From 083bb9b6a4e33a2881da9086c65792148d0d04b1 Mon Sep 17 00:00:00 2001 From: Yousong Zhou Date: Tue, 27 Aug 2019 03:52:56 +0000 Subject: [PATCH] config: kernel: add KERNEL_X86_VSYSCALL_EMULATION Binaries in container images may need this. E.g. nginx:1.7.9 used in k8s default deployment manifest file for demostration [1] [1] https://kubernetes.io/docs/concepts/workloads/controllers/deployment/#creating-a-deployment Signed-off-by: Yousong Zhou --- config/Config-kernel.in | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) diff --git a/config/Config-kernel.in b/config/Config-kernel.in index eeda3e1b6f..d9a9fe687f 100644 --- a/config/Config-kernel.in +++ b/config/Config-kernel.in @@ -54,6 +54,24 @@ config KERNEL_ARM_PMU default n depends on (arm || aarch64) +config KERNEL_X86_VSYSCALL_EMULATION + bool "Enable vsyscall emulation" + default n + depends on x86_64 + help + This enables emulation of the legacy vsyscall page. Disabling + it is roughly equivalent to booting with vsyscall=none, except + that it will also disable the helpful warning if a program + tries to use a vsyscall. With this option set to N, offending + programs will just segfault, citing addresses of the form + 0xffffffffff600?00. + + This option is required by many programs built before 2013, and + care should be used even with newer programs if set to N. + + Disabling this option saves about 7K of kernel size and + possibly 4K of additional runtime pagetable memory. + config KERNEL_PERF_EVENTS bool "Compile the kernel with performance events and counters" default n