4f3e6ab44b
Tobias noticed a compile error on 4.4.115, and it's the same on 4.9.80:
arch/x86/mm/kaiser.c: In function ‘kaiser_init’:
arch/x86/mm/kaiser.c:348:8: error: ‘vsyscall_pgprot’ undeclared
(first use in this function)
It seems like his combination of kernel options doesn't work for KAISER.
X86_VSYSCALL_EMULATION is not set on his system, while LEGACY_VSYSCALL
is set to NONE (LEGACY_VSYSCALL_NONE=y). He managed to get things
compiling again, by moving the 'extern unsigned long vsyscall_pgprot'
outside of the preprocessor statement. This works because the optimizer
removes that code (vsyscall_enabled() is always false) - and that's how
it was done in some older backports.
Reported-by: Tobias Jakobi <tjakobi@math.uni-bielefeld.de>
Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
26 lines
673 B
C
26 lines
673 B
C
#ifndef _ASM_X86_VSYSCALL_H
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#define _ASM_X86_VSYSCALL_H
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#include <linux/seqlock.h>
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#include <uapi/asm/vsyscall.h>
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#ifdef CONFIG_X86_VSYSCALL_EMULATION
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extern void map_vsyscall(void);
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/*
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* Called on instruction fetch fault in vsyscall page.
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* Returns true if handled.
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*/
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extern bool emulate_vsyscall(struct pt_regs *regs, unsigned long address);
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extern bool vsyscall_enabled(void);
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#else
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static inline void map_vsyscall(void) {}
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static inline bool emulate_vsyscall(struct pt_regs *regs, unsigned long address)
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{
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return false;
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}
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static inline bool vsyscall_enabled(void) { return false; }
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#endif
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extern unsigned long vsyscall_pgprot;
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#endif /* _ASM_X86_VSYSCALL_H */
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