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From: tip-bot for Andy Lutomirski <tipbot@zytor.com>
To: linux-tip-commits@vger.kernel.org
Cc: brgerst@gmail.com, dvlasenk@redhat.com, hpa@zytor.com,
	tglx@linutronix.de, luto@kernel.org, peterz@infradead.org,
	jann@thejh.net, linux-kernel@vger.kernel.org, mingo@kernel.org,
	bp@alien8.de, jpoimboe@redhat.com, torvalds@linux-foundation.org
Subject: [tip:x86/asm] x86/asm: Move the thread_info::status field to thread_struct
Date: Thu, 15 Sep 2016 03:41:52 -0700	[thread overview]
Message-ID: <tip-b9d989c7218ac922185d82ad46f3e58b27a4bea9@git.kernel.org> (raw)
In-Reply-To: <ccc8a1b2f41f9c264a41f771bb4a6539a642ad72.1473801993.git.luto@kernel.org>

Commit-ID:  b9d989c7218ac922185d82ad46f3e58b27a4bea9
Gitweb:     http://git.kernel.org/tip/b9d989c7218ac922185d82ad46f3e58b27a4bea9
Author:     Andy Lutomirski <luto@kernel.org>
AuthorDate: Tue, 13 Sep 2016 14:29:21 -0700
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Thu, 15 Sep 2016 08:25:12 +0200

x86/asm: Move the thread_info::status field to thread_struct

Because sched.h and thread_info.h are a tangled mess, I turned
in_compat_syscall() into a macro.  If we had current_thread_struct()
or similar and we could use it from thread_info.h, then this would
be a bit cleaner.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jann Horn <jann@thejh.net>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/ccc8a1b2f41f9c264a41f771bb4a6539a642ad72.1473801993.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 arch/x86/entry/common.c            |  4 ++--
 arch/x86/include/asm/processor.h   | 12 ++++++++++++
 arch/x86/include/asm/syscall.h     | 20 +++++---------------
 arch/x86/include/asm/thread_info.h | 23 ++++-------------------
 arch/x86/kernel/asm-offsets.c      |  1 -
 arch/x86/kernel/fpu/init.c         |  1 -
 arch/x86/kernel/process_64.c       |  4 ++--
 arch/x86/kernel/ptrace.c           |  2 +-
 arch/x86/kernel/signal.c           |  2 +-
 9 files changed, 27 insertions(+), 42 deletions(-)

diff --git a/arch/x86/entry/common.c b/arch/x86/entry/common.c
index 1433f6b..871bbf9 100644
--- a/arch/x86/entry/common.c
+++ b/arch/x86/entry/common.c
@@ -209,7 +209,7 @@ __visible inline void prepare_exit_to_usermode(struct pt_regs *regs)
 	 * special case only applies after poking regs and before the
 	 * very next return to user mode.
 	 */
-	ti->status &= ~(TS_COMPAT|TS_I386_REGS_POKED);
+	current->thread.status &= ~(TS_COMPAT|TS_I386_REGS_POKED);
 #endif
 
 	user_enter_irqoff();
@@ -307,7 +307,7 @@ static __always_inline void do_syscall_32_irqs_on(struct pt_regs *regs)
 	unsigned int nr = (unsigned int)regs->orig_ax;
 
 #ifdef CONFIG_IA32_EMULATION
-	ti->status |= TS_COMPAT;
+	current->thread.status |= TS_COMPAT;
 #endif
 
 	if (READ_ONCE(ti->flags) & _TIF_WORK_SYSCALL_ENTRY) {
diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index b22fb5a..984a7bf 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -389,6 +389,9 @@ struct thread_struct {
 	unsigned short		fsindex;
 	unsigned short		gsindex;
 #endif
+
+	u32			status;		/* thread synchronous flags */
+
 #ifdef CONFIG_X86_64
 	unsigned long		fsbase;
 	unsigned long		gsbase;
@@ -435,6 +438,15 @@ struct thread_struct {
 };
 
