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-rw-r--r--arch/x86/net/bpf_jit_comp.c114
1 files changed, 76 insertions, 38 deletions
diff --git a/arch/x86/net/bpf_jit_comp.c b/arch/x86/net/bpf_jit_comp.c
index c98b8c0ed3b8..c1f6c1c51d99 100644
--- a/arch/x86/net/bpf_jit_comp.c
+++ b/arch/x86/net/bpf_jit_comp.c
@@ -412,16 +412,30 @@ static void emit_indirect_jump(u8 **pprog, int reg, u8 *ip)
{
u8 *prog = *pprog;
-#ifdef CONFIG_RETPOLINE
if (cpu_feature_enabled(X86_FEATURE_RETPOLINE_LFENCE)) {
EMIT_LFENCE();
EMIT2(0xFF, 0xE0 + reg);
} else if (cpu_feature_enabled(X86_FEATURE_RETPOLINE)) {
OPTIMIZER_HIDE_VAR(reg);
emit_jump(&prog, &__x86_indirect_thunk_array[reg], ip);
- } else
-#endif
- EMIT2(0xFF, 0xE0 + reg);
+ } else {
+ EMIT2(0xFF, 0xE0 + reg);
+ }
+
+ *pprog = prog;
+}
+
+static void emit_return(u8 **pprog, u8 *ip)
+{
+ u8 *prog = *pprog;
+
+ if (cpu_feature_enabled(X86_FEATURE_RETHUNK)) {
+ emit_jump(&prog, &__x86_return_thunk, ip);
+ } else {
+ EMIT1(0xC3); /* ret */
+ if (IS_ENABLED(CONFIG_SLS))
+ EMIT1(0xCC); /* int3 */
+ }
*pprog = prog;
}
@@ -1686,7 +1700,7 @@ emit_jmp:
ctx->cleanup_addr = proglen;
pop_callee_regs(&prog, callee_regs_used);
EMIT1(0xC9); /* leave */
- EMIT1(0xC3); /* ret */
+ emit_return(&prog, image + addrs[i - 1] + (prog - temp));
break;
default:
@@ -1771,6 +1785,10 @@ static int invoke_bpf_prog(const struct btf_func_model *m, u8 **pprog,
struct bpf_tramp_link *l, int stack_size,
int run_ctx_off, bool save_ret)
{
+ void (*exit)(struct bpf_prog *prog, u64 start,
+ struct bpf_tramp_run_ctx *run_ctx) = __bpf_prog_exit;
+ u64 (*enter)(struct bpf_prog *prog,
+ struct bpf_tramp_run_ctx *run_ctx) = __bpf_prog_enter;
u8 *prog = *pprog;
u8 *jmp_insn;
int ctx_cookie_off = offsetof(struct bpf_tramp_run_ctx, bpf_cookie);
@@ -1789,15 +1807,21 @@ static int invoke_bpf_prog(const struct btf_func_model *m, u8 **pprog,
*/
emit_stx(&prog, BPF_DW, BPF_REG_FP, BPF_REG_1, -run_ctx_off + ctx_cookie_off);
+ if (p->aux->sleepable) {
+ enter = __bpf_prog_enter_sleepable;
+ exit = __bpf_prog_exit_sleepable;
+ } else if (p->expected_attach_type == BPF_LSM_CGROUP) {
+ enter = __bpf_prog_enter_lsm_cgroup;
+ exit = __bpf_prog_exit_lsm_cgroup;
+ }
+
/* arg1: mov rdi, progs[i] */
emit_mov_imm64(&prog, BPF_REG_1, (long) p >> 32, (u32) (long) p);
/* arg2: lea rsi, [rbp - ctx_cookie_off] */
EMIT4(0x48, 0x8D, 0x75, -run_ctx_off);
- if (emit_call(&prog,
- p->aux->sleepable ? __bpf_prog_enter_sleepable :
- __bpf_prog_enter, prog))
- return -EINVAL;
+ if (emit_call(&prog, enter, prog))
+ return -EINVAL;
/* remember prog start time returned by __bpf_prog_enter */
emit_mov_reg(&prog, true, BPF_REG_6, BPF_REG_0);
@@ -1841,10 +1865,8 @@ static int invoke_bpf_prog(const struct btf_func_model *m, u8 **pprog,
emit_mov_reg(&prog, true, BPF_REG_2, BPF_REG_6);
/* arg3: lea rdx, [rbp - run_ctx_off] */
EMIT4(0x48, 0x8D, 0x55, -run_ctx_off);
- if (emit_call(&prog,
- p->aux->sleepable ? __bpf_prog_exit_sleepable :
- __bpf_prog_exit, prog))
- return -EINVAL;
+ if (emit_call(&prog, exit, prog))
+ return -EINVAL;
*pprog = prog;
return 0;
@@ -1928,23 +1950,6 @@ static int invoke_bpf_mod_ret(const struct btf_func_model *m, u8 **pprog,
return 0;
}
-static bool is_valid_bpf_tramp_flags(unsigned int flags)
-{
- if ((flags & BPF_TRAMP_F_RESTORE_REGS) &&
- (flags & BPF_TRAMP_F_SKIP_FRAME))
- return false;
-
- /*
- * BPF_TRAMP_F_RET_FENTRY_RET is only used by bpf_struct_ops,
- * and it must be used alone.
