mainlining shenanigans
3a7d2fd16c
Lockdep complains about a possible deadlock between mount and unlink (which is technically impossible), but fixing this improves possible future multiple-backend support, and keeps locking in the right order. The lockdep warning could be triggered by unlinking a file in the pstore filesystem: -> #1 (&sb->s_type->i_mutex_key#14){++++++}: lock_acquire+0xc9/0x220 down_write+0x3f/0x70 pstore_mkfile+0x1f4/0x460 pstore_get_records+0x17a/0x320 pstore_fill_super+0xa4/0xc0 mount_single+0x89/0xb0 pstore_mount+0x13/0x20 mount_fs+0xf/0x90 vfs_kern_mount+0x66/0x170 do_mount+0x190/0xd50 SyS_mount+0x90/0xd0 entry_SYSCALL_64_fastpath+0x1c/0xb1 -> #0 (&psinfo->read_mutex){+.+.+.}: __lock_acquire+0x1ac0/0x1bb0 lock_acquire+0xc9/0x220 __mutex_lock+0x6e/0x990 mutex_lock_nested+0x16/0x20 pstore_unlink+0x3f/0xa0 vfs_unlink+0xb5/0x190 do_unlinkat+0x24c/0x2a0 SyS_unlinkat+0x16/0x30 entry_SYSCALL_64_fastpath+0x1c/0xb1 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&sb->s_type->i_mutex_key#14); lock(&psinfo->read_mutex); lock(&sb->s_type->i_mutex_key#14); lock(&psinfo->read_mutex); Reported-by: Marta Lofstedt <marta.lofstedt@intel.com> Reported-by: Chris Wilson <chris@chris-wilson.co.uk> Signed-off-by: Kees Cook <keescook@chromium.org> Acked-by: Namhyung Kim <namhyung@kernel.org> |
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| certs | ||
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| Documentation | ||
| 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 | ||
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.