Unable to compile kernel module Ubuntu/Rocky

smajl87 commented 2 years ago

On newly installed Ubuntu LTS server

root@sp01:/tmp# date
Thu 10 Mar 2022 11:55:42 AM CET

root@sp01:/tmp# cat /etc/os-release
NAME="Ubuntu"
VERSION="20.04.4 LTS (Focal Fossa)"
ID=ubuntu
ID_LIKE=debian
PRETTY_NAME="Ubuntu 20.04.4 LTS"
VERSION_ID="20.04"
HOME_URL="https://www.ubuntu.com/"
SUPPORT_URL="https://help.ubuntu.com/"
BUG_REPORT_URL="https://bugs.launchpad.net/ubuntu/"
PRIVACY_POLICY_URL="https://www.ubuntu.com/legal/terms-and-policies/privacy-policy"
VERSION_CODENAME=focal
UBUNTU_CODENAME=focal

root@sp01:/tmp# uname -a
Linux sp01 5.4.0-100-generic #113-Ubuntu SMP Thu Feb 3 18:43:29 UTC 2022 x86_64 x86_64 x86_64 GNU/Linux

root@sp01:/tmp# git clone https://github.com/markh794/mhvtl.git
Cloning into 'mhvtl'...
remote: Enumerating objects: 8006, done.
remote: Counting objects: 100% (590/590), done.
remote: Compressing objects: 100% (387/387), done.
remote: Total 8006 (delta 381), reused 348 (delta 200), pack-reused 7416
Receiving objects: 100% (8006/8006), 3.18 MiB | 1.61 MiB/s, done.
Resolving deltas: 100% (5761/5761), done.

root@sp01:/tmp# cd mhvtl/kernel/

root@sp01:/tmp/mhvtl/kernel# make
make -C /lib/modules/5.4.0-100-generic/build M=/tmp/mhvtl/kernel modules
make[1]: Entering directory '/usr/src/linux-headers-5.4.0-100-generic'
  CC [M]  /tmp/mhvtl/kernel/mhvtl.o
In file included from /tmp/mhvtl/kernel/mhvtl.c:95:
/tmp/mhvtl/kernel/backport.h:63:12: error: static declaration of ‘sysfs_emit’ follows non-static declaration
   63 | static int sysfs_emit(char *buf, const char *fmt, ...)
      |            ^~~~~~~~~~
In file included from ./include/linux/kobject.h:20,
                 from ./include/linux/module.h:17,
                 from /tmp/mhvtl/kernel/mhvtl.c:45:
./include/linux/sysfs.h:325:5: note: previous declaration of ‘sysfs_emit’ was here
  325 | int sysfs_emit(char *buf, const char *fmt, ...);
      |     ^~~~~~~~~~
make[2]: *** [scripts/Makefile.build:270: /tmp/mhvtl/kernel/mhvtl.o] Error 1
make[1]: *** [Makefile:1762: /tmp/mhvtl/kernel] Error 2
make[1]: Leaving directory '/usr/src/linux-headers-5.4.0-100-generic'
make: *** [Makefile:26: default] Error 2

root@sp01:/tmp/mhvtl/kernel#

Same situation on Rocky Linux 8

[root@sp02 kernel]# make
make -C /lib/modules/4.18.0-348.el8.0.2.x86_64/build M=/tmp/mhvtl/kernel modules
make[1]: Entering directory '/usr/src/kernels/4.18.0-348.12.2.el8_5.x86_64'
  CC [M]  /tmp/mhvtl/kernel/mhvtl.o
In file included from /tmp/mhvtl/kernel/mhvtl.c:95:
/tmp/mhvtl/kernel/backport.h:63:12: error: static declaration of ‘sysfs_emit’ follows non-static declaration
 static int sysfs_emit(char *buf, const char *fmt, ...)
            ^~~~~~~~~~
In file included from ./include/linux/kobject.h:20,
                 from ./include/linux/module.h:17,
                 from /tmp/mhvtl/kernel/mhvtl.c:45:
./include/linux/sysfs.h:336:5: note: previous declaration of ‘sysfs_emit’ was here
 int sysfs_emit(char *buf, const char *fmt, ...);
     ^~~~~~~~~~
make[2]: *** [scripts/Makefile.build:322: /tmp/mhvtl/kernel/mhvtl.o] Error 1
make[1]: *** [Makefile:1571: _module_/tmp/mhvtl/kernel] Error 2
make[1]: Leaving directory '/usr/src/kernels/4.18.0-348.12.2.el8_5.x86_64'
make: *** [Makefile:26: default] Error 2
[root@sp02 kernel]#

gonzoleeman commented 2 years ago

sysfs_emit was added to the kernel starting at version 5.10.

