Merge branch 'x86-x32-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x32 support for x86-64 from Ingo Molnar:
 "This tree introduces the X32 binary format and execution mode for x86:
  32-bit data space binaries using 64-bit instructions and 64-bit kernel
  syscalls.

  This allows applications whose working set fits into a 32 bits address
  space to make use of 64-bit instructions while using a 32-bit address
  space with shorter pointers, more compressed data structures, etc."

Fix up trivial context conflicts in arch/x86/{Kconfig,vdso/vma.c}

* 'x86-x32-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (71 commits)
  x32: Fix alignment fail in struct compat_siginfo
  x32: Fix stupid ia32/x32 inversion in the siginfo format
  x32: Add ptrace for x32
  x32: Switch to a 64-bit clock_t
  x32: Provide separate is_ia32_task() and is_x32_task() predicates
  x86, mtrr: Use explicit sizing and padding for the 64-bit ioctls
  x86/x32: Fix the binutils auto-detect
  x32: Warn and disable rather than error if binutils too old
  x32: Only clear TIF_X32 flag once
  x32: Make sure TS_COMPAT is cleared for x32 tasks
  fs: Remove missed ->fds_bits from cessation use of fd_set structs internally
  fs: Fix close_on_exec pointer in alloc_fdtable
  x32: Drop non-__vdso weak symbols from the x32 VDSO
  x32: Fix coding style violations in the x32 VDSO code
  x32: Add x32 VDSO support
  x32: Allow x32 to be configured
  x32: If configured, add x32 system calls to system call tables
  x32: Handle process creation
  x32: Signal-related system calls
  x86: Add #ifdef CONFIG_COMPAT to <asm/sys_ia32.h>
  ...

1 files changed, 21 insertions, 6 deletions

diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index 2b154da..733ca39 100644
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -258,7 +258,9 @@ start_thread(struct pt_regs *regs, unsigned long new_ip, unsigned long new_sp)
 void start_thread_ia32(struct pt_regs *regs, u32 new_ip, u32 new_sp)
 {
 	start_thread_common(regs, new_ip, new_sp,
-			    __USER32_CS, __USER32_DS, __USER32_DS);
+			    test_thread_flag(TIF_X32)
+			    ? __USER_CS : __USER32_CS,
+			    __USER_DS, __USER_DS);
 }
 #endif
 
@@ -381,6 +383,8 @@ void set_personality_64bit(void)
 
 	/* Make sure to be in 64bit mode */
 	clear_thread_flag(TIF_IA32);
+	clear_thread_flag(TIF_ADDR32);
+	clear_thread_flag(TIF_X32);
 
 	/* Ensure the corresponding mm is not marked. */
 	if (current->mm)
@@ -393,20 +397,31 @@ void set_personality_64bit(void)
 	current->personality &= ~READ_IMPLIES_EXEC;
 }
 
-void set_personality_ia32(void)
+void set_personality_ia32(bool x32)
 {
 	/* inherit personality from parent */
 
 	/* Make sure to be in 32bit mode */
-	set_thread_flag(TIF_IA32);
-	current->personality |= force_personality32;
+	set_thread_flag(TIF_ADDR32);
 
 	/* Mark the associated mm as containing 32-bit tasks. */
 	if (current->mm)
 		current->mm->context.ia32_compat = 1;
 
-	/* Prepare the first "return" to user space */
-	current_thread_info()->status |= TS_COMPAT;
+	if (x32) {
+		clear_thread_flag(TIF_IA32);
+		set_thread_flag(TIF_X32);
+		current->personality &= ~READ_IMPLIES_EXEC;
+		/* is_compat_task() uses the presence of the x32
+		   syscall bit flag to determine compat status */
+		current_thread_info()->status &= ~TS_COMPAT;
+	} else {
+		set_thread_flag(TIF_IA32);
+		clear_thread_flag(TIF_X32);
+		current->personality |= force_personality32;
+		/* Prepare the first "return" to user space */
+		current_thread_info()->status |= TS_COMPAT;
+	}
 }
 
 unsigned long get_wchan(struct task_struct *p)