 /*
+ * Thread-synchronous status.
+ *
+ * This is different from the flags in that nobody else
+ * ever touches our thread-synchronous status, so we don't
+ * have to worry about atomic accesses.
+ */
+#define TS_COMPAT		0x0002	/* 32bit syscall active (64BIT)*/
+
+/*
  * Set IOPL bits in EFLAGS from given mask
  */
 static inline void native_set_iopl_mask(unsigned mask)
diff --git a/arch/x86/include/asm/syscall.h b/arch/x86/include/asm/syscall.h
index 4e23dd1..e3c95e8 100644
--- a/arch/x86/include/asm/syscall.h
+++ b/arch/x86/include/asm/syscall.h
@@ -60,7 +60,7 @@ static inline long syscall_get_error(struct task_struct *task,
 	 * TS_COMPAT is set for 32-bit syscall entries and then
 	 * remains set until we return to user mode.
 	 */
-	if (task_thread_info(task)->status & (TS_COMPAT|TS_I386_REGS_POKED))
+	if (task->thread.status & (TS_COMPAT|TS_I386_REGS_POKED))
 		/*
 		 * Sign-extend the value so (int)-EFOO becomes (long)-EFOO
 		 * and will match correctly in comparisons.
@@ -116,7 +116,7 @@ static inline void syscall_get_arguments(struct task_struct *task,
 					 unsigned long *args)
 {
 # ifdef CONFIG_IA32_EMULATION
-	if (task_thread_info(task)->status & TS_COMPAT)
+	if (task->thread.status & TS_COMPAT)
 		switch (i) {
 		case 0:
 			if (!n--) break;
@@ -177,7 +177,7 @@ static inline void syscall_set_arguments(struct task_struct *task,
 					 const unsigned long *args)
 {
 # ifdef CONFIG_IA32_EMULATION
-	if (task_thread_info(task)->status & TS_COMPAT)
+	if (task->thread.status & TS_COMPAT)
 		switch (i) {
 		case 0:
 			if (!n--) break;
@@ -234,18 +234,8 @@ static inline void syscall_set_arguments(struct task_struct *task,
 
 static inline int syscall_get_arch(void)
 {
-#ifdef CONFIG_IA32_EMULATION
-	/*
-	 * TS_COMPAT is set for 32-bit syscall entry and then
-	 * remains set until we return to user mode.
-	 *
-	 * x32 tasks should be considered AUDIT_ARCH_X86_64.
-	 */
-	if (task_thread_info(current)->status & TS_COMPAT)
-		return AUDIT_ARCH_I386;
-#endif
-	/* Both x32 and x86_64 are considered "64-bit". */
-	return AUDIT_ARCH_X86_64;
+	/* x32 tasks should be considered AUDIT_ARCH_X86_64. */
+	return in_ia32_syscall() ? AUDIT_ARCH_I386 : AUDIT_ARCH_X86_64;
 }
 #endif	/* CONFIG_X86_32 */
 
diff --git a/arch/x86/include/asm/thread_info.h b/arch/x86/include/asm/thread_info.h
index 494c4b5..c9dcfe7 100644
--- a/arch/x86/include/asm/thread_info.h
+++ b/arch/x86/include/asm/thread_info.h
@@ -55,7 +55,6 @@ struct task_struct;
 struct thread_info {
 	struct task_struct	*task;		/* main task structure */
 	__u32			flags;		/* low level flags */
-	__u32			status;		/* thread synchronous flags */
 	__u32			cpu;		/* current CPU */
 };
 
@@ -253,31 +252,17 @@ static inline int arch_within_stack_frames(const void * const stack,
 
 #endif
 
-/*
- * Thread-synchronous status.
- *
- * This is different from the flags in that nobody else
- * ever touches our thread-synchronous status, so we don't
- * have to worry about atomic accesses.
- */
-#define TS_COMPAT		0x0002	/* 32bit syscall active (64BIT)*/
 #ifdef CONFIG_COMPAT
 #define TS_I386_REGS_POKED	0x0004	/* regs poked by 32-bit ptracer */
 #endif
-
 #ifndef __ASSEMBLY__
 
