From: Linus Torvalds <firstname.lastname@example.org> To: Shuah Khan <email@example.com> Cc: Sasha Levin <firstname.lastname@example.org>, Konstantin Khlebnikov <email@example.com>, Joerg Roedel <firstname.lastname@example.org>, Andy Lutomirski <email@example.com>, "Peter Zijlstra (Intel)" <firstname.lastname@example.org>, Takashi Iwai <email@example.com>, Linux Kernel Mailing List <firstname.lastname@example.org>, "the arch/x86 maintainers" <email@example.com> Subject: Re: Linux 5.8-rc1 BUG unable to handle page fault (snd_pcm) Date: Mon, 15 Jun 2020 15:23:24 -0700 [thread overview] Message-ID: <CAHk-=wh_d7dqoC40M9AvU3g8v0AtexV-rMLDkvkiQQCU1TnHGw@mail.gmail.com> (raw) In-Reply-To: <firstname.lastname@example.org> On Mon, Jun 15, 2020 at 2:18 PM Shuah Khan <email@example.com> wrote: > > Yeah. I should have thought about adding module path. With module path > added, I get better results: > > [ 15.341267] ? snd_pcm_hw_params (./include/linux/string.h:391 > /home/shuah/lkml/linux_5.8/sound/core/pcm_native.c:759) snd_pcm > [ 15.341272] snd_pcm_common_ioctl (sound/core/pcm_native.c:792 > /home/shuah/lkml/linux_5.8/sound/core/pcm_native.c:3210) snd_pcm Yeah, now it gives the complete path and you see exactly which memset() it ends up being, ie it's that /* clear the buffer for avoiding possible kernel info leaks */ if (runtime->dma_area && !substream->ops->copy_user) memset(runtime->dma_area, 0, runtime->dma_bytes); Quite often with all the inlining the compiler does it can be really hard to figure out where things come from when you just see the symbol and offset. Ok, in this case there aren't that many calls to memset() in that file, and it might have been obvious which one it was in this case. But sometimes they just come from various inline helper functions too, and when automation can give us the answer easily, it's the thing to do. > > Maybe even just a warning about lacking a module path when there are > > module symbols present? > > > > It does tell you the usage. Yes, it's more that it's very easy to overlook it, and then get a partial decode. Once you know how to use that script, it's very convenient, but the problem tends to be that too few people are aware of it in the first place. Linus
next prev parent reply other threads:[~2020-06-15 22:23 UTC|newest] Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-06-15 18:48 Shuah Khan 2020-06-15 19:47 ` David Rientjes 2020-06-15 19:48 ` Linus Torvalds 2020-06-15 20:41 ` Shuah Khan 2020-06-15 20:55 ` Linus Torvalds 2020-06-15 21:18 ` Shuah Khan 2020-06-15 22:23 ` Linus Torvalds [this message] 2020-06-15 22:24 ` [PATCH] scripts/decode_stacktrace: warn when modpath is needed but is unset Sasha Levin 2020-06-15 22:37 ` Linus Torvalds 2020-06-15 22:43 ` Linus Torvalds 2020-06-15 23:24 ` Sasha Levin 2020-06-15 19:57 ` Linux 5.8-rc1 BUG unable to handle page fault (snd_pcm) Takashi Iwai 2020-06-15 20:53 ` Shuah Khan 2020-06-15 21:04 ` Shuah Khan
Reply instructions: You may reply publicly 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='CAHk-=wh_d7dqoC40M9AvU3g8v0AtexV-rMLDkvkiQQCU1TnHGw@mail.gmail.com' \ --firstname.lastname@example.org \ --email@example.com \ --firstname.lastname@example.org \ --email@example.com \ --firstname.lastname@example.org \ --email@example.com \ --firstname.lastname@example.org \ --email@example.com \ --firstname.lastname@example.org \ --email@example.com \ --subject='Re: Linux 5.8-rc1 BUG unable to handle page fault (snd_pcm)' \ /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
This is a public inbox, see mirroring instructions for how to clone and mirror all data and code used for this inbox; as well as URLs for NNTP newsgroup(s).