https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=219399

--- Comment #215 from Nils Beyer <[email protected]> ---
(In reply to Don Lewis from comment #214)

documentation is the keyword, I don't know; I only have this:
----------------------------------------------------------------------------
from: linux/v4.12/source/arch/x86/include/asm/processor.h - lines 791 and seq
----------------------------------------------------------------------------
#ifdef CONFIG_X86_32
[...]
#else
/*
 * User space process size. 47bits minus one guard page.  The guard
 * page is necessary on Intel CPUs: if a SYSCALL instruction is at
 * the highest possible canonical userspace address, then that
 * syscall will enter the kernel with a non-canonical return
 * address, and SYSRET will explode dangerously.  We avoid this
 * particular problem by preventing anything from being mapped
 * at the maximum canonical address.
 */
#define TASK_SIZE_MAX   ((1UL << 47) - PAGE_SIZE)
----------------------------------------------------------------------------

do we have or need something similar?

-- 
You are receiving this mail because:
You are the assignee for the bug.
_______________________________________________
[email protected] mailing list
https://lists.freebsd.org/mailman/listinfo/freebsd-bugs
To unsubscribe, send any mail to "[email protected]"

Reply via email to