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()
---
arch/powerpc/kernel/kprobes.c | 14 ++++++++++++++
1 file changed, 14 insertions(+)
diff --git a/arch/powerpc/kernel/kprobes.c b/arch/powerpc/kernel/kprobes.c
index 01ab2163659e..3ae27af9b094 100644
--- a/arch/powerpc/kernel/kprobes.c
+++ b/arch/powerpc/kernel/kprobes.c
@@ -25,6 +25,7 @@
#include <asm/sections.h>
#include <asm/inst.h>
#include <linux/uaccess.h>
+#include <linux/vmalloc.h>
DEFINE_PER_CPU(struct kprobe *, current_kprobe) = NULL;
DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk);
@@ -103,6 +104,19 @@ kprobe_opcode_t *kprobe_lookup_name(const char *name,
unsigned int offset)
return addr;
}
+void *alloc_insn_page(void)
+{
+ if (IS_ENABLED(CONFIG_STRICT_KERNEL_RWX)) {
+ return __vmalloc_node_range(PAGE_SIZE, 1, MODULES_VADDR,
MODULES_END,
+ GFP_KERNEL, PAGE_KERNEL_ROX,
VM_FLUSH_RESET_PERMS,
+ NUMA_NO_NODE, __builtin_return_address(0));
+ } else {
+ return __vmalloc_node_range(PAGE_SIZE, 1, MODULES_VADDR,
MODULES_END,
+ GFP_KERNEL, PAGE_KERNEL_EXEC,
VM_FLUSH_RESET_PERMS,
+ NUMA_NO_NODE, __builtin_return_address(0));
+ }
+}
+
int arch_prepare_kprobe(struct kprobe *p)
{
int ret = 0;
--
2.25.1
