Linux-kselftest Archive on lore.kernel.org
 help / color / Atom feed
From: Jeffrin Jose <jeffrin@rajagiritech.edu.in>
To: davem@davemloft.net, willemb@google.com,
	xiyou.wangcong@gmail.com, fw@strlen.de,
	jakub.kicinski@netronome.com, john.hurley@netronome.com,
	pabeni@redhat.com, brouer@redhat.com, bigeasy@linutronix.de,
	jonathan.lemon@gmail.com, edumazet@google.com
Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-kselftest@vger.kernel.org
Subject: objtool: skb_push.cold()+0x15: unreachable instruction
Date: Sun, 10 Nov 2019 04:35:20 +0530
Message-ID: <20191109230520.GA22258@debian> (raw)

hello,

i got a warning during kernel compilation.

net/core/skbuff.o: warning: objtool: skb_push.cold()+0x15: unreachable instruction

related clips...

--------------------x----------------x---------------------

(gdb) l skb_push.cold
1880	void *skb_push(struct sk_buff *skb, unsigned int len)
1881	{
1882		skb->data -= len;
1883		skb->len  += len;
1884		if (unlikely(skb->data < skb->head))
1885			skb_under_panic(skb, len, __builtin_return_address(0));
1886		return skb->data;
1887	}
1888	EXPORT_SYMBOL(skb_push);
1889	
(gdb) l *0xffffffff815ffc8e
0xffffffff815ffc8e is in skb_push (net/core/skbuff.c:1885).
1880	void *skb_push(struct sk_buff *skb, unsigned int len)
1881	{
1882		skb->data -= len;
1883		skb->len  += len;
1884		if (unlikely(skb->data < skb->head))
1885			skb_under_panic(skb, len, __builtin_return_address(0));
1886		return skb->data;
1887	}
1888	EXPORT_SYMBOL(skb_push);
1889	
(gdb)

------------------x-----------------------x------------------------------------

$uname -a
Linux debian 5.4.0-rc1+ #1 SMP Sat Nov 9 21:29:48 IST 2019 x86_64 GNU/Linux
$

this kernel is from linux-kselftest tree

---------------------------x-------------x------------------------------

$gcc --version
gcc (Debian 9.2.1-14) 9.2.1 20191025
Copyright (C) 2019 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

-------------------------x-------------------x-----------------------------

Linux debian 5.4.0-rc1+ #1 SMP Sat Nov 9 21:29:48 IST 2019 x86_64 GNU/Linux

GNU Make            	4.2.1
Binutils            	2.33.1
Util-linux          	2.33.1
Mount               	2.33.1
Linux C Library     	2.29
Dynamic linker (ldd)	2.29
Procps              	3.3.15
Kbd                 	2.0.4
Console-tools       	2.0.4
Sh-utils            	8.30
Udev                	241

-------------------------------x-----------------x----------------------------




--
software engineer
rajagiri school of engineering and technology

                 reply index

Thread overview: [no followups] expand[flat|nested]  mbox.gz  Atom feed

Reply instructions:

You may reply publically 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=20191109230520.GA22258@debian \
    --to=jeffrin@rajagiritech.edu.in \
    --cc=bigeasy@linutronix.de \
    --cc=brouer@redhat.com \
    --cc=davem@davemloft.net \
    --cc=edumazet@google.com \
    --cc=fw@strlen.de \
    --cc=jakub.kicinski@netronome.com \
    --cc=john.hurley@netronome.com \
    --cc=jonathan.lemon@gmail.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-kselftest@vger.kernel.org \
    --cc=netdev@vger.kernel.org \
    --cc=pabeni@redhat.com \
    --cc=willemb@google.com \
    --cc=xiyou.wangcong@gmail.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

Linux-kselftest Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-kselftest/0 linux-kselftest/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-kselftest linux-kselftest/ https://lore.kernel.org/linux-kselftest \
		linux-kselftest@vger.kernel.org
	public-inbox-index linux-kselftest

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-kselftest


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git