From patchwork Tue Oct 15 15:02:06 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Leon Hwang X-Patchwork-Id: 13836605 X-Patchwork-Delegate: bpf@iogearbox.net Received: from out-178.mta1.migadu.com (out-178.mta1.migadu.com [95.215.58.178]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D2C0A1CB9F5 for ; Tue, 15 Oct 2024 15:02:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.178 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729004551; cv=none; b=P7FFwd82mFqS6mUxDy9x/XVpkUlXz3U8JxfozmbsG20OrgfizvxEBrpacajgjRM+/aKGDMWvLNnHFL3cNwayG9A+FUK1jEEMyJ0oqlQyYmBtqft48y4Bs1CSpls/podvSmcT8QyKcZmeWHj6NPcoWitP9r8E/kBPrjnh8VyuzZU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729004551; c=relaxed/simple; bh=AI5iDG8/oSZWTISouQVr5dOe2A6Ps5NKKxwuuG0ow5w=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=OBJ4I5NtcVXmxig2rvhs09gEUFEEII2iLkL47FmN3Ii99oSiGkJyXz3JH4l7YS0MVV5hPzlOmznS7kHHcOCzMd9fIm5pe2nqHHex/YHIDUcwXF7pXK9iiWClWZqBkfnN2l0bSaFPPJ4BdjTUnhqD+uSKawfE1jp8k9LUWjIn208= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=XvWfI/rX; arc=none smtp.client-ip=95.215.58.178 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="XvWfI/rX" X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1729004542; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=k4XJypsELEuBreM3jENIs3zOOqJw0Xomzh5IamblAs8=; b=XvWfI/rXpcH/aJk0Qr8nwbZeIdUk675ljGtURd6Dm+qXnR1EEZm6JnWG9jqY74tlvYjYhX CwH9S4VcueVRhWc9ORncAcD1AstYWuW0CpohZoou8YFY+cTfWiOhB9gJjp4GnX2/7IoHK8 UBmbVEnFu1jaabNG53kdhhMjU9sZsnc= From: Leon Hwang To: bpf@vger.kernel.org Cc: ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org, toke@redhat.com, martin.lau@kernel.org, yonghong.song@linux.dev, puranjay@kernel.org, xukuohai@huaweicloud.com, eddyz87@gmail.com, iii@linux.ibm.com, leon.hwang@linux.dev, kernel-patches-bot@fb.com Subject: [PATCH bpf-next v8 1/2] bpf: Prevent tailcall infinite loop caused by freplace Date: Tue, 15 Oct 2024 23:02:06 +0800 Message-ID: <20241015150207.70264-2-leon.hwang@linux.dev> In-Reply-To: <20241015150207.70264-1-leon.hwang@linux.dev> References: <20241015150207.70264-1-leon.hwang@linux.dev> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Migadu-Flow: FLOW_OUT X-Patchwork-Delegate: bpf@iogearbox.net There is a potential infinite loop issue that can occur when using a combination of tail calls and freplace. In an upcoming selftest, the attach target for entry_freplace of tailcall_freplace.c is subprog_tc of tc_bpf2bpf.c, while the tail call in entry_freplace leads to entry_tc. This results in an infinite loop: entry_tc -> subprog_tc -> entry_freplace --tailcall-> entry_tc. The problem arises because the tail_call_cnt in entry_freplace resets to zero each time entry_freplace is executed, causing the tail call mechanism to never terminate, eventually leading to a kernel panic. To fix this issue, the solution is twofold: 1. Prevent updating a program extended by an freplace program to a prog_array map. 2. Prevent extending a program that is already part of a prog_array map with an freplace program. This ensures that: * If a program or its subprogram has been extended by an freplace program, it can no longer be updated to a prog_array map. * If a program has been added to a prog_array map, neither it nor its subprograms can be extended by an freplace program. Moreover, an extension program should not be tailcalled. As such, return -EINVAL if the program has a type of BPF_PROG_TYPE_EXT when adding it to a prog_array map. Additionally, fix a minor code style