From: Chen Hu <hu1.chen@intel.com>
To: unlisted-recipients:; (no To-header on input)
Cc: hu1.chen@intel.com, jpoimboe@kernel.org, memxor@gmail.com,
bpf@vger.kernel.org, Pengfei Xu <pengfei.xu@intel.com>,
Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Andrii Nakryiko <andrii@kernel.org>,
Martin KaFai Lau <martin.lau@linux.dev>,
Song Liu <song@kernel.org>, Yonghong Song <yhs@fb.com>,
John Fastabend <john.fastabend@gmail.com>,
KP Singh <kpsingh@kernel.org>,
Stanislav Fomichev <sdf@google.com>, Hao Luo <haoluo@google.com>,
Jiri Olsa <jolsa@kernel.org>,
"David S. Miller" <davem@davemloft.net>,
Eric Dumazet <edumazet@google.com>,
Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
linux-kernel@vger.kernel.org, netdev@vger.kernel.org
Subject: [PATCH bpf v2] selftests/bpf: Fix "missing ENDBR" BUG for destructor kfunc
Date: Mon, 21 Nov 2022 23:32:43 -0800 [thread overview]
Message-ID: <20221122073244.21279-1-hu1.chen@intel.com> (raw)
With CONFIG_X86_KERNEL_IBT enabled, the test_verifier triggers the
following BUG:
traps: Missing ENDBR: bpf_kfunc_call_test_release+0x0/0x30
------------[ cut here ]------------
kernel BUG at arch/x86/kernel/traps.c:254!
invalid opcode: 0000 [#1] PREEMPT SMP
<TASK>
asm_exc_control_protection+0x26/0x50
RIP: 0010:bpf_kfunc_call_test_release+0x0/0x30
Code: 00 48 c7 c7 18 f2 e1 b4 e8 0d ca 8c ff 48 c7 c0 00 f2 e1 b4 c3
0f 1f 44 00 00 66 0f 1f 00 0f 1f 44 00 00 0f 0b 31 c0 c3 66 90
<66> 0f 1f 00 0f 1f 44 00 00 48 85 ff 74 13 4c 8d 47 18 b8 ff ff ff
bpf_map_free_kptrs+0x2e/0x70
array_map_free+0x57/0x140
process_one_work+0x194/0x3a0
worker_thread+0x54/0x3a0
? rescuer_thread+0x390/0x390
kthread+0xe9/0x110
? kthread_complete_and_exit+0x20/0x20
This is because there are no compile-time references to the destructor
kfuncs, bpf_kfunc_call_test_release() for example. So objtool marked
them sealable and ENDBR in the functions were sealed (converted to NOP)
by apply_ibt_endbr().
This fix creates dummy compile-time references to destructor kfuncs so
ENDBR stay there.
Fixes: 05a945deefaa ("selftests/bpf: Add verifier tests for kptr")
Signed-off-by: Chen Hu <hu1.chen@intel.com>
Tested-by: Pengfei Xu <pengfei.xu@intel.com>
---
v2:
- Use generic macro name and place the macro after function body as
- suggested by Jiri Olsa
v1: https://lore.kernel.org/all/20221121085113.611504-1-hu1.chen@intel.com/
include/linux/btf_ids.h | 7 +++++++
net/bpf/test_run.c | 4 ++++
2 files changed, 11 insertions(+)
diff --git a/include/linux/btf_ids.h b/include/linux/btf_ids.h
index 2aea877d644f..db02691b506d 100644
--- a/include/linux/btf_ids.h
+++ b/include/linux/btf_ids.h
@@ -266,4 +266,11 @@ MAX_BTF_TRACING_TYPE,
extern u32 btf_tracing_ids[];
+#if defined(CONFIG_X86_KERNEL_IBT) && !defined(__DISABLE_EXPORTS)
+#define FUNC_IBT_NOSEAL(name) \
+ asm(IBT_NOSEAL(#name));
+#else
+#define FUNC_IBT_NOSEAL(name)
+#endif /* CONFIG_X86_KERNEL_IBT */
+
#endif
diff --git a/net/bpf/test_run.c b/net/bpf/test_run.c
index 13d578ce2a09..07263b7cc12d 100644
--- a/net/bpf/test_run.c
+++ b/net/bpf/test_run.c
@@ -597,10 +597,14 @@ noinline void bpf_kfunc_call_test_release(struct prog_test_ref_kfunc *p)
refcount_dec(&p->cnt);
}
+FUNC_IBT_NOSEAL(bpf_kfunc_call_test_release)
+
noinline void bpf_kfunc_call_memb_release(struct prog_test_member *p)
{
}
+FUNC_IBT_NOSEAL(bpf_kfunc_call_memb_release)
+
noinline void bpf_kfunc_call_memb1_release(struct prog_test_member1 *p)
{
WARN_ON_ONCE(1);
--
2.34.1
next reply other threads:[~2022-11-22 7:34 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-11-22 7:32 Chen Hu [this message]
2022-11-22 13:48 ` [PATCH bpf v2] selftests/bpf: Fix "missing ENDBR" BUG for destructor kfunc Jiri Olsa
2022-11-22 14:14 ` Peter Zijlstra
2022-11-25 13:44 ` Chen, Hu1
2022-11-27 22:04 ` Jiri Olsa
2022-11-27 22:13 ` Alexei Starovoitov
2022-11-25 13:28 ` Chen, Hu1
2022-11-27 21:58 ` Jiri Olsa
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20221122073244.21279-1-hu1.chen@intel.com \
--to=hu1.chen@intel.com \
--cc=andrii@kernel.org \
--cc=ast@kernel.org \
--cc=bpf@vger.kernel.org \
--cc=daniel@iogearbox.net \
--cc=davem@davemloft.net \
--cc=edumazet@google.com \
--cc=haoluo@google.com \
--cc=john.fastabend@gmail.com \
--cc=jolsa@kernel.org \
--cc=jpoimboe@kernel.org \
--cc=kpsingh@kernel.org \
--cc=kuba@kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=martin.lau@linux.dev \
--cc=memxor@gmail.com \
--cc=netdev@vger.kernel.org \
--cc=pabeni@redhat.com \
--cc=pengfei.xu@intel.com \
--cc=sdf@google.com \
--cc=song@kernel.org \
--cc=yhs@fb.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.