On Mon, Dec 1, 2025 at 12:36 PM David Matlack <[email protected]> wrote: > > On 2025-12-01 05:32 PM, David Matlack wrote: > > On 2025-12-01 09:16 AM, Zhu Yanjun wrote: > > > > > > 在 2025/12/1 9:10, David Matlack 写道: > > > > On Mon, Dec 1, 2025 at 7:49 AM Zhu Yanjun <[email protected]> wrote: > > > > > 在 2025/11/27 20:56, Zhu Yanjun 写道: > > > > > > Hi, David > > > > > > > > > > > > ERROR: modpost: "liveupdate_register_file_handler" > > > > > > [drivers/vfio/pci/ > > > > > > vfio-pci-core.ko] undefined! > > > > > > > > > > > > ERROR: modpost: "vfio_pci_ops" [drivers/vfio/pci/vfio-pci-core.ko] > > > > > > undefined! > > > > > > ERROR: modpost: "liveupdate_enabled" > > > > > > [drivers/vfio/pci/vfio-pci-core.ko] > > > > > > undefined! > > > > > > ERROR: modpost: "liveupdate_unregister_file_handler" > > > > > > [drivers/vfio/pci/ > > > > > > vfio-pci-core.ko] undefined! > > > > > > ERROR: modpost: "vfio_device_fops" > > > > > > [drivers/vfio/pci/vfio-pci-core.ko] > > > > > > undefined! > > > > > > ERROR: modpost: "vfio_pci_is_intel_display" > > > > > > [drivers/vfio/pci/vfio-pci- > > > > > > core.ko] undefined! > > > > > > ERROR: modpost: "vfio_pci_liveupdate_init" [drivers/vfio/pci/vfio- > > > > > > pci.ko] undefined! > > > > > > ERROR: modpost: "vfio_pci_liveupdate_cleanup" > > > > > > [drivers/vfio/pci/vfio- > > > > > > pci.ko] undefined! > > > > > > make[4]: *** [scripts/Makefile.modpost:147: Module.symvers] Error 1 > > > > > > make[3]: *** [Makefile:1960: modpost] Error 2 > > > > > > > > > > > > After I git clone the source code from the link https://github.com/ > > > > > > dmatlack/linux/tree/liveupdate/vfio/cdev/v1, > > > > > > > > > > > > I found the above errors when I built the source code. > > > > > > > > > > > > Perhaps the above errors can be solved by EXPORT_SYMBOL. > > > > > > > > > > > > But I am not sure if a better solution can solve the above problems > > > > > > or not. > > > > > I reviewed this patch series in detail. If I’m understanding it > > > > > correctly, there appears to be a cyclic dependency issue. > > > > > Specifically, > > > > > some functions in kernel module A depend on kernel module B, while at > > > > > the same time certain functions in module B depend on module A. > > > > > > > > > > I’m not entirely sure whether this constitutes a real problem or if > > > > > it’s > > > > > intentional design. > > > > Thanks for your report. Can you share the .config file you used to > > > > generate these errors? > > > > > > > > > IIRC, I used FC 42 default config. Perhaps you can make tests with it. If > > > this problem can not be reproduced, I will share my config with you. > > > > > > > What does "FC 42 default config" mean? > > > > Either way I was able to reproduce the errors you posted above by > > changing CONFIG_VFIO_PCI{_CORE} from "y" to "m". > > > > To unblock building and testing this series you can change these configs > > from "m" to "y", or the following patch (which fixed things for me): > > Oops, sorry, something went wrong when I posted that diff. Here's the > correct diff: > > diff --git a/drivers/vfio/pci/Makefile b/drivers/vfio/pci/Makefile > index 929df22c079b..c2cca16e99a8 100644 > --- a/drivers/vfio/pci/Makefile > +++ b/drivers/vfio/pci/Makefile > @@ -2,11 +2,11 @@ > > vfio-pci-core-y := vfio_pci_core.o vfio_pci_intrs.o vfio_pci_rdwr.o > vfio_pci_config.o > vfio-pci-core-$(CONFIG_VFIO_PCI_ZDEV_KVM) += vfio_pci_zdev.o > -vfio-pci-core-$(CONFIG_LIVEUPDATE) += vfio_pci_liveupdate.o > obj-$(CONFIG_VFIO_PCI_CORE) += vfio-pci-core.o > > vfio-pci-y := vfio_pci.o > vfio-pci-$(CONFIG_VFIO_PCI_IGD) += vfio_pci_igd.o > +vfio-pci-$(CONFIG_LIVEUPDATE) += vfio_pci_liveupdate.o > obj-$(CONFIG_VFIO_PCI) += vfio-pci.o > > obj-$(CONFIG_MLX5_VFIO_PCI) += mlx5/ > diff --git a/drivers/vfio/vfio_main.c b/drivers/vfio/vfio_main.c > index c5b5eb509474..b9805861763a 100644 > --- a/drivers/vfio/vfio_main.c > +++ b/drivers/vfio/vfio_main.c > @@ -1386,6 +1386,7 @@ const struct file_operations vfio_device_fops = { > .show_fdinfo = vfio_device_show_fdinfo, > #endif > }; > +EXPORT_SYMBOL_GPL(vfio_device_fops); > > /** > * vfio_file_is_valid - True if the file is valid vfio file > diff --git a/kernel/liveupdate/luo_core.c b/kernel/liveupdate/luo_core.c > index 69298d82f404..c7a0c9c3b6a8 100644 > --- a/kernel/liveupdate/luo_core.c > +++ b/kernel/liveupdate/luo_core.c > @@ -256,6 +256,7 @@ bool liveupdate_enabled(void) > { > return luo_global.enabled; > } > +EXPORT_SYMBOL_GPL(liveupdate_enabled); > > /** > * DOC: LUO ioctl Interface > diff --git a/kernel/liveupdate/luo_file.c b/kernel/liveupdate/luo_file.c > index fca3806dae28..9baa88966f04 100644 > --- a/kernel/liveupdate/luo_file.c > +++ b/kernel/liveupdate/luo_file.c > @@ -868,6 +868,7 @@ int liveupdate_register_file_handler(struct > liveupdate_file_handler *fh) > luo_session_resume(); > return err; > } > +EXPORT_SYMBOL_GPL(liveupdate_register_file_handler); > > /** > * liveupdate_unregister_file_handler - Unregister a liveupdate file handler > @@ -913,3 +914,4 @@ int liveupdate_unregister_file_handler(struct > liveupdate_file_handler *fh) > liveupdate_test_register(fh); > return err; > } > +EXPORT_SYMBOL_GPL(liveupdate_unregister_file_handler);
Please add the EXPORT_SYMBOL_GPL() to the public LUO API as needed, I was asked to stay conservative and not export until it is actually needed by modules.