issue by replacing eight spaces with a tab for proper formatting. Reviewed-by: Eduard Zingerman Signed-off-by: Leon Hwang --- include/linux/bpf.h | 17 +++++++++++---- kernel/bpf/arraymap.c | 26 +++++++++++++++++++++-- kernel/bpf/core.c | 1 + kernel/bpf/syscall.c | 7 +++--- kernel/bpf/trampoline.c | 47 ++++++++++++++++++++++++++++++++++------- 5 files changed, 81 insertions(+), 17 deletions(-) diff --git a/include/linux/bpf.h b/include/linux/bpf.h index 19d8ca8ac960f..0c216e71cec76 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -1292,8 +1292,12 @@ void *__bpf_dynptr_data_rw(const struct bpf_dynptr_kern *ptr, u32 len); bool __bpf_dynptr_is_rdonly(const struct bpf_dynptr_kern *ptr); #ifdef CONFIG_BPF_JIT -int bpf_trampoline_link_prog(struct bpf_tramp_link *link, struct bpf_trampoline *tr); -int bpf_trampoline_unlink_prog(struct bpf_tramp_link *link, struct bpf_trampoline *tr); +int bpf_trampoline_link_prog(struct bpf_tramp_link *link, + struct bpf_trampoline *tr, + struct bpf_prog *tgt_prog); +int bpf_trampoline_unlink_prog(struct bpf_tramp_link *link, + struct bpf_trampoline *tr, + struct bpf_prog *tgt_prog); struct bpf_trampoline *bpf_trampoline_get(u64 key, struct bpf_attach_target_info *tgt_info); void bpf_trampoline_put(struct bpf_trampoline *tr); @@ -1374,12 +1378,14 @@ void bpf_jit_uncharge_modmem(u32 size); bool bpf_prog_has_trampoline(const struct bpf_prog *prog); #else static inline int bpf_trampoline_link_prog(struct bpf_tramp_link *link, - struct bpf_trampoline *tr) + struct bpf_trampoline *tr, + struct bpf_prog *tgt_prog) { return -ENOTSUPP; } static inline int bpf_trampoline_unlink_prog(struct bpf_tramp_link *link, - struct bpf_trampoline *tr) + struct bpf_trampoline *tr, + struct bpf_prog *tgt_prog) { return -ENOTSUPP; } @@ -1483,6 +1489,9 @@ struct bpf_prog_aux { bool xdp_has_frags; bool exception_cb; bool exception_boundary; + bool is_extended; /* true if extended by freplace program */ + u64 prog_array_member_cnt; /* counts how many times as member of prog_array */ + struct mutex ext_mutex; /* mutex for is_extended and prog_array_member_cnt */ struct bpf_arena *arena; /* BTF_KIND_FUNC_PROTO for valid attach_btf_id */ const struct btf_type *attach_func_proto; diff --git a/kernel/bpf/arraymap.c b/kernel/bpf/arraymap.c index 79660e3fca4c1..6cdbb4c33d31d 100644 --- a/kernel/bpf/arraymap.c +++ b/kernel/bpf/arraymap.c @@ -947,22 +947,44 @@ static void *prog_fd_array_get_ptr(struct bpf_map *map, struct file *map_file, int fd) { struct bpf_prog *prog = bpf_prog_get(fd); + bool is_extended; if (IS_ERR(prog)) return prog; - if (!bpf_prog_map_compatible(map, prog)) { + if (prog->type == BPF_PROG_TYPE_EXT || + !bpf_prog_map_compatible(map, prog)) { bpf_prog_put(prog); return ERR_PTR(-EINVAL); } + mutex_lock(&prog->aux->ext_mutex); + is_extended = prog->aux->is_extended; + if (!is_extended) + prog->aux->prog_array_member_cnt++; + mutex_unlock(&prog->aux->ext_mutex); + if (is_extended) { + /* Extended prog can not be tail callee. It's to prevent a + * potential infinite loop like: + * tail callee prog entry -> tail callee prog subprog -> + * freplace prog entry --tailcall-> tail callee prog entry. + */ + bpf_prog_put(prog); + return ERR_PTR(-EBUSY); + } + return prog; } static void prog_fd_array_put_ptr(struct bpf_map *map, void *ptr, bool need_defer) { + struct bpf_prog *prog = ptr; + + mutex_lock(&prog->aux->ext_mutex); + prog->aux->prog_array_member_cnt--; + mutex_unlock(&prog->aux->ext_mutex); /* bpf_prog is freed after