struct loongarch_vdso_data {
struct vdso_pcpu_data pdata[NR_CPUS];
- struct vdso_data data[CS_BASES]; /* Arch-independent data */
};
-#define VDSO_DATA_SIZE PAGE_ALIGN(sizeof(struct loongarch_vdso_data))
+/*
+ * The layout of vvar:
+ *
+ * high
+ * +---------------------+--------------------------+
+ * | loongarch vdso data | LOONGARCH_VDSO_DATA_SIZE |
+ * +---------------------+--------------------------+
+ * | time-ns vdso data | PAGE_SIZE |
+ * +---------------------+--------------------------+
+ * | generic vdso data | PAGE_SIZE |
+ * +---------------------+--------------------------+
+ * low
+ */
+#define LOONGARCH_VDSO_DATA_SIZE PAGE_ALIGN(sizeof(struct loongarch_vdso_data))
+#define LOONGARCH_VDSO_DATA_PAGES (LOONGARCH_VDSO_DATA_SIZE >> PAGE_SHIFT)
+
+enum vvar_pages {
+ VVAR_GENERIC_PAGE_OFFSET,
+ VVAR_TIMENS_PAGE_OFFSET,
+ VVAR_LOONGARCH_PAGES_START,
+ VVAR_LOONGARCH_PAGES_END = VVAR_LOONGARCH_PAGES_START + LOONGARCH_VDSO_DATA_PAGES - 1,
+ VVAR_NR_PAGES,
+};
+
+#define VVAR_SIZE (VVAR_NR_PAGES << PAGE_SHIFT)
static inline unsigned long get_vdso_base(void)
{
return addr;
}
-static inline const struct vdso_data *get_vdso_data(void)
+static inline unsigned long get_vdso_data(void)
{
- return (const struct vdso_data *)(get_vdso_base()
- - VDSO_DATA_SIZE + SMP_CACHE_BYTES * NR_CPUS);
+ return get_vdso_base() - VVAR_SIZE;
}
#endif /* __ASSEMBLY__ */
#include <linux/random.h>
#include <linux/sched.h>
#include <linux/slab.h>
+#include <linux/time_namespace.h>
#include <linux/timekeeper_internal.h>
#include <asm/page.h>
/* Kernel-provided data used by the VDSO. */
static union {
- u8 page[VDSO_DATA_SIZE];
+ u8 page[PAGE_SIZE];
+ struct vdso_data data[CS_BASES];
+} generic_vdso_data __page_aligned_data;
+
+static union {
+ u8 page[LOONGARCH_VDSO_DATA_SIZE];
struct loongarch_vdso_data vdata;
} loongarch_vdso_data __page_aligned_data;
static struct page *vdso_pages[] = { NULL };
-struct vdso_data *vdso_data = loongarch_vdso_data.vdata.data;
+struct vdso_data *vdso_data = generic_vdso_data.data;
struct vdso_pcpu_data *vdso_pdata = loongarch_vdso_data.vdata.pdata;
static int vdso_mremap(const struct vm_special_mapping *sm, struct vm_area_struct *new_vma)
return 0;
}
+static vm_fault_t vvar_fault(const struct vm_special_mapping *sm,
+ struct vm_area_struct *vma, struct vm_fault *vmf)
+{
+ unsigned long pfn;
+ struct page *timens_page = find_timens_vvar_page(vma);
+
+ switch (vmf->pgoff) {
+ case VVAR_GENERIC_PAGE_OFFSET:
+ if (!timens_page)
+ pfn = sym_to_pfn(vdso_data);
+ else
+ pfn = page_to_pfn(timens_page);
+ break;
+#ifdef CONFIG_TIME_NS
+ case VVAR_TIMENS_PAGE_OFFSET:
+ /*
+ * If a task belongs to a time namespace then a namespace specific
+ * VVAR is mapped with the VVAR_GENERIC_PAGE_OFFSET and the real
+ * VVAR page is mapped with the VVAR_TIMENS_PAGE_OFFSET offset.
