; Copyright (c) 2015-2017, Intel Corporation ; ; Redistribution and use in source and binary forms, with or without ; modification, are permitted provided that the following conditions are met: ; ; * Redistributions of source code must retain the above copyright notice, ; this list of conditions and the following disclaimer. ; * Redistributions in binary form must reproduce the above copyright notice, ; this list of conditions and the following disclaimer in the documentation ; and/or other materials provided with the distribution. ; * Neither the name of Intel Corporation nor the names of its contributors ; may be used to endorse or promote products derived from this software ; without specific prior written permission. ; ; THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" ; AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE ; IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ; ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE ; LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR ; CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF ; SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS ; INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN ; CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ; ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE ; POSSIBILITY OF SUCH DAMAGE. ; SKD007: Intel(R) PT Buffer Overflow May Result in Incorrect Packets. ; ; Under complex micro-architectural conditions, an Intel PT (Processor ; Trace) OVF (Overflow) packet may be issued after the first byte of a ; multi-byte CYC (Cycle Count) packet, instead of any remaining bytes ; of the CYC. ; ; cpu 6/78 ; cpu 6/94 ; org 0x1000 bits 64 ; @pt p0: psb() ; @pt p1: mode.exec(64bit) ; @pt p2: fup(3: %l0) l0: nop ; The first CYC has its 2nd byte overwritten by OVF, which appears as ; another CYC packet. The two CYCs will have payloads of: ; ; 0x3* or 0x2* and ; 0x1e ; ; @pt p3: cyc(0x3e) ; @pt p4: cyc(0x1e) ; @pt p5: pad() ; @pt p6: fup(3: %l1) l1: nop ; @pt p7: fup(1: %l2) ; @pt p8: tip.pgd(0: %l3) l2: nop l3: hlt ; @pt .exp(ptdump) ;%0p0 psb ;%0p1 mode.exec cs.l ;%0p2 fup 3: %?l0 ;%0p3 cyc 3e ;%0p4 cyc 1e ;%0p5 pad ;%0p6 fup 3: %?l1 ;%0p7 fup 1: %?l2.2 ;%0p8 tip.pgd 0: %?l3.0 ; @pt .exp(ptxed) ;[overflow] ;%0l1 # nop ;[disabled]