159537 2016-07-07 16:49:31 -0700 REGRESSION(184445): Need to insert a StoreBarrier when we don't know child's epoch 2016-07-07 20:48:36 -0700 1 1 1 Unclassified WebKit JavaScriptCore WebKit Nightly Build Unspecified Unspecified RESOLVED FIXED InRadar P2 Major --- 1 msaboff msaboff commit-queue keith_miller mark.lam saam oldest_to_newest 1208898 0 msaboff 2016-07-07 16:49:31 -0700 In StoreBarrierInsertionPhase::considerBarrier(Edge base, Edge child), there is the following comment and code: // Something we watch out for here is that the null epoch is a catch-all for objects // allocated before we did any epoch tracking. Two objects being in the null epoch // means that we don't know their epoch relationship. if (!!base->epoch() && base->epoch() >= child->epoch()) { if (verbose) dataLog(" Rejecting because of epoch ordering.\n"); return; } The test doesn't check that the child's epoch is null and therefore we won't insert a barrier for the case where we allocate the base object, but don't know when the child object was allocated. <rdar://problem/23438751> 1208943 1 283101 msaboff 2016-07-07 19:58:54 -0700 Created attachment 283101 Patch 1208956 2 msaboff 2016-07-07 20:48:36 -0700 Committed r202955: <http://trac.webkit.org/changeset/202955> 283101 2016-07-07 19:58:54 -0700 2016-07-07 20:00:35 -0700 Patch 159537.patch text/plain 3867 msaboff SW5kZXg6IFNvdXJjZS9KYXZhU2NyaXB0Q29yZS9DaGFuZ2VMb2cKPT09PT09PT09PT09PT09PT09 PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PQotLS0gU291 cmNlL0phdmFTY3JpcHRDb3JlL0NoYW5nZUxvZwkocmV2aXNpb24gMjAyOTUzKQorKysgU291cmNl L0phdmFTY3JpcHRDb3JlL0NoYW5nZUxvZwkod29ya2luZyBjb3B5KQpAQCAtMSwzICsxLDI5IEBA CisyMDE2LTA3LTA3ICBNaWNoYWVsIFNhYm9mZiAgPG1zYWJvZmZAYXBwbGUuY29tPgorCisgICAg ICAgIFJFR1JFU1NJT04oMTg0NDQ1KTogTmVlZCB0byBpbnNlcnQgYSBTdG9yZUJhcnJpZXIgd2hl biB3ZSBkb24ndCBrbm93IGNoaWxkJ3MgZXBvY2gKKyAgICAgICAgaHR0cHM6Ly9idWdzLndlYmtp dC5vcmcvc2hvd19idWcuY2dpP2lkPTE1OTUzNworCisgICAgICAgIFJldmlld2VkIGJ5IE5PQk9E WSAoT09QUyEpLgorCisgICAgICAgIFdlIHdlcmVuJ3QgY2hlY2tpbmcgdGhlIGNhc2Ugb2YgYSBj aGlsZCBub2RlIHdpdGggYSBudWxsIGVwb2NoLiAgVGhlIHByb2JsZW0gc3VyZmFjZXMKKyAgICAg ICAgd2hlbiB0aGUgYmFzZSBub2RlIG9mIGEgUHV0QnlWYWwgdmFyaWFudCBoYXMgYSBub24tbnVs