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-rw-r--r--arch/riscv/kernel/cfi.c53
1 files changed, 53 insertions, 0 deletions
diff --git a/arch/riscv/kernel/cfi.c b/arch/riscv/kernel/cfi.c
index 6ec9dbd729..64bdd3e1ab 100644
--- a/arch/riscv/kernel/cfi.c
+++ b/arch/riscv/kernel/cfi.c
@@ -75,3 +75,56 @@ enum bug_trap_type handle_cfi_failure(struct pt_regs *regs)
return report_cfi_failure(regs, regs->epc, &target, type);
}
+
+#ifdef CONFIG_CFI_CLANG
+struct bpf_insn;
+
+/* Must match bpf_func_t / DEFINE_BPF_PROG_RUN() */
+extern unsigned int __bpf_prog_runX(const void *ctx,
+ const struct bpf_insn *insn);
+
+/*
+ * Force a reference to the external symbol so the compiler generates
+ * __kcfi_typid.
+ */
+__ADDRESSABLE(__bpf_prog_runX);
+
+/* u32 __ro_after_init cfi_bpf_hash = __kcfi_typeid___bpf_prog_runX; */
+asm (
+" .pushsection .data..ro_after_init,\"aw\",@progbits \n"
+" .type cfi_bpf_hash,@object \n"
+" .globl cfi_bpf_hash \n"
+" .p2align 2, 0x0 \n"
+"cfi_bpf_hash: \n"
+" .word __kcfi_typeid___bpf_prog_runX \n"
+" .size cfi_bpf_hash, 4 \n"
+" .popsection \n"
+);
+
+/* Must match bpf_callback_t */
+extern u64 __bpf_callback_fn(u64, u64, u64, u64, u64);
+
+__ADDRESSABLE(__bpf_callback_fn);
+
+/* u32 __ro_after_init cfi_bpf_subprog_hash = __kcfi_typeid___bpf_callback_fn; */
+asm (
+" .pushsection .data..ro_after_init,\"aw\",@progbits \n"
+" .type cfi_bpf_subprog_hash,@object \n"
+" .globl cfi_bpf_subprog_hash \n"
+" .p2align 2, 0x0 \n"
+"cfi_bpf_subprog_hash: \n"
+" .word __kcfi_typeid___bpf_callback_fn \n"
+" .size cfi_bpf_subprog_hash, 4 \n"
+" .popsection \n"
+);
+
+u32 cfi_get_func_hash(void *func)
+{
+ u32 hash;
+
+ if (get_kernel_nofault(hash, func - cfi_get_offset()))
+ return 0;
+
+ return hash;
+}
+#endif