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From: Florian Weimer <fweimer@redhat.com>
To: "H.J. Lu" <hjl.tools@gmail.com>
Cc: libc-alpha@sourceware.org
Subject: Re: [PATCH] x86: Set FSGSBASE to active if enabled by kernel
References: <20230309182603.205394-1-hjl.tools@gmail.com>
Date: Mon, 13 Mar 2023 14:44:36 +0100
In-Reply-To: <20230309182603.205394-1-hjl.tools@gmail.com> (H. J. Lu's message
	of "Thu, 9 Mar 2023 10:26:03 -0800")
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* H. J. Lu:

> Linux kernel uses AT_HWCAP2 to indicate if FSGSBASE instructions are
> enabled.  If the HWCAP2_FSGSBASE bit in AT_HWCAP2 is set, FSGSBASE
> instructions can be used in user space.  Define dl_check_hwcap2 to set
> the FSGSBASE feature to active on Linux when the HWCAP2_FSGSBASE bit is
> set.

Could you add a test against /proc/cpuinfo flags?  It should be a
perfect match on current kernels.

Thanks,
Florian