Add valgrind suppressions for wcsrtombs optimizations
wcsrtombs (called through wchar2char from common functions like lower,
upper, etc.) uses various optimizations that may look like access to
uninitialized data, triggering valgrind reports.
For example AVX2 instructions load data in 256-bit chunks, and gconv
does something similar with 32-bit chunks. This is faster than accessing
the bytes one by one, and the uninitialized part of the buffer is not
actually used. So suppress the bogus reports.
The exact stack depends on possible optimizations - it might be AVX, SSE
(as in the report by Aleksander Alekseev) or something else. Hence the
last frame is wildcarded, to deal with this.
Backpatch all the way back to 9.4.
Author: Tomas Vondra
Discussion: https://www.postgresql.org/message-id/flat/90ac0452-e907-e7a4-b3c8-15bd33780e62%402ndquadrant.com
Discussion: https://www.postgresql.org/message-id/20180220150838.GD18315@e733.localdomain
Branch
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REL_10_STABLE
Details
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https://git.postgresql.org/pg/commitdiff/5b16a353543ecec36ffda68269defb7b1b002f60
Modified Files
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src/tools/valgrind.supp | 36 ++++++++++++++++++++++++++++++++++++
1 file changed, 36 insertions(+)