![Linus Torvalds](/assets/img/avatar_default.png)
These macros had two bugs: - the type of the mask was not correctly expanded to the full size of the argument being expanded, resulting in possible loss of high bits when mixing types. - the alignment argument was evaluated twice, despite the macro looking like a fancy function (but it really does need to be a macro, since it works on arbitrary integer types) Noticed by Peter Anvin, and with a fix that is a modification of his suggestion (bug noticed by Yinghai Lu). Cc: Peter Anvin <hpa@zytor.com> Cc: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
36 lines
913 B
C
36 lines
913 B
C
#ifndef _ASM_X86_PROTO_H
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#define _ASM_X86_PROTO_H
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#include <asm/ldt.h>
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/* misc architecture specific prototypes */
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extern void early_idt_handler(void);
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extern void system_call(void);
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extern void syscall_init(void);
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extern void ia32_syscall(void);
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extern void ia32_cstar_target(void);
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extern void ia32_sysenter_target(void);
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extern void syscall32_cpu_init(void);
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extern void check_efer(void);
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extern int reboot_force;
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long do_arch_prctl(struct task_struct *task, int code, unsigned long addr);
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/*
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* This looks more complex than it should be. But we need to
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* get the type for the ~ right in round_down (it needs to be
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* as wide as the result!), and we want to evaluate the macro
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* arguments just once each.
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*/
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#define __round_mask(x,y) ((__typeof__(x))((y)-1))
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#define round_up(x,y) ((((x)-1) | __round_mask(x,y))+1)
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#define round_down(x,y) ((x) & ~__round_mask(x,y))
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#endif /* _ASM_X86_PROTO_H */
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