---

yaml
---
r: 164468
b: refs/heads/master
c: f3e8fcc
h: refs/heads/master
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 1c3aff1ceec2cc86810e2690e67873ff0c505862
+refs/heads/master: f3e8fccd06d27773186a0094371daf2d84c79469

trunk/fs/binfmt_elf.c

@@ -1280,9 +1280,6 @@ static int writenote(struct memelfnote *men, struct file *file,
 #define DUMP_WRITE(addr, nr)	\
 	if ((size += (nr)) > limit || !dump_write(file, (addr), (nr))) \
 		goto end_coredump;
-#define DUMP_SEEK(off)	\
-	if (!dump_seek(file, (off))) \
-		goto end_coredump;
 
 static void fill_elf_header(struct elfhdr *elf, int segs,
 			    u16 machine, u32 flags, u8 osabi)
@@ -2016,7 +2013,8 @@ static int elf_core_dump(long signr, struct pt_regs *regs, struct file *file, un
 		goto end_coredump;
 
 	/* Align to page */
-	DUMP_SEEK(dataoff - foffset);
+	if (!dump_seek(file, dataoff - foffset))
+		goto end_coredump;
 
 	for (vma = first_vma(current, gate_vma); vma != NULL;
 			vma = next_vma(vma, gate_vma)) {
@@ -2027,33 +2025,19 @@ static int elf_core_dump(long signr, struct pt_regs *regs, struct file *file, un
 
 		for (addr = vma->vm_start; addr < end; addr += PAGE_SIZE) {
 			struct page *page;
-			struct vm_area_struct *tmp_vma;
-
-			if (get_user_pages(current, current->mm, addr, 1, 0, 1,
-						&page, &tmp_vma) <= 0) {
-				DUMP_SEEK(PAGE_SIZE);
-			} else {
-				if (page == ZERO_PAGE(0)) {
-					if (!dump_seek(file, PAGE_SIZE)) {
-						page_cache_release(page);
-						goto end_coredump;
-					}
-				} else {
-					void *kaddr;
-					flush_cache_page(tmp_vma, addr,
-							 page_to_pfn(page));
-					kaddr = kmap(page);
-					if ((size += PAGE_SIZE) > limit ||
-					    !dump_write(file, kaddr,
-					    PAGE_SIZE)) {
-						kunmap(page);
-						page_cache_release(page);
-						goto end_coredump;
-					}
-					kunmap(page);
-				}
+			int stop;
+
+			page = get_dump_page(addr);
+			if (page) {
+				void *kaddr = kmap(page);
+				stop = ((size += PAGE_SIZE) > limit) ||
+					!dump_write(file, kaddr, PAGE_SIZE);
+				kunmap(page);
 				page_cache_release(page);
-			}
+			} else
+				stop = !dump_seek(file, PAGE_SIZE);
+			if (stop)
+				goto end_coredump;
 		}
 	}
 

trunk/fs/binfmt_elf_fdpic.c

@@ -1325,9 +1325,6 @@ static int writenote(struct memelfnote *men, struct file *file)
 #define DUMP_WRITE(addr, nr)	\
 	if ((size += (nr)) > limit || !dump_write(file, (addr), (nr))) \
 		goto end_coredump;
-#define DUMP_SEEK(off)	\
-	if (!dump_seek(file, (off))) \
-		goto end_coredump;
 
 static inline void fill_elf_fdpic_header(struct elfhdr *elf, int segs)
 {
@@ -1518,50 +1515,34 @@ static int elf_fdpic_dump_segments(struct file *file, size_t *size,
 			   unsigned long *limit, unsigned long mm_flags)
 {
 	struct vm_area_struct *vma;
+	int err = 0;
 
 	for (vma = current->mm->mmap; vma; vma = vma->vm_next) {
 		unsigned long addr;
 
 		if (!maydump(vma, mm_flags))
 			continue;
 