On Mar 10, 2022, at 3:17 AM, smajl87 @.***> wrote:

On newly installed Ubuntu LTS server

@.***:/tmp# date Thu 10 Mar 2022 11:55:42 AM CET

@.***:/tmp# cat /etc/os-release NAME="Ubuntu" VERSION="20.04.4 LTS (Focal Fossa)" ID=ubuntu ID_LIKE=debian PRETTY_NAME="Ubuntu 20.04.4 LTS" VERSION_ID="20.04" HOME_URL="https://www.ubuntu.com/" SUPPORT_URL="https://help.ubuntu.com/" BUG_REPORT_URL="https://bugs.launchpad.net/ubuntu/" PRIVACY_POLICY_URL="https://www.ubuntu.com/legal/terms-and-policies/privacy-policy" VERSION_CODENAME=focal UBUNTU_CODENAME=focal

@.***:/tmp# uname -a Linux sp01 5.4.0-100-generic #113-Ubuntu SMP Thu Feb 3 18:43:29 UTC 2022 x86_64 x86_64 x86_64 GNU/Linux

@.***:/tmp# git clone https://github.com/markh794/mhvtl.git Cloning into 'mhvtl'... remote: Enumerating objects: 8006, done. remote: Counting objects: 100% (590/590), done. remote: Compressing objects: 100% (387/387), done. remote: Total 8006 (delta 381), reused 348 (delta 200), pack-reused 7416 Receiving objects: 100% (8006/8006), 3.18 MiB | 1.61 MiB/s, done. Resolving deltas: 100% (5761/5761), done.

@.***:/tmp# cd mhvtl/kernel/

@.:/tmp/mhvtl/kernel# make make -C /lib/modules/5.4.0-100-generic/build M=/tmp/mhvtl/kernel modules make[1]: Entering directory '/usr/src/linux-headers-5.4.0-100-generic' CC [M] /tmp/mhvtl/kernel/mhvtl.o In file included from /tmp/mhvtl/kernel/mhvtl.c:95: /tmp/mhvtl/kernel/backport.h:63:12: error: static declaration of ‘sysfs_emit’ follows non-static declaration 63 | static int sysfs_emit(char buf, const char fmt, ...) | ^~~~~~ In file included from ./include/linux/kobject.h:20, from ./include/linux/module.h:17, from /tmp/mhvtl/kernel/mhvtl.c:45: ./include/linux/sysfs.h:325:5: note: previous declaration of ‘sysfs_emit’ was here 325 | int sysfs_emit(char buf, const char fmt, ...); | ^~~~~~ make[2]: [scripts/Makefile.build:270: /tmp/mhvtl/kernel/mhvtl.o] Error 1 make[1]: [Makefile:1762: /tmp/mhvtl/kernel] Error 2 make[1]: Leaving directory '/usr/src/linux-headers-5.4.0-100-generic' make: [Makefile:26: default] Error 2

@.***:/tmp/mhvtl/kernel# Same situation on Rocky Linux 8

@. kernel]# make make -C /lib/modules/4.18.0-348.el8.0.2.x86_64/build M=/tmp/mhvtl/kernel modules make[1]: Entering directory '/usr/src/kernels/4.18.0-348.12.2.el8_5.x86_64' CC [M] /tmp/mhvtl/kernel/mhvtl.o In file included from /tmp/mhvtl/kernel/mhvtl.c:95: /tmp/mhvtl/kernel/backport.h:63:12: error: static declaration of ‘sysfs_emit’ follows non-static declaration static int sysfs_emit(char buf, const char fmt, ...) ^~~~~~ In file included from ./include/linux/kobject.h:20, from ./include/linux/module.h:17, from /tmp/mhvtl/kernel/mhvtl.c:45: ./include/linux/sysfs.h:336:5: note: previous declaration of ‘sysfs_emit’ was here int sysfs_emit(char buf, const char fmt, ...); ^~~~~~ make[2]: [scripts/Makefile.build:322: /tmp/mhvtl/kernel/mhvtl.o] Error 1 make[1]: [Makefile:1571: module/tmp/mhvtl/kernel] Error 2 make[1]: Leaving directory '/usr/src/kernels/4.18.0-348.12.2.el8_5.x86_64' make: [Makefile:26: default] Error 2 @.*** kernel]# — Reply to this email directly, view it on GitHub https://github.com/markh794/mhvtl/issues/95, or unsubscribe https://github.com/notifications/unsubscribe-auth/AAOJGHFQ2BV7QFHFKK2BSDLU7HK43ANCNFSM5QMKBXPQ. Triage notifications on the go with GitHub Mobile for iOS https://apps.apple.com/app/apple-store/id1477376905?ct=notification-email&mt=8&pt=524675 or Android https://play.google.com/store/apps/details?id=com.github.android&referrer=utm_campaign%3Dnotification-email%26utm_medium%3Demail%26utm_source%3Dgithub. You are receiving this because you are subscribed to this thread.

