linux/arch/arc/include/asm/thread_info.h
Vineet Gupta 3be80aaef8 ARC: Fundamental ARCH data-types/defines
* L1_CACHE_SHIFT
* PAGE_SIZE, PAGE_OFFSET
* struct pt_regs, struct user_regs_struct
* struct thread_struct, cpu_relax(), task_pt_regs(), start_thread(), ...
* struct thread_info, THREAD_SIZE, INIT_THREAD_INFO(), TIF_*, ...
* BUG()
* ELF_*
* Elf_*

To disallow user-space visibility into some of the core kernel data-types
such as struct pt_regs, #ifdef __KERNEL__ which also makes the UAPI header
spit (further patch in the series) to NOT export it to asm/uapi/ptrace.h

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Jonas Bonn <jonas.bonn@gmail.com>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Acked-by: Arnd Bergmann <arnd@arndb.de>
2013-02-11 20:00:34 +05:30

122 lines
3.6 KiB
C

/*
* Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* Vineetg: Oct 2009
* No need for ARC specific thread_info allocator (kmalloc/free). This is
* anyways one page allocation, thus slab alloc can be short-circuited and
* the generic version (get_free_page) would be loads better.
*
* Sameer Dhavale: Codito Technologies 2004
*/
#ifndef _ASM_THREAD_INFO_H
#define _ASM_THREAD_INFO_H
#ifdef __KERNEL__
#include <asm/page.h>
#ifdef CONFIG_16KSTACKS
#define THREAD_SIZE_ORDER 1
#else
#define THREAD_SIZE_ORDER 0
#endif
#define THREAD_SIZE (PAGE_SIZE << THREAD_SIZE_ORDER)
#ifndef __ASSEMBLY__
#include <linux/thread_info.h>
#include <asm/segment.h>
/*
* 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
*/
struct thread_info {
unsigned long flags; /* low level flags */
int preempt_count; /* 0 => preemptable, <0 => BUG */
struct task_struct *task; /* main task structure */
mm_segment_t addr_limit; /* thread address space */
struct exec_domain *exec_domain;/* execution domain */
__u32 cpu; /* current CPU */
unsigned long thr_ptr; /* TLS ptr */
struct restart_block restart_block;
};
/*
* macros/functions for gaining access to the thread information structure
*
* preempt_count needs to be 1 initially, until the scheduler is functional.
*/
#define INIT_THREAD_INFO(tsk) \
{ \
.task = &tsk, \
.exec_domain = &default_exec_domain, \
.flags = 0, \
.cpu = 0, \
.preempt_count = INIT_PREEMPT_COUNT, \
.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)
static inline __attribute_const__ struct thread_info *current_thread_info(void)
{
register unsigned long sp asm("sp");
return (struct thread_info *)(sp & ~(THREAD_SIZE - 1));
}
#endif /* !__ASSEMBLY__ */
#define PREEMPT_ACTIVE 0x10000000
/*
* 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_RESTORE_SIGMASK 0 /* restore sig mask in do_signal() */
#define TIF_NOTIFY_RESUME 1 /* resumption notification requested */
#define TIF_SIGPENDING 2 /* signal pending */
#define TIF_NEED_RESCHED 3 /* rescheduling necessary */
#define TIF_SYSCALL_AUDIT 4 /* syscall auditing active */
#define TIF_SYSCALL_TRACE 15 /* syscall trace active */
/* true if poll_idle() is polling TIF_NEED_RESCHED */
#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_SYSCALL_AUDIT (1<<TIF_SYSCALL_AUDIT)
#define _TIF_MEMDIE (1<<TIF_MEMDIE)
/* work to do on interrupt/exception return */
#define _TIF_WORK_MASK (_TIF_NEED_RESCHED | _TIF_SIGPENDING | \
_TIF_NOTIFY_RESUME)
/*
* _TIF_ALLWORK_MASK includes SYSCALL_TRACE, but we don't need it.
* SYSCALL_TRACE is anways seperately/unconditionally tested right after a
* syscall, so all that reamins to be tested is _TIF_WORK_MASK
*/
#endif /* __KERNEL__ */
#endif /* _ASM_THREAD_INFO_H */