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From: Laurent Vivier <laurent@vivier.eu>
To: Tobias Koch <tobias.koch@nonterra.com>, qemu-devel@nongnu.org
Cc: riku.voipio@iki.fi
Subject: Re: [PATCH] linux-user: mremap fails with EFAULT if address range overlaps with stack guard
Date: Thu, 7 May 2020 16:35:49 +0200	[thread overview]
Message-ID: <d643f0d0-d5e7-d1f3-d3e2-7d62661774e8@vivier.eu> (raw)
In-Reply-To: <20200305210534.28392-1-tobias.koch@nonterra.com>

Le 05/03/2020 à 22:05, Tobias Koch a écrit :
> If the address range starting at old_address overlaps with the stack guard it
> is invalid and mremap must fail with EFAULT. The musl c library relies on this
> behavior to detect the stack size, which it does by doing consecutive mremaps
> until it hits the stack guard. Without this patch, software (such as the Ruby
> interpreter) that calls pthread_getattr_np under musl will crash on 32 bit
> targets emulated on a 64 bit host.

Could you share some pointers to the code that is doing this?

We have already this kind of code in linux-user/elfload.c,
setup_arg_pages(): could you check why it doesn't work?

Thanks,
Laurent


  reply	other threads:[~2020-05-07 14:38 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-03-05 21:05 [PATCH] linux-user: mremap fails with EFAULT if address range overlaps with stack guard Tobias Koch
2020-05-07 14:35 ` Laurent Vivier [this message]
2020-06-15  7:17   ` Tobias Koch
2020-06-15 20:28     ` Tobias Koch
2020-06-15 21:10       ` Tobias Koch
2020-07-04 14:44         ` Tobias Koch

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