bCBlcG9jaCwgYmVjYXVzZSBpdCByZXByZXNlbnRzIGFuCisgICAgICAgIGFsbG9jYXRpb24gaW4g dGhlIGN1cnJlbnQgZnVuY3Rpb24sIHdoaWxlIHRoZSBjaGlsZCBvZiB0aGUgc2FtZSBub2RlIGhh cyBhbiB1bmtub3duIGVwb2NoLgorICAgICAgICBBZGRlZCBhIGNoZWNrIHRoYXQgdGhlIGNoaWxk IG5vZGUgaXMgbm90IG51bGwgYmVmb3JlIGNvbXBhcmluZyB0aGUgZXBvY2hzIG9mIHRoZSBiYXNl IGFuZAorICAgICAgICBjaGlsZCBub2Rlcy4KKworICAgICAgICBUaGUgYWRkZWQgdGVzdCBjcmVh dGVzIHRoZSBwcm9ibGVtIGNpcmN1bXN0YW5jZSBieSBkb2luZyBhIGZ1bGwgR0MgdG8gcGxhY2Ug YW4gYXJyYXkgaW4KKyAgICAgICAgcmVtZW1iZXJlZCBzcGFjZSwgYWxsb2NhdGluZyBhIG5ldyBv YmplY3QgZm9sbG93ZWQgYnkgYW4gZWRlbiBHQy4gIFRoZSBuZXcgb2JqZWN0IGlzCisgICAgICAg IG9ubHkgcmVmZXJlbmNlZCBieSB0aGUgYXJyYXkgYW5kIHRoZXJlZm9yZSB3b24ndCBiZSB2aXNp dGVkIFdpdGhvdXQgdGhlIHN0b3JlIGJhcnJpZXIuCisgICAgICAgIFRoZSB0ZXN0IG1heSBjcmFz aCBvciBtb3JlIGxpa2VseSBnZXQgdGhlIHdyb25nIGFuc3dlciB3aXRoIHRoZSBidWcuCisKKyAg ICAgICAgKiBkZmcvREZHU3RvcmVCYXJyaWVySW5zZXJ0aW9uUGhhc2UuY3BwOgorICAgICAgICAq IHRlc3RzL3N0cmVzcy9yZWdyZXNzLTE1OTUzNy5qczogQWRkZWQgdGVzdC4KKyAgICAgICAgKE15 TnVtYmVyKToKKyAgICAgICAgKE15TnVtYmVyLnByb3RvdHlwZS5wbHVzT25lKToKKyAgICAgICAg KGJhcik6CisgICAgICAgIChmb28pOgorICAgICAgICAodGVzdCk6CisKIDIwMTYtMDctMDcgIEJl bmphbWluIFBvdWxhaW4gIDxiZW5qYW1pbkB3ZWJraXQub3JnPgogCiAgICAgICAgIFtKU0NdIEFy cmF5LnByb3RvdHlwZVtTeW1ib2wudW5zY29wYWJsZXNdIHNob3VsZCBoYXZlIHRoZSAiaW5jbHVk ZXMiIHByb3BlcnR5CkluZGV4OiBTb3VyY2UvSmF2YVNjcmlwdENvcmUvZGZnL0RGR1N0b3JlQmFy cmllckluc2VydGlvblBoYXNlLmNwcAo9PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09 PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09Ci0tLSBTb3VyY2UvSmF2YVNjcmlwdENv cmUvZGZnL0RGR1N0b3JlQmFycmllckluc2VydGlvblBoYXNlLmNwcAkocmV2aXNpb24gMjAyOTQ0 KQorKysgU291cmNlL0phdmFTY3JpcHRDb3JlL2RmZy9ERkdTdG9yZUJhcnJpZXJJbnNlcnRpb25Q aGFzZS5jcHAJKHdvcmtpbmcgY29weSkKQEAgLTQ1OSwxMiArNDU5LDEyIEBAIHByaXZhdGU6CiAg ICAgICAgIC8vIFNvbWV0aGluZyB3ZSB3YXRjaCBvdXQgZm9yIGhlcmUgaXMgdGhhdCB0aGUgbnVs bCBlcG9jaCBpcyBhIGNhdGNoLWFsbCBmb3Igb2JqZWN0cwogICAgICAgICAvLyBhbGxvY2F0ZWQg YmVmb3JlIHdlIGRpZCBhbnkgZXBvY2ggdHJhY2tpbmcuIFR3byBvYmplY3RzIGJlaW5nIGluIHRo ZSBudWxsIGVwb2NoCiAgICAgICAgIC8vIG1lYW5zIHRoYXQgd2UgZG9uJ3Qga25vdyB0aGVpciBl cG9jaCByZWxhdGlvbnNoaXAuCi0gICAgICAgIGlmICghIWJhc2UtPmVwb2NoKCkgJiYgYmFzZS0+ ZXBvY2goKSA+PSBjaGlsZC0+ZXBvY2goKSkgeworICAgICAgICBpZiAoISFiYXNlLT5lcG9jaCgp ICYmICEhY2hpbGQtPmVwb2NoKCkgJiYgYmFzZS0+ZXBvY2goKSA+PSBjaGlsZC0+ZXBvY2goKSkg ewogICAgICAgICAgICAgaWYgKHZlcmJvc2UpCiAgICAgICAgICAgICAgICAgZGF0YUxvZygiICAg ICAgICAgICAgUmVqZWN0aW5nIGJlY2F1c2Ugb2YgZXBvY2ggb3JkZXJpbmcuXG4iKTsKICAgICAg ICAgICAgIHJldHVybjsKICAgICAgICAgfQotICAgICAgICAKKwogICAgICAgICBjb25zaWRlckJh cnJpZXIoYmFzZSk7CiAgICAgfQogICAgIApJbmRleDogU291cmNlL0phdmFTY3JpcHRDb3JlL3Rl c3RzL3N0cmVzcy9yZWdyZXNzLTE1OTUzNy5qcwo9PT09PT09PT09PT09PT09PT09PT09PT09PT09 PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09Ci0tLSBTb3VyY2UvSmF2YVNj cmlwdENvcmUvdGVzdHMvc3RyZXNzL3JlZ3Jlc3MtMTU5NTM3LmpzCShub25leGlzdGVudCkKKysr IFNvdXJjZS9KYXZhU2NyaXB0Q29yZS90ZXN0cy9zdHJlc3MvcmVncmVzcy0xNTk1MzcuanMJKHdv cmtpbmcgY29weSkKQEAgLTAsMCArMSw2MiBAQAorLy8gVGhpcyB0ZXN0IHZlcmlmaWVzIHRoYXQg d2UgZG9uJ3QgY3Jhc2ggaW4gRlRMIGdlbmVyYXRlZCBjb2RlIGR1ZSB0byBsYWNrIG9mIGEgc3Rv cmUgYmFycmllcgorLy8gZm9yIGEgcHV0LWJ5LXZhbCB3aGVuIHdlIGRvbid0IGtub3cgd2hlbiB0 aGUgdmFsdWUgd2FzIGFsbG9jYXRlZC4KKworY2xhc3MgTXlOdW1iZXIKK3sKKyAgICBjb25zdHJ1 Y3Rvcih2KQorICAgIHsKKyAgICAgICAgdGhpcy5fdiA9IHY7CisgICAgfQorCisgICAgcGx1c09u ZSgpCisgICAgeworICAgICAgICByZXR1cm4gdGhpcy5fdiArIDE7CisgICAgfQorfQorCitub0RG RyhNeU51bWJlci5wbHVzT25lKTsKKworbGV0IGNvdW50ID0gMDsKK2xldCBib2d1cyA9IG51bGw7 CisKK2Z1bmN0aW9uIGJhcigpCit7CisgICAgY291bnQrKzsKKworICAgIGlmICghKGNvdW50ICUg MTAwKSkKKyAgICAgICAgZnVsbEdDKCk7CisgICAgcmV0dXJuIG5ldyBNeU51bWJlcihjb3VudCk7 Cit9CisKK25vREZHKGJhcik7Citub0lubGluZShiYXIpOworCitmdW5jdGlvbiBmb28oaW5kZXgs IGFyZykKK3sKKyAgICB2YXIgcmVzdWx0ID0gW2FyZ1swXV07CisgICAgaWYgKGFyZy5sZW5ndGgg PiAxKQorICAgICAgICByZXN1bHRbMV0gPSBiYXIoKTsKKyAgICByZXR1cm4gcmVzdWx0OworfQor Citub0lubGluZShmb28pOworCitmdW5jdGlvbiB0ZXN0KCkKK3sKKyAgICBmb3IgKGxldCBpID0g MDsgaSA8IDUwMDAwOyBpKyspCisgICAgeworICAgICAgICBsZXQgYSA9IFsxLCBpXTsKKyAgICAg ICAgbGV0IHggPSBmb28oaSwgYSk7CisKKyAgICAgICAgaWYgKCEoY291bnQgJSAxMDApKQorICAg ICAgICAgICAgZWRlbkdDKCk7CisKKyAgICAgICAgZm9yIChsZXQgaiA9IDA7IGogPCAxMDA7IGor KykKKyAgICAgICAgICAgIGJvZ3VzID0gbmV3IE15TnVtYmVyKC0xKTsKKyAgICAgICAgCisgICAg ICAgIGlmICgoY291bnQgKyAxKSAhPSB4WzFdLnBsdXNPbmUoKSkKKyAgICAgICAgICAgIHRocm93 KCJXcm9uZyB2YWx1ZSBmb3IgY291bnQiKTsKKyAgICB9Cit9CisKK3Rlc3QoKTsK