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authorAndi Kleen <ak@suse.de>2007-07-22 11:12:31 +0200
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-07-22 11:03:37 -0700
commit19d36ccdc34f5ed444f8a6af0cbfdb6790eb1177 (patch)
tree39942efb826f2793692da60b04fc0e7b015fa23d /arch/x86_64
parentf51c94528a9bc73504928926ca4d791a2b7ddd7c (diff)
x86: Fix alternatives and kprobes to remap write-protected kernel text
Reenable kprobes and alternative patching when the kernel text is write protected by DEBUG_RODATA Add a general utility function to change write protected text. The new function remaps the code using vmap to write it and takes care of CPU synchronization. It also does CLFLUSH to make icache recovery faster. There are some limitations on when the function can be used, see the comment. This is a newer version that also changes the paravirt_ops code. text_poke also supports multi byte patching now. Contains bug fixes from Zach Amsden and suggestions from Mathieu Desnoyers. Cc: Jan Beulich <jbeulich@novell.com> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Cc: Mathieu Desnoyers <compudj@krystal.dyndns.org> Cc: Zach Amsden <zach@vmware.com> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/x86_64')
-rw-r--r--arch/x86_64/kernel/kprobes.c10
-rw-r--r--arch/x86_64/mm/init.c10
-rw-r--r--arch/x86_64/mm/pageattr.c2
3 files changed, 4 insertions, 18 deletions
diff --git a/arch/x86_64/kernel/kprobes.c b/arch/x86_64/kernel/kprobes.c
index d4a0d0ac993..a30e004682e 100644
--- a/arch/x86_64/kernel/kprobes.c
+++ b/arch/x86_64/kernel/kprobes.c
@@ -39,9 +39,9 @@
#include <linux/module.h>
#include <linux/kdebug.h>
-#include <asm/cacheflush.h>
#include <asm/pgtable.h>
#include <asm/uaccess.h>
+#include <asm/alternative.h>
void jprobe_return_end(void);
static void __kprobes arch_copy_kprobe(struct kprobe *p);
@@ -209,16 +209,12 @@ static void __kprobes arch_copy_kprobe(struct kprobe *p)
void __kprobes arch_arm_kprobe(struct kprobe *p)
{
- *p->addr = BREAKPOINT_INSTRUCTION;
- flush_icache_range((unsigned long) p->addr,
- (unsigned long) p->addr + sizeof(kprobe_opcode_t));
+ text_poke(p->addr, ((unsigned char []){BREAKPOINT_INSTRUCTION}), 1);
}
void __kprobes arch_disarm_kprobe(struct kprobe *p)
{
- *p->addr = p->opcode;
- flush_icache_range((unsigned long) p->addr,
- (unsigned long) p->addr + sizeof(kprobe_opcode_t));
+ text_poke(p->addr, &p->opcode, 1);
}
void __kprobes arch_remove_kprobe(struct kprobe *p)
diff --git a/arch/x86_64/mm/init.c b/arch/x86_64/mm/init.c
index 2044fa961c0..314e12b2209 100644
--- a/arch/x86_64/mm/init.c
+++ b/arch/x86_64/mm/init.c
@@ -600,16 +600,6 @@ void mark_rodata_ro(void)
{
unsigned long start = (unsigned long)_stext, end;
-#ifdef CONFIG_HOTPLUG_CPU
- /* It must still be possible to apply SMP alternatives. */
- 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;
diff --git a/arch/x86_64/mm/pageattr.c b/arch/x86_64/mm/pageattr.c
index 36377b6b8ef..7e161c698af 100644
--- a/arch/x86_64/mm/pageattr.c
+++ b/arch/x86_64/mm/pageattr.c
@@ -13,7 +13,7 @@
#include <asm/tlbflush.h>
#include <asm/io.h>
-static inline pte_t *lookup_address(unsigned long address)
+pte_t *lookup_address(unsigned long address)
{
pgd_t *pgd = pgd_offset_k(address);
pud_t *pud;