public inbox for glibc-bugs@sourceware.org help / color / mirror / Atom feed
From: "wdtj at yahoo dot com" <sourceware-bugzilla@sourceware.org> To: glibc-bugs@sources.redhat.com Subject: [Bug libc/9939] New: MCheck is not thread safe - can report false errors on multi threaded apps Date: Wed, 11 Mar 2009 15:08:00 -0000 [thread overview] Message-ID: <20090311150827.9939.wdtj@yahoo.com> (raw) MCheck is not thread safe - can report false errors on multi threaded apps. mcheck.c uses the __malloc_hook (et al) feature of malloc.c & arena.c to intercept memory requests. During it's processing, it swaps the _hooks back to their original values and recursively calls the memory request in order to do the actual memory request. While this hook is swapped out, another thread could call the memory request and at that point get memory that bypassed mcheck. This memory will then be reported as corrupt if it is freed with the mcheck hook back in place. Possible fixes: 1) Add linkage to malloc.c's _int_malloc (el al) functions that would allow mcheck to access the memory allocation without having to go through the code implementing the hooks. 2) Change or add a new hook set that allows the hooker to wrapper the call, not just intercept it. 3) Write a separate memory pool routine for use in mcheck. (yuck). -- Summary: MCheck is not thread safe - can report false errors on multi threaded apps Product: glibc Version: 2.4 Status: NEW Severity: normal Priority: P2 Component: libc AssignedTo: drepper at redhat dot com ReportedBy: wdtj at yahoo dot com CC: glibc-bugs at sources dot redhat dot com http://sourceware.org/bugzilla/show_bug.cgi?id=9939 ------- You are receiving this mail because: ------- You are on the CC list for the bug, or are watching someone who is.
next reply other threads:[~2009-03-11 15:08 UTC|newest] Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top 2009-03-11 15:08 wdtj at yahoo dot com [this message] 2009-03-11 15:14 ` [Bug libc/9939] " drepper at redhat 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=20090311150827.9939.wdtj@yahoo.com \ --to=sourceware-bugzilla@sourceware.org \ --cc=glibc-bugs@sources.redhat.com \ /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).