From 0864a4e201b1ea442f4c8b887418a29f67e24d30 Mon Sep 17 00:00:00 2001 From: Arjan van de Ven Date: Wed, 20 Jun 2007 22:23:21 -0700 Subject: [PATCH] Allow DEBUG_RODATA and KPROBES to co-exist Do not mark the kernel text read only if KPROBES is in the kernel; kprobes needs to hot-patch the kernel text to insert it's instrumentation. In this case, only mark the .rodata segment as read only. Signed-off-by: Arjan van de Ven Tested-by: S. P. Prasanna Cc: Andi Kleen Cc: William Cohen Cc: Ian McDonald Signed-off-by: Linus Torvalds --- arch/i386/Kconfig.debug | 1 - arch/i386/mm/init.c | 3 ++- arch/x86_64/Kconfig.debug | 1 - arch/x86_64/mm/init.c | 5 +++++ 4 files changed, 7 insertions(+), 3 deletions(-) diff --git a/arch/i386/Kconfig.debug b/arch/i386/Kconfig.debug index 6293920cd1b..b31c0802e1c 100644 --- a/arch/i386/Kconfig.debug +++ b/arch/i386/Kconfig.debug @@ -49,7 +49,6 @@ config DEBUG_PAGEALLOC config DEBUG_RODATA bool "Write protect kernel read-only data structures" depends on DEBUG_KERNEL - depends on !KPROBES # temporary for 2.6.22 help Mark the kernel read-only data as write-protected in the pagetables, in order to catch accidental (and incorrect) writes to such const diff --git a/arch/i386/mm/init.c b/arch/i386/mm/init.c index b22ce8d6b1b..7135946d366 100644 --- a/arch/i386/mm/init.c +++ b/arch/i386/mm/init.c @@ -799,6 +799,7 @@ void mark_rodata_ro(void) unsigned long start = PFN_ALIGN(_text); unsigned long size = PFN_ALIGN(_etext) - start; +#ifndef CONFIG_KPROBES #ifdef CONFIG_HOTPLUG_CPU /* It must still be possible to apply SMP alternatives. */ if (num_possible_cpus() <= 1) @@ -808,7 +809,7 @@ void mark_rodata_ro(void) 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), diff --git a/arch/x86_64/Kconfig.debug b/arch/x86_64/Kconfig.debug index 8a867751844..775d211a5cf 100644 --- a/arch/x86_64/Kconfig.debug +++ b/arch/x86_64/Kconfig.debug @@ -9,7 +9,6 @@ source "lib/Kconfig.debug" config DEBUG_RODATA bool "Write protect kernel read-only data structures" depends on DEBUG_KERNEL - depends on !KPROBES # temporary for 2.6.22 help Mark the kernel read-only data as write-protected in the pagetables, in order to catch accidental (and incorrect) writes to such const data. diff --git a/arch/x86_64/mm/init.c b/arch/x86_64/mm/init.c index efb6e845114..9a0e98accf0 100644 --- a/arch/x86_64/mm/init.c +++ b/arch/x86_64/mm/init.c @@ -605,6 +605,11 @@ void mark_rodata_ro(void) if (num_possible_cpus() > 1) start = (unsigned long)_etext; #endif + +#ifdef CONFIG_KPROBES + start = (unsigned long)__start_rodata; +#endif + end = (unsigned long)__end_rodata; start = (start + PAGE_SIZE - 1) & PAGE_MASK; end &= PAGE_MASK; -- 2.20.1