On Thu 14-03-19 09:51:42, Dave Hansen wrote: [...] > From: Dave Hansen <[email protected]> > > MPX is being removed from the kernel due to a lack of support > in the toolchain going forward (gcc). > > The first thing we need to do is remove the userspace-visible > ABIs so that applications will stop using it. The most visible > one are the enable/disable prctl()s. Remove them first. > > This is the most minimal and least invasive patch needed to > start removing MPX.
Is this something we _want_ to push to stable trees? > > Signed-off-by: Dave Hansen <[email protected]> > --- > > b/include/uapi/linux/prctl.h | 2 +- > b/kernel/sys.c | 16 ++-------------- > 2 files changed, 3 insertions(+), 15 deletions(-) > > diff -puN include/uapi/linux/prctl.h~mpx-remove-apis > include/uapi/linux/prctl.h > --- a/include/uapi/linux/prctl.h~mpx-remove-apis 2019-01-04 > 14:40:06.853514089 -0800 > +++ b/include/uapi/linux/prctl.h 2019-01-04 14:40:06.860514089 -0800 > @@ -181,7 +181,7 @@ struct prctl_mm_map { > #define PR_GET_THP_DISABLE 42 > > /* > - * Tell the kernel to start/stop helping userspace manage bounds tables. > + * No longer implemented, but left here to ensure the numbers stay reserved: > */ > #define PR_MPX_ENABLE_MANAGEMENT 43 > #define PR_MPX_DISABLE_MANAGEMENT 44 > diff -puN kernel/sys.c~mpx-remove-apis kernel/sys.c > --- a/kernel/sys.c~mpx-remove-apis 2019-01-04 14:40:06.857514089 -0800 > +++ b/kernel/sys.c 2019-01-04 14:40:06.860514089 -0800 > @@ -103,12 +103,6 @@ > #ifndef SET_TSC_CTL > # define SET_TSC_CTL(a) (-EINVAL) > #endif > -#ifndef MPX_ENABLE_MANAGEMENT > -# define MPX_ENABLE_MANAGEMENT() (-EINVAL) > -#endif > -#ifndef MPX_DISABLE_MANAGEMENT > -# define MPX_DISABLE_MANAGEMENT() (-EINVAL) > -#endif > #ifndef GET_FP_MODE > # define GET_FP_MODE(a) (-EINVAL) > #endif > @@ -2448,15 +2442,9 @@ SYSCALL_DEFINE5(prctl, int, option, unsi > up_write(&me->mm->mmap_sem); > break; > case PR_MPX_ENABLE_MANAGEMENT: > - if (arg2 || arg3 || arg4 || arg5) > - return -EINVAL; > - error = MPX_ENABLE_MANAGEMENT(); > - break; > case PR_MPX_DISABLE_MANAGEMENT: > - if (arg2 || arg3 || arg4 || arg5) > - return -EINVAL; > - error = MPX_DISABLE_MANAGEMENT(); > - break; > + /* No longer implemented: */ > + return -EINVAL; > case PR_SET_FP_MODE: > error = SET_FP_MODE(me, arg2); > break; > _ -- Michal Hocko SUSE Labs
