}
if (image) {
- if (unlikely(proglen + ilen > oldproglen)) {
+ /*
+ * When populating the image, assert that:
+ *
+ * i) We do not write beyond the allocated space, and
+ * ii) addrs[i] did not change from the prior run, in order
+ * to validate assumptions made for computing branch
+ * displacements.
+ */
+ if (unlikely(proglen + ilen > oldproglen ||
+ proglen + ilen != addrs[i])) {
pr_err("bpf_jit: fatal error\n");
return -EFAULT;
}
* add rsp, 8 // skip eth_type_trans's frame
* ret // return to its caller
*/
-int arch_prepare_bpf_trampoline(void *image, void *image_end,
+int arch_prepare_bpf_trampoline(struct bpf_tramp_image *im, void *image, void *image_end,
const struct btf_func_model *m, u32 flags,
struct bpf_tramp_progs *tprogs,
void *orig_call)
save_regs(m, &prog, nr_args, stack_size);
+ if (flags & BPF_TRAMP_F_CALL_ORIG) {
+ /* arg1: mov rdi, im */
+ emit_mov_imm64(&prog, BPF_REG_1, (long) im >> 32, (u32) (long) im);
+ if (emit_call(&prog, __bpf_tramp_enter, prog)) {
+ ret = -EINVAL;
+ goto cleanup;
+ }
+ }
+
if (fentry->nr_progs)
if (invoke_bpf(m, &prog, fentry, stack_size))
return -EINVAL;
}
if (flags & BPF_TRAMP_F_CALL_ORIG) {
- if (fentry->nr_progs || fmod_ret->nr_progs)
- restore_regs(m, &prog, nr_args, stack_size);
+ restore_regs(m, &prog, nr_args, stack_size);
/* call original function */
if (emit_call(&prog, orig_call, prog)) {
}
/* remember return value in a stack for bpf prog to access */
emit_stx(&prog, BPF_DW, BPF_REG_FP, BPF_REG_0, -8);
+ im->ip_after_call = prog;
+ memcpy(prog, ideal_nops[NOP_ATOMIC5], X86_PATCH_SIZE);
+ prog += X86_PATCH_SIZE;
}
if (fmod_ret->nr_progs) {
* the return value is only updated on the stack and still needs to be
* restored to R0.
*/
- if (flags & BPF_TRAMP_F_CALL_ORIG)
+ if (flags & BPF_TRAMP_F_CALL_ORIG) {
+ im->ip_epilogue = prog;
+ /* arg1: mov rdi, im */
+ emit_mov_imm64(&prog, BPF_REG_1, (long) im >> 32, (u32) (long) im);
+ if (emit_call(&prog, __bpf_tramp_exit, prog)) {
+ ret = -EINVAL;
+ goto cleanup;
+ }
/* restore original return value back into RAX */
emit_ldx(&prog, BPF_DW, BPF_REG_0, BPF_REG_FP, -8);
+ }
EMIT1(0x5B); /* pop rbx */
EMIT1(0xC9); /* leave */