pm215

100 ms·

901.
by pm215 11y ago
Note that it says "by the group that disclosed the issue". Xen's security process says that it's the people who disclose issues to xen-security that get to make this decision about pre-deployment.
902.
by pm215 11y ago
The compilers not doing array bounds checks is exactly exploiting UB to give faster code. If out-of-bounds accesses were not UB (ie they had a defined behaviour) the compiler would be required to insert a bounds check in order to catch the
903.
by pm215 11y ago
Even the "art project" use may be illegal in some jurisdictions. For instance UK law (Forgery and Counterfeiting Act 1981 s18) states: "It is an offence for any person, unless the relevant authority has previously consented i
904.
by pm215 11y ago
The FSF is very clear what they mean by "source code"; the GPL defines it as "the preferred form of the work for making modifications to it". Decompiled .wasm isn't the preferred form (as you say yourself it's
905.
by pm215 11y ago
Even if there are no problems with github PRs in themselves, the tmux developers will certainly have an established workflow for reviewing patches and applying them. The last thing they want to do while they're migrating from one hosti
906.
by pm215 11y ago
Not all Exchange setups are configured to allow IMAP access...
907.
by pm215 11y ago
The term "WTF-8" has been around for a long time. Here's an example from 2008: http://www-uxsup.csx.cam.ac.uk/~fanf2/hermes/doc/qsmtp/draft...
908.
by pm215 11y ago
Putting it in a standalone repo has been proposed recently: https://lkml.org/lkml/2015/2/13/116 and the idea doesn't seem to have been rejected, at least.
909.
by pm215 11y ago
kvmtool may not be in the mainline kernel source tree, but that doesn't mean it's dead or that it's failed. It had no need to be in the kernel source tree in the first place -- it's a standalone userspace tool that uses
910.
by pm215 12y ago
If you want an actually usably fast Free Software reversible debugger, I recommend giving rr a go ( http://rr-project.org/ ). It works by record-and-replay, and you can do step-backwards in the replay part. It's not perf
911.
by pm215 12y ago
Speaking as a QEMU developer, I really don't like the coroutine use. They're a portability mess, they tend to expose bugs in dusty corners of the compiler, and they can be painful to debug around. I would much rather take a view t
912.
by pm215 12y ago
The hardware support is that the CPU ignores the top (tag) byte of the pointer when it's used in eg a load or store instruction, so you don't have to manually mask out the tag to use the value.
913.
by pm215 12y ago
The order is guaranteed by the architecture though (not merely by the implementation), provided the target is Device or Strongly Ordered memory. ("For a VLDM, VSTM, LDM and STM instruction with a register list that does not include the
914.
by pm215 12y ago
I think the key insight is that there are whole classes of problems where the answer your brain is likely to come up with by default is just flat out wrong. That way when you encounter them in real life you know to break out the mathematics
915.
by pm215 12y ago
Cheap 32-bit ARM boards, sure. Cheap 64-bit ARM devboards? I'm not aware of any on the market just yet... In a year's time your statement will probably be correct but I don't think it is just at this moment.
916.
by pm215 12y ago
Those aren't portable (in particular they don't exist on Windows, and occasionally they exist but are buggy), and "write a pile of assembly" is even less portable. Personally I think the correct conclusion to draw is &qu
917.
by pm215 12y ago
I think 'resources' there generally means "engineering resources", ie skilled people, not 'funding'. It's not necessarily easy for an open source project to translate money into engineers. A pot of donated
918.
by pm215 12y ago
This only works if you already have a virtual machine with a high quality model of the hardware you're trying to test the driver for. For core PC devices like VESA and SATA this is mostly OK (though you still have a high risk of introd
919.
by pm215 12y ago
The quoted /proc/cpuinfo reports vfpv3 and neon, so it does have an FPU (and it even has the Neon SIMD instructions, which not all SoCs of that era do). From my perspective the softfloat-vs-hardfloat balance has tipped and I would
920.
by pm215 12y ago
I think that high-profile projects have a necessary tendency to default to a fairly high bar for contribution quality and a more heavyweight process for how much testing/review/rework needs to be done to get the patch in. This flo
921.
by pm215 12y ago
"OK on 96% of PDFs" is all very well, but that means that almost 1 document in 20 is performing poorly. It only takes a few slow-rendering documents to make me switch to something else, so if I look at (say) 3 PDF files a day then
922.
by pm215 13y ago
The "just mmap" pattern has also got portability issues if you might move the data file between systems which could have different endianness, pointer size, alignment requirements, etc. (Serialization done properly avoids this bec
923.
by pm215 13y ago
The project I work on compiles for eight different target architectures. Debian supports at least fourteen. Every program in a Linux distribution which has any inline assembly code means extra work that has to be done to support porting tha
924.
by pm215 13y ago
There are a bunch of errors here: * QEMU calls itself an emulator because emulation was its original intent; that it was possible to relatively easily modify it to use hardware virtualization rather than emulating the CPU was a happy accide
925.
by pm215 13y ago
Yes, I think Richard Henderson put in some effort in optimising TCG, which has helped. My take on the KVM vs TCG split is simply that in the end open source projects are driven by the people who put in the work, and inevitably if there&#x27
926.
by pm215 13y ago
Whether you think it's "slow" for cross-architecture use depends on your standards. It's always going to be slower than using the native CPU, because we have to emulate everything, and even with a JIT that's not goi
927.
by pm215 13y ago
Yeah, that's a legitimate use; it is (judging by the code) relying on the fact that it's glue between two calling conventions where the outer one has more callee-saves registers, so we can save LR in a register rather than putting
928.
by pm215 13y ago
Ha, I'd forgotten about that bug report (just closed it) -- it was only in the SuSE version of the aarch64 QEMU, not in the mainline one. I expect most code generators use BR for "jump to destination in arbitrary register" --
929.
by pm215 13y ago
Using fused-multiply-add unless the user has given the compiler option to deviate from strict IEEE754 results would be a compiler bug. I'm pretty sure gcc gets this right -- it will use FMAC on ARM (for instance) only if you pass it th
930.
by pm215 13y ago
If everybody follows the "state your argument and leave" rule then you don't have a discussion forum at all...

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