Where is getname () defined

Where is getname () defined

[Vulturus]

Dear kernelnewbies subscribers,

I was reading the kernel source tree in an
attempt to understand how the chroot syscall workes.
(I was using the linux-6.17-rc3 tarball from kernel.org.)

At line 1429 of the fs/open.c file, inside the
definition of the do_sys_openat2() function getname() is called.

I am having trouble finding its definition.

In particular,
$ grep -rn 'getname' fs
doesn't return a line like 'struct file *getname (args)'
or similar, as I would expect.

Can someone point me to the file/line where getname() is defined?

Thank you,
Vulturus

_______________________________________________
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: Where is getname () defined

[Dan Bokser]

[-- Attachment #1.1: Type: text/plain, Size: 1136 bytes --]

On Fri, Aug 29, 2025 at 2:43 PM Vulturus <vulturus@vulturus.xyz> wrote:

> Dear kernelnewbies subscribers,
>
> I was reading the kernel source tree in an
> attempt to understand how the chroot syscall workes.
> (I was using the linux-6.17-rc3 tarball from kernel.org.)
>
> At line 1429 of the fs/open.c file, inside the
> definition of the do_sys_openat2() function getname() is called.
>
> I am having trouble finding its definition.
>
> In particular,
> $ grep -rn 'getname' fs
> doesn't return a line like 'struct file *getname (args)'
> or similar, as I would expect.
>
> Can someone point me to the file/line where getname() is defined?
>
> Thank you,
> Vulturus
>
> _______________________________________________
> Kernelnewbies mailing list
> Kernelnewbies@kernelnewbies.org
> https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies


Looks like it's an inline function defined in a header in
/include/linux/fs.h:
https://elixir.bootlin.com/linux/v6.17-rc3/source/include/linux/fs.h#L2916

Bootlin is a fantastic tool to find where things are defined in the kernel.

-Daniel

>
>

[-- Attachment #1.2: Type: text/html, Size: 2393 bytes --]

[-- Attachment #2: Type: text/plain, Size: 170 bytes --]

_______________________________________________
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: Where is getname () defined

[Alison Schofield]

On Fri, Aug 29, 2025 at 03:19:59PM -0400, Dan Bokser wrote:
> On Fri, Aug 29, 2025 at 2:43 PM Vulturus <vulturus@vulturus.xyz> wrote:
> 
> > Dear kernelnewbies subscribers,
> >
> > I was reading the kernel source tree in an
> > attempt to understand how the chroot syscall workes.
> > (I was using the linux-6.17-rc3 tarball from kernel.org.)
> >
> > At line 1429 of the fs/open.c file, inside the
> > definition of the do_sys_openat2() function getname() is called.
> >
> > I am having trouble finding its definition.
> >
> > In particular,
> > $ grep -rn 'getname' fs
> > doesn't return a line like 'struct file *getname (args)'
> > or similar, as I would expect.
> >
> > Can someone point me to the file/line where getname() is defined?

See include/linux/fs.h

The search directory scope was too high, not in fs.
You may find cscope, ctags, or bootlin[1] useful.

[1] https://elixir.bootlin.com/linux/v6.17-rc3/source/include/linux/fs.h#L2916


> >
> > Thank you,
> > Vulturus
> >
> > _______________________________________________
> > Kernelnewbies mailing list
> > Kernelnewbies@kernelnewbies.org
> > https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
> 
> 
> Looks like it's an inline function defined in a header in
> /include/linux/fs.h:
> https://elixir.bootlin.com/linux/v6.17-rc3/source/include/linux/fs.h#L2916
> 
> Bootlin is a fantastic tool to find where things are defined in the kernel.
> 
> -Daniel
> 
> >
> >

> _______________________________________________
> Kernelnewbies mailing list
> Kernelnewbies@kernelnewbies.org
> https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies


_______________________________________________
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: Where is getname () defined

[Partha P. Mukherjee]

On 8/29/25 2:43 PM, Vulturus wrote:
> Dear kernelnewbies subscribers,
> 
> I was reading the kernel source tree in an
> attempt to understand how the chroot syscall workes.
> (I was using the linux-6.17-rc3 tarball from kernel.org.)
> 
> At line 1429 of the fs/open.c file, inside the
> definition of the do_sys_openat2() function getname() is called.
> 
> I am having trouble finding its definition.
> 
> In particular,
> $ grep -rn 'getname' fs
> doesn't return a line like 'struct file *getname (args)'
> or similar, as I would expect.
> 
> Can someone point me to the file/line where getname() is defined?

You can use GNU Global [1] to find definition and references.

$ make gtags
$ global -x getname
getname          2916 include/linux/fs.h static inline struct filename *getname(const char __user *name)
$ global -xr getname
getname           484 crypto/af_alg.c  	.getname	=	sock_no_getname,
...
<snip>

[1] https://www.gnu.org/software/global/

> Thank you,
> Vulturus

_______________________________________________
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies