diff options
| author | cinap_lenrek <cinap_lenrek@felloff.net> | 2015-04-01 01:30:16 +0200 |
|---|---|---|
| committer | cinap_lenrek <cinap_lenrek@felloff.net> | 2015-04-01 01:30:16 +0200 |
| commit | ebf85fb7b75f0bdc3cb27693641bc34c11ca7bed (patch) | |
| tree | 4cd81823ab4db780db70ca3e3f8888876fc554fa | |
| parent | 2a03ed80e4fc52c327e47e1749c97b4e2c1aa1d8 (diff) | |
| download | plan9front-ebf85fb7b75f0bdc3cb27693641bc34c11ca7bed.tar.xz | |
vl: prevent stack altering instructions to be hoisted above loads
fixes bug with libmemdraw where the linker would hoist
the final ADD $const, SP at the end over loads from the
stack causing the front to fall off once a interrupt hits.
| -rw-r--r-- | sys/src/cmd/vl/sched.c | 5 |
1 files changed, 2 insertions, 3 deletions
diff --git a/sys/src/cmd/vl/sched.c b/sys/src/cmd/vl/sched.c index efa88a755..7537cf1c6 100644 --- a/sys/src/cmd/vl/sched.c +++ b/sys/src/cmd/vl/sched.c @@ -85,7 +85,7 @@ sched(Prog *p0, Prog *pe) for(t=s+1; t<=se; t++) { if(!(t->p.mark & LOAD)) continue; - if(t->p.mark & BRANCH) + if(t->p.mark & BRANCH || t->set.ireg & (1<<REGSP)) break; if(conflict(s, t)) break; @@ -102,7 +102,7 @@ sched(Prog *p0, Prog *pe) /* put schedule fodder above load */ for(t=s+1; t<=se; t++) { - if(t->p.mark & BRANCH) + if(t->p.mark & BRANCH || t->set.ireg & (1<<REGSP)) break; if(s > sch && conflict(s-1, t)) continue; @@ -634,7 +634,6 @@ offoverlap(Sch *sa, Sch *sb) int conflict(Sch *sa, Sch *sb) { - if(sa->set.ireg & sb->used.ireg) return 1; if(sa->set.freg & sb->used.freg) |