-static inline bool in_ia32_syscall(void)
-{
 #ifdef CONFIG_X86_32
-	return true;
-#endif
-#ifdef CONFIG_IA32_EMULATION
-	if (current_thread_info()->status & TS_COMPAT)
-		return true;
+#define in_ia32_syscall() true
+#else
+#define in_ia32_syscall() (IS_ENABLED(CONFIG_IA32_EMULATION) && \
+			   current->thread.status & TS_COMPAT)
 #endif
-	return false;
-}
 
 /*
  * Force syscall return via IRET by making it look as if there was
diff --git a/arch/x86/kernel/asm-offsets.c b/arch/x86/kernel/asm-offsets.c
index db3a0af..add5f90 100644
--- a/arch/x86/kernel/asm-offsets.c
+++ b/arch/x86/kernel/asm-offsets.c
@@ -36,7 +36,6 @@ void common(void) {
 
 	BLANK();
 	OFFSET(TI_flags, thread_info, flags);
-	OFFSET(TI_status, thread_info, status);
 
 	BLANK();
 	OFFSET(TASK_addr_limit, task_struct, thread.addr_limit);
diff --git a/arch/x86/kernel/fpu/init.c b/arch/x86/kernel/fpu/init.c
index 93982ae..2f2b8c7 100644
--- a/arch/x86/kernel/fpu/init.c
+++ b/arch/x86/kernel/fpu/init.c
@@ -317,7 +317,6 @@ static void __init fpu__init_system_ctx_switch(void)
 	on_boot_cpu = 0;
 
 	WARN_ON_FPU(current->thread.fpu.fpstate_active);
-	current_thread_info()->status = 0;
 
 	if (boot_cpu_has(X86_FEATURE_XSAVEOPT) && eagerfpu != DISABLE)
 		eagerfpu = ENABLE;
diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index b812cd0..de9acaf 100644
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -510,7 +510,7 @@ void set_personality_ia32(bool x32)
 		current->personality &= ~READ_IMPLIES_EXEC;
 		/* in_compat_syscall() uses the presence of the x32
 		   syscall bit flag to determine compat status */
-		current_thread_info()->status &= ~TS_COMPAT;
+		current->thread.status &= ~TS_COMPAT;
 	} else {
 		set_thread_flag(TIF_IA32);
 		clear_thread_flag(TIF_X32);
@@ -518,7 +518,7 @@ void set_personality_ia32(bool x32)
 			current->mm->context.ia32_compat = TIF_IA32;
 		current->personality |= force_personality32;
 		/* Prepare the first "return" to user space */
-		current_thread_info()->status |= TS_COMPAT;
+		current->thread.status |= TS_COMPAT;
 	}
 }
 EXPORT_SYMBOL_GPL(set_personality_ia32);
diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c
index 5b88a1b..ce94c38 100644
--- a/arch/x86/kernel/ptrace.c
+++ b/arch/x86/kernel/ptrace.c
@@ -934,7 +934,7 @@ static int putreg32(struct task_struct *child, unsigned regno, u32 value)
 		 */
 		regs->orig_ax = value;
 		if (syscall_get_nr(child, regs) >= 0)
-			task_thread_info(child)->status |= TS_I386_REGS_POKED;
+			child->thread.status |= TS_I386_REGS_POKED;
 		break;
 
 	case offsetof(struct user32, regs.eflags):
diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c
index 04cb321..da20ecb 100644
--- a/arch/x86/kernel/signal.c
+++ b/arch/x86/kernel/signal.c
@@ -783,7 +783,7 @@ static inline unsigned long get_nr_restart_syscall(const struct pt_regs *regs)
 	 * than the tracee.
 	 */
 #ifdef CONFIG_IA32_EMULATION
-	if (current_thread_info()->status & (TS_COMPAT|TS_I386_REGS_POKED))
+	if (current->thread.status & (TS_COMPAT|TS_I386_REGS_POKED))
 		return __NR_ia32_restart_syscall;
 #endif
 #ifdef CONFIG_X86_X32_ABI

  reply	other threads:[~2016-09-15 10:42 UTC|newest]

