From ca4e12839aa7234104c5d455046c8ea20af64dec Mon Sep 17 00:00:00 2001 From: cinap_lenrek Date: Wed, 8 Apr 2015 21:04:10 +0200 Subject: [PATCH] pool: avoid triggering assert(b->magic != FREE_MAGIC) in blocksetsize() for mallocalignl() when we trim the front of a block with freefromfront(), the block magic of the back was not initialized which could sometimes trigger the assert in blocksetsize() to fail. fix is to just move the initialization of the magic field before the blocksetsize() call. the second b->magic = UNALLOC_MAGIC isnt really required but just done for consistency with the trim() code above. --- sys/src/libc/port/pool.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/sys/src/libc/port/pool.c b/sys/src/libc/port/pool.c index 201215aa9..3dad7f74f 100644 --- a/sys/src/libc/port/pool.c +++ b/sys/src/libc/port/pool.c @@ -520,10 +520,10 @@ freefromfront(Pool *p, Alloc *b, ulong skip) skip = skip&~(p->quantum-1); if(skip >= 0x1000 || (skip >= b->size>>2 && skip >= MINBLOCKSIZE && skip >= p->minblock)){ bb = (Alloc*)((uchar*)b+skip); - blocksetsize(bb, b->size-skip); bb->magic = UNALLOC_MAGIC; - blocksetsize(b, skip); + blocksetsize(bb, b->size-skip); b->magic = UNALLOC_MAGIC; + blocksetsize(b, skip); pooladd(p, b); return bb; }