From 602033ed5907a59ce86f709082a35be047743a86 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Thu, 26 Jul 2007 12:07:21 -0700 Subject: Revert most of "x86: Fix alternatives and kprobes to remap write-protected kernel text" This reverts most of commit 19d36ccdc34f5ed444f8a6af0cbfdb6790eb1177. The way to DEBUG_RODATA interactions with KPROBES and CPU hotplug is to just not mark the text as being write-protected in the first place. Both of those facilities depend on rewriting instructions. Having "helpful" debug facilities that just cause more problem is not being helpful. It just adds complexity and bugs. Not worth it. Reported-by: Rafael J. Wysocki Cc: Andi Kleen Cc: Andrew Morton Signed-off-by: Linus Torvalds --- arch/i386/mm/init.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) (limited to 'arch/i386/mm/init.c') diff --git a/arch/i386/mm/init.c b/arch/i386/mm/init.c index 1b1a1e66d099..4c4809f13cb1 100644 --- a/arch/i386/mm/init.c +++ b/arch/i386/mm/init.c @@ -800,9 +800,17 @@ void mark_rodata_ro(void) unsigned long start = PFN_ALIGN(_text); unsigned long size = PFN_ALIGN(_etext) - start; - change_page_attr(virt_to_page(start), - size >> PAGE_SHIFT, PAGE_KERNEL_RX); - printk("Write protecting the kernel text: %luk\n", size >> 10); +#ifndef CONFIG_KPROBES +#ifdef CONFIG_HOTPLUG_CPU + /* It must still be possible to apply SMP alternatives. */ + if (num_possible_cpus() <= 1) +#endif + { + change_page_attr(virt_to_page(start), + size >> PAGE_SHIFT, PAGE_KERNEL_RX); + printk("Write protecting the kernel text: %luk\n", size >> 10); + } +#endif start += size; size = (unsigned long)__end_rodata - start; change_page_attr(virt_to_page(start), -- cgit v1.2.3-59-g8ed1b