Thread overview: 41+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-09-13 21:29 [PATCH 00/12] thread_info cleanups and stack caching Andy Lutomirski
2016-09-13 21:29 ` [PATCH 01/12] x86/asm: Move 'status' from struct thread_info to struct thread_struct Andy Lutomirski
2016-09-15 10:41   ` tip-bot for Andy Lutomirski [this message]
2016-09-13 21:29 ` [PATCH 02/12] x86/entry: Get rid of pt_regs_to_thread_info() Andy Lutomirski
2016-09-15  6:21   ` Ingo Molnar
2016-09-15 10:42   ` [tip:x86/asm] " tip-bot for Linus Torvalds
2016-09-13 21:29 ` [PATCH 03/12] um: Stop conflating task_struct::stack with thread_info Andy Lutomirski
2016-09-15  6:21   ` Ingo Molnar
2016-09-15 10:42   ` [tip:x86/asm] um/Stop " tip-bot for Linus Torvalds
2016-09-13 21:29 ` [PATCH 04/12] sched: Allow putting thread_info into task_struct Andy Lutomirski
2016-09-15 10:43   ` [tip:x86/asm] sched/core: " tip-bot for Andy Lutomirski
2016-09-13 21:29 ` [PATCH 05/12] x86: Move " Andy Lutomirski
2016-09-15 10:43   ` [tip:x86/asm] " tip-bot for Andy Lutomirski
2016-09-13 21:29 ` [PATCH 06/12] sched: Add try_get_task_stack() and put_task_stack() Andy Lutomirski
2016-09-13 21:29 ` [PATCH 07/12] kthread: to_live_kthread() needs try_get_task_stack() Andy Lutomirski
2016-09-13 21:29 ` [PATCH 08/12] x86/dumpstack: Pin the target stack in save_stack_trace_tsk() Andy Lutomirski
2016-09-14 14:55   ` Josh Poimboeuf
2016-09-14 18:22     ` Andy Lutomirski
2016-09-14 18:35       ` Josh Poimboeuf
2016-09-15 18:04         ` Andy Lutomirski
2016-09-15 18:37           ` Josh Poimboeuf
2016-09-15 18:41             ` Andy Lutomirski
2016-09-15 19:19               ` Josh Poimboeuf
2016-09-16  7:47                 ` Peter Zijlstra
2016-09-16 15:12                   ` Andy Lutomirski
2016-09-16 15:31                     ` Peter Zijlstra
2016-09-16 15:32                       ` Andy Lutomirski
2016-09-16 16:35                         ` Peter Zijlstra
2016-09-15  6:37   ` Ingo Molnar
     [not found]     ` <CA+55aFxt=HLrELBE=BXUrWdh6LYs4gtu9S=yCruiDffq4HN80w@mail.gmail.com>
2016-09-15  9:27       ` Ingo Molnar
2016-09-13 21:29 ` [PATCH 09/12] x86/process: Pin the target stack in get_wchan() Andy Lutomirski
2016-09-17  2:00   ` Jann Horn
2016-09-22 22:44     ` Andy Lutomirski
2016-09-22 22:50       ` Andy Lutomirski
2016-09-23  7:43       ` Jann Horn
2016-09-23 18:28         ` Kees Cook
2016-09-23 18:34           ` Jann Horn
2016-09-26  5:10             ` Tycho Andersen
2016-09-13 21:29 ` [PATCH 10/12] lib/syscall: Pin the task stack in collect_syscall() Andy Lutomirski
2016-09-13 21:29 ` [PATCH 11/12] sched: Free the stack early if CONFIG_THREAD_INFO_IN_TASK Andy Lutomirski
2016-09-13 21:29 ` [PATCH 12/12] fork: Cache two thread stacks per cpu if CONFIG_VMAP_STACK is set Andy Lutomirski

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