Examples of using Speculative execution in English and their translations into Japanese
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Thus, speculative execution is normally completely invisible to the programmer, or to other users of the same system. The attacks described in this article rely upon breaking open the black box that is the internal state of the microprocessor during speculative execution.
Microsoft says that the risk to users from this bug is"low," and it should be noted that some programs and operating systems are already protected from speculative execution attacks by previous patches meant to mitigate the initial Meltdown/Spectre flaws.
The public disclosure on January 3rd that multiple research teams had discovered security issues related to how modern microprocessors handle speculative execution has brought to the forefront the constant vigilance needed to protect and secure data.
Acronis SDI Update Available to Counter the MDS Vulnerabilities in Intel Processors| Acronis Blog Last week it was revealed that certain Intel processors contain a new set of hardware vulnerabilities that allow hackers to exploit Intel's speculative execution process, which helps improve a CPU's speed and performance.
However, in speculative execution, we objected to this stance. We will face it with the stance that"In the meantime it is a waste to have more than 100 orders waiting without doing anything! Let's do what you can do before you read the data! If it was useless it should be done again!
Red Hat has released an updated Atomic Host for this use case. Attack Description and ImpactTraditional Host Attack Vector: When a processor supports speculative execution of instructions, a speculative load from a virtual address which cannot be resolved to a physical address leads to a page-fault exception during its translation process.
Before arr1->length is loaded and the branch by the if statement in the green frame is finalized(ie. during speculative execution), calculate value
A specially crafted program can then be designed to speculatively perform loads into the cache from privileged memory locations, and monitor the results which can be used to infer the content of that privileged memory. One case that triggers CPU speculative execution is branches.
on impacted microprocessors, during speculative execution of instruction permission faults, exception generation triggered by a faulting access is suppressed until the retirement of the whole instruction block.
While translating Guest physical addresses to Host physical addresses, just like page-fault exceptions on the host, EPT Violation exceptions cause VM exits, indicating that the given guest physical address translation can not resolve to a host physical address OR the guest does not have permissions to access the given host memory. Similar to the host, speculative execution of instructions by a guest user can leverage those EPT violations-induced VM exits to read data from host physical memory via cache side-channel attacks.
That is Speculative Execution.
Windows Server guidance to protect against speculative execution side-channel vulnerabilities.
In scientific terms, the techniques responsible for this feature are referred to as speculative execution and branch prediction.
Both vulnerabilities exploit performance features(caching and speculative execution) common to many modern processors to leak data via a so-called side-channel attack.
Because of speculative execution, the memory read, multiplication, and array index instructions all likely finish before the exception is generated for the privileged memory access.
Out-of-order Execution originally had no implementation of speculative execution, and it was simply to" execute the program first in a range that does not affect consistency".
However, because of its nature, it turned out that compatibility seems to be good when implemented in combination with speculative execution In 1992,"An Out-of-Order Superscalar Processor with Speculative.
Even if both X and Y were cancelled as a result, would there be a trace of the internal result left over from the speculative execution of the illegal instruction X?
Before this page-fault exception is delivered, speculative execution of the load instruction uses the physical address from the not present(P flag 0) OR reserved bits set paging structure entry to access the physical memory.
Variant 3a: Rogue System Register Read- CVE-2018-3640: Allows the attacker to read special privileged(accessible only from kernel) registers by means of speculative execution of unprivileged instructions and later recover value using side channel attack.