On Fri, 09 Dec 2022 22:14:33 +0100
Thomas Monjalon <tho...@monjalon.net> wrote:
> 09/12/2022 17:48, Stephen Hemminger:
> > On Fri, 09 Dec 2022 08:53:57 +0100
> > Thomas Monjalon <tho...@monjalon.net> wrote:
> >
> > > > > If some execution environment doesn't support thread names, it could
> > > > > return a string that makes it possible for a human to identify the
> > > > > thread, e.g. the tread id. Again, this is assuming that it is only
> > > > > used for debugging, trace, and similar.
> > > >
> > > > i think this raises a good question. is the purpose of setting a thread
> > > > name
> > > > meant to be something we can use from the application or is it
> > > > something that
> > > > is for debugging diagnostics and may be a best effort?
> > >
> > > I think yes it is only for debugging.
> > > So best effort looks to be a good approach.
> > > I'm not sure you need to replace the functions.
> > > Can you just complete the implementations?
> >
> >
> > Surprisingly, thread names are not preserved in core dumps.
> > The core dump standard used by Linux does not put thread name in the image.
> > Since this is a ELF ABI unlikely to be ever be added.
>
> What is missing exactly to have thread name in the core dump?
>
>
Linux core dump file format is ELF.
The thread info is storewd in the file notes as NT_PRPSINFO
which contains info but not the thread name. In the kernel
thread name is under comm.
typedef struct prpsinfo { /* Information about process */
unsigned char pr_state; /* Numeric process state */
char pr_sname; /* Char for pr_state */
unsigned char pr_zomb; /* Zombie */
signed char pr_nice; /* Nice val */
unsigned long pr_flag; /* Flags */
uint32_t pr_uid; /* User ID */
uint32_t pr_gid; /* Group ID */
pid_t pr_pid; /* Process ID */
pid_t pr_ppid; /* Parent's process ID */
pid_t pr_pgrp; /* Group ID */
pid_t pr_sid; /* Session ID */
char pr_fname[16]; /* Filename of executable */
char pr_psargs[80]; /* Initial part of arg list */
} prpsinfo;
Stack Overflow leads to this pages
https://www.gabriel.urdhr.fr/2015/05/29/core-file/
https://uhlo.blogspot.com/2012/05/brief-look-into-core-dumps.html
Only know this because of investigating how to get thread names
to show up in Azure with Watson.
