From: Peter Zijlstra <peterz@infradead.org>
To: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Jiri Olsa <olsajiri@gmail.com>, Song Liu <song@kernel.org>,
Song Liu <songliubraving@meta.com>,
Paul Walmsley <paul.walmsley@sifive.com>,
Palmer Dabbelt <palmer@dabbelt.com>,
Albert Ou <aou@eecs.berkeley.edu>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
Dave Hansen <dave.hansen@linux.intel.com>,
X86 ML <x86@kernel.org>, "H. Peter Anvin" <hpa@zytor.com>,
"David S. Miller" <davem@davemloft.net>,
David Ahern <dsahern@kernel.org>,
Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Andrii Nakryiko <andrii@kernel.org>,
Martin KaFai Lau <martin.lau@linux.dev>,
Yonghong Song <yonghong.song@linux.dev>,
John Fastabend <john.fastabend@gmail.com>,
KP Singh <kpsingh@kernel.org>,
Stanislav Fomichev <sdf@google.com>, Hao Luo <haoluo@google.com>,
Arnd Bergmann <arnd@arndb.de>,
Sami Tolvanen <samitolvanen@google.com>,
Kees Cook <keescook@chromium.org>,
Nathan Chancellor <nathan@kernel.org>,
Nick Desaulniers <ndesaulniers@google.com>,
linux-riscv <linux-riscv@lists.infradead.org>,
LKML <linux-kernel@vger.kernel.org>,
Network Development <netdev@vger.kernel.org>,
bpf <bpf@vger.kernel.org>,
linux-arch <linux-arch@vger.kernel.org>,
clang-built-linux <llvm@lists.linux.dev>,
Josh Poimboeuf <jpoimboe@kernel.org>,
Joao Moreira <joao@overdrivepizza.com>,
Mark Rutland <mark.rutland@arm.com>
Subject: Re: [PATCH v2 2/2] x86/cfi,bpf: Fix BPF JIT call
Date: Fri, 8 Dec 2023 18:21:52 +0100 [thread overview]
Message-ID: <20231208172152.GD36716@noisy.programming.kicks-ass.net> (raw)
In-Reply-To: <20231208134041.GD28727@noisy.programming.kicks-ass.net>
On Fri, Dec 08, 2023 at 02:40:41PM +0100, Peter Zijlstra wrote:
> On Fri, Dec 08, 2023 at 11:29:40AM +0100, Peter Zijlstra wrote:
> > The only problem I now have is the one XXX, I'm not entirely sure what
> > signature to use there.
>
> > @@ -119,6 +119,7 @@ int bpf_struct_ops_test_run(struct bpf_p
> > op_idx = prog->expected_attach_type;
> > err = bpf_struct_ops_prepare_trampoline(tlinks, link,
> > &st_ops->func_models[op_idx],
> > + /* XXX */ NULL,
> > image, image + PAGE_SIZE);
> > if (err < 0)
> > goto out;
>
> Duh, that should ofcourse be something of dummy_ops_test_ret_fn type.
> Let me go fix that.
Next one.. bpf_obj_free_fields: field->kptr.dtor(xchg_field);
The one that trips is bpf_cgroup_release().
objtool doesn't think the address of that function 'escapes' and
'helpfully' seals that function, and then BPF thinks it does escape and
manages the above indirect call and *boom*.
How can I tell which functions escape according to BPF such that I might
teach objtool this?
next prev parent reply other threads:[~2023-12-08 17:22 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-11-30 13:36 [PATCH v2 0/2] x86/bpf: Fix FineIBT vs eBPF Peter Zijlstra
2023-11-30 13:36 ` [PATCH v2 1/2] cfi: Flip headers Peter Zijlstra
2023-12-04 19:18 ` Sami Tolvanen
2023-11-30 13:36 ` [PATCH v2 2/2] x86/cfi,bpf: Fix BPF JIT call Peter Zijlstra
2023-12-03 22:56 ` Alexei Starovoitov
2023-12-04 9:13 ` Peter Zijlstra
2023-12-04 11:11 ` Peter Zijlstra
2023-12-04 12:52 ` Peter Zijlstra
2023-12-04 17:25 ` Jiri Olsa
2023-12-04 18:16 ` Peter Zijlstra
2023-12-04 18:33 ` Peter Zijlstra
2023-12-04 18:58 ` Sami Tolvanen
2023-12-05 1:18 ` Alexei Starovoitov
2023-12-06 15:35 ` Peter Zijlstra
2023-12-06 16:38 ` Peter Zijlstra
2023-12-06 18:37 ` Peter Zijlstra
2023-12-06 21:39 ` Alexei Starovoitov
2023-12-07 9:31 ` Peter Zijlstra
2023-12-07 22:32 ` Alexei Starovoitov
2023-12-08 10:29 ` Peter Zijlstra
2023-12-08 13:40 ` Peter Zijlstra
2023-12-08 17:21 ` Peter Zijlstra [this message]
2023-12-08 19:40 ` Alexei Starovoitov
2023-12-08 20:27 ` Peter Zijlstra
2023-12-08 20:35 ` Peter Zijlstra
2023-12-08 20:41 ` Alexei Starovoitov
2023-12-08 20:52 ` Peter Zijlstra
2023-12-08 20:58 ` Alexei Starovoitov
2023-12-08 22:45 ` Peter Zijlstra
2023-12-09 4:51 ` Alexei Starovoitov
2023-12-08 19:32 ` Alexei Starovoitov
2023-12-08 20:18 ` Peter Zijlstra
2023-12-08 20:45 ` Alexei Starovoitov
2023-12-08 20:56 ` Peter Zijlstra
2023-12-08 21:04 ` Alexei Starovoitov
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