mirror of
https://github.com/torvalds/linux.git
synced 2026-06-05 13:06:59 +02:00
Linux kernel source tree
1697c4bb52
As pointed out by Jiri, there is still a race condition between tcf_block_put() and tcf_chain_destroy() in a RCU callback. There is no way to make it correct without proper locking or synchronization, because both operate on a shared list. Locking is hard, because the only lock we can pick here is a spinlock, however, in tc_dump_tfilter() we iterate this list with a sleeping function called (tcf_chain_dump()), which makes using a lock to protect chain_list almost impossible. Jiri suggested the idea of holding a refcnt before flushing, this works because it guarantees us there would be no parallel tcf_chain_destroy() during the loop, therefore the race condition is gone. But we have to be very careful with proper synchronization with RCU callbacks. Suggested-by: Jiri Pirko <jiri@mellanox.com> Cc: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Acked-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net> |
||
|---|---|---|
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| 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.