Commit eb3710efffce1dcff83761db4615f91d93aabfcb ("LoongArch: Add support to clone a time namespace") backports the TIMENS support for LoongArch (corresponding upstream commit aa5e65dc0818bbf676bf06927368ec46867778fd) but causes build errors:

CC arch/loongarch/kernel/vdso.o arch/loongarch/kernel/vdso.c: In function ‘vvar_fault’: arch/loongarch/kernel/vdso.c:54:36: error: implicit declaration of function ‘find_timens_vvar_page’ [-Werror=implicit-function-declaration] 54 | struct page *timens_page = find_timens_vvar_page(vma); | ^~~~~~~~~~~~~~~~~~~~~ arch/loongarch/kernel/vdso.c:54:36: warning: initialization of ‘struct page *’ from ‘int’ makes pointer from integer without a cast [-Wint-conversion] arch/loongarch/kernel/vdso.c: In function ‘vdso_join_timens’: arch/loongarch/kernel/vdso.c:143:25: error: implicit declaration of function ‘zap_vma_pages’; did you mean ‘zap_vma_ptes’? [-Werror=implicit-function-declaration] 143 | zap_vma_pages(vma); | ^~~~~~~~~~~~~ | zap_vma_ptes cc1: some warnings being treated as errors

Because in 6.1.y we should define find_timens_vvar_page() by ourselves and use zap_page_range() instead of zap_vma_pages(), so fix it.

Signed-off-by: Huacai Chen chenhuacai@loongson.cn --- arch/loongarch/kernel/vdso.c | 28 +++++++++++++++++++++++++++- 1 file changed, 27 insertions(+), 1 deletion(-)

diff --git a/arch/loongarch/kernel/vdso.c b/arch/loongarch/kernel/vdso.c index 59aa9dd466e8..64eb5386e7b2 100644 --- a/arch/loongarch/kernel/vdso.c +++ b/arch/loongarch/kernel/vdso.c @@ -40,6 +40,8 @@ static struct page *vdso_pages[] = { NULL }; struct vdso_data *vdso_data = generic_vdso_data.data; struct vdso_pcpu_data *vdso_pdata = loongarch_vdso_data.vdata.pdata;

+static struct page *find_timens_vvar_page(struct vm_area_struct *vma); + static int vdso_mremap(const struct vm_special_mapping *sm, struct vm_area_struct *new_vma) { current->mm->context.vdso = (void *)(new_vma->vm_start); @@ -139,13 +141,37 @@ int vdso_join_timens(struct task_struct *task, struct time_namespace *ns)

mmap_read_lock(mm); for_each_vma(vmi, vma) { + unsigned long size = vma->vm_end - vma->vm_start; + if (vma_is_special_mapping(vma, &vdso_info.data_mapping)) - zap_vma_pages(vma); + zap_page_range(vma, vma->vm_start, size); } mmap_read_unlock(mm);

return 0; } + +static struct page *find_timens_vvar_page(struct vm_area_struct *vma) +{ + if (likely(vma->vm_mm == current->mm)) + return current->nsproxy->time_ns->vvar_page; + + /* + * VM_PFNMAP | VM_IO protect .fault() handler from being called + * through interfaces like /proc/$pid/mem or + * process_vm_{readv,writev}() as long as there's no .access() + * in special_mapping_vmops. + * For more details check_vma_flags() and __access_remote_vm() + */ + WARN(1, "vvar_page accessed remotely"); + + return NULL; +} +#else +static struct page *find_timens_vvar_page(struct vm_area_struct *vma) +{ + return NULL; +} #endif

static unsigned long vdso_base(void)