[v3,06/10] riscv: kprobes: Implement alloc_insn_page()

Commit Message

Jisheng Zhang April 12, 2021, 4:17 p.m. UTC

From: Jisheng Zhang <[e-mail]>

Allocate PAGE_KERNEL_READ_EXEC(read only, executable) page for kprobes
insn page. This is to prepare for STRICT_MODULE_RWX.

Signed-off-by: Jisheng Zhang <[e-mail]>
Reviewed-by: Anup Patel <[e-mail]>
---
 arch/riscv/kernel/probes/kprobes.c | 8 ++++++++
 1 file changed, 8 insertions(+)

Patch

diff --git a/arch/riscv/kernel/probes/kprobes.c b/arch/riscv/kernel/probes/kprobes.c
index 7e2c78e2ca6b..8c1f7a30aeed 100644
--- a/arch/riscv/kernel/probes/kprobes.c
+++ b/arch/riscv/kernel/probes/kprobes.c
@@ -84,6 +84,14 @@  int __kprobes arch_prepare_kprobe(struct kprobe *p)
 	return 0;
 }
 
+void *alloc_insn_page(void)
+{
+	return  __vmalloc_node_range(PAGE_SIZE, 1, VMALLOC_START, VMALLOC_END,
+				     GFP_KERNEL, PAGE_KERNEL_READ_EXEC,
+				     VM_FLUSH_RESET_PERMS, NUMA_NO_NODE,
+				     __builtin_return_address(0));
+}
+
 /* install breakpoint in text */
 void __kprobes arch_arm_kprobe(struct kprobe *p)
 {