-		for (addr = vma->vm_start;
-		     addr < vma->vm_end;
-		     addr += PAGE_SIZE
-		     ) {
-			struct vm_area_struct *vma;
-			struct page *page;
-
-			if (get_user_pages(current, current->mm, addr, 1, 0, 1,
-					   &page, &vma) <= 0) {
-				DUMP_SEEK(file->f_pos + PAGE_SIZE);
-			}
-			else if (page == ZERO_PAGE(0)) {
-				page_cache_release(page);
-				DUMP_SEEK(file->f_pos + PAGE_SIZE);
-			}
-			else {
-				void *kaddr;
-
-				flush_cache_page(vma, addr, page_to_pfn(page));
-				kaddr = kmap(page);
-				if ((*size += PAGE_SIZE) > *limit ||
-				    !dump_write(file, kaddr, PAGE_SIZE)
-				    ) {
-					kunmap(page);
-					page_cache_release(page);
-					return -EIO;
-				}
+		for (addr = vma->vm_start; addr < vma->vm_end;
+							addr += PAGE_SIZE) {
+			struct page *page = get_dump_page(addr);
+			if (page) {
+				void *kaddr = kmap(page);
+				*size += PAGE_SIZE;
+				if (*size > *limit)
+					err = -EFBIG;
+				else if (!dump_write(file, kaddr, PAGE_SIZE))
+					err = -EIO;
 				kunmap(page);
 				page_cache_release(page);
-			}
+			} else if (!dump_seek(file, file->f_pos + PAGE_SIZE))
+				err = -EFBIG;
+			if (err)
+				goto out;
 		}
 	}
-
-	return 0;
-
-end_coredump:
-	return -EFBIG;
+out:
+	return err;
 }
 #endif
 
@@ -1802,7 +1783,8 @@ static int elf_fdpic_core_dump(long signr, struct pt_regs *regs,
 				goto end_coredump;
 	}
 
-	DUMP_SEEK(dataoff);
+	if (!dump_seek(file, dataoff))
+		goto end_coredump;
 
 	if (elf_fdpic_dump_segments(file, &size, &limit, mm_flags) < 0)
 		goto end_coredump;

trunk/include/linux/mm.h

@@ -817,6 +817,7 @@ int get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
 			struct page **pages, struct vm_area_struct **vmas);
 int get_user_pages_fast(unsigned long start, int nr_pages, int write,
 			struct page **pages);
+struct page *get_dump_page(unsigned long addr);
 
 extern int try_to_release_page(struct page * page, gfp_t gfp_mask);
 extern void do_invalidatepage(struct page *page, unsigned long offset);

trunk/mm/memory.c

@@ -1423,9 +1423,40 @@ int get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
 
 	return __get_user_pages(tsk, mm, start, nr_pages, flags, pages, vmas);
 }
-
 EXPORT_SYMBOL(get_user_pages);
 
+/**
+ * get_dump_page() - pin user page in memory while writing it to core dump
+ * @addr: user address
+ *
+ * Returns struct page pointer of user page pinned for dump,
+ * to be freed afterwards by page_cache_release() or put_page().
+ *
+ * Returns NULL on any kind of failure - a hole must then be inserted into
+ * the corefile, to preserve alignment with its headers; and also returns
+ * NULL wherever the ZERO_PAGE, or an anonymous pte_none, has been found -
+ * allowing a hole to be left in the corefile to save diskspace.
+ *
+ * Called without mmap_sem, but after all other threads have been killed.
+ */
+#ifdef CONFIG_ELF_CORE
+struct page *get_dump_page(unsigned long addr)
+{
+	struct vm_area_struct *vma;
+	struct page *page;
+
+	if (__get_user_pages(current, current->mm, addr, 1,
+				GUP_FLAGS_FORCE, &page, &vma) < 1)
+		return NULL;
+	if (page == ZERO_PAGE(0)) {
+		page_cache_release(page);
+		return NULL;
+	}
+	flush_cache_page(vma, addr, page_to_pfn(page));
+	return page;
+}
+#endif /* CONFIG_ELF_CORE */
+
 pte_t *get_locked_pte(struct mm_struct *mm, unsigned long addr,
 			spinlock_t **ptl)
 {