Re: writing a (userland) core dump with incomplete info

[email protected] (Christos Zoulas) Sat, 28 Dec 2024 18:34:19 -0000 (UTC)
Newsgroups gmane.os.netbsd.devel.toolchain
Message-ID <[email protected]>
In article <[email protected]>,
Martin Husemann  <[email protected]> wrote:
>Hey folks,
>
>a mabye stupid question: PR 58936 describes a userland process smashing
>its memory and triggering a core dump, but due to the memory corruption
>we get invalid addresses for the environmen and then fail to find the
>proper auxv vector:
>
>proc_getauxv(pid 21737 cmd swipl) - 
>   ps_envstr 0x697220616e737765  nenvstr 1920154122  auxv 0x69722065020d47bd
>
>
>proc_getauxv() then fails with EFAULT and we fail writing the auxv note
>in the core dump, and then stop the whole core writing process early, leaving
>the user with a zero sized swipl.core file.
>
>Can we do better? Does it make sense try debugging stuff w/o the auxv vector?

Well, perhaps the core writer can be more careful about making sure that
the environment is well-formed.

christos