diff options
Diffstat (limited to 'src/runtime/stack1.go')
| -rw-r--r-- | src/runtime/stack1.go | 22 |
1 files changed, 14 insertions, 8 deletions
diff --git a/src/runtime/stack1.go b/src/runtime/stack1.go index 27427af955..e593b8a3a8 100644 --- a/src/runtime/stack1.go +++ b/src/runtime/stack1.go @@ -246,13 +246,15 @@ func stackalloc(n uint32) stack { return stack{uintptr(v), uintptr(v) + uintptr(n)} } -func stackfree(stk stack) { +func stackfree(stk stack, n uintptr) { gp := getg() - n := stk.hi - stk.lo v := (unsafe.Pointer)(stk.lo) if n&(n-1) != 0 { throw("stack not a power of 2") } + if stk.lo+n < stk.hi { + throw("bad stack size") + } if stackDebug >= 1 { println("stackfree", v, n) memclr(v, n) // for testing, clobber stack data @@ -584,14 +586,16 @@ func copystack(gp *g, newsize uintptr) { gp.stack = new gp.stackguard0 = new.lo + _StackGuard // NOTE: might clobber a preempt request gp.sched.sp = new.hi - used + oldsize := gp.stackAlloc + gp.stackAlloc = newsize // free old stack if stackPoisonCopy != 0 { fillstack(old, 0xfc) } - if newsize > old.hi-old.lo { + if newsize > oldsize { // growing, free stack immediately - stackfree(old) + stackfree(old, oldsize) } else { // shrinking, queue up free operation. We can't actually free the stack // just yet because we might run into the following situation: @@ -604,6 +608,7 @@ func copystack(gp *g, newsize uintptr) { // By not freeing, we prevent step #4 until GC is done. lock(&stackpoolmu) *(*stack)(unsafe.Pointer(old.lo)) = stackfreequeue + *(*uintptr)(unsafe.Pointer(old.lo + ptrSize)) = oldsize stackfreequeue = old unlock(&stackpoolmu) } @@ -743,7 +748,7 @@ func newstack() { } // Allocate a bigger segment and move the stack. - oldsize := int(gp.stack.hi - gp.stack.lo) + oldsize := int(gp.stackAlloc) newsize := oldsize * 2 if uintptr(newsize) > maxstacksize { print("runtime: goroutine stack exceeds ", maxstacksize, "-byte limit\n") @@ -786,7 +791,7 @@ func shrinkstack(gp *g) { if gp.stack.lo != 0 { // Free whole stack - it will get reallocated // if G is used again. - stackfree(gp.stack) + stackfree(gp.stack, gp.stackAlloc) gp.stack.lo = 0 gp.stack.hi = 0 } @@ -796,7 +801,7 @@ func shrinkstack(gp *g) { throw("missing stack in shrinkstack") } - oldsize := gp.stack.hi - gp.stack.lo + oldsize := gp.stackAlloc newsize := oldsize / 2 if newsize < _FixedStack { return // don't shrink below the minimum-sized stack @@ -832,7 +837,8 @@ func shrinkfinish() { unlock(&stackpoolmu) for s.lo != 0 { t := *(*stack)(unsafe.Pointer(s.lo)) - stackfree(s) + n := *(*uintptr)(unsafe.Pointer(s.lo + ptrSize)) + stackfree(s, n) s = t } } |