957ac8c421
PMD faults on a zero length file on a file system mounted with -o dax
will not generate SIGBUS as expected.
fd = open(...O_TRUNC);
addr = mmap(NULL, 2*1024*1024, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0);
*addr = 'a';
<expect SIGBUS>
The problem is this code in dax_iomap_pmd_fault:
max_pgoff = (i_size_read(inode) - 1) >> PAGE_SHIFT;
If the inode size is zero, we end up with a max_pgoff that is way larger
than 0. :) Fix it by using DIV_ROUND_UP, as is done elsewhere in the
kernel.
I tested this with some simple test code that ensured that SIGBUS was
received where expected.
Cc: <stable@vger.kernel.org>
Fixes:
|
||
|---|---|---|
| Documentation | ||
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| drivers | ||
| firmware | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
README
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.