From b741de23e214763ba4ffcd95829315dd315897ea Mon Sep 17 00:00:00 2001 From: Siddhesh Poyarekar Date: Thu, 18 Oct 2012 08:25:03 +0530 Subject: [PATCH] Add note on free list pointers overwriting M_PERTURB bytes Fixes BZ #12140. --- ChangeLog | 7 +++++++ NEWS | 14 +++++++------- manual/memory.texi | 5 ++++- 3 files changed, 18 insertions(+), 8 deletions(-) diff --git a/ChangeLog b/ChangeLog index 21857af..dd3d301 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,10 @@ +2012-10-18 Siddhesh Poyarekar + + [BZ #12140] + * manual/memory.texi (Malloc Tunable Parameters): Add note + about free list pointers overwriting some perturb bytes. + Wording suggested by Roland McGrath. + 2012-10-17 Joseph Myers * math/libm-test.inc (gamma_test): Do not call feclearexcept. diff --git a/NEWS b/NEWS index 9526702..80402e6 100644 --- a/NEWS +++ b/NEWS @@ -10,13 +10,13 @@ Version 2.17 * The following bugs are resolved with this release: 1349, 3479, 5044, 5298, 5400, 6530, 6778, 6808, 9685, 9914, 10014, 10038, - 10631, 11438, 11607, 13412, 13542, 13629, 13679, 13696, 13717, 13741, - 13939, 13966, 14042, 14090, 14150, 14151, 14154, 14157, 14166, 14173, - 14195, 14237, 14251, 14252, 14283, 14298, 14303, 14307, 14328, 14331, - 14336, 14337, 14347, 14349, 14376, 14417, 14459, 14476, 14477, 14505, - 14510, 14516, 14518, 14519, 14530, 14532, 14538, 14543, 14544, 14545, - 14557, 14562, 14568, 14576, 14579, 14583, 14587, 14602, 14621, 14638, - 14645, 14648, 14652, 14660, 14661, 14716. + 10631, 11438, 11607, 12140, 13412, 13542, 13629, 13679, 13696, 13717, + 13741, 13939, 13966, 14042, 14090, 14150, 14151, 14154, 14157, 14166, + 14173, 14195, 14237, 14251, 14252, 14283, 14298, 14303, 14307, 14328, + 14331, 14336, 14337, 14347, 14349, 14376, 14417, 14459, 14476, 14477, + 14505, 14510, 14516, 14518, 14519, 14530, 14532, 14538, 14543, 14544, + 14545, 14557, 14562, 14568, 14576, 14579, 14583, 14587, 14602, 14621, + 14638, 14645, 14648, 14652, 14660, 14661, 14716. * Support for STT_GNU_IFUNC symbols added for s390 and s390x. Optimized versions of memcpy, memset, and memcmp added for System z10 and diff --git a/manual/memory.texi b/manual/memory.texi index fba3a2c..5b14aa6 100644 --- a/manual/memory.texi +++ b/manual/memory.texi @@ -706,7 +706,10 @@ to zero disables all use of @code{mmap}. If non-zero, memory blocks are filled with values depending on some low order bits of this parameter when they are allocated (except when allocated by @code{calloc}) and freed. This can be used to debug the -use of uninitialized or freed heap memory. +use of uninitialized or freed heap memory. Note that this option does not +guarantee that the freed block will have any specific values. It only +guarantees that the content the block had before it was freed will be +overwritten. @end table @end deftypefun -- 2.7.4