melak commented 2 years ago

In the age of backports, this mean nothing, unfortunately.

gonzoleeman commented 2 years ago

Hi:

On Mar 10, 2022, at 12:51 PM, melak @.***> wrote:

In the age of backports, this mean nothing, unfortunately.

So your distro has sysfs_emit() backported, and the code in mhvtl.c is assuming that for 5.4 kernel it needs to define it’s own. So you get a duplicate definition.

Side note: this wouldn’t be an issue if mhvtl.c was merged in the kernel. :) [I had to say that.]

You will have to make your own branch, and change the code in backport.h. I don’t know any generic cleaner way to address it, but perhaps somebody else does.

— Lee Duncan

markh794 commented 2 years ago

It would be nice if distros that back port functions would add a #define so it could be tested at compile time.

Lets see what we can come up with. As Lee states, the sysfs_emit function will need to be commented out of mhvtl kernel/backport.h

Re: mhvtl.c was merged. I hear you :) Or I use an available module - perhaps virtio_scsi, or lio. It's all just a matter of spare time.

gonzoleeman commented 2 years ago

On Mar 10, 2022, at 2:10 PM, Mark Harvey @.***> wrote:

It would be nice if distros that back port functions would add a #define so it could be tested at compile time.

Lets see what we can come up with. As Lee states, the sysfs_emit function will need to be commented out of mhvtl kernel/backport.h

Re: mhvtl.c was merged. I hear you :) Or I use an available module - perhaps virtio_scsi, or lio. It's all just a matter of spare time.

Time! :O LOL. Ya, who has enough of that?

I planned, once, to try using tcmu-runner for mhvtl, but like you I never found the time. And, honestly, it’d be purely a labor of love, since I don’t need that for my daily job. Maybe when I retire … :P

— Lee Duncan

melak commented 2 years ago

Two things I can think of off the top of my head. Both are ugly and will need some continued TLC as new items arise (which I'm sure they will).

ubuntu2004:/tmp/mhvtl/kernel$ git diff
diff --git a/kernel/Makefile b/kernel/Makefile
index 5a81dcc..8437b09 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -20,6 +20,10 @@ KDIR := /usr/src/linux-headers-$(V)
 endif
 endif

+ifeq ($(shell grep -q sysfs_emit $(KDIR)/include/linux/sysfs.h && echo yes),yes)
+EXTRA_CFLAGS += -DHAVE_SYSFS_EMIT
+endif
+
 PWD    := $(shell pwd)

 default:
diff --git a/kernel/backport.h b/kernel/backport.h
index ef70aef..eecbcd7 100644
--- a/kernel/backport.h
+++ b/kernel/backport.h
@@ -49,7 +49,7 @@ static inline struct inode *file_inode(struct file *f)
 #define HAVE_UNLOCKED_IOCTL 1 
 #endif

