From e76623d69408d0bd66a296c6ee5eae1b17a6adfc Mon Sep 17 00:00:00 2001 From: Al Viro Date: Thu, 2 Aug 2012 22:12:06 +0400 Subject: [PATCH] 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: Al Viro --- arch/x86/include/asm/thread_info.h | 2 -- arch/x86/kernel/process.c | 8 -------- arch/x86/kernel/process_32.c | 5 +++++ arch/x86/kernel/signal.c | 4 ---- arch/x86/kernel/vm86_32.c | 6 +++--- 5 files changed, 8 insertions(+), 17 deletions(-) diff --git a/arch/x86/include/asm/thread_info.h b/arch/x86/include/asm/thread_info.h index 89f794f007ec..c509d07bdbd7 100644 --- a/arch/x86/include/asm/thread_info.h +++ b/arch/x86/include/asm/thread_info.h @@ -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) diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c index ef6a8456f719..7162e9c1f598 100644 --- a/arch/x86/kernel/process.c +++ b/arch/x86/kernel/process.c @@ -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; } diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c index 516fa186121b..75fcad146def 100644 --- a/arch/x86/kernel/process_32.c +++ b/arch/x86/kernel/process_32.c @@ -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); diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c index b280908a376e..c648fc529872 100644 --- a/arch/x86/kernel/signal.c +++ b/arch/x86/kernel/signal.c @@ -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) diff --git a/arch/x86/kernel/vm86_32.c b/arch/x86/kernel/vm86_32.c index 54abcc0baf23..5c9687b1bde6 100644 --- a/arch/x86/kernel/vm86_32.c +++ b/arch/x86/kernel/vm86_32.c @@ -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)); -- 2.20.1