Date: Mon, 3 Jan 2022 08:05:27 +0100 From: Markus Wichmann <nullplan@....net> To: musl@...ts.openwall.com Subject: Re: building statically linked DSOs with musl On Mon, Jan 03, 2022 at 09:37:00AM +0800, Sebastien Bourdeauducq wrote: > On 1/1/22 20:56, Joakim Sindholt wrote: > > Musl will set up its own internal global libc structure > > with a bunch of values during the initial dynamic loading phase; among > > the members is libc.auxv, which is what __vdsosym will look through when > > trying to find the VDSO. Since you never ran musl's dynamic linker (and > > even if your host binary was musl-based, not the one that would have > > initialized the libc.auxv baked in to your statically linked DSO) it > > won't have set up this and a whole host of other things. > > Thanks for the hint. > > libc.auxv seems to be set up by __dls2b, which itself is called by __dls2 > via find_sym(&ldso, "__dls2b", 0). > How does this code work when a program is statically linked against musl? > It doesn't. This code only runs in the dynamic linking case. In the static linking one, the program is linked against crt0.c, which contains _start and _start_c, which will call __libc_start_main, which itself will call __init_libc. Note that you cannot call __init_libc, because for that you need the original stack pointer, which you don't have. Ciao, Markus
Powered by blists - more mailing lists
Confused about mailing lists and their use? Read about mailing lists on Wikipedia and check out these guidelines on proper formatting of your messages.