forked from luck/tmp_suning_uos_patched
1ad83c858c
This adds CONFIG_X86_VSYSCALL_EMULATION, guarded by CONFIG_EXPERT. Turning it off completely disables vsyscall emulation, saving ~3.5k for vsyscall_64.c, 4k for vsyscall_emu_64.S (the fake vsyscall page), some tiny amount of core mm code that supports a gate area, and possibly 4k for a wasted pagetable. The latter is because the vsyscall addresses are misaligned and fit poorly in the fixmap. Signed-off-by: Andy Lutomirski <luto@amacapital.net> Reviewed-by: Josh Triplett <josh@joshtriplett.org> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Link: http://lkml.kernel.org/r/406db88b8dd5f0cbbf38216d11be34bbb43c7eae.1414618407.git.luto@amacapital.net Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
24 lines
539 B
C
24 lines
539 B
C
#ifndef _ASM_X86_VSYSCALL_H
|
|
#define _ASM_X86_VSYSCALL_H
|
|
|
|
#include <linux/seqlock.h>
|
|
#include <uapi/asm/vsyscall.h>
|
|
|
|
#ifdef CONFIG_X86_VSYSCALL_EMULATION
|
|
extern void map_vsyscall(void);
|
|
|
|
/*
|
|
* Called on instruction fetch fault in vsyscall page.
|
|
* Returns true if handled.
|
|
*/
|
|
extern bool emulate_vsyscall(struct pt_regs *regs, unsigned long address);
|
|
#else
|
|
static inline void map_vsyscall(void) {}
|
|
static inline bool emulate_vsyscall(struct pt_regs *regs, unsigned long address)
|
|
{
|
|
return false;
|
|
}
|
|
#endif
|
|
|
|
#endif /* _ASM_X86_VSYSCALL_H */
|