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![]() | The contents of the Data execution prevention page were merged into Executable-space protection on 3 March 2016. For the contribution history and old versions of the redirected page, please see its history; for the discussion at that location, see its talk page. |
![]() | The contents of the NX bit page were merged into Executable-space protection on 6 March 2016. For the contribution history and old versions of the redirected page, please see its history; for the discussion at that location, see its talk page. |
On google "data execution prevention" returns 356K hits while "executable space protection" returns 2700 hits. Whereas this article says that basically DEP is Windows implementation of ESP, I think it's pretty clear from Google that DEP is by far the most common term for this technique for all OS. 76.119.30.87 ( talk) 18:10, 3 March 2015 (UTC)
I propose (this is a modified version of an earlier proposal btw) that we merge NX bit#Software emulation of feature and NX bit#Functional comparison of technologies into this article, so that this article is about OS implementations of executable space protection, and NX bit is about the hardware feature. Granted, this would make NX Bit a stub but it should be easily expandable. I already deleted a section of that article that was a copy of the OS Implementations section in this article. WikiWisePowder ( talk) 22:07, 3 March 2016 (UTC)
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So, NX is basically available when enabling PAE mode, which can be used on suitable processors, even if one wants to use only 32-bit of physical address space. This does change slightly page tables and page directories, but only a bit.
However, since 386, segmentation in protected mode, still allowed to protect against executing non-executable segments. There is a bit in GDT/LDT entries in GDT/LDT tables. (Also in IDT actually), that marks if the segment is executable or not. I believe this was used in Linux since day 0, on 386, and is still used to this day on 32-bit x86 machines. (This method can't be used on x86-64 because amd64 does forces flat memory model, and things like CS, DS, ES, SS are all set to zero, and GDT/LDT are not inspected when loading values into registers. FS, GS still do trigger checks in GDT/LDT. But, because all x86-64 uses PAE anyway, it can use NX bit in page tables to achieve the same). 81.6.34.185 ( talk) 15:01, 12 January 2021 (UTC)
This is the
talk page for discussing improvements to the
Executable-space protection article. This is not a forum for general discussion of the article's subject. |
Article policies
|
Find sources: Google ( books · news · scholar · free images · WP refs) · FENS · JSTOR · TWL |
![]() | This article is rated C-class on Wikipedia's
content assessment scale. It is of interest to the following WikiProjects: | |||||||||||||||||||||||||||||||
|
![]() | The contents of the Data execution prevention page were merged into Executable-space protection on 3 March 2016. For the contribution history and old versions of the redirected page, please see its history; for the discussion at that location, see its talk page. |
![]() | The contents of the NX bit page were merged into Executable-space protection on 6 March 2016. For the contribution history and old versions of the redirected page, please see its history; for the discussion at that location, see its talk page. |
On google "data execution prevention" returns 356K hits while "executable space protection" returns 2700 hits. Whereas this article says that basically DEP is Windows implementation of ESP, I think it's pretty clear from Google that DEP is by far the most common term for this technique for all OS. 76.119.30.87 ( talk) 18:10, 3 March 2015 (UTC)
I propose (this is a modified version of an earlier proposal btw) that we merge NX bit#Software emulation of feature and NX bit#Functional comparison of technologies into this article, so that this article is about OS implementations of executable space protection, and NX bit is about the hardware feature. Granted, this would make NX Bit a stub but it should be easily expandable. I already deleted a section of that article that was a copy of the OS Implementations section in this article. WikiWisePowder ( talk) 22:07, 3 March 2016 (UTC)
Hello fellow Wikipedians,
I have just added archive links to one external link on
Executable space protection. Please take a moment to review
my edit. You may add {{
cbignore}}
after the link to keep me from modifying it, if I keep adding bad data, but formatting bugs should be reported instead. Alternatively, you can add {{
nobots|deny=InternetArchiveBot}}
to keep me off the page altogether, but should be used as a last resort. I made the following changes:
When you have finished reviewing my changes, please set the checked parameter below to true or failed to let others know (documentation at {{
Sourcecheck}}
).
An editor has reviewed this edit and fixed any errors that were found.
Cheers.— cyberbot II Talk to my owner:Online 19:14, 29 March 2016 (UTC)
Hello fellow Wikipedians,
I have just modified one external link on Executable space protection. Please take a moment to review my edit. If you have any questions, or need the bot to ignore the links, or the page altogether, please visit this simple FaQ for additional information. I made the following changes:
When you have finished reviewing my changes, you may follow the instructions on the template below to fix any issues with the URLs.
An editor has reviewed this edit and fixed any errors that were found.
Cheers.— InternetArchiveBot ( Report bug) 03:56, 26 September 2017 (UTC)
So, NX is basically available when enabling PAE mode, which can be used on suitable processors, even if one wants to use only 32-bit of physical address space. This does change slightly page tables and page directories, but only a bit.
However, since 386, segmentation in protected mode, still allowed to protect against executing non-executable segments. There is a bit in GDT/LDT entries in GDT/LDT tables. (Also in IDT actually), that marks if the segment is executable or not. I believe this was used in Linux since day 0, on 386, and is still used to this day on 32-bit x86 machines. (This method can't be used on x86-64 because amd64 does forces flat memory model, and things like CS, DS, ES, SS are all set to zero, and GDT/LDT are not inspected when loading values into registers. FS, GS still do trigger checks in GDT/LDT. But, because all x86-64 uses PAE anyway, it can use NX bit in page tables to achieve the same). 81.6.34.185 ( talk) 15:01, 12 January 2021 (UTC)