On Wed, Nov 22, 2017 at 04:35:18PM -0800, Dave Hansen wrote: > > From: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> > > Currently, all of the checks for KAISER are compile-time checks. > > Runtime checks are needed for turning it on/off at runtime. > > Add a function to do that. > > Signed-off-by: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> > Cc: Moritz Lipp <moritz.lipp@xxxxxxxxxxxxxx> > Cc: Daniel Gruss <daniel.gruss@xxxxxxxxxxxxxx> > Cc: Michael Schwarz <michael.schwarz@xxxxxxxxxxxxxx> > Cc: Richard Fellner <richard.fellner@xxxxxxxxxxxxxxxxx> > Cc: Andy Lutomirski <luto@xxxxxxxxxx> > Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> > Cc: Kees Cook <keescook@xxxxxxxxxx> > Cc: Hugh Dickins <hughd@xxxxxxxxxx> > Cc: x86@xxxxxxxxxx > --- > > b/arch/x86/include/asm/kaiser.h | 5 +++++ > b/include/linux/kaiser.h | 5 +++++ > 2 files changed, 10 insertions(+) > > diff -puN arch/x86/include/asm/kaiser.h~kaiser-dynamic-check-func arch/x86/include/asm/kaiser.h > --- a/arch/x86/include/asm/kaiser.h~kaiser-dynamic-check-func 2017-11-22 15:45:55.262619723 -0800 > +++ b/arch/x86/include/asm/kaiser.h 2017-11-22 15:45:55.267619723 -0800 > @@ -56,6 +56,11 @@ extern void kaiser_remove_mapping(unsign > */ > extern void kaiser_init(void); > > +static inline bool kaiser_active(void) > +{ > + extern int kaiser_enabled; Should this really be extern ? I am getting a compilation error while linking the bzImage with this series: arch/x86/boot/compressed/pagetable.o: In function `kernel_ident_mapping_init': pagetable.c:(.text+0x336): undefined reference to `kaiser_enabled' arch/x86/boot/compressed/Makefile:109: recipe for target 'arch/x86/boot/compressed/vmlinux' failed make[2]: *** [arch/x86/boot/compressed/vmlinux] Error 1 arch/x86/boot/Makefile:112: recipe for target 'arch/x86/boot/compressed/vmlinux' failed make[1]: *** [arch/x86/boot/compressed/vmlinux] Error 2 arch/x86/Makefile:296: recipe for target 'bzImage' failed make: *** [bzImage] Error 2 What I did was to remove the extern and EXPORT_SYMBOL(kaiser_enabled) and initialize kaiser_enabled as 0, after that I got a proper bzImage. > + return kaiser_enabled; > +} > #endif > > #endif /* __ASSEMBLY__ */ > diff -puN include/linux/kaiser.h~kaiser-dynamic-check-func include/linux/kaiser.h > --- a/include/linux/kaiser.h~kaiser-dynamic-check-func 2017-11-22 15:45:55.264619723 -0800 > +++ b/include/linux/kaiser.h 2017-11-22 15:45:55.268619723 -0800 > @@ -28,5 +28,10 @@ static inline int kaiser_add_mapping(uns > static inline void kaiser_add_mapping_cpu_entry(int cpu) > { > } > + > +static inline bool kaiser_active(void) > +{ > + return 0; > +} > #endif /* !CONFIG_KAISER */ > #endif /* _INCLUDE_KAISER_H */ > _ > -- All the best, Eduardo Valentin -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx"> email@xxxxxxxxx </a>