From bdc109bdc7dcb4ec98de9605c24fbd9afef5f3bc Mon Sep 17 00:00:00 2001 From: sasha-s Date: Thu, 26 Mar 2015 16:47:24 -0700 Subject: fix `slice bounds out of range`/maxAllocSize bugs when accessing the node data we used to use cast to *[maxAllocSize]byte, which breaks if we try to go across maxAllocSize boundary. This leads to occasional panics. Sample stacktrace: ``` panic: runtime error: slice bounds out of range goroutine 1 [running]: github.com/boltdb/bolt.(*node).write(0xc208010f50, 0xc27452a000) $GOPATH/src/github.com/boltdb/bolt/node.go:228 +0x5a5 github.com/boltdb/bolt.(*node).spill(0xc208010f50, 0x0, 0x0) $GOPATH/src/github.com/boltdb/bolt/node.go:364 +0x506 github.com/boltdb/bolt.(*node).spill(0xc208010700, 0x0, 0x0) $GOPATH/src/github.com/boltdb/bolt/node.go:336 +0x12d github.com/boltdb/bolt.(*node).spill(0xc208010620, 0x0, 0x0) $GOPATH/src/github.com/boltdb/bolt/node.go:336 +0x12d github.com/boltdb/bolt.(*Bucket).spill(0xc22b6ae880, 0x0, 0x0) $GOPATH/src/github.com/boltdb/bolt/bucket.go:535 +0x1c4 github.com/boltdb/bolt.(*Bucket).spill(0xc22b6ae840, 0x0, 0x0) $GOPATH/src/github.com/boltdb/bolt/bucket.go:502 +0xac2 github.com/boltdb/bolt.(*Bucket).spill(0xc22f4e2018, 0x0, 0x0) $GOPATH/src/github.com/boltdb/bolt/bucket.go:502 +0xac2 github.com/boltdb/bolt.(*Tx).Commit(0xc22f4e2000, 0x0, 0x0) $GOPATH/src/github.com/boltdb/bolt/tx.go:150 +0x1ee github.com/boltdb/bolt.(*DB).Update(0xc2080e4000, 0xc24d077508, 0x0, 0x0) $GOPATH/src/github.com/boltdb/bolt/db.go:483 +0x169 ``` It usually happens when working with large (50M/100M) values. One way to reproduce it is to change maxAllocSize in bolt_amd64.go to 70000 and run the tests. TestBucket_Put_Large crashes. --- page.go | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'page.go') diff --git a/page.go b/page.go index 58e43c4..bc0d333 100644 --- a/page.go +++ b/page.go @@ -96,7 +96,7 @@ type branchPageElement struct { // key returns a byte slice of the node key. func (n *branchPageElement) key() []byte { buf := (*[maxAllocSize]byte)(unsafe.Pointer(n)) - return buf[n.pos : n.pos+n.ksize] + return (*[maxAllocSize]byte)(unsafe.Pointer(&buf[n.pos]))[:n.ksize] } // leafPageElement represents a node on a leaf page. @@ -110,13 +110,13 @@ type leafPageElement struct { // key returns a byte slice of the node key. func (n *leafPageElement) key() []byte { buf := (*[maxAllocSize]byte)(unsafe.Pointer(n)) - return buf[n.pos : n.pos+n.ksize] + return (*[maxAllocSize]byte)(unsafe.Pointer(&buf[n.pos]))[:n.ksize] } // value returns a byte slice of the node value. func (n *leafPageElement) value() []byte { buf := (*[maxAllocSize]byte)(unsafe.Pointer(n)) - return buf[n.pos+n.ksize : n.pos+n.ksize+n.vsize] + return (*[maxAllocSize]byte)(unsafe.Pointer(&buf[n.pos+n.ksize]))[:n.vsize] } // PageInfo represents human readable information about a page. -- cgit v1.2.3