Linux/64-bit /LARGEADDRESSAWARE equivalent

Question

Windows enables you to restrict address-space usage to a 32-bit resolution by setting a flag in the PE header (/LARGEADDRESSAWARE). To elaborate: When set, this flag effectively emulates a 32-bit virtual address space environment (image is loaded at/allocations return- addresses <= 0xFFFFFFFF)

Does Linux have an equivalent feature?

Is there some specific requirement for this, or is an academic inquiry? — Ignacio Vazquez-Abrams, Jul 18 '12 at 02:13
Porting software that makes makes -alot- of assumptions about pointers being 4 bytes. — Emjayen, Jul 18 '12 at 02:15

score 0 · Answer 1 · edited Mar 04 '22 at 03:11

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/LARGEADDRESSAWARE allows an extended address space from 2 to 4 gigabytes for 32-bit Windows applications. Otherwise, a 32-bit application on Windows cannot reach those addresses. Linux from early on could reach them, so a /LARGEADRSSAWARE link flag is not needed.

edited Mar 04 '22 at 03:11

phuclv

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answered Jul 18 '12 at 02:19

NickyP

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In a 32-bit PE, yes. 64-bit PEs use it differently. – Ignacio Vazquez-Abrams Jul 18 '12 at 02:20

score 0 · Accepted Answer · answered Jul 18 '12 at 02:19

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Allocating memory in 32-bit space on x86-64 can be done by performing mmap(2) with the MAP_32BIT flag.

answered Jul 18 '12 at 02:19

Ignacio Vazquez-Abrams

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What about the issue of the load address? Particularly in respect to shared libraries. – Emjayen Jul 18 '12 at 02:29
I don't think there's much you can do about that. You'll probably have to copy memory contents around. – Ignacio Vazquez-Abrams Jul 18 '12 at 02:39

Linux/64-bit /LARGEADDRESSAWARE equivalent

2 Answers2