-#if LINUX_VERSION_CODE < KERNEL_VERSION(5, 10, 0)
+#if LINUX_VERSION_CODE < KERNEL_VERSION(5, 10, 0) && !defined(HAVE_SYSFS_EMIT)
 /* https://patches.linaro.org/project/stable/patch/20210305120853.392925382@linuxfoundation.org/ */
 /**
  *     sysfs_emit - scnprintf equivalent, aware of PAGE_SIZE buffer.
ubuntu2004:/tmp/mhvtl/kernel$ make clean
rm -f mhvtl.ko
rm -f TAGS
ubuntu2004:/tmp/mhvtl/kernel$ make
make -C /lib/modules/5.4.0-104-generic/build M=/tmp/mhvtl/kernel modules
make[1]: Entering directory '/usr/src/linux-headers-5.4.0-104-generic'
  Building modules, stage 2.   
  MODPOST 1 modules
  LD [M]  /tmp/mhvtl/kernel/mhvtl.ko
make[1]: Leaving directory '/usr/src/linux-headers-5.4.0-104-generic'
ubuntu2004:/tmp/mhvtl/kernel$ ls -l mhvtl.ko
-rw-r--r-- 1 ice 1000 54488 Mar 10 23:28 mhvtl.ko
ubuntu2004:/tmp/mhvtl/kernel$ lsb_release -ir
Distributor ID: Ubuntu
Release:        20.04
ubuntu2004:/tmp/mhvtl/kernel$ lsmod | grep mhvtl
ubuntu2004:/tmp/mhvtl/kernel$ sudo insmod ./mhvtl.ko
ubuntu2004:/tmp/mhvtl/kernel$ lsmod | grep mhvtl
mhvtl                  40960  0
ubuntu2004:/tmp/mhvtl/kernel$

Another option might be to look for the symbol in /boot/System.map-$(uname -r), but that requires root (the symbol map is only readable by root usually), and, if memory serves, some distros (in some circumstances only maybe? memory serves not) put it elsewhere.

I don't know of a "clean" solution.

melak commented 2 years ago

Actually, $(KDIR)/Module.symvers looks better a source of truth.

markh794 commented 2 years ago

Two things I can think of off the top of my head. Both are ugly and will need some continued TLC as new items arise (which I'm sure they will).

ubuntu2004:/tmp/mhvtl/kernel$ git diff
diff --git a/kernel/Makefile b/kernel/Makefile
index 5a81dcc..8437b09 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -20,6 +20,10 @@ KDIR := /usr/src/linux-headers-$(V)
 endif
 endif

+ifeq ($(shell grep -q sysfs_emit $(KDIR)/include/linux/sysfs.h && echo yes),yes)
+EXTRA_CFLAGS += -DHAVE_SYSFS_EMIT
+endif
+
 PWD    := $(shell pwd)

 default:
diff --git a/kernel/backport.h b/kernel/backport.h
index ef70aef..eecbcd7 100644
--- a/kernel/backport.h
+++ b/kernel/backport.h
@@ -49,7 +49,7 @@ static inline struct inode *file_inode(struct file *f)
 #define HAVE_UNLOCKED_IOCTL 1 
 #endif

-#if LINUX_VERSION_CODE < KERNEL_VERSION(5, 10, 0)
+#if LINUX_VERSION_CODE < KERNEL_VERSION(5, 10, 0) && !defined(HAVE_SYSFS_EMIT)
 /* https://patches.linaro.org/project/stable/patch/20210305120853.392925382@linuxfoundation.org/ */
 /**
  *     sysfs_emit - scnprintf equivalent, aware of PAGE_SIZE buffer.
ubuntu2004:/tmp/mhvtl/kernel$ make clean
rm -f mhvtl.ko
rm -f TAGS
ubuntu2004:/tmp/mhvtl/kernel$ make
make -C /lib/modules/5.4.0-104-generic/build M=/tmp/mhvtl/kernel modules
make[1]: Entering directory '/usr/src/linux-headers-5.4.0-104-generic'
  Building modules, stage 2.   
  MODPOST 1 modules
  LD [M]  /tmp/mhvtl/kernel/mhvtl.ko
make[1]: Leaving directory '/usr/src/linux-headers-5.4.0-104-generic'
ubuntu2004:/tmp/mhvtl/kernel$ ls -l mhvtl.ko
-rw-r--r-- 1 ice 1000 54488 Mar 10 23:28 mhvtl.ko
ubuntu2004:/tmp/mhvtl/kernel$ lsb_release -ir
Distributor ID: Ubuntu
Release:        20.04
ubuntu2004:/tmp/mhvtl/kernel$ lsmod | grep mhvtl
ubuntu2004:/tmp/mhvtl/kernel$ sudo insmod ./mhvtl.ko
ubuntu2004:/tmp/mhvtl/kernel$ lsmod | grep mhvtl
mhvtl                  40960  0
ubuntu2004:/tmp/mhvtl/kernel$

Another option might be to look for the symbol in /boot/System.map-$(uname -r), but that requires root (the symbol map is only readable by root usually), and, if memory serves, some distros (in some circumstances only maybe? memory serves not) put it elsewhere.