one RCU or tasks trace grace period */ - bpf_prog_put(ptr); + bpf_prog_put(prog); } static u32 prog_fd_array_sys_lookup_elem(void *ptr) diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index 5e77c58e06010..233ea78f8f1bd 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -131,6 +131,7 @@ struct bpf_prog *bpf_prog_alloc_no_stats(unsigned int size, gfp_t gfp_extra_flag INIT_LIST_HEAD_RCU(&fp->aux->ksym_prefix.lnode); #endif mutex_init(&fp->aux->used_maps_mutex); + mutex_init(&fp->aux->ext_mutex); mutex_init(&fp->aux->dst_mutex); return fp; diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index a8f1808a1ca54..4d04d4d9c1f30 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -3214,7 +3214,8 @@ static void bpf_tracing_link_release(struct bpf_link *link) container_of(link, struct bpf_tracing_link, link.link); WARN_ON_ONCE(bpf_trampoline_unlink_prog(&tr_link->link, - tr_link->trampoline)); + tr_link->trampoline, + tr_link->tgt_prog)); bpf_trampoline_put(tr_link->trampoline); @@ -3354,7 +3355,7 @@ static int bpf_tracing_prog_attach(struct bpf_prog *prog, * in prog->aux * * - if prog->aux->dst_trampoline is NULL, the program has already been - * attached to a target and its initial target was cleared (below) + * attached to a target and its initial target was cleared (below) * * - if tgt_prog != NULL, the caller specified tgt_prog_fd + * target_btf_id using the link_create API. @@ -3429,7 +3430,7 @@ static int bpf_tracing_prog_attach(struct bpf_prog *prog, if (err) goto out_unlock; - err = bpf_trampoline_link_prog(&link->link, tr); + err = bpf_trampoline_link_prog(&link->link, tr, tgt_prog); if (err) { bpf_link_cleanup(&link_primer); link = NULL; diff --git a/kernel/bpf/trampoline.c b/kernel/bpf/trampoline.c index f8302a5ca400d..9f36c049f4c28 100644 --- a/kernel/bpf/trampoline.c +++ b/kernel/bpf/trampoline.c @@ -523,7 +523,27 @@ static enum bpf_tramp_prog_type bpf_attach_type_to_tramp(struct bpf_prog *prog) } } -static int __bpf_trampoline_link_prog(struct bpf_tramp_link *link, struct bpf_trampoline *tr) +static int bpf_freplace_check_tgt_prog(struct bpf_prog *tgt_prog) +{ + struct bpf_prog_aux *aux = tgt_prog->aux; + + guard(mutex)(&aux->ext_mutex); + if (aux->prog_array_member_cnt) + /* Program extensions can not extend target prog when the target + * prog has been updated to any prog_array map as tail callee. + * It's to prevent a potential infinite loop like: + * tgt prog entry -> tgt prog subprog -> freplace prog entry + * --tailcall-> tgt prog entry. + */ + return -EBUSY; + + aux->is_extended = true; + return 0; +} + +static int __bpf_trampoline_link_prog(struct bpf_tramp_link *link, + struct bpf_trampoline *tr, + struct bpf_prog *tgt_prog) { enum bpf_tramp_prog_type kind; struct bpf_tramp_link *link_exiting; @@ -544,6 +564,9 @@ static int __bpf_trampoline_link_prog(struct bpf_tramp_link *link, struct bpf_tr /* Cannot attach extension if fentry/fexit are in use. */ if (cnt) return -EBUSY; + err = bpf_freplace_check_tgt_prog(tgt_prog); + if (err) + return err; tr->extension_prog = link->link.prog; return bpf_arch_text_poke(tr->func.addr, BPF_MOD_JUMP, NULL, link->link.prog->bpf_func); @@ -570,17 +593,21 @@ static int __bpf_trampoline_link_prog(struct bpf_tramp_link *link, struct bpf_tr return err; } -int bpf_trampoline_link_prog(struct bpf_tramp_link *link, struct bpf_trampoline *tr) +int bpf_trampoline_link_prog(struct bpf_tramp_link *link, + struct bpf_trampoline *tr, + struct bpf_prog *tgt_prog) { int err; mutex_lock(&tr->mutex); - err = __bpf_trampoline_link_prog(link, tr); + err = __bpf_trampoline_link_prog(link, tr, tgt_prog); mutex_unlock(&tr->mutex); return err; } -static int __bpf_trampoline_unlink_prog(struct bpf_tramp_link *link, struct bpf_trampoline *tr) +static int __bpf_trampoline_unlink_prog(struct bpf_tramp_link *link, + struct bpf_trampoline *tr, + struct bpf_prog *tgt_prog) { enum bpf_tramp_prog_type kind; int err; @@ -591,6 +618,8 @@ static int __bpf_trampoline_unlink_prog(struct bpf_tramp_link *link, struct bpf_ err = bpf_arch_text_poke(tr->func.addr, BPF_MOD_JUMP, tr->extension_prog->bpf_func, NULL); tr->extension_prog = NULL; + guard(mutex)(&tgt_prog->aux->ext_mutex); + tgt_prog->aux->is_extended = false; return err; } hlist_del_init(&link->tramp_hlist); @@ -599,12 +628,14 @@ static int __bpf_trampoline_unlink_prog(struct bpf_tramp_link *link, struct bpf_ } /* bpf_trampoline_unlink_prog() should never fail. */ -int bpf_trampoline_unlink_prog(struct bpf_tramp_link *link, struct bpf_trampoline *tr) +int bpf_trampoline_unlink_prog(struct bpf_tramp_link *link, + struct bpf_trampoline *tr, + struct bpf_prog *tgt_prog) { int err; mutex_lock(&tr->mutex); - err = __bpf_trampoline_unlink_prog(link, tr); + err = __bpf_trampoline_unlink_prog(link, tr, tgt_prog); mutex_unlock(&tr->mutex); return err; } @@ -619,7 +650,7 @@ static void bpf_shim_tramp_link_release(struct bpf_link *link) if (!shim_link->trampoline) return; - WARN_ON_ONCE(bpf_trampoline_unlink_prog(&shim_link->link, shim_link->trampoline)); + WARN_ON_ONCE(bpf_trampoline_unlink_prog(&shim_link->link, shim_link->trampoline, NULL)); bpf_trampoline_put(shim_link->trampoline); } @@ -733,7 +764,7 @@ int bpf_trampoline_link_cgroup_shim(struct bpf_prog *prog, goto err; } - err = __bpf_trampoline_link_prog(&shim_link->link, tr); + err = __bpf_trampoline_link_prog(&shim_link->link, tr, NULL); if (err) goto err; From patchwork Tue Oct 15 15:02:07 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Leon Hwang X-Patchwork-Id: 13836604 X-Patchwork-Delegate: bpf@iogearbox.net Received: from out-172.mta1.migadu.com (out-172.mta1.migadu.com [95.215.58.172]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3925E1B2193 for ; 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DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1729004546; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=xm7vD+ot9hV0jmvDOnv/maUvrHWU6TJadixg8YRieMo=; b=Md4dD1k/thU5fhoFoKMusInIUOSRXuCcFSi5BkAHFyCOyV+oAvt3PeeKtXh+ppvinr+dL3 FDx3Ln90vFso6pP9D+1VjeXB9wNA9BsQ0JQ9xMfKLofSJo6vaf55sZxp5ZmJZ64WBpdmg2 p69SsCgdmN6sjXDR4W459k9gKfzlKbY= From: Leon Hwang To: bpf@vger.kernel.org Cc: ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org, toke@redhat.com, martin.lau@kernel.org, yonghong.song@linux.dev, puranjay@kernel.org, xukuohai@huaweicloud.com, eddyz87@gmail.com, iii@linux.ibm.com, leon.hwang@linux.dev, kernel-patches-bot@fb.com Subject: [PATCH bpf-next v8 2/2] selftests/bpf: Add test to verify tailcall and freplace restrictions Date: Tue, 15 Oct 2024 23:02:07 +0800 Message-ID: <20241015150207.70264-3-leon.hwang@linux.dev> In-Reply-To: <20241015150207.70264-1-leon.hwang@linux.dev> References: <20241015150207.70264-1-leon.hwang@linux.dev> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Migadu-Flow: FLOW_OUT X-Patchwork-Delegate: bpf@iogearbox.net Add a test case to ensure that attaching a tail callee program with an freplace program fails, and that updating an extended program to a prog_array map is also