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Re: Should glibc be fully reentrant? -- No. (Roland was right).
- From: Florian Weimer <fweimer at redhat dot com>
- To: "Carlos O'Donell" <carlos at redhat dot com>, GNU C Library <libc-alpha at sourceware dot org>
- Cc: Roland McGrath <roland at hack dot frob dot com>, Siddhesh Poyarekar <siddhesh at redhat dot com>
- Date: Thu, 11 Dec 2014 13:36:48 +0100
- Subject: Re: Should glibc be fully reentrant? -- No. (Roland was right).
- Authentication-results: sourceware.org; auth=none
- References: <5488F9C6 dot 9080605 at redhat dot com>
On 12/11/2014 02:56 AM, Carlos O'Donell wrote:
After serious review it seems like we will need to start by
saying that an interposed malloc must operate as-if it were
in async-signal context and use only those functions which
are marked as async-signal-safe.
Practically speaking, this seems rather restrictive. Most mallocs need
locking, and implementations may want to use pthread mutexes. Those are
not async-signal-safe, and I doubt they can be made reentrant, either.
To clarify, I think the idea is fine, it's just the wording that needs
fine-tuning.
--
Florian Weimer / Red Hat Product Security