From 1c298fd3dc7894fa0718765a161fd4617e6df986 Mon Sep 17 00:00:00 2001 From: Karina Litskevich Date: Tue, 14 Feb 2023 17:13:17 +0300 Subject: [PATCH v2 1/2] Fix VALGRIND_MAKE_MEM_DEFINED() calls --- src/backend/utils/mmgr/aset.c | 32 ++++++++++++++++++++------------ 1 file changed, 20 insertions(+), 12 deletions(-) diff --git a/src/backend/utils/mmgr/aset.c b/src/backend/utils/mmgr/aset.c index 740729b5d0..ace4907ce9 100644 --- a/src/backend/utils/mmgr/aset.c +++ b/src/backend/utils/mmgr/aset.c @@ -1187,21 +1187,26 @@ AllocSetRealloc(void *pointer, Size size) #ifdef MEMORY_CONTEXT_CHECKING #ifdef RANDOMIZE_ALLOCATED_MEMORY - /* We can only fill the extra space if we know the prior request */ + /* + * We can only fill the extra space if we know the prior request. + * Note: randomize_mem() also marks memory UNDEFINED. + */ if (size > chunk->requested_size) randomize_mem((char *) pointer + chunk->requested_size, size - chunk->requested_size); -#endif - +#else /* - * realloc() (or randomize_mem()) will have left any newly-allocated - * part UNDEFINED, but we may need to adjust trailing bytes from the - * old allocation. + * If this is an increase, realloc() will have left any newly-allocated + * part (from oldsize to chksize) UNDEFINED, but we may need to adjust + * trailing bytes from the old allocation (from chunk->requested_size to + * oldsize) as they are marked NOACCESS. Make sure not to mark extra + * bytes in case chunk->requested_size < size < oldsize. */ #ifdef USE_VALGRIND - if (oldsize > chunk->requested_size) + if (Min(size, oldsize) > chunk->requested_size) VALGRIND_MAKE_MEM_UNDEFINED((char *) pointer + chunk->requested_size, - oldsize - chunk->requested_size); + Min(size, oldsize) - chunk->requested_size); +#endif #endif chunk->requested_size = size; @@ -1211,11 +1216,14 @@ AllocSetRealloc(void *pointer, Size size) #else /* !MEMORY_CONTEXT_CHECKING */ /* - * We don't know how much of the old chunk size was the actual - * allocation; it could have been as small as one byte. We have to be - * conservative and just mark the entire old portion DEFINED. + * We may need to adjust marking of bytes from the old allocation as + * some of them may be marked NOACCESS. We don't know how much of the + * old chunk size was the requested size; it could have been as small as + * one byte. We have to be conservative and just mark the entire old + * portion DEFINED. Make sure not to mark memory behind the new + * allocation in case it's smaller than old one. */ - VALGRIND_MAKE_MEM_DEFINED(pointer, oldsize); + VALGRIND_MAKE_MEM_DEFINED(pointer, Min(size, oldsize)); #endif /* Ensure any padding bytes are marked NOACCESS. */ -- 2.25.1