Re: [PATCH v3] modules_install: make missing $DEPMOD a warning instead of an error

[Masahiro Yamada]

Hi Randy,


2018-08-24 3:13 GMT+09:00 Randy Dunlap <rdunlap@xxxxxxxxxxxxx>:
> From: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
>
> When $DEPMOD is not found, only print a warning instead of exiting
> with an error message and error status.


Could you add the motivation of this change
(as Nikolaus reported) ?

Without the reason recorded in git-log,
somebody may wonder why this commit is useful.





> Warning: 'make modules_install' requires /sbin/depmod. Please install it.
> This is probably in the kmod package.
>
> Signed-off-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
> Fixes: 934193a654c1 ("kbuild: verify that $DEPMOD is installed")
> Cc: stable@xxxxxxxxxxxxxxx
> Cc: Lucas De Marchi <lucas.demarchi@xxxxxxxxxxxxxx>
> Cc: Lucas De Marchi <lucas.de.marchi@xxxxxxxxx>
> Cc: Michal Marek <michal.lkml@xxxxxxxxxxx>
> Cc: Jessica Yu <jeyu@xxxxxxxxxx>
> Cc: Chih-Wei Huang <cwhuang@xxxxxxxxxxxx>
> Cc: H. Nikolaus Schaller <hns@xxxxxxxxxxxxx>

Reported-by: H. Nikolaus Schaller <hns@xxxxxxxxxxxxx>




> ---
> v2: add missing "exit 0" and update the commit message (no Error).
> v3: add Fixes: and Cc: stable
>
>  scripts/depmod.sh |    4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> --- lnx-418.orig/scripts/depmod.sh
> +++ lnx-418/scripts/depmod.sh
> @@ -15,9 +15,9 @@ if ! test -r System.map ; then
>  fi
>
>  if [ -z $(command -v $DEPMOD) ]; then
> -       echo "'make modules_install' requires $DEPMOD. Please install it." >&2
> +       echo "Warning: 'make modules_install' requires $DEPMOD. Please install it." >&2
>         echo "This is probably in the kmod package." >&2
> -       exit 1
> +       exit 0
>  fi
>
>  # older versions of depmod require the version string to start with three



BTW, if System.map is missing, depmod is silently skipped.


I think if System.map is missing, a user is doing something wrong,
but you could do like this:

$ make mrproper
   [snip]
$ make defconfig
   [snip]
$ make modules
   [snip]
$ make modules_install
  INSTALL drivers/thermal/x86_pkg_temp_thermal.ko
  INSTALL fs/efivarfs/efivarfs.ko
  INSTALL net/ipv4/netfilter/ipt_MASQUERADE.ko
  INSTALL net/ipv4/netfilter/iptable_nat.ko
  INSTALL net/ipv4/netfilter/nf_log_arp.ko
  INSTALL net/ipv4/netfilter/nf_log_ipv4.ko
  INSTALL net/ipv4/netfilter/nf_nat_ipv4.ko
  INSTALL net/ipv6/netfilter/nf_log_ipv6.ko
  INSTALL net/netfilter/nf_log_common.ko
  INSTALL net/netfilter/nf_nat.ko
  INSTALL net/netfilter/nf_nat_ftp.ko
  INSTALL net/netfilter/nf_nat_irc.ko
  INSTALL net/netfilter/nf_nat_sip.ko
  INSTALL net/netfilter/xt_LOG.ko
  INSTALL net/netfilter/xt_addrtype.ko
  INSTALL net/netfilter/xt_mark.ko
  INSTALL net/netfilter/xt_nat.ko
  DEPMOD  4.18.0+


The log looks like all the process went well,
but depmod is actually skipped because System.map is
generated by "make vmlinux"


What do you think we should do about this case?

Skip depmod silently?
Make it fail?
Print noisy warning like missing depmod case?


-- 
Best Regards
Masahiro Yamada