On Tue, Mar 21, 2017 at 10:17 AM, Cyrill Gorcunov <gorcunov@xxxxxxxxx> wrote: > On Tue, Mar 21, 2017 at 07:37:12PM +0300, Dmitry Safonov wrote: > ... >> diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c >> index d6b784a5520d..d3d4d9abcaf8 100644 >> --- a/arch/x86/kernel/process_64.c >> +++ b/arch/x86/kernel/process_64.c >> @@ -519,8 +519,14 @@ void set_personality_ia32(bool x32) >> if (current->mm) >> current->mm->context.ia32_compat = TIF_X32; >> current->personality &= ~READ_IMPLIES_EXEC; >> - /* in_compat_syscall() uses the presence of the x32 >> - syscall bit flag to determine compat status */ >> + /* >> + * in_compat_syscall() uses the presence of the x32 >> + * syscall bit flag to determine compat status. >> + * On the bitness of syscall relies x86 mmap() code, >> + * so set x32 syscall bit right here to make >> + * in_compat_syscall() work during exec(). >> + */ >> + task_pt_regs(current)->orig_ax |= __X32_SYSCALL_BIT; >> current->thread.status &= ~TS_COMPAT; > > Hi! I must admit I didn't follow close the overall series (so can't > comment much here :) but I have a slightly unrelated question -- is > there a way to figure out if task is running in x32 mode say with > some ptrace or procfs sign? You should be able to figure out of a *syscall* is x32 by simply looking at bit 30 in the syscall number. (This is unlike i386, which is currently not reflected in ptrace.) Do we actually have an x32 per-task mode at all? If so, maybe we can just remove it on top of Dmitry's series. -- 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>
