From: Denys Vlasenko <dvlasenk@redhat.com>
To: Jan Beulich <JBeulich@suse.com>,
Frederic Weisbecker <fweisbec@gmail.com>,
Denys Vlasenko <vda.linux@googlemail.com>
Cc: Andy Lutomirski <luto@amacapital.net>,
Kees Cook <keescook@chromium.org>, Will Drewry <wad@chromium.org>,
X86 ML <x86@kernel.org>, Alexei Starovoitov <ast@plumgrid.com>,
Oleg Nesterov <oleg@redhat.com>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
"H. Peter Anvin" <hpa@zytor.com>
Subject: Re: [PATCH 4/5] x86: entry_64.S: always allocate complete "struct pt_regs"
Date: Mon, 11 Aug 2014 15:26:14 +0200 [thread overview]
Message-ID: <53E8C476.8000800@redhat.com> (raw)
In-Reply-To: <53E89DA3020000780002B00B@mail.emea.novell.com>
On 08/11/2014 10:40 AM, Jan Beulich wrote:
>>>>> CFI_ESCAPE 0x0f /* DW_CFA_def_cfa_expression */, 6, \
>>>>> 0x77 /* DW_OP_breg7 */, 0, \
>>>>> 0x06 /* DW_OP_deref */, \
>>>>> - 0x08 /* DW_OP_const1u */, SS+8-RBP, \
>>>>> + 0x08 /* DW_OP_const1u */, SS+8, \
>>>>> 0x22 /* DW_OP_plus */
>>>>> /* We entered an interrupt context - irqs are off: */
>>>>> TRACE_IRQS_OFF
...
...
>>> While we are at it, what this CFI_ESCAPE thing does here?
>>> As usual, it has no comment :/
>
> Each of its lines has a comment; with other CFI annotations not
> each having comments, I don't see what else is needed here.
The existing comments explain what every byte means.
They are useful if CFI-literate reader wants to check correctness
of the encoding of this annotation.
There is no overall comment what this CFI annotation
*achieves*. In human language, what do we say
to DWARF decoder here?
next prev parent reply other threads:[~2014-08-11 13:26 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-08-01 14:48 [PATCH 1/5] x86: entry_64.S: delete unused code Denys Vlasenko
2014-08-01 14:48 ` [PATCH 2/5] x86: open-code register save/restore in trace_hardirqs thunks Denys Vlasenko
2014-08-01 14:48 ` [PATCH 3/5] x86: entry_64.S: fold SAVE_ARGS_IRQ macro into its sole user Denys Vlasenko
2014-08-01 18:30 ` Frederic Weisbecker
2014-08-01 14:48 ` [PATCH 4/5] x86: entry_64.S: always allocate complete "struct pt_regs" Denys Vlasenko
2014-08-01 17:04 ` Andy Lutomirski
2014-08-04 14:28 ` Denys Vlasenko
2014-08-04 14:47 ` Oleg Nesterov
2014-08-04 15:34 ` Oleg Nesterov
2014-08-04 21:03 ` Andy Lutomirski
2014-08-04 21:23 ` Borislav Petkov
2014-08-05 10:35 ` Denys Vlasenko
2014-08-05 14:53 ` Andy Lutomirski
2014-08-05 15:17 ` Denys Vlasenko
2014-08-05 23:02 ` Andy Lutomirski
2014-08-07 9:54 ` Denys Vlasenko
2014-08-01 18:09 ` Alexei Starovoitov
2014-08-01 18:30 ` Oleg Nesterov
2014-08-01 18:35 ` H. Peter Anvin
2014-08-01 22:11 ` Denys Vlasenko
2014-08-01 22:13 ` H. Peter Anvin
2014-08-02 21:14 ` Andy Lutomirski
2014-08-02 21:23 ` H. Peter Anvin
2014-08-02 21:38 ` Andy Lutomirski
2014-08-01 22:52 ` Frederic Weisbecker
2014-08-01 23:19 ` Frederic Weisbecker
2014-08-04 3:03 ` Denys Vlasenko
2014-08-04 7:57 ` Borislav Petkov
2014-08-11 0:46 ` Frederic Weisbecker
2014-08-11 8:40 ` Jan Beulich
2014-08-11 9:07 ` Andy Lutomirski
2014-08-11 9:31 ` Jan Beulich
2014-08-11 13:26 ` Denys Vlasenko [this message]
2014-08-11 14:17 ` Jan Beulich
2014-08-11 14:53 ` H. Peter Anvin
2014-08-11 15:08 ` Jan Beulich
2014-08-11 15:13 ` H. Peter Anvin
2014-08-12 9:31 ` Denys Vlasenko
2014-08-12 9:50 ` Jan Beulich
2014-08-01 14:48 ` [PATCH 5/5] x86: mass removal of ARGOFFSET Denys Vlasenko
2014-08-01 18:00 ` [PATCH 1/5] x86: entry_64.S: delete unused code Frederic Weisbecker
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