Date: Fri, 25 Sep 2020 21:14:18 -0700 From: Fangrui Song <i@...kray.me> To: musl@...ts.openwall.com Cc: Rich Felker <dalias@...c.org> Subject: Re: SIGSEGV with TEXTREL On Fri, Sep 25, 2020 at 7:53 PM Dominic Chen <d.c.ddcc@...il.com> wrote: > > On 9/25/2020 6:46 PM, Rich Felker wrote: > > > > The right way to make this more friendly, I think, would be tracking > > the writable mapping range for each DSO (technically this is > > incomplete since it could be multiple ranges, but in that case we'd > > just take the convex hull of them and accept false negatives because > > anything else is almost surely too big a performance hit), and > > erroring out before processing a relocation at an address that's not > > writable for its DSO. This would also go part of the way towards > > making it possible for ldd to process untrusted files. > > I agree that that seems to be a better solution, and it was also > discussed in the previous mailing list thread. But my point is just that > given how this issue has been reoccurring, I think it'd be useful to do > something now (e.g. emit a non-fail warning if TEXTRELs are present), > rather than deferring any changes. > > Thanks, > > Dominic binutils 2.35 can be configured with --enable-textrel-check=yes, and Linux/x86 defaults to 'yes'. ld emits a warning upon a text relocation: warning: creating DT_TEXTREL in a PIE (LLD always disallows text relocations by default (-z text). You need -z notext to enable DF_TEXTREL and text relocations.)
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.