Subject: Re: [PATCH 00/11] ARMv8.3 pointer authentication userspace support
To: Mark Rutland <mark.rutland@arm.com>,
        linux-arm-kernel@lists.infradead.org
References: <1500480092-28480-1-git-send-email-mark.rutland@arm.com>
Cc: arnd@arndb.de, catalin.marinas@arm.com, christoffer.dall@linaro.org,
        Dave.Martin@arm.com, jiong.wang@arm.com, kvmarm@lists.cs.columbia.edu,
        linux-arch@vger.kernel.org, marc.zyngier@arm.com,
        suzuki.poulose@arm.com, will.deacon@arm.com,
        linux-kernel@vger.kernel.org, kernel-hardening@lists.openwall.com
From: Yao Qi <yao.qi@arm.com>
Message-ID: <bb507ee1-c7ba-4c73-0d0f-058c4821793c@arm.com>
Date: Tue, 25 Jul 2017 12:32:10 +0100
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On 19/07/17 17:01, Mark Rutland wrote:
> If authentication fails, bits are set in the pointer such that it is guaranteed
> to cause a fault if used.

How does user space know the fault is caused by authentication fail?
When GDB is debugging a program, and it failed in pointer
authentication, I assume GDB only knows that the program receives signal
SIGSEGV, but how does GDB or user know why does the program get SIGSEGV?
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