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authorArjan van de Ven <arjan@infradead.org>2007-06-20 22:23:21 -0700
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-06-21 16:02:50 -0700
commit0864a4e201b1ea442f4c8b887418a29f67e24d30 (patch)
treecee5372bb22502e52029543dfb72c571a1e89faa
parent79d9a72f87d0a6f910be262a9dd4c36e96972a92 (diff)
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 <arjan@linux.intel.com> Tested-by: S. P. Prasanna <prasanna@in.ibm.com> Cc: Andi Kleen <ak@suse.de> Cc: William Cohen <wcohen@redhat.com> Cc: Ian McDonald <ian.mcdonald@jandi.co.nz> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--arch/i386/Kconfig.debug1
-rw-r--r--arch/i386/mm/init.c3
-rw-r--r--arch/x86_64/Kconfig.debug1
-rw-r--r--arch/x86_64/mm/init.c5
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;