From: Andy Lutomirski Date: Wed, 29 Oct 2014 21:33:47 +0000 (-0700) Subject: x86_64,vsyscall: Make vsyscall emulation configurable X-Git-Tag: omap-for-v3.20/drop-legacy-3517~149^2~2 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=1ad83c858c7d4ea210429142c99a1548e6715a35;p=pandora-kernel.git x86_64,vsyscall: Make vsyscall emulation configurable 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 Reviewed-by: Josh Triplett Cc: Konrad Rzeszutek Wilk Link: http://lkml.kernel.org/r/406db88b8dd5f0cbbf38216d11be34bbb43c7eae.1414618407.git.luto@amacapital.net Signed-off-by: Thomas Gleixner --- Reading git-diff-tree failed