forked from mirrors/linux
		
	There are a number of bits of code sprinkled around the kernel to set a thread flag if a certain condition is true, and clear it otherwise. To help make those call sites terser and less cumbersome, this patch adds a new family of thread flag manipulators update*_thread_flag([...,] flag, cond) which do the equivalent of: if (cond) set*_thread_flag([...,] flag); else clear*_thread_flag([...,] flag); Signed-off-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
		
			
				
	
	
		
			160 lines
		
	
	
	
		
			4.1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			160 lines
		
	
	
	
		
			4.1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/* SPDX-License-Identifier: GPL-2.0 */
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/* 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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#include <linux/restart_block.h>
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#ifdef CONFIG_THREAD_INFO_IN_TASK
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/*
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 * For CONFIG_THREAD_INFO_IN_TASK kernels we need <asm/current.h> for the
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 * definition of current, but for !CONFIG_THREAD_INFO_IN_TASK kernels,
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 * including <asm/current.h> can cause a circular dependency on some platforms.
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 */
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#include <asm/current.h>
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#define current_thread_info() ((struct thread_info *)current)
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#endif
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#include <linux/bitops.h>
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/*
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 * For per-arch arch_within_stack_frames() implementations, defined in
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 * asm/thread_info.h.
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 */
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enum {
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	BAD_STACK = -1,
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	NOT_STACK = 0,
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	GOOD_FRAME,
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	GOOD_STACK,
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};
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#include <asm/thread_info.h>
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#ifdef __KERNEL__
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#ifndef THREAD_ALIGN
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#define THREAD_ALIGN	THREAD_SIZE
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#endif
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#define THREADINFO_GFP		(GFP_KERNEL_ACCOUNT | __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 void update_ti_thread_flag(struct thread_info *ti, int flag,
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					 bool value)
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{
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	if (value)
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		set_ti_thread_flag(ti, flag);
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	else
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		clear_ti_thread_flag(ti, flag);
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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 update_thread_flag(flag, value) \
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	update_ti_thread_flag(current_thread_info(), flag, value)
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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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#ifndef CONFIG_HAVE_ARCH_WITHIN_STACK_FRAMES
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static inline int arch_within_stack_frames(const void * const stack,
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					   const void * const stackend,
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					   const void *obj, unsigned long len)
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{
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	return 0;
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}
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#endif
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#ifdef CONFIG_HARDENED_USERCOPY
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extern void __check_object_size(const void *ptr, unsigned long n,
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					bool to_user);
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static __always_inline void check_object_size(const void *ptr, unsigned long n,
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					      bool to_user)
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{
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	if (!__builtin_constant_p(n))
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		__check_object_size(ptr, n, to_user);
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}
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#else
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static inline void check_object_size(const void *ptr, unsigned long n,
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				     bool to_user)
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{ }
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#endif /* CONFIG_HARDENED_USERCOPY */
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extern void __compiletime_error("copy source size is too small")
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__bad_copy_from(void);
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extern void __compiletime_error("copy destination size is too small")
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__bad_copy_to(void);
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static inline void copy_overflow(int size, unsigned long count)
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{
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	WARN(1, "Buffer overflow detected (%d < %lu)!\n", size, count);
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}
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static __always_inline bool
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check_copy_size(const void *addr, size_t bytes, bool is_source)
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{
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	int sz = __compiletime_object_size(addr);
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	if (unlikely(sz >= 0 && sz < bytes)) {
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		if (!__builtin_constant_p(bytes))
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			copy_overflow(sz, bytes);
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		else if (is_source)
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			__bad_copy_from();
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		else
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			__bad_copy_to();
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		return false;
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	}
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	check_object_size(addr, bytes, is_source);
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	return true;
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}
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#ifndef arch_setup_new_exec
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static inline void arch_setup_new_exec(void) { }
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#endif
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#endif	/* __KERNEL__ */
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#endif /* _LINUX_THREAD_INFO_H */
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