depmod: Handle installing modules under a prefix

Message ID 20230711153457.29497-1-msuchanek@suse.de
State New
Headers
Series depmod: Handle installing modules under a prefix |

Commit Message

Michal Suchánek July 11, 2023, 3:34 p.m. UTC
  Some distributions aim at not shipping any files in / ustside of usr.

The path under which kernel modules are instaleld is hardcoded to /lib
which conflicts with this goal.

When kmod provides the config command use it to determine the correct
module installation prefix.

On kmod that does not provide the command / is used as before.

Signed-off-by: Michal Suchanek <msuchanek@suse.de>
---
 Makefile          | 4 +++-
 scripts/depmod.sh | 8 ++++----
 2 files changed, 7 insertions(+), 5 deletions(-)
  

Comments

Jiri Slaby July 12, 2023, 5:47 a.m. UTC | #1
On 11. 07. 23, 17:34, Michal Suchanek wrote:
> Some distributions aim at not shipping any files in / ustside of usr.
> 
> The path under which kernel modules are instaleld is hardcoded to /lib
> which conflicts with this goal.
> 
> When kmod provides the config command use it to determine the correct
> module installation prefix.
> 
> On kmod that does not provide the command / is used as before.
> 
> Signed-off-by: Michal Suchanek <msuchanek@suse.de>
> ---
>   Makefile          | 4 +++-
>   scripts/depmod.sh | 8 ++++----
>   2 files changed, 7 insertions(+), 5 deletions(-)
> 
> diff --git a/Makefile b/Makefile
> index 47690c28456a..b05d696f06bd 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -1165,7 +1165,9 @@ export INSTALL_DTBS_PATH ?= $(INSTALL_PATH)/dtbs/$(KERNELRELEASE)
>   # makefile but the argument can be passed to make if needed.
>   #
>   
> -MODLIB	= $(INSTALL_MOD_PATH)/lib/modules/$(KERNELRELEASE)
> +export KERNEL_MODULE_PREFIX := $(shell kmod config | jq -r .module_prefix)

echo -e 'KERNEL_MODULE_PREFIX := $(shell kmod config | jq -r 
.module_prefix)\nall:'|make -f -
invalid command 'config'
parse error: Invalid numeric literal at line 1, column 5

I think you should pipe kmod's 2> /dev/null to support older kmod. Ah, 
but you'd need 2> /dev/null for jq too. That would not be good as jq 
might not be installed and a user wouldn't see the error. So instead, I 
would do:

$(shell kmod config &> /dev/null && kmod config | jq -r .module_prefix)

thanks,
  
Michal Suchánek July 12, 2023, 7:38 a.m. UTC | #2
On Wed, Jul 12, 2023 at 07:47:13AM +0200, Jiri Slaby wrote:
> On 11. 07. 23, 17:34, Michal Suchanek wrote:
> > Some distributions aim at not shipping any files in / ustside of usr.
> > 
> > The path under which kernel modules are instaleld is hardcoded to /lib
> > which conflicts with this goal.
> > 
> > When kmod provides the config command use it to determine the correct
> > module installation prefix.
> > 
> > On kmod that does not provide the command / is used as before.
> > 
> > Signed-off-by: Michal Suchanek <msuchanek@suse.de>
> > ---
> >   Makefile          | 4 +++-
> >   scripts/depmod.sh | 8 ++++----
> >   2 files changed, 7 insertions(+), 5 deletions(-)
> > 
> > diff --git a/Makefile b/Makefile
> > index 47690c28456a..b05d696f06bd 100644
> > --- a/Makefile
> > +++ b/Makefile
> > @@ -1165,7 +1165,9 @@ export INSTALL_DTBS_PATH ?= $(INSTALL_PATH)/dtbs/$(KERNELRELEASE)
> >   # makefile but the argument can be passed to make if needed.
> >   #
> > -MODLIB	= $(INSTALL_MOD_PATH)/lib/modules/$(KERNELRELEASE)
> > +export KERNEL_MODULE_PREFIX := $(shell kmod config | jq -r .module_prefix)
> 
> echo -e 'KERNEL_MODULE_PREFIX := $(shell kmod config | jq -r
> .module_prefix)\nall:'|make -f -
> invalid command 'config'
> parse error: Invalid numeric literal at line 1, column 5
> 
> I think you should pipe kmod's 2> /dev/null to support older kmod. Ah, but
> you'd need 2> /dev/null for jq too. That would not be good as jq might not
> be installed and a user wouldn't see the error. So instead, I would do:
> 
> $(shell kmod config &> /dev/null && kmod config | jq -r .module_prefix)

Yes, that sounds reasonable. Also would cover the potential problem of
kmod changing the error output into something that is a valid JSON in
the future.

Thanks

Michal
  

Patch

diff --git a/Makefile b/Makefile
index 47690c28456a..b05d696f06bd 100644
--- a/Makefile
+++ b/Makefile
@@ -1165,7 +1165,9 @@  export INSTALL_DTBS_PATH ?= $(INSTALL_PATH)/dtbs/$(KERNELRELEASE)
 # makefile but the argument can be passed to make if needed.
 #
 
-MODLIB	= $(INSTALL_MOD_PATH)/lib/modules/$(KERNELRELEASE)
+export KERNEL_MODULE_PREFIX := $(shell kmod config | jq -r .module_prefix)
+
+MODLIB	= $(INSTALL_MOD_PATH)$(KERNEL_MODULE_PREFIX)/lib/modules/$(KERNELRELEASE)
 export MODLIB
 
 PHONY += prepare0
diff --git a/scripts/depmod.sh b/scripts/depmod.sh
index 3643b4f896ed..88ac79056153 100755
--- a/scripts/depmod.sh
+++ b/scripts/depmod.sh
@@ -27,16 +27,16 @@  fi
 # numbers, so we cheat with a symlink here
 depmod_hack_needed=true
 tmp_dir=$(mktemp -d ${TMPDIR:-/tmp}/depmod.XXXXXX)
-mkdir -p "$tmp_dir/lib/modules/$KERNELRELEASE"
+mkdir -p "$tmp_dir$KERNEL_MODULE_PREFIX/lib/modules/$KERNELRELEASE"
 if "$DEPMOD" -b "$tmp_dir" $KERNELRELEASE 2>/dev/null; then
-	if test -e "$tmp_dir/lib/modules/$KERNELRELEASE/modules.dep" -o \
-		-e "$tmp_dir/lib/modules/$KERNELRELEASE/modules.dep.bin"; then
+	if test -e "$tmp_dir$KERNEL_MODULE_PREFIX/lib/modules/$KERNELRELEASE/modules.dep" -o \
+		-e "$tmp_dir$KERNEL_MODULE_PREFIX/lib/modules/$KERNELRELEASE/modules.dep.bin"; then
 		depmod_hack_needed=false
 	fi
 fi
 rm -rf "$tmp_dir"
 if $depmod_hack_needed; then
-	symlink="$INSTALL_MOD_PATH/lib/modules/99.98.$KERNELRELEASE"
+	symlink="$INSTALL_MOD_PATH$KERNEL_MODULE_PREFIX/lib/modules/99.98.$KERNELRELEASE"
 	ln -s "$KERNELRELEASE" "$symlink"
 	KERNELRELEASE=99.98.$KERNELRELEASE
 fi