Hello, Andrew Eggenberger, le ven. 26 juil. 2019 20:36:20 -0500, a ecrit: > I've been trying to compile and run the trivfs example [1] in the Hurd > Hacking Guide. It compiles with the slightly amended command: > > gcc -g -o one -ltrivfs -lports
Indeed, it is using a libports function and nowadays tools don't let that implicitly taken from libtrivfs. > mmap fails to allocate memory. When I checked the errno string, it said > there was an invalid argument. The mmap manual says MAP_SHARED or > MAP_PRIVATE need to appear in the flags argument (the fourth one). MAP_PRIVATE is actually #defined to 0, so it's not actually "mandatory". The idea here is that MAP_ANON means MAP_PRIVATE anyway, so people were not putting the latter. > I tried adding each and the error persisted. Another possible reason > for the error according to the man page is an amount that is too > high. I checked the variable and it is a large number, but I don't > know how to check to see how much is too much. Print it in hex: gdb> p/x amount 0xffffffff That is way too much (2^32-1) for the 32bit address space. That's where the problem comes from. The issue here is actually that the source code is missing #define _FILE_OFFSET_BITS 64 at the very top of the file. It seems that compatibility symbols have not been introduced, and thus your translator was using 32bit off_t while libtrivfs uses 64bit off_t. Recompile with that #define and it should work. I have updated the webpage, I guess that will show up after mirrors catch up. Samuel
