{
char *buf = file->private_data;
size_t phdrs_offset, notes_offset, data_offset;
+ size_t page_offline_frozen = 1;
size_t phdrs_len, notes_len;
struct kcore_list *m;
size_t tsz;
int ret = 0;
down_read(&kclist_lock);
+ /*
+ * Don't race against drivers that set PageOffline() and expect no
+ * further page access.
+ */
+ page_offline_freeze();
get_kcore_size(&nphdr, &phdrs_len, ¬es_len, &data_offset);
phdrs_offset = sizeof(struct elfhdr);
phdr->p_type = PT_LOAD;
phdr->p_flags = PF_R | PF_W | PF_X;
phdr->p_offset = kc_vaddr_to_offset(m->addr) + data_offset;
- if (m->type == KCORE_REMAP)
- phdr->p_vaddr = (size_t)m->vaddr;
- else
- phdr->p_vaddr = (size_t)m->addr;
- if (m->type == KCORE_RAM || m->type == KCORE_REMAP)
+ phdr->p_vaddr = (size_t)m->addr;
+ if (m->type == KCORE_RAM)
phdr->p_paddr = __pa(m->addr);
else if (m->type == KCORE_TEXT)
phdr->p_paddr = __pa_symbol(m->addr);
m = NULL;
while (buflen) {
+ struct page *page;
+ unsigned long pfn;
+
/*
* If this is the first iteration or the address is not within
* the previous entry, search for a matching entry.
}
}
+ if (page_offline_frozen++ % MAX_ORDER_NR_PAGES == 0) {
+ page_offline_thaw();
+ cond_resched();
+ page_offline_freeze();
+ }
+
if (&m->list == &kclist_head) {
if (clear_user(buffer, tsz)) {
ret = -EFAULT;
goto out;
}
m = NULL; /* skip the list anchor */
- } else if (!pfn_is_ram(__pa(start) >> PAGE_SHIFT)) {
- if (clear_user(buffer, tsz)) {
- ret = -EFAULT;
- goto out;
- }
- } else if (m->type == KCORE_VMALLOC) {
+ goto skip;
+ }
+
+ switch (m->type) {
+ case KCORE_VMALLOC:
vread(buf, (char *)start, tsz);
/* we have to zero-fill user buffer even if no read */
if (copy_to_user(buffer, buf, tsz)) {
ret = -EFAULT;
goto out;
}
- } else if (m->type == KCORE_USER) {
+ break;
+ case KCORE_USER:
/* User page is handled prior to normal kernel page: */
if (copy_to_user(buffer, (char *)start, tsz)) {
ret = -EFAULT;
goto out;
}
- } else {
+ break;
+ case KCORE_RAM:
+ pfn = __pa(start) >> PAGE_SHIFT;
+ page = pfn_to_online_page(pfn);
+
+ /*
+ * Don't read offline sections, logically offline pages
+ * (e.g., inflated in a balloon), hwpoisoned pages,
+ * and explicitly excluded physical ranges.
+ */
+ if (!page || PageOffline(page) ||
+ is_page_hwpoison(page) || !pfn_is_ram(pfn)) {
+ if (clear_user(buffer, tsz)) {
+ ret = -EFAULT;
+ goto out;
+ }
+ break;
+ }
+ fallthrough;
+ case KCORE_VMEMMAP:
+ case KCORE_TEXT:
if (kern_addr_valid(start)) {
/*
* Using bounce buffer to bypass the
goto out;
}
}
+ break;
+ default:
+ pr_warn_once("Unhandled KCORE type: %d\n", m->type);
+ if (clear_user(buffer, tsz)) {
+ ret = -EFAULT;
+ goto out;
+ }
}
+skip:
buflen -= tsz;
*fpos += tsz;
buffer += tsz;
}
out:
+ page_offline_thaw();
up_read(&kclist_lock);
if (ret)
return ret;