From b9d989c7218ac922185d82ad46f3e58b27a4bea9 Mon Sep 17 00:00:00 2001 From: Andy Lutomirski Date: Tue, 13 Sep 2016 14:29:21 -0700 Subject: [PATCH] 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 Cc: Borislav Petkov Cc: Brian Gerst Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Jann Horn Cc: Josh Poimboeuf Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/ccc8a1b2f41f9c264a41f771bb4a6539a642ad72.1473801993.git.luto@kernel.org Signed-off-by: Ingo Molnar --- 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 1433f6b4607d..871bbf975d4c 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 b22fb5a4ff3c..984a7bf17f6a 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; @@ -434,6 +437,15 @@ 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 */ diff --git a/arch/x86/include/asm/syscall.h b/arch/x86/include/asm/syscall.h index 4e23dd15c661..e3c95e8e61c5 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 494c4b5ada34..c9dcfe7c7e4b 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 db3a0af9b9ec..add5f90b93d4 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 93982aebb398..2f2b8c7ccb85 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 b812cd0d7889..de9acaf2d371 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 5b88a1b26fc7..ce94c38cf4d6 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 04cb3212db2d..da20ecb5397a 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 -- 2.30.2