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Commit e76623d6 authored by Al Viro's avatar Al Viro
Browse files

x86: get rid of TIF_IRET hackery 



TIF_NOTIFY_RESUME will work in precisely the same way; all that
is achieved by TIF_IRET is appearing that there's some work to be
done, so we end up on the iret exit path.  Just use NOTIFY_RESUME.
And for execve() do that in 32bit start_thread(), not sys_execve()
itself.

Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent c46de226

arch/x86/include/asm/thread_info.h

+0 −2
Original line number Diff line number Diff line
@@ -79,7 +79,6 @@ struct thread_info { 
#define TIF_SIGPENDING		2	/* signal pending */

#define TIF_NEED_RESCHED	3	/* rescheduling necessary */

#define TIF_SINGLESTEP		4	/* reenable singlestep on user return*/

#define TIF_IRET		5	/* force IRET */

#define TIF_SYSCALL_EMU		6	/* syscall emulation active */

#define TIF_SYSCALL_AUDIT	7	/* syscall auditing active */

#define TIF_SECCOMP		8	/* secure computing */
@@ -104,7 +103,6 @@ struct thread_info { 
#define _TIF_SIGPENDING		(1 << TIF_SIGPENDING)

#define _TIF_SINGLESTEP		(1 << TIF_SINGLESTEP)

#define _TIF_NEED_RESCHED	(1 << TIF_NEED_RESCHED)

#define _TIF_IRET		(1 << TIF_IRET)

#define _TIF_SYSCALL_EMU	(1 << TIF_SYSCALL_EMU)

#define _TIF_SYSCALL_AUDIT	(1 << TIF_SYSCALL_AUDIT)

#define _TIF_SECCOMP		(1 << TIF_SECCOMP)

arch/x86/kernel/process.c

+0 −8
Original line number Diff line number Diff line
@@ -351,14 +351,6 @@ long sys_execve(const char __user *name, 
	if (IS_ERR(filename))

		return error;

	error = do_execve(filename, argv, envp, regs);



#ifdef CONFIG_X86_32

	if (error == 0) {

		/* Make sure we don't return using sysenter.. */

                set_thread_flag(TIF_IRET);

        }

#endif



	putname(filename);

	return error;

}

arch/x86/kernel/process_32.c

+5 −0
Original line number Diff line number Diff line
@@ -194,6 +194,11 @@ start_thread(struct pt_regs *regs, unsigned long new_ip, unsigned long new_sp) 
	 * Free the old FP and other extended state

	 */

	free_thread_xstate(current);

	/*

	 * force it to the iret return path by making it look as if there was

	 * some work pending.

	 */

	set_thread_flag(TIF_NOTIFY_RESUME);

}

EXPORT_SYMBOL_GPL(start_thread);

arch/x86/kernel/signal.c

+0 −4
Original line number Diff line number Diff line
@@ -800,10 +800,6 @@ do_notify_resume(struct pt_regs *regs, void *unused, __u32 thread_info_flags) 
	}

	if (thread_info_flags & _TIF_USER_RETURN_NOTIFY)

		fire_user_return_notifiers();



#ifdef CONFIG_X86_32

	clear_thread_flag(TIF_IRET);

#endif /* CONFIG_X86_32 */

}



void signal_fault(struct pt_regs *regs, void __user *frame, char *where)

arch/x86/kernel/vm86_32.c

+3 −3
Original line number Diff line number Diff line
@@ -561,9 +561,9 @@ int handle_vm86_trap(struct kernel_vm86_regs *regs, long error_code, int trapno) 
		if ((trapno == 3) || (trapno == 1)) {

			KVM86->regs32->ax = VM86_TRAP + (trapno << 8);

			/* setting this flag forces the code in entry_32.S to

			   call save_v86_state() and change the stack pointer

			   to KVM86->regs32 */

			set_thread_flag(TIF_IRET);

			   the path where we call save_v86_state() and change

			   the stack pointer to KVM86->regs32 */

			set_thread_flag(TIF_NOTIFY_RESUME);

			return 0;

		}

		do_int(regs, trapno, (unsigned char __user *) (regs->pt.ss << 4), SP(regs));