prohibited. This test is designed to prevent the potential infinite loop issue caused by the combination of tail calls and freplace, ensuring the correct behavior and stability of the system. Additionally, fix the broken tailcalls/tailcall_freplace selftest because an extension prog should not be tailcalled. cd tools/testing/selftests/bpf; ./test_progs -t tailcalls 337/25 tailcalls/tailcall_freplace:OK 337/26 tailcalls/tailcall_bpf2bpf_freplace:OK 337 tailcalls:OK Summary: 1/26 PASSED, 0 SKIPPED, 0 FAILED Acked-by: Eduard Zingerman Signed-off-by: Leon Hwang --- .../selftests/bpf/prog_tests/tailcalls.c | 120 ++++++++++++++++-- .../testing/selftests/bpf/progs/tc_bpf2bpf.c | 5 +- 2 files changed, 109 insertions(+), 16 deletions(-) diff --git a/tools/testing/selftests/bpf/prog_tests/tailcalls.c b/tools/testing/selftests/bpf/prog_tests/tailcalls.c index 21c5a37846ade..40f22454cf05b 100644 --- a/tools/testing/selftests/bpf/prog_tests/tailcalls.c +++ b/tools/testing/selftests/bpf/prog_tests/tailcalls.c @@ -1496,8 +1496,8 @@ static void test_tailcall_bpf2bpf_hierarchy_3(void) RUN_TESTS(tailcall_bpf2bpf_hierarchy3); } -/* test_tailcall_freplace checks that the attached freplace prog is OK to - * update the prog_array map. +/* test_tailcall_freplace checks that the freplace prog fails to update the + * prog_array map, no matter whether the freplace prog attaches to its target. */ static void test_tailcall_freplace(void) { @@ -1505,7 +1505,7 @@ static void test_tailcall_freplace(void) struct bpf_link *freplace_link = NULL; struct bpf_program *freplace_prog; struct tc_bpf2bpf *tc_skel = NULL; - int prog_fd, map_fd; + int prog_fd, tc_prog_fd, map_fd; char buff[128] = {}; int err, key; @@ -1523,9 +1523,10 @@ static void test_tailcall_freplace(void) if (!ASSERT_OK_PTR(tc_skel, "tc_bpf2bpf__open_and_load")) goto out; - prog_fd = bpf_program__fd(tc_skel->progs.entry_tc); + tc_prog_fd = bpf_program__fd(tc_skel->progs.entry_tc); freplace_prog = freplace_skel->progs.entry_freplace; - err = bpf_program__set_attach_target(freplace_prog, prog_fd, "subprog"); + err = bpf_program__set_attach_target(freplace_prog, tc_prog_fd, + "subprog_tc"); if (!ASSERT_OK(err, "set_attach_target")) goto out; @@ -1533,27 +1534,116 @@ static void test_tailcall_freplace(void) if (!ASSERT_OK(err, "tailcall_freplace__load")) goto out; - freplace_link = bpf_program__attach_freplace(freplace_prog, prog_fd, - "subprog"); + map_fd = bpf_map__fd(freplace_skel->maps.jmp_table); + prog_fd = bpf_program__fd(freplace_prog); + key = 0; + err = bpf_map_update_elem(map_fd, &key, &prog_fd, BPF_ANY); + ASSERT_ERR(err, "update jmp_table failure"); + + freplace_link = bpf_program__attach_freplace(freplace_prog, tc_prog_fd, + "subprog_tc"); if (!ASSERT_OK_PTR(freplace_link, "attach_freplace")) goto out; - map_fd = bpf_map__fd(freplace_skel->maps.jmp_table); - prog_fd = bpf_program__fd(freplace_prog); + err = bpf_map_update_elem(map_fd, &key, &prog_fd, BPF_ANY); + ASSERT_ERR(err, "update jmp_table failure"); + +out: + bpf_link__destroy(freplace_link); + tailcall_freplace__destroy(freplace_skel); + tc_bpf2bpf__destroy(tc_skel); +} + +/* test_tailcall_bpf2bpf_freplace checks the failure that fails to attach a tail + * callee prog with freplace prog or fails to update an extended prog to + * prog_array map. + */ +static void test_tailcall_bpf2bpf_freplace(void) +{ + struct tailcall_freplace *freplace_skel = NULL; + struct bpf_link *freplace_link = NULL; + struct tc_bpf2bpf *tc_skel = NULL; + char