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-rw-r--r--fs/binfmt_elf.c44
-rw-r--r--fs/binfmt_elf_fdpic.c56
-rw-r--r--include/linux/mm.h1
-rw-r--r--mm/memory.c33
4 files changed, 66 insertions, 68 deletions
diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
index 7c1e65d54872..442d94fe255c 100644
--- a/fs/binfmt_elf.c
+++ b/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;
}
}
diff --git a/fs/binfmt_elf_fdpic.c b/fs/binfmt_elf_fdpic.c
index 20fbeced472b..76285471073e 100644
--- a/fs/binfmt_elf_fdpic.c
+++ b/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)
{
@@ -1518,6 +1515,7 @@ 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;
@@ -1525,43 +1523,26 @@ static int elf_fdpic_dump_segments(struct file *file, size_t *size,
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;
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 19ff81c49ba6..e41795bba95d 100644
--- a/include/linux/mm.h
+++ b/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);
diff --git a/mm/memory.c b/mm/memory.c
index 4b5200f5f35a..a8430ff13837 100644
--- a/mm/memory.c
+++ b/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)
{
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-10 14:37:11 +0000