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authorBenjamin Peterson <benjamin@python.org>2012-02-21 16:08:05 -0500
committerBenjamin Peterson <benjamin@python.org>2012-02-21 16:08:05 -0500
commitc9f54cf512996790266c17f81584c9725ee99d47 (patch)
treef1208c4e6d7a2f2065a9ebcac6d602eedf8aae66 /Misc/python.man
parent6ca5a4d49fdc55c2555a9692097e9966fd8b804f (diff)
downloadcpython-git-c9f54cf512996790266c17f81584c9725ee99d47.tar.gz
enable hash randomization by default
Diffstat (limited to 'Misc/python.man')
-rw-r--r--Misc/python.man23
1 files changed, 3 insertions, 20 deletions
diff --git a/Misc/python.man b/Misc/python.man
index ef42c4ef94..757d4d8949 100644
--- a/Misc/python.man
+++ b/Misc/python.man
@@ -37,9 +37,6 @@ python \- an interpreted, interactive, object-oriented programming language
.B \-OO
]
[
-.B \-R
-]
-[
.B \-s
]
[
@@ -151,18 +148,6 @@ Discard docstrings in addition to the \fB-O\fP optimizations.
Do not print the version and copyright messages. These messages are
also suppressed in non-interactive mode.
.TP
-.B \-R
-Turn on "hash randomization", so that the hash() values of str, bytes and
-datetime objects are "salted" with an unpredictable pseudo-random value.
-Although they remain constant within an individual Python process, they are
-not predictable between repeated invocations of Python.
-.IP
-This is intended to provide protection against a denial of service
-caused by carefully-chosen inputs that exploit the worst case performance
-of a dict insertion, O(n^2) complexity. See
-http://www.ocert.org/advisories/ocert-2011-003.html
-for details.
-.TP
.B \-s
Don't add user site directory to sys.path.
.TP
@@ -418,9 +403,8 @@ specifying \fB\-v\fP multiple times.
If this is set to a comma-separated string it is equivalent to
specifying the \fB\-W\fP option for each separate value.
.IP PYTHONHASHSEED
-If this variable is set to "random", the effect is the same as specifying
-the \fB-R\fP option: a random value is used to seed the hashes of str,
-bytes and datetime objects.
+If this variable is set to "random", a random value is used to seed the hashes
+of str, bytes and datetime objects.
If PYTHONHASHSEED is set to an integer value, it is used as a fixed seed for
generating the hash() of the types covered by the hash randomization. Its
@@ -429,8 +413,7 @@ interpreter itself, or to allow a cluster of python processes to share hash
values.
The integer must be a decimal number in the range [0,4294967295]. Specifying
-the value 0 will lead to the same hash values as when hash randomization is
-disabled.
+the value 0 will disable hash randomization.
.SH AUTHOR
The Python Software Foundation: http://www.python.org/psf
.SH INTERNET RESOURCES