commit c8061485a0d7569a865a3cc3c63347b0f42b3765 upstream.
The following commit:
c65eacbe290b ("sched/core: Allow putting thread_info into task_struct")
... made 'struct thread_info' a generic struct with only a
single ::flags member, if CONFIG_THREAD_INFO_IN_TASK_STRUCT=y is
selected.
This change however seems to be quite x86 centric, since at least the
generic preemption code (asm-generic/preempt.h) assumes that struct
thread_info also has a preempt_count member, which apparently was not
true for x86.
We could add a bit more #ifdefs to solve this problem too, but it seems
to be much simpler to make struct thread_info arch specific
again. This also makes the conversion to THREAD_INFO_IN_TASK_STRUCT a
bit easier for architectures that have a couple of arch specific stuff
in their thread_info definition.
The arch specific stuff _could_ be moved to thread_struct. However
keeping them in thread_info makes it easier: accessing thread_info
members is simple, since it is at the beginning of the task_struct,
while the thread_struct is at the end. At least on s390 the offsets
needed to access members of the thread_struct (with task_struct as
base) are too large for various asm instructions. This is not a
problem when keeping these members within thread_info.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: keescook@chromium.org
Cc: linux-arch@vger.kernel.org
Link: http://lkml.kernel.org/r/1476901693-8492-2-git-send-email-mark.rutland@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
[ zhangyi: skip defination of INIT_THREAD_INFO and struct thread_info ]
Signed-off-by: zhangyi (F) <yi.zhang@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
151 lines
3.9 KiB
C
151 lines
3.9 KiB
C
/* thread_info.h: common low-level thread information accessors
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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
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*/
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#ifndef _LINUX_THREAD_INFO_H
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#define _LINUX_THREAD_INFO_H
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#include <linux/types.h>
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#include <linux/bug.h>
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struct timespec;
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struct compat_timespec;
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#ifdef CONFIG_THREAD_INFO_IN_TASK
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#define current_thread_info() ((struct thread_info *)current)
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#endif
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/*
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* System call restart block.
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*/
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struct restart_block {
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long (*fn)(struct restart_block *);
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union {
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/* For futex_wait and futex_wait_requeue_pi */
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struct {
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u32 __user *uaddr;
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u32 val;
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u32 flags;
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u32 bitset;
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u64 time;
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u32 __user *uaddr2;
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} futex;
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/* For nanosleep */
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struct {
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clockid_t clockid;
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struct timespec __user *rmtp;
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#ifdef CONFIG_COMPAT
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struct compat_timespec __user *compat_rmtp;
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#endif
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u64 expires;
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} nanosleep;
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/* For poll */
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struct {
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struct pollfd __user *ufds;
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int nfds;
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int has_timeout;
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unsigned long tv_sec;
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unsigned long tv_nsec;
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} poll;
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};
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};
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extern long do_no_restart_syscall(struct restart_block *parm);
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#include <linux/bitops.h>
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#include <asm/thread_info.h>
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#ifdef __KERNEL__
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#define THREADINFO_GFP (GFP_KERNEL | __GFP_NOTRACK | __GFP_ZERO)
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/*
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* flag set/clear/test wrappers
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* - pass TIF_xxxx constants to these functions
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*/
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static inline void set_ti_thread_flag(struct thread_info *ti, int flag)
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{
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set_bit(flag, (unsigned long *)&ti->flags);
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}
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static inline void clear_ti_thread_flag(struct thread_info *ti, int flag)
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{
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clear_bit(flag, (unsigned long *)&ti->flags);
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}
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static inline int test_and_set_ti_thread_flag(struct thread_info *ti, int flag)
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{
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return test_and_set_bit(flag, (unsigned long *)&ti->flags);
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}
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static inline int test_and_clear_ti_thread_flag(struct thread_info *ti, int flag)
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{
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return test_and_clear_bit(flag, (unsigned long *)&ti->flags);
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}
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static inline int test_ti_thread_flag(struct thread_info *ti, int flag)
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{
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return test_bit(flag, (unsigned long *)&ti->flags);
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}
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#define set_thread_flag(flag) \
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set_ti_thread_flag(current_thread_info(), flag)
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#define clear_thread_flag(flag) \
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clear_ti_thread_flag(current_thread_info(), flag)
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#define test_and_set_thread_flag(flag) \
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test_and_set_ti_thread_flag(current_thread_info(), flag)
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#define test_and_clear_thread_flag(flag) \
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test_and_clear_ti_thread_flag(current_thread_info(), flag)
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#define test_thread_flag(flag) \
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test_ti_thread_flag(current_thread_info(), flag)
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#define tif_need_resched() test_thread_flag(TIF_NEED_RESCHED)
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#if defined TIF_RESTORE_SIGMASK && !defined HAVE_SET_RESTORE_SIGMASK
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/*
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* An arch can define its own version of set_restore_sigmask() to get the
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* job done however works, with or without TIF_RESTORE_SIGMASK.
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*/
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#define HAVE_SET_RESTORE_SIGMASK 1
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/**
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* set_restore_sigmask() - make sure saved_sigmask processing gets done
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*
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* This sets TIF_RESTORE_SIGMASK and ensures that the arch signal code
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* will run before returning to user mode, to process the flag. For
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* all callers, TIF_SIGPENDING is already set or it's no harm to set
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* it. TIF_RESTORE_SIGMASK need not be in the set of bits that the
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* arch code will notice on return to user mode, in case those bits
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* are scarce. We set TIF_SIGPENDING here to ensure that the arch
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* signal code always gets run when TIF_RESTORE_SIGMASK is set.
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*/
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static inline void set_restore_sigmask(void)
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{
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set_thread_flag(TIF_RESTORE_SIGMASK);
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WARN_ON(!test_thread_flag(TIF_SIGPENDING));
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}
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static inline void clear_restore_sigmask(void)
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{
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clear_thread_flag(TIF_RESTORE_SIGMASK);
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}
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static inline bool test_restore_sigmask(void)
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{
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return test_thread_flag(TIF_RESTORE_SIGMASK);
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}
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static inline bool test_and_clear_restore_sigmask(void)
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{
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return test_and_clear_thread_flag(TIF_RESTORE_SIGMASK);
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}
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#endif /* TIF_RESTORE_SIGMASK && !HAVE_SET_RESTORE_SIGMASK */
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#ifndef HAVE_SET_RESTORE_SIGMASK
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#error "no set_restore_sigmask() provided and default one won't work"
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#endif
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#endif /* __KERNEL__ */
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#endif /* _LINUX_THREAD_INFO_H */
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