- */
- if ((flags & BPF_TRAMP_F_RET_FENTRY_RET) &&
- (flags & ~BPF_TRAMP_F_RET_FENTRY_RET))
- return false;
-
- return true;
-}
-
/* Example:
* __be16 eth_type_trans(struct sk_buff *skb, struct net_device *dev);
* its 'struct btf_func_model' will be nr_args=2
@@ -2023,9 +2028,6 @@ int arch_prepare_bpf_trampoline(struct bpf_tramp_image *im, void *image, void *i
if (nr_args > 6)
return -ENOTSUPP;
- if (!is_valid_bpf_tramp_flags(flags))
- return -EINVAL;
-
/* Generated trampoline stack layout:
*
* RBP + 8 [ return address ]
@@ -2131,10 +2133,15 @@ int arch_prepare_bpf_trampoline(struct bpf_tramp_image *im, void *image, void *i
if (flags & BPF_TRAMP_F_CALL_ORIG) {
restore_regs(m, &prog, nr_args, regs_off);
- /* call original function */
- if (emit_call(&prog, orig_call, prog)) {
- ret = -EINVAL;
- goto cleanup;
+ if (flags & BPF_TRAMP_F_ORIG_STACK) {
+ emit_ldx(&prog, BPF_DW, BPF_REG_0, BPF_REG_FP, 8);
+ EMIT2(0xff, 0xd0); /* call *rax */
+ } else {
+ /* call original function */
+ if (emit_call(&prog, orig_call, prog)) {
+ ret = -EINVAL;
+ goto cleanup;
+ }
}
/* remember return value in a stack for bpf prog to access */
emit_stx(&prog, BPF_DW, BPF_REG_FP, BPF_REG_0, -8);
@@ -2189,7 +2196,7 @@ int arch_prepare_bpf_trampoline(struct bpf_tramp_image *im, void *image, void *i
if (flags & BPF_TRAMP_F_SKIP_FRAME)
/* skip our return address and return to parent */
EMIT4(0x48, 0x83, 0xC4, 8); /* add rsp, 8 */
- EMIT1(0xC3); /* ret */
+ emit_return(&prog, prog);
/* Make sure the trampoline generation logic doesn't overflow */
if (WARN_ON_ONCE(prog > (u8 *)image_end - BPF_INSN_SAFETY)) {
ret = -EFAULT;
@@ -2492,3 +2499,34 @@ void *bpf_arch_text_copy(void *dst, void *src, size_t len)
return ERR_PTR(-EINVAL);
return dst;
}
+
+/* Indicate the JIT backend supports mixing bpf2bpf and tailcalls. */
+bool bpf_jit_supports_subprog_tailcalls(void)
+{
+ return true;
+}
+
+void bpf_jit_free(struct bpf_prog *prog)
+{
+ if (prog->jited) {
+ struct x64_jit_data *jit_data = prog->aux->jit_data;
+ struct bpf_binary_header *hdr;
+
+ /*
+ * If we fail the final pass of JIT (from jit_subprogs),
+ * the program may not be finalized yet. Call finalize here
+ * before freeing it.
+ */
+ if (jit_data) {
+ bpf_jit_binary_pack_finalize(prog, jit_data->header,
+ jit_data->rw_header);
+ kvfree(jit_data->addrs);
+ kfree(jit_data);
+ }
+ hdr = bpf_jit_binary_pack_hdr(prog);
+ bpf_jit_binary_pack_free(hdr, NULL);
+ WARN_ON_ONCE(!bpf_prog_kallsyms_verify_off(prog));
+ }
+
+ bpf_prog_unlock_free(prog);
+}
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