buff[128] = {}; + int prog_fd, map_fd; + int err, key; + + LIBBPF_OPTS(bpf_test_run_opts, topts, + .data_in = buff, + .data_size_in = sizeof(buff), + .repeat = 1, + ); + + tc_skel = tc_bpf2bpf__open_and_load(); + if (!ASSERT_OK_PTR(tc_skel, "tc_bpf2bpf__open_and_load")) + goto out; + + prog_fd = bpf_program__fd(tc_skel->progs.entry_tc); + freplace_skel = tailcall_freplace__open(); + if (!ASSERT_OK_PTR(freplace_skel, "tailcall_freplace__open")) + goto out; + + err = bpf_program__set_attach_target(freplace_skel->progs.entry_freplace, + prog_fd, "subprog_tc"); + if (!ASSERT_OK(err, "set_attach_target")) + goto out; + + err = tailcall_freplace__load(freplace_skel); + if (!ASSERT_OK(err, "tailcall_freplace__load")) + goto out; + + /* OK to attach then detach freplace prog. */ + + freplace_link = bpf_program__attach_freplace(freplace_skel->progs.entry_freplace, + prog_fd, "subprog_tc"); + if (!ASSERT_OK_PTR(freplace_link, "attach_freplace")) + goto out; + + err = bpf_link__destroy(freplace_link); + if (!ASSERT_OK(err, "destroy link")) + goto out; + + /* OK to update prog_array map then delete element from the map. */ + key = 0; + map_fd = bpf_map__fd(freplace_skel->maps.jmp_table); err = bpf_map_update_elem(map_fd, &key, &prog_fd, BPF_ANY); if (!ASSERT_OK(err, "update jmp_table")) goto out; - prog_fd = bpf_program__fd(tc_skel->progs.entry_tc); - err = bpf_prog_test_run_opts(prog_fd, &topts); - ASSERT_OK(err, "test_run"); - ASSERT_EQ(topts.retval, 34, "test_run retval"); + err = bpf_map_delete_elem(map_fd, &key); + if (!ASSERT_OK(err, "delete_elem from jmp_table")) + goto out; + + /* Fail to attach a tail callee prog with freplace prog. */ + + err = bpf_map_update_elem(map_fd, &key, &prog_fd, BPF_ANY); + if (!ASSERT_OK(err, "update jmp_table")) + goto out; + + freplace_link = bpf_program__attach_freplace(freplace_skel->progs.entry_freplace, + prog_fd, "subprog_tc"); + if (!ASSERT_ERR_PTR(freplace_link, "attach_freplace failure")) + goto out; + + err = bpf_map_delete_elem(map_fd, &key); + if (!ASSERT_OK(err, "delete_elem from jmp_table")) + goto out; + + /* Fail to update an extended prog to prog_array map. */ + + freplace_link = bpf_program__attach_freplace(freplace_skel->progs.entry_freplace, + prog_fd, "subprog_tc"); + if (!ASSERT_OK_PTR(freplace_link, "attach_freplace")) + goto out; + + err = bpf_map_update_elem(map_fd, &key, &prog_fd, BPF_ANY); + if (!ASSERT_ERR(err, "update jmp_table failure")) + goto out; out: bpf_link__destroy(freplace_link); - tc_bpf2bpf__destroy(tc_skel); tailcall_freplace__destroy(freplace_skel); + tc_bpf2bpf__destroy(tc_skel); } void test_tailcalls(void) @@ -1606,4 +1696,6 @@ void test_tailcalls(void) test_tailcall_bpf2bpf_hierarchy_3(); if (test__start_subtest("tailcall_freplace")) test_tailcall_freplace(); + if (test__start_subtest("tailcall_bpf2bpf_freplace")) + test_tailcall_bpf2bpf_freplace(); } diff --git a/tools/testing/selftests/bpf/progs/tc_bpf2bpf.c b/tools/testing/selftests/bpf/progs/tc_bpf2bpf.c index 8a0632c37839a..d1a57f7d09bd8 100644 --- a/tools/testing/selftests/bpf/progs/tc_bpf2bpf.c +++ b/tools/testing/selftests/bpf/progs/tc_bpf2bpf.c @@ -5,10 +5,11 @@ #include "bpf_misc.h" __noinline -int subprog(struct __sk_buff *skb) +int subprog_tc(struct __sk_buff *skb) { int ret = 1; + __sink(skb); __sink(ret); return ret; } @@ -16,7 +17,7 @@ int subprog(struct __sk_buff *skb) SEC("tc") int entry_tc(struct __sk_buff *skb) { - return subprog(skb); + return subprog_tc(skb); } char __license[] SEC("license") = "GPL";