I don't know of a "clean" solution.

If we're defining/checking for sysfs_emit function in sysfs.h/Module.symvers - there is no real reason to include the kernel version test in the backport.h i.e. Simplify +#if LINUX_VERSION_CODE < KERNEL_VERSION(5, 10, 0) && !defined(HAVE_SYSFS_EMIT) to +#if !defined(HAVE_SYSFS_EMIT)

melak commented 2 years ago

If we're defining/checking for sysfs_emit function in sysfs.h/Module.symvers - there is no real reason to include the kernel version test in the backport.h

Makes sense. I'm trying to cobble something reusable together, but we are fast approaching the limits of my make-fu.

gonzoleeman commented 1 year ago

How about a Make option, like HAVE_SYSFS_EMIT=yes? Also not pretty and not very generic.

-- Lee-Man Duncan Sent from my iPhone, dude

On Mar 10, 2022, at 2:41 PM, melak @.***> wrote:

Two things I can think of off the top of my head. Both are ugly and will need some continued TLC as new items arise (which I'm sure they will).

ubuntu2004:/tmp/mhvtl/kernel$ git diff diff --git a/kernel/Makefile b/kernel/Makefile index 5a81dcc..8437b09 100644 --- a/kernel/Makefile +++ b/kernel/Makefile @@ -20,6 +20,10 @@ KDIR := /usr/src/linux-headers-$(V) endif endif

+ifeq ($(shell grep -q sysfs_emit $(KDIR)/include/linux/sysfs.h && echo yes),yes) +EXTRA_CFLAGS += -DHAVE_SYSFS_EMIT +endif + PWD := $(shell pwd)

default: diff --git a/kernel/backport.h b/kernel/backport.h index ef70aef..eecbcd7 100644 --- a/kernel/backport.h +++ b/kernel/backport.h @@ -49,7 +49,7 @@ static inline struct inode file_inode(struct file f)

define HAVE_UNLOCKED_IOCTL 1

endif

-#if LINUX_VERSION_CODE < KERNEL_VERSION(5, 10, 0) +#if LINUX_VERSION_CODE < KERNEL_VERSION(5, 10, 0) && !defined(HAVE_SYSFS_EMIT) /* @./ / /

sysfs_emit - scnprintf equivalent, aware of PAGE_SIZE buffer. ubuntu2004:/tmp/mhvtl/kernel$ make clean rm -f mhvtl.ko rm -f TAGS ubuntu2004:/tmp/mhvtl/kernel$ make make -C /lib/modules/5.4.0-104-generic/build M=/tmp/mhvtl/kernel modules make[1]: Entering directory '/usr/src/linux-headers-5.4.0-104-generic' Building modules, stage 2.
MODPOST 1 modules LD [M] /tmp/mhvtl/kernel/mhvtl.ko make[1]: Leaving directory '/usr/src/linux-headers-5.4.0-104-generic' ubuntu2004:/tmp/mhvtl/kernel$ ls -l mhvtl.ko -rw-r--r-- 1 ice 1000 54488 Mar 10 23:28 mhvtl.ko ubuntu2004:/tmp/mhvtl/kernel$ lsb_release -ir Distributor ID: Ubuntu Release: 20.04 ubuntu2004:/tmp/mhvtl/kernel$ lsmod | grep mhvtl ubuntu2004:/tmp/mhvtl/kernel$ sudo insmod ./mhvtl.ko ubuntu2004:/tmp/mhvtl/kernel$ lsmod | grep mhvtl mhvtl 40960 0 ubuntu2004:/tmp/mhvtl/kernel$ Another option might be to look for the symbol in /boot/System.map-$(uname -r), but that requires root (the symbol map is only readable to root usually), and, if memory serves, some distros (in some circumstances only maybe? memory serves not) put it elsewhere.

I don't know of a "clean" solution.

— Reply to this email directly, view it on GitHub, or unsubscribe. Triage notifications on the go with GitHub Mobile for iOS or Android. You are receiving this because you commented.

markh794 / mhvtl

Unable to compile kernel module Ubuntu/Rocky #95

define HAVE_UNLOCKED_IOCTL 1

endif