Bug 38076 - Memory Mapped File on Embedded environment
Summary: Memory Mapped File on Embedded environment
Alias: None
Product: Class Libraries
Classification: Mono
Component: System.Core ()
Version: 4.2.0 (C6)
Hardware: PC Windows
: --- normal
Target Milestone: Untriaged
Assignee: Bugzilla
Depends on:
Reported: 2016-01-26 22:05 UTC by nicholas.rudh
Modified: 2016-01-27 13:49 UTC (History)
1 user (show)

Is this bug a regression?: ---
Last known good build:

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Description nicholas.rudh 2016-01-26 22:05:41 UTC
Overview: I am trying to use /dev/mem on an embedded environment as a memory mapped file; however when I try to perform the function MemoryMappedFile.CreateOrOpen I get an error which states, "System.IO.IOException: Could not map file" the error code returned is "9" and I have tracked it down to failing in file "/mono/metadata/file-mmap-posix.c" function "open_memory_map." https://github.com/mono/mono/blob/mono-4.2.0-branch/mono/metadata/file-mmap-posix.c (line 349) is the place where the error is thrown.

347 		fd = mkstemp (file_name); 
348 		if (fd == -1) { 
349 			*error = COULD_NOT_MAP_MEMORY; 
350 			goto done; 
351 		} 

I have run this exact same code on my Ubuntu machine and it works perfect, is there any known problems/fixes to this?

Steps to Reproduce: build mono for Xilinx board running embedded Linux, try to open a memorymappedfile /dev/mem

Actual Results: exits with error

Expected Results: allow writing to memorymappedfile

Build Date & Hardware: 4.2.0, built on Ubuntu desktop for Xilinx running embedded Linux. 

Additional Builds and Platforms: does not break on Ubuntu machine built for itself
Comment 1 nicholas.rudh 2016-01-26 23:00:26 UTC
Problem solved the /tmp directory was corrupted on my embedded Linux image.