[tip:x86/asm] x86/asm: Move the thread_info::status field to thread_struct

From: tip-bot for Andy Lutomirski
Date: Thu Sep 15 2016 - 06:42:56 EST

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Commit-ID: b9d989c7218ac922185d82ad46f3e58b27a4bea9
Gitweb: http://git.kernel.org/tip/b9d989c7218ac922185d82ad46f3e58b27a4bea9
Author: Andy Lutomirski <luto@xxxxxxxxxx>
AuthorDate: Tue, 13 Sep 2016 14:29:21 -0700
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
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@xxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Brian Gerst <brgerst@xxxxxxxxx>
Cc: Denys Vlasenko <dvlasenk@xxxxxxxxxx>
Cc: H. Peter Anvin <hpa@xxxxxxxxx>
Cc: Jann Horn <jann@xxxxxxxxx>
Cc: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Link: http://lkml.kernel.org/r/ccc8a1b2f41f9c264a41f771bb4a6539a642ad72.1473801993.git.luto@xxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
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

Next message: Greg Kroah-Hartman: "Re: [PATCH 0/9] tty: tty_struct dependency clean-ups"
Previous message: tip-bot for Josh Poimboeuf: "[tip:x86/asm] x86/dumpstack: Add recursion checking for all stacks"
In reply to: Andy Lutomirski: "[PATCH 01/12] x86/asm: Move 'status' from struct thread_info to struct thread_struct"
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