From 9c9c17613a78545a4a93b1370924f62eb282c903 Mon Sep 17 00:00:00 2001 From: Heiko Carstens Date: Mon, 5 Mar 2007 23:35:45 +0100 Subject: [PATCH] [S390] nss: disable kexec. nss and kexec don't work together since kexec wants to write to the read-only text section of the shared kernel image. Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky --- arch/s390/Kconfig | 2 ++ arch/s390/kernel/machine_kexec.c | 5 +++++ 2 files changed, 7 insertions(+) diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig index d9425f59be9..0f293aa7b0f 100644 --- a/arch/s390/Kconfig +++ b/arch/s390/Kconfig @@ -376,6 +376,8 @@ config SHARED_KERNEL Select this option, if you want to share the text segment of the Linux kernel between different VM guests. This reduces memory usage with lots of guests but greatly increases kernel size. + Also if a kernel was IPL'ed from a shared segment the kexec system + call will not work. You should only select this option if you know what you are doing and want to exploit this feature. diff --git a/arch/s390/kernel/machine_kexec.c b/arch/s390/kernel/machine_kexec.c index 52f57af252b..3c77dd36994 100644 --- a/arch/s390/kernel/machine_kexec.c +++ b/arch/s390/kernel/machine_kexec.c @@ -19,6 +19,7 @@ #include #include #include +#include typedef void (*relocate_kernel_t)(kimage_entry_t *, unsigned long); @@ -29,6 +30,10 @@ int machine_kexec_prepare(struct kimage *image) { void *reboot_code_buffer; + /* Can't replace kernel image since it is read-only. */ + if (ipl_flags & IPL_NSS_VALID) + return -ENOSYS; + /* We don't support anything but the default image type for now. */ if (image->type != KEXEC_TYPE_DEFAULT) return -EINVAL;