From 00fbdd622aeb6ab3665a9970d7acb6bdd225028b Mon Sep 17 00:00:00 2001 From: cinap_lenrek Date: Wed, 5 Apr 2017 00:34:07 +0200 Subject: kernel: avoid waserror() botch in devwalk (from drawterm, thanks aiju) calculate alloc flag before waserror(), as compilers like gcc will not notice the value changing later because setjump() restores the old value due to callee-saves. change is applies here to make it easier to merge with drawterm. thanks to aiju for debugging this; used to cause drawterm memory leak until compiled with gcc -O0. --- sys/src/9/port/dev.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) diff --git a/sys/src/9/port/dev.c b/sys/src/9/port/dev.c index 3d0eb4280..464aedc48 100644 --- a/sys/src/9/port/dev.c +++ b/sys/src/9/port/dev.c @@ -176,18 +176,17 @@ devwalk(Chan *c, Chan *nc, char **name, int nname, Dirtab *tab, int ntab, Devgen if(nname > 0) isdir(c); - alloc = 0; + alloc = (nc == nil); wq = smalloc(sizeof(Walkqid)+(nname-1)*sizeof(Qid)); if(waserror()){ - if(alloc && wq->clone!=nil) + if(alloc && wq->clone != nil) cclose(wq->clone); free(wq); return nil; } - if(nc == nil){ + if(alloc){ nc = devclone(c); nc->type = 0; /* device doesn't know about this channel yet */ - alloc = 1; } wq->clone = nc; @@ -252,7 +251,7 @@ Done: if(alloc) cclose(wq->clone); wq->clone = nil; - }else if(wq->clone){ + }else if(wq->clone != nil){ /* attach cloned channel to same device */ wq->clone->type = c->type; } -- cgit v1.2.3