ea..e4bcf0c002680d2ea867691362dab00785dc909b 100644 (file)
--- a/arch/x86/include/asm/thread_info.h
+++ b/arch/x86/include/asm/thread_info.h
@@ -86,7 +86,6 @@ struct thread_info {
 #define TIF_NOTSC              16      /* TSC is not accessible in userland */
 #define TIF_IA32               17      /* 32bit process */
 #define TIF_FORK               18      /* ret_from_fork */
-#define TIF_ABI_PENDING                19
 #define TIF_MEMDIE             20
 #define TIF_DEBUG              21      /* uses debug registers */
 #define TIF_IO_BITMAP          22      /* uses I/O bitmap */
@@ -110,7 +109,6 @@ struct thread_info {
 #define _TIF_NOTSC             (1 << TIF_NOTSC)
 #define _TIF_IA32              (1 << TIF_IA32)
 #define _TIF_FORK              (1 << TIF_FORK)
-#define _TIF_ABI_PENDING       (1 << TIF_ABI_PENDING)
 #define _TIF_DEBUG             (1 << TIF_DEBUG)
 #define _TIF_IO_BITMAP         (1 << TIF_IO_BITMAP)
 #define _TIF_FREEZE            (1 << TIF_FREEZE)

diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index 071166a4ba83b893cf3a91aeb2ee52606e9bd056..a35fcbd9fe38fcfd9902666d868cf372b901cb5e 100644 (file)
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -94,18 +94,6 @@ void flush_thread(void)
 {
        struct task_struct *tsk = current;
 
-#ifdef CONFIG_X86_64
-       if (test_tsk_thread_flag(tsk, TIF_ABI_PENDING)) {
-               clear_tsk_thread_flag(tsk, TIF_ABI_PENDING);
-               if (test_tsk_thread_flag(tsk, TIF_IA32)) {
-                       clear_tsk_thread_flag(tsk, TIF_IA32);
-               } else {
-                       set_tsk_thread_flag(tsk, TIF_IA32);
-                       current_thread_info()->status |= TS_COMPAT;
-               }
-       }
-#endif
-
        clear_tsk_thread_flag(tsk, TIF_DEBUG);
 
        tsk->thread.debugreg0 = 0;

diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index ebefb5407b9d36f5ccbb1c458708fb8a647ff19b..80c2372ec3cb0f2684e476d8df4e05bbbd997f2d 100644 (file)
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -534,6 +534,17 @@ sys_clone(unsigned long clone_flags, unsigned long newsp,
        return do_fork(clone_flags, newsp, regs, 0, parent_tid, child_tid);
 }
 
+void set_personality_ia32(void)
+{
+       /* inherit personality from parent */
+
+       /* Make sure to be in 32bit mode */
+       set_thread_flag(TIF_IA32);
+
+       /* Prepare the first "return" to user space */
+       current_thread_info()->status |= TS_COMPAT;
+}
+
 unsigned long get_wchan(struct task_struct *p)
 {
        unsigned long stack;