From: Jisheng Zhang <jszhang@kernel.org>
Date: Mon, 29 Mar 2021 18:24:21 +0000 (+0800)
Subject: riscv: kprobes: Implement alloc_insn_page()
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=cdd1b2bd358ffda2638fe18ff47191e84e18525f;p=linux.git

riscv: kprobes: Implement alloc_insn_page()

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 <jszhang@kernel.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
---

diff --git a/arch/riscv/kernel/probes/kprobes.c b/arch/riscv/kernel/probes/kprobes.c
index a2ec18662fee0..0b451ff76d552 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)
 {