diff options
Diffstat (limited to 'src/runtime/stack1.go')
| -rw-r--r-- | src/runtime/stack1.go | 23 |
1 files changed, 19 insertions, 4 deletions
diff --git a/src/runtime/stack1.go b/src/runtime/stack1.go index e593b8a3a8..f77e87cdf9 100644 --- a/src/runtime/stack1.go +++ b/src/runtime/stack1.go @@ -175,7 +175,7 @@ func stackcache_clear(c *mcache) { unlock(&stackpoolmu) } -func stackalloc(n uint32) stack { +func stackalloc(n uint32) (stack, []stkbar) { // Stackalloc must be called on scheduler stack, so that we // never try to grow the stack during the code that stackalloc runs. // Doing so would cause a deadlock (issue 1547). @@ -190,12 +190,18 @@ func stackalloc(n uint32) stack { print("stackalloc ", n, "\n") } + // Compute the size of stack barrier array. + maxstkbar := gcMaxStackBarriers(int(n)) + nstkbar := unsafe.Sizeof(stkbar{}) * uintptr(maxstkbar) + if debug.efence != 0 || stackFromSystem != 0 { v := sysAlloc(round(uintptr(n), _PageSize), &memstats.stacks_sys) if v == nil { throw("out of memory (stackalloc)") } - return stack{uintptr(v), uintptr(v) + uintptr(n)} + top := uintptr(n) - nstkbar + stkbarSlice := slice{add(v, top), 0, maxstkbar} + return stack{uintptr(v), uintptr(v) + top}, *(*[]stkbar)(unsafe.Pointer(&stkbarSlice)) } // Small stacks are allocated with a fixed-size free-list allocator. @@ -243,7 +249,9 @@ func stackalloc(n uint32) stack { if stackDebug >= 1 { print(" allocated ", v, "\n") } - return stack{uintptr(v), uintptr(v) + uintptr(n)} + top := uintptr(n) - nstkbar + stkbarSlice := slice{add(v, top), 0, maxstkbar} + return stack{uintptr(v), uintptr(v) + top}, *(*[]stkbar)(unsafe.Pointer(&stkbarSlice)) } func stackfree(stk stack, n uintptr) { @@ -556,7 +564,7 @@ func copystack(gp *g, newsize uintptr) { used := old.hi - gp.sched.sp // allocate new stack - new := stackalloc(uint32(newsize)) + new, newstkbar := stackalloc(uint32(newsize)) if stackPoisonCopy != 0 { fillstack(new, 0xfd) } @@ -582,12 +590,17 @@ func copystack(gp *g, newsize uintptr) { } memmove(unsafe.Pointer(new.hi-used), unsafe.Pointer(old.hi-used), used) + // copy old stack barriers to new stack barrier array + newstkbar = newstkbar[:len(gp.stkbar)] + copy(newstkbar, gp.stkbar) + // Swap out old stack for new one 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 + gp.stkbar = newstkbar // free old stack if stackPoisonCopy != 0 { @@ -794,6 +807,8 @@ func shrinkstack(gp *g) { stackfree(gp.stack, gp.stackAlloc) gp.stack.lo = 0 gp.stack.hi = 0 + gp.stkbar = nil + gp.stkbarPos = 0 } return } |