>>>> DEFINE_SHOW_ATTRIBUTE(fadump_region); >>>> >>>> static void fadump_init_files(void) >>>> @@ -1435,6 +1448,11 @@ static void fadump_init_files(void) >>>> struct dentry *debugfs_file; >>>> int rc = 0; >>>> >>>> + fadump_kobj = kobject_create_and_add("fadump", kernel_kobj); >>>> + if (!fadump_kobj) { >>>> + pr_err("failed to create fadump kobject\n"); >>>> + return; >>>> + } >>>> rc = sysfs_create_file(kernel_kobj, &fadump_attr.attr); >>>> if (rc) >>>> printk(KERN_ERR "fadump: unable to create sysfs file" >>>> @@ -1458,6 +1476,26 @@ static void fadump_init_files(void) >>>> printk(KERN_ERR "fadump: unable to create sysfs file" >>>> " fadump_release_mem (%d)\n", rc); >>>> } >>>> + /* Replicating the following sysfs attributes under FADump kobject. >>>> + * >>>> + * - fadump_enabled -> enabled >>>> + * - fadump_registered -> registered >>>> + * - fadump_release_mem -> release_mem >>>> + */ >>>> + rc = sysfs_create_file(fadump_kobj, &enable_attr.attr); >>>> + if (rc) >>>> + pr_err("unable to create enabled sysfs file (%d)\n", >>>> + rc); >>>> + rc = sysfs_create_file(fadump_kobj, ®ister_attr.attr); >>>> + if (rc) >>>> + pr_err("unable to create registered sysfs file (%d)\n", >>>> + rc); >>>> + if (fw_dump.dump_active) { >>>> + rc = sysfs_create_file(fadump_kobj, &release_attr.attr); >>>> + if (rc) >>>> + pr_err("unable to create release_mem sysfs file (%d)\n", >>>> + rc); >>>> + } >>>> return; >>>> } >>> Hello, >>> >> >> I’m so sorry for taking this long to write you back. >> >>> wouldn't it make more sense to create the files in the new location and >>> add a symlink at the old location? >> >> There are APIs which allow to create a symlink for an entire kobject but >> I did not find a way to create symlink of an individual sysfs file. >> >> Do you have any approach in mind to achieve the same? > > There is at least one example of plain symlink: > > find /sys -type l -xtype f > /sys/kernel/security/evm > > If there is no interface to do one sanely duplicationg the files is > better than nothing.
Hello Michal, I found a function (__compat_only_sysfs_link_entry_to_kobj) that adds a symlink to a kobject. But the problem is __compat_only_sysfs_link_entry_to_kobj function keeps the symlink file name similar to sysfs file and has no option to change it. We can't use the __compat_only_sysfs_link_entry_to_kobj function directly because our symlink file name must be different from the target file name. fadump_enabled -> fadump/enabled But the good thing is we can tweak the __compat_only_sysfs_link_entry_to_kobj function and allow the caller to change the sysmlink file name. So I am writing a separate patch that adds a wrapper function around the __compat_only_sysfs_link_entry_to_kobj function which will allow to have a custom symlink file name. Thanks, Sourabh Jain