public inbox for gcc-bugs@sourceware.org help / color / mirror / Atom feed
From: "rguenth at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug pch/48004] doesn't work with randomize_va_space Date: Mon, 07 Mar 2011 11:07:00 -0000 [thread overview] Message-ID: <bug-48004-4-4iJP7qzZNt@http.gcc.gnu.org/bugzilla/> (raw) In-Reply-To: <bug-48004-4@http.gcc.gnu.org/bugzilla/> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48004 Richard Guenther <rguenth at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|WAITING |NEW --- Comment #5 from Richard Guenther <rguenth at gcc dot gnu.org> 2011-03-07 11:07:33 UTC --- We can't simply use MAP_FIXED, as that will discard existing overlapping mappings. MAP_FIXED Don't interpret addr as a hint: place the mapping at exactly that address. addr must be a multiple of the page size. If the memory region specified by addr and len overlaps pages of any existing mapping(s), then the overlapped part of the existing mapping(s) will be discarded. If the specified address cannot be used, mmap() will fail. Because requiring a fixed address for a mapping is less portable, the use of this option is dis- couraged. So we'd need to portably check for existing mappings in the range we want to request. I don't think that is desirable (if only from a performance perspective). The only way to do this that I can think of is parsing /proc or installing a SIGSEGV/SIGBUS handler and poking every page ...
next prev parent reply other threads:[~2011-03-07 11:07 UTC|newest] Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top 2011-03-06 12:42 [Bug pch/48004] New: " wbrana at gmail dot com 2011-03-06 21:07 ` [Bug pch/48004] " pinskia at gcc dot gnu.org 2011-03-06 21:11 ` wbrana at gmail dot com 2011-03-07 10:24 ` rguenth at gcc dot gnu.org 2011-03-07 10:54 ` wbrana at gmail dot com 2011-03-07 11:07 ` rguenth at gcc dot gnu.org [this message] 2011-03-07 11:21 ` wbrana at gmail dot com 2011-03-07 12:35 ` wbrana at gmail dot com 2012-07-19 18:57 ` wbrana at gmail dot com
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=bug-48004-4-4iJP7qzZNt@http.gcc.gnu.org/bugzilla/ \ --to=gcc-bugzilla@gcc.gnu.org \ --cc=gcc-bugs@gcc.gnu.org \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: linkBe sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions for how to clone and mirror all data and code used for this inbox; as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).