From: Will Deacon <will.deacon@arm.com>
To: Dave Martin <Dave.Martin@arm.com>
Cc: linux-arch@vger.kernel.org, linux-api@vger.kernel.org,
James Morse <james.morse@arm.com>,
"Eric W. Biederman" <ebiederm@xmission.com>,
Catalin Marinas <catalin.marinas@arm.com>,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH v2 2/3] arm64: fpsimd: Fix bad si_code for undiagnosed SIGFPE
Date: Thu, 8 Mar 2018 17:11:53 +0000 [thread overview]
Message-ID: <20180308171153.GD14918@arm.com> (raw)
In-Reply-To: <1519926248-12591-3-git-send-email-Dave.Martin@arm.com>
On Thu, Mar 01, 2018 at 05:44:07PM +0000, Dave Martin wrote:
> Currently a SIGFPE delivered in response to a floating-point
> exception trap may have si_code set to 0 on arm64. As reported by
> Eric, this is a bad idea since this is the value of SI_USER -- yet
> this signal is definitely not the result of kill(2), tgkill(2) etc.
> and si_uid and si_pid make limited sense whereas we do want to
> yield a value for si_addr (which doesn't exist for SI_USER).
[...]
> diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c
> index e7226c4..9040038 100644
> --- a/arch/arm64/kernel/fpsimd.c
> +++ b/arch/arm64/kernel/fpsimd.c
> @@ -39,6 +39,7 @@
> #include <linux/slab.h>
> #include <linux/sysctl.h>
>
> +#include <asm/esr.h>
> #include <asm/fpsimd.h>
> #include <asm/cputype.h>
> #include <asm/simd.h>
> @@ -867,18 +868,20 @@ asmlinkage void do_fpsimd_acc(unsigned int esr, struct pt_regs *regs)
> asmlinkage void do_fpsimd_exc(unsigned int esr, struct pt_regs *regs)
> {
> siginfo_t info;
> - unsigned int si_code = FPE_FIXME;
> -
> - if (esr & FPEXC_IOF)
> - si_code = FPE_FLTINV;
> - else if (esr & FPEXC_DZF)
> - si_code = FPE_FLTDIV;
> - else if (esr & FPEXC_OFF)
> - si_code = FPE_FLTOVF;
> - else if (esr & FPEXC_UFF)
> - si_code = FPE_FLTUND;
> - else if (esr & FPEXC_IXF)
> - si_code = FPE_FLTRES;
> + unsigned int si_code = FPE_FLTUNK;
Happy to take this patch once the dependency on FPE_FLTUNK in core code is
resolved.
Will
next prev parent reply other threads:[~2018-03-08 17:11 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-03-01 17:44 [PATCH v2 0/3] arm64: Fix invalid si_codes for fault signals Dave Martin
2018-03-01 17:44 ` [PATCH v2 1/3] signal: Add FPE_FLTUNK si_code for undiagnosable fp exceptions Dave Martin
2018-03-08 17:11 ` Will Deacon
2018-03-08 22:35 ` Eric W. Biederman
2018-03-01 17:44 ` [PATCH v2 2/3] arm64: fpsimd: Fix bad si_code for undiagnosed SIGFPE Dave Martin
2018-03-08 17:11 ` Will Deacon [this message]
2018-03-08 22:40 ` Eric W. Biederman
2018-03-09 13:10 ` Will Deacon
2018-03-09 14:25 ` Dave Martin
2018-03-15 21:13 ` Eric W. Biederman
2018-03-20 10:04 ` Will Deacon
2018-03-08 22:37 ` Eric W. Biederman
2018-03-01 17:44 ` [PATCH v2 3/3] arm64: signal: Ensure si_code is valid for all fault signals Dave Martin
2018-03-08 16:37 ` Will Deacon
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