author: Jann Horn <jannh@google.com> 2020-10-15 20:12:46 -0700
committer: Linus Torvalds <torvalds@linux-foundation.org> 2020-10-16 11:11:21 -0700
commit: afc63a97b764bc5a715762d0d9cc9785c2ef4e75
parent: df0c09c0117300cd03f6e8532527bf591d4eee65
Commit Summary:
Diffstat:
1 file changed, 31 insertions, 0 deletions
diff --git a/fs/coredump.c b/fs/coredump.c
index 5e24c06092c9..6042d15acd51 100644
--- a/fs/coredump.c
+++ b/fs/coredump.c
@@ -876,6 +876,40 @@ int dump_skip(struct coredump_params *cprm, size_t nr)
}
EXPORT_SYMBOL(dump_skip);
+#ifdef CONFIG_ELF_CORE
+int dump_user_range(struct coredump_params *cprm, unsigned long start,
+ unsigned long len)
+{
+ unsigned long addr;
+
+ for (addr = start; addr < start + len; addr += PAGE_SIZE) {
+ struct page *page;
+ int stop;
+
+ /*
+ * To avoid having to allocate page tables for virtual address
+ * ranges that have never been used yet, and also to make it
+ * easy to generate sparse core files, use a helper that returns
+ * NULL when encountering an empty page table entry that would
+ * otherwise have been filled with the zero page.
+ */
+ page = get_dump_page(addr);
+ if (page) {
+ void *kaddr = kmap(page);
+
+ stop = !dump_emit(cprm, kaddr, PAGE_SIZE);
+ kunmap(page);
+ put_page(page);
+ } else {
+ stop = !dump_skip(cprm, PAGE_SIZE);
+ }
+ if (stop)
+ return 0;
+ }
+ return 1;
+}
+#endif
+
int dump_align(struct coredump_params *cprm, int align)
{
unsigned mod = cprm->pos & (align - 1);