haproxy/doc
Willy Tarreau 9192d20f02 MINOR: pools: make DEBUG_UAF a runtime setting
Since the massive pools cleanup that happened in 2.6, the pools
architecture was made quite more hierarchical and many alternate code
blocks could be moved to runtime flags set by -dM. One of them had not
been converted by then, DEBUG_UAF. It's not much more difficult actually,
since it only acts on a pair of functions indirection on the slow path
(OS-level allocator) and a default setting for the cache activation.

This patch adds the "uaf" setting to the options permitted in -dM so
that it now becomes possible to set or unset UAF at boot time without
recompiling. This is particularly convenient, because every 3 months on
average, developers ask a user to recompile haproxy with DEBUG_UAF to
understand a bug. Now it will not be needed anymore, instead the user
will only have to disable pools and enable uaf using -dMuaf. Note that
-dMuaf only disables previously enabled pools, but it remains possible
to re-enable caching by specifying the cache after, like -dMuaf,cache.
A few tests with this mode show that it can be an interesting combination
which catches significantly less UAF but will do so with much less
overhead, so it might be compatible with some high-traffic deployments.

The change is very small and isolated. It could be helpful to backport
this at least to 2.7 once confirmed not to cause build issues on exotic
systems, and even to 2.6 a bit later as this has proven to be useful
over time, and could be even more if it did not require a rebuild. If
a backport is desired, the following patches are needed as well:

  CLEANUP: pools: move the write before free to the uaf-only function
  CLEANUP: pool: only include pool-os from pool.c not pool.h
  REORG: pool: move all the OS specific code to pool-os.h
  CLEANUP: pools: get rid of CONFIG_HAP_POOLS
  DEBUG: pool: show a few examples in -dMhelp
2022-12-08 18:54:59 +01:00
..
design-thoughts CLEANUP: assorted typo fixes in the code and comments 2022-10-30 17:17:56 +01:00
internals MINOR: pools: make DEBUG_UAF a runtime setting 2022-12-08 18:54:59 +01:00
lua-api CLEANUP: assorted typo fixes in the code and comments 2022-12-07 09:08:18 +01:00
51Degrees-device-detection.txt MEDIUM: 51d: add support for 51Degrees V4 with Hash algorithm 2022-12-01 16:12:21 +01:00
acl.fig [DOC] add diagrams of queuing and future ACL design 2009-02-22 16:46:38 +01:00
architecture.txt DOC: fix a few remainig cases of "Haproxy" and "HAproxy" in doc and comments 2021-05-09 06:50:46 +02:00
close-options.txt MINOR: config: reject long-deprecated "option forceclose" 2021-06-11 16:57:34 +02:00
coding-style.txt DOC: fix a few remainig cases of "Haproxy" and "HAproxy" in doc and comments 2021-05-09 06:50:46 +02:00
configuration.txt CLEANUP: assorted typo fixes in the code and comments 2022-12-07 09:08:18 +01:00
cookie-options.txt DOC: fix a few typos in the documentation 2018-11-18 22:23:15 +01:00
DeviceAtlas-device-detection.txt MEDIUM: da: update doc and build for new scheduler mode service. 2022-01-28 07:28:53 +01:00
gpl.txt [LICENSE] licensing clarifications 2006-06-15 21:48:13 +02:00
haproxy.1 DOC: add description of pidfile in master-worker mode 2020-08-26 18:40:53 +02:00
intro.txt [RELEASE] Released version 2.8-dev0 2022-12-01 15:25:34 +01:00
lgpl.txt [LICENSE] licensing clarifications 2006-06-15 21:48:13 +02:00
linux-syn-cookies.txt DOC: add doc/linux-syn-cookies.txt 2015-08-11 12:17:41 +02:00
lua.txt [RELEASE] Released version 2.6-dev6 2022-04-16 12:15:47 +02:00
management.txt [RELEASE] Released version 2.8-dev0 2022-12-01 15:25:34 +01:00
netscaler-client-ip-insertion-protocol.txt DOC: fix typos 2019-05-25 07:34:24 +02:00
network-namespaces.txt MAJOR: namespace: add Linux network namespace support 2014-11-21 07:51:57 +01:00
peers-v2.0.txt CLEANUP: assorted typo fixes in the code and comments 2022-12-07 09:08:18 +01:00
peers.txt CLEANUP: assorted typo fixes in the code and comments 2022-12-07 09:08:18 +01:00
proxy-protocol.txt DOC: fix a few remainig cases of "Haproxy" and "HAproxy" in doc and comments 2021-05-09 06:50:46 +02:00
queuing.fig [DOC] add diagrams of queuing and future ACL design 2009-02-22 16:46:38 +01:00
regression-testing.txt DOC: fix a few remainig cases of "Haproxy" and "HAproxy" in doc and comments 2021-05-09 06:50:46 +02:00
seamless_reload.txt CLEANUP: removed obsolete examples an move a few to better places 2019-06-15 21:25:06 +02:00
SOCKS4.protocol.txt MEDIUM: connection: Upstream SOCKS4 proxy support 2019-05-31 17:24:06 +02:00
SPOE.txt DOC: spoe: Clarify use of the event directive in spoe-message section 2021-12-03 10:18:11 +01:00
WURFL-device-detection.txt CONTRIB: move src/wurfl.c and contrib/wurfl to addons/wurfl 2021-04-02 17:48:42 +02:00