On 03/05/2010 02:30 PM, Laine Stump wrote:
doTunnelSendAll function (used by QEMU migration) uses a 64k buffer on the stack, which could be problematic. This patch replaces that with a buffer from the heap.
There's a lot more large stacks noted by Coverity, but this is a good start.
While in the neighborhood, this patch also improves error reporting in the case that saferead fails - previously, virStreamAbort() was called (resetting errno) before reporting the error. It's been changed to report the error first.
Yep.
- char buffer[65536]; - int nbytes = sizeof(buffer); + char *buffer; + int nbytes = TUNNEL_SEND_BUF_SIZE; + + if (VIR_ALLOC_N(buffer, TUNNEL_SEND_BUF_SIZE) < 0) { + virStreamAbort(st); + virReportOOMError();
Is this backwards?
+ return -1; + }
/* XXX should honour the 'resource' parameter here */ for (;;) { nbytes = saferead(sock, buffer, nbytes); if (nbytes < 0) { - virStreamAbort(st); virReportSystemError(errno, "%s", _("tunnelled migration failed to read from qemu")); + virStreamAbort(st); + VIR_FREE(buffer);
Especially given that you just reordered the virStreamAbort to come last here? If the above was not a mistake, then ACK to the patch. -- Eric Blake eblake@redhat.com +1-801-349-2682 Libvirt virtualization library http://libvirt.org