3 ms·
OpenBSD just chose not to implement x86 debug register access from userspace. FYI, Joyent SmartOS/illumos is also similarly not vulnerable, at least by default
by notaplumber 8y ago
OpenBSD just chose not to implement x86 debug register access from userspace.
FYI, Joyent SmartOS/illumos is also similarly not vulnerable, at least by default.
https://kb.cert.org/vuls/id/631579 https://kb.cert.org/vuls/id/631579
- ajross 8y agoWhich is to say, no hardware support for watchpoints in gdb[1]? That seems like not such a great "feature"... This is Theo being Theo. No one sane believes that if someone had come to OpenBSD with an implementation of this (very useful!) feature that they wouldn't have committed it. They just didn't get around to it. [1] In which the fallback is, IIRC, to turn off access to the location at the mapping level and take a SIGSEGV on every access to the 4k region containing the address.
- bionsystem 8y agoIt's crazy that DragonFlyBSD took so little time to fix it. I can understand from Microsoft/Xen/Ubuntu to take only 1 day since they have so much people working/depending on it, but it shows great competence and dedication for such a "small" project as DF to solve it in 1 day. Respect.