/* thread_info.h: i386 low-level thread information * * Copyright (C) 2002 David Howells (dhowells@redhat.com) * - Incorporating suggestions made by Linus Torvalds and Dave Miller */ #ifndef _ASM_THREAD_INFO_H #define _ASM_THREAD_INFO_H #ifdef __KERNEL__ #include <linux/compiler.h> #include <asm/page.h> #ifndef __ASSEMBLY__ #include <asm/processor.h> #endif /* * low level task data that entry.S needs immediate access to * - this struct should fit entirely inside of one cache line * - this struct shares the supervisor stack pages * - if the contents of this structure are changed, the assembly constants must also be changed */ #ifndef __ASSEMBLY__ struct thread_info { struct task_struct *task; /* main task structure */ struct exec_domain *exec_domain; /* execution domain */ unsigned long flags; /* low level flags */ unsigned long status; /* thread-synchronous flags */ __u32 cpu; /* current CPU */ int preempt_count; /* 0 => preemptable, <0 => BUG */ mm_segment_t addr_limit; /* thread address space: 0-0xBFFFFFFF for user-thead 0-0xFFFFFFFF for kernel-thread */ void *sysenter_return; struct restart_block restart_block; unsigned long previous_esp; /* ESP of the previous stack in case of nested (IRQ) stacks */ __u8 supervisor_stack[0]; }; #else /* !__ASSEMBLY__ */ #include <asm/asm-offsets.h> #endif #define PREEMPT_ACTIVE 0x10000000 #ifdef CONFIG_4KSTACKS #define THREAD_SIZE (4096) #else #define THREAD_SIZE (8192) #endif #define STACK_WARN (THREAD_SIZE/8) /* * macros/functions for gaining access to the thread information structure * * preempt_count needs to be 1 initially, until the scheduler is functional. */ #ifndef __ASSEMBLY__ #define INIT_THREAD_INFO(tsk) \ { \ .task = &tsk, \ .exec_domain = &default_exec_domain, \ .flags = 0, \ .cpu = 0, \ .preempt_count = 1, \ .addr_limit = KERNEL_DS, \ .restart_block = { \ .fn = do_no_restart_syscall, \ }, \ } #define init_thread_info (init_thread_union.thread_info) #define init_stack (init_thread_union.stack) /* how to get the current stack pointer from C */ register unsigned long current_stack_pointer asm("esp") __attribute_used__; /* how to get the thread information struct from C */ static inline struct thread_info *current_thread_info(void) { return (struct thread_info *)(current_stack_pointer & ~(THREAD_SIZE - 1)); } /* thread information allocation */ #ifdef CONFIG_DEBUG_STACK_USAGE #define alloc_thread_info(tsk) \ ({ \ struct thread_info *ret; \ \ ret = kmalloc(THREAD_SIZE, GFP_KERNEL); \ if (ret) \ memset(ret, 0, THREAD_SIZE); \ ret; \ }) #else #define alloc_thread_info(tsk) kmalloc(THREAD_SIZE, GFP_KERNEL) #endif #define free_thread_info(info) kfree(info) #else /* !__ASSEMBLY__ */ /* how to get the thread information struct from ASM */ #define GET_THREAD_INFO(reg) \ movl $-THREAD_SIZE, reg; \ andl %esp, reg /* use this one if reg already contains %esp */ #define GET_THREAD_INFO_WITH_ESP(reg) \ andl $-THREAD_SIZE, reg #endif /* * thread information flags * - these are process state flags that various assembly files may need to access * - pending work-to-be-done flags are in LSW * - other flags in MSW */ #define TIF_SYSCALL_TRACE 0 /* syscall trace active */ #define TIF_NOTIFY_RESUME 1 /* resumption notification requested */ #define TIF_SIGPENDING 2 /* signal pending */ #define TIF_NEED_RESCHED 3 /* rescheduling necessary */ #define TIF_SINGLESTEP 4 /* restore singlestep on return to user mode */ #define TIF_IRET 5 /* return with iret */ #define TIF_SYSCALL_EMU 6 /* syscall emulation active */ #define TIF_SYSCALL_AUDIT 7 /* syscall auditing active */ #define TIF_SECCOMP 8 /* secure computing */ #define TIF_RESTORE_SIGMASK 9 /* restore signal mask in do_signal() */ #define TIF_MEMDIE 16 #define _TIF_SYSCALL_TRACE (1<<TIF_SYSCALL_TRACE) #define _TIF_NOTIFY_RESUME (1<<TIF_NOTIFY_RESUME) #define _TIF_SIGPENDING (1<<TIF_SIGPENDING) #define _TIF_NEED_RESCHED (1<<TIF_NEED_RESCHED) #define _TIF_SINGLESTEP (1<<TIF_SINGLESTEP) #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) #define _TIF_RESTORE_SIGMASK (1<<TIF_RESTORE_SIGMASK) /* work to do on interrupt/exception return */ #define _TIF_WORK_MASK \ (0x0000FFFF & ~(_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | \ _TIF_SECCOMP | _TIF_SYSCALL_EMU)) /* work to do on any return to u-space */ #define _TIF_ALLWORK_MASK (0x0000FFFF & ~_TIF_SECCOMP) /* * 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_USEDFPU 0x0001 /* FPU was used by this task this quantum (SMP) */ #define TS_POLLING 0x0002 /* True if in idle loop and not sleeping */ #define tsk_is_polling(t) ((t)->thread_info->status & TS_POLLING) #endif /* __KERNEL__ */ #endif /* _ASM_THREAD_INFO_H */