![Jesper Juhl](/assets/img/avatar_default.png)
The preempt_count member of struct thread_info is currently either defined as int, unsigned int or __s32 depending on arch. This patch makes the type of preempt_count an int on all archs. Having preempt_count be an unsigned type prevents the catching of preempt_count < 0 bugs, and using int on some archs and __s32 on others is not exactely "neat" - much nicer when it's just int all over. A previous version of this patch was already ACK'ed by Robert Love, and the only change in this version of the patch compared to the one he ACK'ed is that this one also makes sure the preempt_count member is consistently commented. Signed-off-by: Jesper Juhl <juhl-lkml@dif.dk> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
126 lines
3.7 KiB
C
126 lines
3.7 KiB
C
/* thread_info.h: PPC low-level thread information
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* adapted from the i386 version by Paul Mackerras
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*
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* Copyright (C) 2002 David Howells (dhowells@redhat.com)
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* - Incorporating suggestions made by Linus Torvalds and Dave Miller
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*/
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#ifndef _ASM_THREAD_INFO_H
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#define _ASM_THREAD_INFO_H
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#ifdef __KERNEL__
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#ifndef __ASSEMBLY__
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#include <linux/config.h>
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#include <linux/cache.h>
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#include <asm/processor.h>
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#include <asm/page.h>
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#include <linux/stringify.h>
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/*
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* low level task data.
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*/
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struct thread_info {
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struct task_struct *task; /* main task structure */
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struct exec_domain *exec_domain; /* execution domain */
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int cpu; /* cpu we're on */
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int preempt_count; /* 0 => preemptable, <0 => BUG */
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struct restart_block restart_block;
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/* set by force_successful_syscall_return */
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unsigned char syscall_noerror;
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/* low level flags - has atomic operations done on it */
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unsigned long flags ____cacheline_aligned_in_smp;
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};
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/*
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* macros/functions for gaining access to the thread information structure
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*
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* preempt_count needs to be 1 initially, until the scheduler is functional.
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*/
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#define INIT_THREAD_INFO(tsk) \
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{ \
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.task = &tsk, \
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.exec_domain = &default_exec_domain, \
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.cpu = 0, \
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.preempt_count = 1, \
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.restart_block = { \
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.fn = do_no_restart_syscall, \
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}, \
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.flags = 0, \
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}
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#define init_thread_info (init_thread_union.thread_info)
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#define init_stack (init_thread_union.stack)
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/* thread information allocation */
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#define THREAD_ORDER 2
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#define THREAD_SIZE (PAGE_SIZE << THREAD_ORDER)
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#define THREAD_SHIFT (PAGE_SHIFT + THREAD_ORDER)
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#ifdef CONFIG_DEBUG_STACK_USAGE
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#define alloc_thread_info(tsk) \
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({ \
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struct thread_info *ret; \
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\
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ret = kmalloc(THREAD_SIZE, GFP_KERNEL); \
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if (ret) \
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memset(ret, 0, THREAD_SIZE); \
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ret; \
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})
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#else
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#define alloc_thread_info(tsk) kmalloc(THREAD_SIZE, GFP_KERNEL)
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#endif
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#define free_thread_info(ti) kfree(ti)
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#define get_thread_info(ti) get_task_struct((ti)->task)
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#define put_thread_info(ti) put_task_struct((ti)->task)
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/* how to get the thread information struct from C */
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static inline struct thread_info *current_thread_info(void)
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{
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struct thread_info *ti;
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__asm__("clrrdi %0,1,%1" : "=r"(ti) : "i" (THREAD_SHIFT));
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return ti;
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}
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#endif /* __ASSEMBLY__ */
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#define PREEMPT_ACTIVE 0x10000000
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/*
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* thread information flag bit numbers
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*/
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#define TIF_SYSCALL_TRACE 0 /* syscall trace active */
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#define TIF_NOTIFY_RESUME 1 /* resumption notification requested */
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#define TIF_SIGPENDING 2 /* signal pending */
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#define TIF_NEED_RESCHED 3 /* rescheduling necessary */
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#define TIF_POLLING_NRFLAG 4 /* true if poll_idle() is polling
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TIF_NEED_RESCHED */
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#define TIF_32BIT 5 /* 32 bit binary */
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/* #define SPARE 6 */
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#define TIF_ABI_PENDING 7 /* 32/64 bit switch needed */
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#define TIF_SYSCALL_AUDIT 8 /* syscall auditing active */
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#define TIF_SINGLESTEP 9 /* singlestepping active */
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#define TIF_MEMDIE 10
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#define TIF_SECCOMP 11 /* secure computing */
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/* as above, but as bit values */
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#define _TIF_SYSCALL_TRACE (1<<TIF_SYSCALL_TRACE)
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#define _TIF_NOTIFY_RESUME (1<<TIF_NOTIFY_RESUME)
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#define _TIF_SIGPENDING (1<<TIF_SIGPENDING)
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#define _TIF_NEED_RESCHED (1<<TIF_NEED_RESCHED)
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#define _TIF_POLLING_NRFLAG (1<<TIF_POLLING_NRFLAG)
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#define _TIF_32BIT (1<<TIF_32BIT)
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/* #define _SPARE (1<<SPARE) */
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#define _TIF_ABI_PENDING (1<<TIF_ABI_PENDING)
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#define _TIF_SYSCALL_AUDIT (1<<TIF_SYSCALL_AUDIT)
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#define _TIF_SINGLESTEP (1<<TIF_SINGLESTEP)
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#define _TIF_SECCOMP (1<<TIF_SECCOMP)
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#define _TIF_SYSCALL_T_OR_A (_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT|_TIF_SECCOMP)
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#define _TIF_USER_WORK_MASK (_TIF_NOTIFY_RESUME | _TIF_SIGPENDING | \
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_TIF_NEED_RESCHED)
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#endif /* __KERNEL__ */
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#endif /* _ASM_THREAD_INFO_H */
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