From: Jiri Slaby <jslaby@suse.cz>
To: Josh Poimboeuf <jpoimboe@redhat.com>,
Peter Zijlstra <peterz@infradead.org>
Cc: x86@kernel.org, linux-kernel@vger.kernel.org,
live-patching@vger.kernel.org,
Linus Torvalds <torvalds@linux-foundation.org>,
Andy Lutomirski <luto@kernel.org>, Ingo Molnar <mingo@kernel.org>,
"H. Peter Anvin" <hpa@zytor.com>
Subject: Re: [RFC PATCH 10/10] x86/unwind: add undwarf unwinder
Date: Thu, 1 Jun 2017 14:47:48 +0200 [thread overview]
Message-ID: <66294b55-46c1-e339-52df-da9639227e78@suse.cz> (raw)
In-Reply-To: <20170601122651.g6xtofvyy3mbo7lq@treble>
On 06/01/2017, 02:26 PM, Josh Poimboeuf wrote:
> On Thu, Jun 01, 2017 at 01:05:39PM +0200, Peter Zijlstra wrote:
>> On Thu, Jun 01, 2017 at 12:44:16AM -0500, Josh Poimboeuf wrote:
>>
>>> +static struct undwarf *__undwarf_lookup(struct undwarf *undwarf,
>>> + unsigned int num, unsigned long ip)
>>> +{
>>> + struct undwarf *first = undwarf;
>>> + struct undwarf *last = undwarf + num - 1;
>>> + struct undwarf *mid;
>>> + unsigned long u_ip;
>>> +
>>> + while (first <= last) {
>>> + mid = first + ((last - first) / 2);
>>> + u_ip = undwarf_ip(mid);
>>> +
>>> + if (ip >= u_ip) {
>>> + if (ip < u_ip + mid->len)
>>> + return mid;
>>> + first = mid + 1;
>>> + } else
>>> + last = mid - 1;
>>> + }
>>> +
>>> + return NULL;
>>> +}
>>
>> That's a bog standard binary search thing, don't we have a helper for
>> that someplace?
>
> I wasn't able to find one...
There is bsearch, but that doesn't support searching for a value in
between of 2 keys. I.e. what we typically have is these keys:
some_function1 at 0x1000
some_function2 at 0x2000
and we look for IP which can be e.g. 0x1010. The bsearch's cmp function
currently has no option to say, yes, the last one you asked me was the
right one, this one is after it already.
thanks,
--
js
suse labs
next prev parent reply other threads:[~2017-06-01 12:47 UTC|newest]
Thread overview: 55+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-06-01 5:44 [RFC PATCH 00/10] x86: undwarf unwinder Josh Poimboeuf
2017-06-01 5:44 ` [RFC PATCH 01/10] objtool: move checking code to check.c Josh Poimboeuf
2017-06-14 7:22 ` Jiri Slaby
2017-06-01 5:44 ` [RFC PATCH 02/10] objtool, x86: add several functions and files to the objtool whitelist Josh Poimboeuf
2017-06-14 7:24 ` Jiri Slaby
2017-06-14 13:03 ` Josh Poimboeuf
2017-06-01 5:44 ` [RFC PATCH 03/10] objtool: stack validation 2.0 Josh Poimboeuf
2017-06-01 5:44 ` [RFC PATCH 04/10] objtool: add undwarf debuginfo generation Josh Poimboeuf
2017-06-14 8:42 ` Jiri Slaby
2017-06-14 13:27 ` Josh Poimboeuf
2017-06-22 7:47 ` Jiri Slaby
2017-06-22 12:49 ` Josh Poimboeuf
2017-06-01 5:44 ` [RFC PATCH 05/10] objtool, x86: add facility for asm code to provide CFI hints Josh Poimboeuf
2017-06-01 13:57 ` Andy Lutomirski
2017-06-01 14:16 ` Josh Poimboeuf
2017-06-01 14:40 ` Andy Lutomirski
2017-06-01 15:02 ` Josh Poimboeuf
2017-06-01 5:44 ` [RFC PATCH 06/10] x86/entry: add CFI hint undwarf annotations Josh Poimboeuf
2017-06-01 14:03 ` Andy Lutomirski
2017-06-01 14:23 ` Josh Poimboeuf
2017-06-01 14:28 ` Josh Poimboeuf
2017-06-01 14:39 ` Andy Lutomirski
2017-06-01 15:01 ` Josh Poimboeuf
2017-06-01 5:44 ` [RFC PATCH 07/10] x86/asm: add CFI hint annotations to sync_core() Josh Poimboeuf
2017-06-01 5:44 ` [RFC PATCH 08/10] extable: rename 'sortextable' script to 'sorttable' Josh Poimboeuf
2017-06-01 5:44 ` [RFC PATCH 09/10] extable: add undwarf table sorting ability to sorttable script Josh Poimboeuf
2017-06-01 5:44 ` [RFC PATCH 10/10] x86/unwind: add undwarf unwinder Josh Poimboeuf
2017-06-01 11:05 ` Peter Zijlstra
2017-06-01 12:26 ` Josh Poimboeuf
2017-06-01 12:47 ` Jiri Slaby [this message]
2017-06-01 13:02 ` Josh Poimboeuf
2017-06-01 13:42 ` Peter Zijlstra
2017-06-01 13:10 ` Peter Zijlstra
2017-06-01 12:13 ` Peter Zijlstra
2017-06-01 12:36 ` Josh Poimboeuf
2017-06-01 13:12 ` Peter Zijlstra
2017-06-01 15:03 ` Josh Poimboeuf
2017-06-14 11:45 ` Jiri Slaby
2017-06-14 13:44 ` Josh Poimboeuf
2017-06-01 6:08 ` [RFC PATCH 00/10] x86: " Ingo Molnar
2017-06-01 11:58 ` Josh Poimboeuf
2017-06-01 12:17 ` Peter Zijlstra
2017-06-01 12:33 ` Jiri Slaby
2017-06-01 12:52 ` Josh Poimboeuf
2017-06-01 12:57 ` Jiri Slaby
2017-06-01 12:47 ` Josh Poimboeuf
2017-06-01 13:25 ` Peter Zijlstra
2017-06-06 14:14 ` Sergey Senozhatsky
2017-06-01 13:50 ` Andy Lutomirski
2017-06-01 13:50 ` Ingo Molnar
2017-06-01 13:58 ` Jiri Slaby
2017-06-02 8:30 ` Jiri Slaby
2017-06-01 14:05 ` Josh Poimboeuf
2017-06-01 14:08 ` Jiri Slaby
2017-06-02 10:40 ` Mel Gorman
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