From: Russell Currey <rus...@russell.cc>
Add the arch specific insn page allocator for powerpc. This allocates
ROX pages if STRICT_KERNEL_RWX is enabled. These pages are only written
to with patch_instruction() which is able to write RO pages.
Reviewed-by: Daniel Axtens <d...@axtens.net>
Signed-off-by: Russell Currey <rus...@russell.cc>
Signed-off-by: Christophe Leroy <christophe.le...@csgroup.eu>
[jpn: Reword commit message, switch to __vmalloc_node_range()]
Signed-off-by: Jordan Niethe <jniet...@gmail.com>
---
v9: - vmalloc_exec() no longer exists
- Set the page to RW before freeing it
v10: - use __vmalloc_node_range()
v11: - Neaten up
v12: - Switch from __vmalloc_node_range() to module_alloc()
v13: Use strict_kernel_rwx_enabled()
v14: Use strict_module_rwx_enabled()
---
arch/powerpc/kernel/kprobes.c | 17 +++++++++++++++++
1 file changed, 17 insertions(+)
diff --git a/arch/powerpc/kernel/kprobes.c b/arch/powerpc/kernel/kprobes.c
index 01ab2163659e..937e338053ff 100644
--- a/arch/powerpc/kernel/kprobes.c
+++ b/arch/powerpc/kernel/kprobes.c
@@ -19,11 +19,13 @@
#include <linux/extable.h>
#include <linux/kdebug.h>
#include <linux/slab.h>
+#include <linux/moduleloader.h>
#include <asm/code-patching.h>
#include <asm/cacheflush.h>
#include <asm/sstep.h>
#include <asm/sections.h>
#include <asm/inst.h>
+#include <asm/set_memory.h>
#include <linux/uaccess.h>
DEFINE_PER_CPU(struct kprobe *, current_kprobe) = NULL;
@@ -103,6 +105,21 @@ kprobe_opcode_t *kprobe_lookup_name(const char *name,
unsigned int offset)
return addr;
}
+void *alloc_insn_page(void)
+{
+ void *page;
+
+ page = module_alloc(PAGE_SIZE);
+ if (!page)
+ return NULL;
+
+ if (strict_module_rwx_enabled()) {
+ set_memory_ro((unsigned long)page, 1);
+ set_memory_x((unsigned long)page, 1);
+ }
+ return page;
+}
+
int arch_prepare_kprobe(struct kprobe *p)
{
int ret = 0;
--
2.25.1
