Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Date:   Mon, 12 Oct 2020 12:03:18 +0200
From:   Sebastian Andrzej Siewior <bigeasy@linutronix.de>
To:     Russell King - ARM Linux admin <linux@armlinux.org.uk>
Cc:     Xiaoming Ni <nixiaoming@huawei.com>, dima@arista.com,
        will@kernel.org, jpoimboe@redhat.com, akpm@linux-foundation.org,
        christian.brauner@ubuntu.com, viro@zeniv.linux.org.uk,
        ldufour@linux.ibm.com, amanieu@gmail.com, walken@google.com,
        ben.dooks@codethink.co.uk, tglx@linutronix.de, mingo@kernel.org,
        vincent.whitchurch@axis.com, linux-arm-kernel@lists.infradead.org,
        linux-kernel@vger.kernel.org, wangle6@huawei.com,
        luohaizheng@huawei.com
Subject: Re: [PATCH] arm:traps: Don't print stack or raw PC/LR values in
 backtraces
Message-ID: <20201012100318.4ikyffo3mcnq6bnl@linutronix.de>
References: <20201009075957.110017-1-nixiaoming@huawei.com>
 <20201009080849.GM1551@shell.armlinux.org.uk>
 <20201009081820.jargnmck6zfkzegx@linutronix.de>
 <20201011213238.GN1551@shell.armlinux.org.uk>
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Disposition: inline
In-Reply-To: <20201011213238.GN1551@shell.armlinux.org.uk>
Precedence: bulk

On 2020-10-11 22:32:38 [+0100], Russell King - ARM Linux admin wrote:
> I don't have a problem getting rid of the hex numbers in [< >]
> although then I will need to convert the symbol back to an address
> using the vmlinux to then calculate its address to then find the
> appropriate place in the objdump output - because objdump does
> _not_ use the symbol+offset annotation.  Yes, I really do look up
> the numeric addresses in the objdump output to then read the
> disassembly.
> 
> $ objdump -d vmlinux | less
> 
> and then search for the address is the fastest and most convenient
> way for me rather than having to deal with some random script.
> 
> Maybe I'm just antequated about how I do my debugging, but this
> seems to me to be the most efficient and fastest way.

besides what Josh mentioned, there is also 
         scripts/decode_stacktrace.sh path-vmlinux
 
where you can copy/paste your complete stack trace / dmesg and it will
decode it line by line. So if you invoke
        scripts/decode_stacktrace.sh vmlinux.o

and paste this:

|[    7.568155] 001: PC is at do_work_pending+0x190/0x5c4
|[    7.568641] 001: LR is at slow_work_pending+0xc/0x20
|[    7.569232] 001: Backtrace:
|[    7.569367] 001: [<c020c2d0>] (do_work_pending) from [<c02000cc>] (slow_work_pending+0xc/0x20)

you get this in return:
|[    7.568155] 001: PC is at do_work_pending (arch/arm/kernel/signal.c:616 arch/arm/kernel/signal.c:670)
|[    7.568641] 001: LR is at slow_work_pending (arch/arm/kernel/entry-common.S:112)
|[    7.569232] 001: Backtrace:
|[    7.569367] 001: (do_work_pending) from slow_work_pending (arch/arm/kernel/entry-common.S:112)

Sebastian