[Devel] [PATCH vz10 11/14] ve: guard vdso and cpuid code with CONFIG_X86

[Eva Kurchatova]

kernel/ve/ve.c references x86-specific symbols (vdso_image_64,
vdso_image_32, TIF_CPUID_OVERRIDE, cpuid_override_on()) that are not
available under UML.  Guard all VDSO image copying, freeing, and
version-code patching, as well as the CPUID override flag propagation,
with #ifdef CONFIG_X86.

Provide a static inline no-op stub for ve_free_vdso() on UML.

Also guard the ve_get_vdso_32/64() stubs in the !CONFIG_VE section
of ve.h with the same #ifdef CONFIG_X86, since the vdso_image_32
and vdso_image_64 externs they reference are equally unavailable.

Signed-off-by: Eva Kurchatova <eva.kurchatova at virtuozzo.com>

https://virtuozzo.atlassian.net/browse/VSTOR-134732
Feature: fix kunit
---
 include/linux/ve.h |  2 +-
 kernel/ve/ve.c     | 12 ++++++++++++
 2 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/include/linux/ve.h b/include/linux/ve.h
index 1d32f6f57f8b..778dd4890c6a 100644
--- a/include/linux/ve.h
+++ b/include/linux/ve.h
@@ -367,7 +367,7 @@ static inline void ve_setup_task(struct task_struct *p, struct ve_struct *ve) {
 
 static inline void ve_set_rpc_kill_fn(void (*fn)(struct net *, bool)) { }
 
-#if defined(CONFIG_X86) && !defined(CONFIG_UML)
+#ifdef CONFIG_X86
 static inline struct vdso_image *ve_get_vdso_32(struct ve_struct *ve)
 {
 	return (struct vdso_image *)&vdso_image_32;
diff --git a/kernel/ve/ve.c b/kernel/ve/ve.c
index e58ffb22da87..a4d445c80333 100644
--- a/kernel/ve/ve.c
+++ b/kernel/ve/ve.c
@@ -82,8 +82,10 @@ struct ve_struct ve0 = {
 	.meminfo_val		= VE_MEMINFO_SYSTEM,
 	.umh_running_helpers    = ATOMIC_INIT(0),
 	.umh_helpers_waitq      = __WAIT_QUEUE_HEAD_INITIALIZER(ve0.umh_helpers_waitq),
+#ifdef CONFIG_X86
 	.vdso_64		= (struct vdso_image*)&vdso_image_64,
 	.vdso_32		= (struct vdso_image*)&vdso_image_32,
+#endif
 };
 EXPORT_SYMBOL(ve0);
 
@@ -672,6 +674,7 @@ u64 ve_get_uptime(struct ve_struct *ve)
 }
 EXPORT_SYMBOL(ve_get_uptime);
 
+#ifdef CONFIG_X86
 static int copy_vdso(struct vdso_image **vdso_dst, const struct vdso_image *vdso_src)
 {
 	struct vdso_image *vdso;
@@ -709,6 +712,9 @@ static void ve_free_vdso(struct ve_struct *ve)
 		kfree(ve->vdso_32);
 	}
 }
+#else
+static inline void ve_free_vdso(struct ve_struct *ve) { }
+#endif
 
 static struct cgroup_subsys_state *ve_create(struct cgroup_subsys_state *parent_css)
 {
@@ -755,6 +761,7 @@ static struct cgroup_subsys_state *ve_create(struct cgroup_subsys_state *parent_
 	if (err)
 		goto err_log;
 
+#ifdef CONFIG_X86
 	err = copy_vdso(&ve->vdso_64, &vdso_image_64);
 	if (err)
 		goto err_vdso;
@@ -762,6 +769,7 @@ static struct cgroup_subsys_state *ve_create(struct cgroup_subsys_state *parent_
 	err = copy_vdso(&ve->vdso_32, &vdso_image_32);
 	if (err)
 		goto err_vdso;
+#endif
 
 	err = ve_mount_devtmpfs(ve);
 	if (err)
@@ -1152,8 +1160,10 @@ static ssize_t ve_os_release_write(struct kernfs_open_file *of, char *buf,
 
 	if (sscanf(buf, "%d.%d.%d", &n1, &n2, &n3) == 3) {
 		new_version = ((n1 << 16) + (n2 << 8)) + n3;
+#ifdef CONFIG_X86
 		*((int *)(ve->vdso_64->data + ve->vdso_64->sym_linux_version_code)) = new_version;
 		*((int *)(ve->vdso_32->data + ve->vdso_32->sym_linux_version_code)) = new_version;
+#endif
 	}
 
 	down_write(&uts_sem);
@@ -1836,8 +1846,10 @@ void ve_setup_task(struct task_struct *task, struct ve_struct *ve)
 
 	ve_set_task_start_time(ve, task);
 
+#ifdef CONFIG_X86
 	if (cpuid_override_on())
 		set_tsk_thread_flag(task, TIF_CPUID_OVERRIDE);
+#endif
 }
 EXPORT_SYMBOL(ve_setup_task);
 
-- 
2.54.0