cpython/Misc
Devin Jeanpierre 31729366e2
bpo-40791: Make compare_digest more constant-time. (GH-20444)
* bpo-40791: Make compare_digest more constant-time.

The existing volatile `left`/`right` pointers guarantee that the reads will all occur, but does not guarantee that they will be _used_. So a compiler can still short-circuit the loop, saving e.g. the overhead of doing the xors and especially the overhead of the data dependency between `result` and the reads. That would change performance depending on where the first unequal byte occurs. This change removes that optimization.

(This is change #1 from https://bugs.python.org/issue40791 .)
2020-11-21 00:55:23 -08:00
..
NEWS.d bpo-40791: Make compare_digest more constant-time. (GH-20444) 2020-11-21 00:55:23 -08:00
ACKS bpo-35498: Added slice support to PathLib parents attribute. (GH-11165) 2020-11-20 10:40:39 -05:00
HISTORY Fix typos mostly in comments, docs and test names (GH-15209) 2019-08-30 16:21:19 -04:00
Porting
README
README.AIX bpo-42087: Remove support for AIX 5.3 and below (GH-22830) 2020-11-16 16:16:10 +01:00
README.coverity
README.valgrind bpo-18859: Document --with-valgrind option in README.valgrind (#10591) 2018-11-20 12:10:49 +01:00
SpecialBuilds.txt bpo-39489: Remove COUNT_ALLOCS special build (GH-18259) 2020-02-03 15:17:15 +01:00
coverity_model.c bpo-35808: Retire pgen and use pgen2 to generate the parser (GH-11814) 2019-03-01 15:34:44 -08:00
gdbinit gdbinit: Use proper define syntax (GH-19557) 2020-04-23 05:49:26 -07:00
indent.pro
python-config.in bpo-38468 : Refactor python-config (#16749) 2019-10-15 11:18:47 -03:00
python-config.sh.in bpo-37925: Mention --embed in python-config usage (GH-15458) 2019-08-26 23:45:36 +02:00
python-embed.pc.in bpo-36721: Add --embed option to python-config (GH-13500) 2019-05-23 03:30:23 +02:00
python-wing3.wpr Mark files as executable that are meant as scripts. (GH-15354) 2019-09-09 07:16:33 -07:00
python-wing4.wpr Mark files as executable that are meant as scripts. (GH-15354) 2019-09-09 07:16:33 -07:00
python-wing5.wpr Mark files as executable that are meant as scripts. (GH-15354) 2019-09-09 07:16:33 -07:00
python.man bpo-41525: Make the Python program help ASCII-only (GH-21836) 2020-09-09 01:28:02 +01:00
python.pc.in bpo-36721: Add --embed option to python-config (GH-13500) 2019-05-23 03:30:23 +02:00
requirements-test.txt Update tzdata to 2020.3 (GH-22856) 2020-10-21 06:40:43 -07:00
svnmap.txt
valgrind-python.supp bpo-35561: Supress valgrind false alarm on epoll_ctl(event) (GH-18060) 2020-01-19 23:38:37 +01:00
vgrindefs

README

Python Misc subdirectory
========================

This directory contains files that wouldn't fit in elsewhere.  Some
documents are only of historic importance.

Files found here
----------------

ACKS                    Acknowledgements
gdbinit                 Handy stuff to put in your .gdbinit file, if you use gdb
HISTORY                 News from previous releases -- oldest last
indent.pro              GNU indent profile approximating my C style
NEWS                    News for this release (for some meaning of "this")
Porting                 Mini-FAQ on porting to new platforms
python-config.in        Python script template for python-config
python.man              UNIX man page for the python interpreter
python.pc.in            Package configuration info template for pkg-config
python-wing*.wpr        Wing IDE project file
README                  The file you're reading now
README.AIX              Information about using Python on AIX
README.coverity         Information about running Coverity's Prevent on Python
README.valgrind         Information for Valgrind users, see valgrind-python.supp
SpecialBuilds.txt       Describes extra symbols you can set for debug builds
svnmap.txt              Map of old SVN revs and branches to hg changeset ids,
                        help history-digging
valgrind-python.supp    Valgrind suppression file, see README.valgrind
vgrindefs               Python configuration for vgrind (a generic pretty printer)