+ * See also the comment near timens_setup_vdso_data().
+ */
+ if (!timens_page)
+ return VM_FAULT_SIGBUS;
+ else
+ pfn = sym_to_pfn(vdso_data);
+ break;
+#endif /* CONFIG_TIME_NS */
+ case VVAR_LOONGARCH_PAGES_START ... VVAR_LOONGARCH_PAGES_END:
+ pfn = sym_to_pfn(&loongarch_vdso_data) + vmf->pgoff - VVAR_LOONGARCH_PAGES_START;
+ break;
+ default:
+ return VM_FAULT_SIGBUS;
+ }
+
+ return vmf_insert_pfn(vma, vmf->address, pfn);
+}
+
struct loongarch_vdso_info vdso_info = {
.vdso = vdso_start,
.size = PAGE_SIZE,
},
.data_mapping = {
.name = "[vvar]",
+ .fault = vvar_fault,
},
.offset_sigreturn = vdso_offset_sigreturn,
};
}
subsys_initcall(init_vdso);
+#ifdef CONFIG_TIME_NS
+struct vdso_data *arch_get_vdso_data(void *vvar_page)
+{
+ return (struct vdso_data *)(vvar_page);
+}
+
+/*
+ * The vvar mapping contains data for a specific time namespace, so when a
+ * task changes namespace we must unmap its vvar data for the old namespace.
+ * Subsequent faults will map in data for the new namespace.
+ *
+ * For more details see timens_setup_vdso_data().
+ */
+int vdso_join_timens(struct task_struct *task, struct time_namespace *ns)
+{
+ struct mm_struct *mm = task->mm;
+ struct vm_area_struct *vma;
+
+ VMA_ITERATOR(vmi, mm, 0);
+
+ mmap_read_lock(mm);
+ for_each_vma(vmi, vma) {
+ if (vma_is_special_mapping(vma, &vdso_info.data_mapping))
+ zap_vma_pages(vma);
+ }
+ mmap_read_unlock(mm);
+
+ return 0;
+}
+#endif
+
static unsigned long vdso_base(void)
{
unsigned long base = STACK_TOP;
int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
{
int ret;
- unsigned long vvar_size, size, data_addr, vdso_addr;
+ unsigned long size, data_addr, vdso_addr;
struct mm_struct *mm = current->mm;
struct vm_area_struct *vma;
struct loongarch_vdso_info *info = current->thread.vdso;
* Determine total area size. This includes the VDSO data itself
* and the data pages.
*/
- vvar_size = VDSO_DATA_SIZE;
- size = vvar_size + info->size;
+ size = VVAR_SIZE + info->size;
data_addr = get_unmapped_area(NULL, vdso_base(), size, 0, 0);
if (IS_ERR_VALUE(data_addr)) {
ret = data_addr;
goto out;
}
- vdso_addr = data_addr + VDSO_DATA_SIZE;
- vma = _install_special_mapping(mm, data_addr, vvar_size,
- VM_READ | VM_MAYREAD,
+ vma = _install_special_mapping(mm, data_addr, VVAR_SIZE,
+ VM_READ | VM_MAYREAD | VM_PFNMAP,
&info->data_mapping);
if (IS_ERR(vma)) {
ret = PTR_ERR(vma);
goto out;
}
- /* Map VDSO data page. */
- ret = remap_pfn_range(vma, data_addr,
- virt_to_phys(&loongarch_vdso_data) >> PAGE_SHIFT,
- vvar_size, PAGE_READONLY);
- if (ret)
- goto out;
-
- /* Map VDSO code page. */
+ vdso_addr = data_addr + VVAR_SIZE;
vma = _install_special_mapping(mm, vdso_addr, info->size,
VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC,
&info->code_mapping);
projects / platform / kernel / linux-rpi.git / commitdiff