public inbox for glibc-bugs@sourceware.org help / color / mirror / Atom feed
From: "vries at gcc dot gnu.org" <sourceware-bugzilla@sourceware.org> To: glibc-bugs@sourceware.org Subject: [Bug manual/26959] New: __malloc_hook example does not adhere to documented usage Date: Fri, 27 Nov 2020 08:38:08 +0000 [thread overview] Message-ID: <bug-26959-131@http.sourceware.org/bugzilla/> (raw) https://sourceware.org/bugzilla/show_bug.cgi?id=26959 Bug ID: 26959 Summary: __malloc_hook example does not adhere to documented usage Product: glibc Version: unspecified Status: NEW Severity: minor Priority: P2 Component: manual Assignee: unassigned at sourceware dot org Reporter: vries at gcc dot gnu.org CC: mtk.manpages at gmail dot com Target Milestone: --- Consider https://www.gnu.org/software/libc/manual/html_node/Hooks-for-Malloc.html . It states: ... An issue to look out for is the time at which the malloc hook functions can be safely installed. If the hook functions call the malloc-related functions recursively, it is necessary that malloc has already properly initialized itself at the time when __malloc_hook etc. is assigned to. ... Then an example follows, which does call malloc recursively, but does nothing specific before __malloc_hook is assigned to for the first time. [ My guess is that the doc list two solutions for the same problem: the first call to malloc may change __malloc_hook from malloc_hook_ini to malloc_check, say if you run with GLIBC_TUNABLES=glibc.malloc.check=3. The first solution is to ensure that malloc is called once before saving and then assigning __malloc_hook, such that the saved __malloc_hook value can be assumed to remain constant, and does not need to be saved again after every recursive call to malloc. The second solution is to make sure the __malloc_hook value is saved again after every recursive call to malloc. ] -- You are receiving this mail because: You are on the CC list for the bug.
next reply other threads:[~2020-11-27 8:38 UTC|newest] Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-11-27 8:38 vries at gcc dot gnu.org [this message] 2021-07-14 3:06 ` [Bug manual/26959] " siddhesh at sourceware dot org 2021-07-14 4:15 ` siddhesh at sourceware dot org
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-26959-131@http.sourceware.org/bugzilla/ \ --to=sourceware-bugzilla@sourceware.org \ --cc=glibc-bugs@sourceware.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).