From: Peter Zijlstra <peterz@infradead.org>
To: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>,
x86@kernel.org, linux-kernel@vger.kernel.org,
Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
netdev@vger.kernel.org, bpf@vger.kernel.org,
Song Liu <songliubraving@fb.com>, Kairui Song <kasong@redhat.com>
Subject: Re: [PATCH 2/9] objtool: Fix ORC unwinding in non-JIT BPF generated code
Date: Fri, 14 Jun 2019 10:11:16 +0200 [thread overview]
Message-ID: <20190614081116.GU3436@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <20190614073536.d3xkhwhq3fuivwt5@ast-mbp.dhcp.thefacebook.com>
On Fri, Jun 14, 2019 at 12:35:38AM -0700, Alexei Starovoitov wrote:
> On Fri, Jun 14, 2019 at 09:08:52AM +0200, Peter Zijlstra wrote:
> > On Thu, Jun 13, 2019 at 08:20:30PM -0500, Josh Poimboeuf wrote:
> > > On Thu, Jun 13, 2019 at 01:57:11PM -0700, Alexei Starovoitov wrote:
> >
> > > > and to patches 8 and 9.
> > >
> > > Well, it's your code, but ... can I ask why? AT&T syntax is the
> > > standard for Linux, which is in fact the OS we are developing for.
> >
> > I agree, all assembly in Linux is AT&T, adding Intel notation only
> > serves to cause confusion.
>
> It's not assembly. It's C code that generates binary and here
> we're talking about comments.
And comments are useless if they don't clarify. Intel syntax confuses.
> I'm sure you're not proposing to do:
> /* mov src, dst */
> #define EMIT_mov(DST, SRC) \
> right?
Which is why Josh reversed both of them. The current Intel order is just
terribly confusing. And I don't see any of the other JITs having
confusing comments like this.
> bpf_jit_comp.c stays as-is. Enough of it.
I think you're forgetting this is also arch/x86 code, and no, it needs
changes because its broken wrt unwinding.
next prev parent reply other threads:[~2019-06-14 8:11 UTC|newest]
Thread overview: 49+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-13 13:20 [PATCH 0/9] x86/bpf: unwinder fixes Josh Poimboeuf
2019-06-13 13:20 ` [PATCH 1/9] perf/x86: Always store regs->ip in perf_callchain_kernel() Josh Poimboeuf
2019-06-13 13:20 ` [PATCH 2/9] objtool: Fix ORC unwinding in non-JIT BPF generated code Josh Poimboeuf
2019-06-13 20:57 ` Alexei Starovoitov
2019-06-14 1:20 ` Josh Poimboeuf
2019-06-14 1:37 ` Alexei Starovoitov
2019-06-14 1:51 ` Josh Poimboeuf
2019-06-14 7:08 ` Peter Zijlstra
2019-06-14 7:35 ` Alexei Starovoitov
2019-06-14 8:11 ` Peter Zijlstra [this message]
2019-06-14 15:13 ` Alexei Starovoitov
2019-06-14 16:11 ` Josh Poimboeuf
2019-06-13 13:21 ` [PATCH 3/9] x86/bpf: Move epilogue generation to a dedicated function Josh Poimboeuf
2019-06-13 18:57 ` Song Liu
2019-06-13 19:12 ` Josh Poimboeuf
2019-06-13 13:21 ` [PATCH 4/9] x86/bpf: Simplify prologue generation Josh Poimboeuf
2019-06-13 13:21 ` [PATCH 5/9] x86/bpf: Support SIB byte generation Josh Poimboeuf
2019-06-13 13:21 ` [PATCH 6/9] x86/bpf: Fix JIT frame pointer usage Josh Poimboeuf
2019-06-13 21:58 ` Alexei Starovoitov
2019-06-14 1:22 ` Josh Poimboeuf
2019-06-14 1:39 ` Alexei Starovoitov
2019-06-14 1:52 ` Josh Poimboeuf
2019-06-14 10:50 ` David Laight
2019-06-14 13:44 ` Josh Poimboeuf
2019-06-14 13:58 ` David Laight
2019-06-14 17:07 ` Josh Poimboeuf
2019-06-17 15:07 ` David Laight
2019-06-13 13:21 ` [PATCH 7/9] x86/unwind/orc: Fall back to using frame pointers for generated code Josh Poimboeuf
2019-06-13 22:00 ` Alexei Starovoitov
2019-06-14 1:30 ` Josh Poimboeuf
2019-06-14 1:42 ` Alexei Starovoitov
2019-06-14 1:58 ` Josh Poimboeuf
2019-06-14 2:28 ` Josh Poimboeuf
2019-06-14 4:50 ` Josh Poimboeuf
2019-06-14 6:00 ` Alexei Starovoitov
2019-06-14 7:41 ` Peter Zijlstra
2019-06-14 13:31 ` Josh Poimboeuf
2019-06-14 15:29 ` Alexei Starovoitov
2019-06-14 13:34 ` Josh Poimboeuf
2019-06-14 15:31 ` Alexei Starovoitov
2019-06-14 15:56 ` Josh Poimboeuf
2019-06-13 13:21 ` [PATCH 8/9] x86/bpf: Convert asm comments to AT&T syntax Josh Poimboeuf
2019-06-13 18:52 ` Song Liu
2019-06-13 19:11 ` Josh Poimboeuf
2019-06-14 7:42 ` Peter Zijlstra
2019-06-14 15:13 ` Song Liu
2019-06-13 13:21 ` [PATCH 9/9] x86/bpf: Convert MOV function/macro argument ordering " Josh Poimboeuf
2019-06-13 19:00 ` [PATCH 0/9] x86/bpf: unwinder fixes Song Liu
2019-06-13 20:41 ` Peter Zijlstra
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