From: Ben Hutchings <ben@decadent.org.uk>
To: Vineet Gupta <vgupta@synopsys.com>
Cc: stable@vger.kernel.org,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 4.4 12/23] ARC: [arcompact] handle unaligned access delay slot corner case
Date: Fri, 10 Feb 2017 12:51:48 +0000 [thread overview]
Message-ID: <1486731108.2900.68.camel@decadent.org.uk> (raw)
In-Reply-To: <20170131053625.463159338@linuxfoundation.org>
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On Tue, 2017-01-31 at 06:37 +0100, Greg Kroah-Hartman wrote:
> 4.4-stable review patch. If anyone has any objections, please let me know.
>
> ------------------
>
> From: Vineet Gupta <vgupta@synopsys.com>
>
> commit 9aed02feae57bf7a40cb04ea0e3017cb7a998db4 upstream.
>
> After emulating an unaligned access in delay slot of a branch, we
> pretend as the delay slot never happened - so return back to actual
> branch target (or next PC if branch was not taken).
>
> Curently we did this by handling STATUS32.DE, we also need to clear the
> BTA.T bit, which is disregarded when returning from original misaligned
> exception, but could cause weirdness if it took the interrupt return
> path (in case interrupt was acive too)
>
> One ARC700 customer ran into this when enabling unaligned access fixup
> for kernel mode accesses as well
>
> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
>
> ---
> arch/arc/kernel/unaligned.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> --- a/arch/arc/kernel/unaligned.c
> +++ b/arch/arc/kernel/unaligned.c
> @@ -241,8 +241,9 @@ int misaligned_fixup(unsigned long addre
> if (state.fault)
> goto fault;
>
> + /* clear any remanants of delay slot */
> if (delay_mode(regs)) {
> - regs->ret = regs->bta;
> + regs->ret = regs->bta ~1U;
Unless you're doing something terrible with macros, this is missing an
& operator. I doubt this even compiled (looks like it's only used in
some ARC configurations).
Ben.
> regs->status32 &= ~STATUS_DE_MASK;
> } else {
> regs->ret += state.instr_len;
--
Ben Hutchings
It's easier to fight for one's principles than to live up to them.
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next prev parent reply other threads:[~2017-02-10 12:54 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-01-31 5:37 [PATCH 4.4 00/23] 4.4.46-stable review Greg Kroah-Hartman
2017-01-31 5:37 ` [PATCH 4.4 01/23] fbdev: color map copying bounds checking Greg Kroah-Hartman
2017-01-31 5:37 ` [PATCH 4.4 02/23] tile/ptrace: Preserve previous registers for short regset write Greg Kroah-Hartman
2017-01-31 5:37 ` [PATCH 4.4 04/23] mm/mempolicy.c: do not put mempolicy before using its nodemask Greg Kroah-Hartman
2017-01-31 5:37 ` [PATCH 4.4 05/23] sysctl: fix proc_doulongvec_ms_jiffies_minmax() Greg Kroah-Hartman
2017-01-31 5:37 ` [PATCH 4.4 06/23] ISDN: eicon: silence misleading array-bounds warning Greg Kroah-Hartman
2017-01-31 5:37 ` [PATCH 4.4 07/23] RDMA/cma: Fix unknown symbol when CONFIG_IPV6 is not enabled Greg Kroah-Hartman
2017-01-31 5:37 ` [PATCH 4.4 08/23] s390/ptrace: Preserve previous registers for short regset write Greg Kroah-Hartman
2017-01-31 5:37 ` [PATCH 4.4 10/23] can: ti_hecc: add missing prepare and unprepare of the clock Greg Kroah-Hartman
2017-01-31 5:37 ` [PATCH 4.4 11/23] ARC: udelay: fix inline assembler by adding LP_COUNT to clobber list Greg Kroah-Hartman
2017-01-31 5:37 ` [PATCH 4.4 12/23] ARC: [arcompact] handle unaligned access delay slot corner case Greg Kroah-Hartman
2017-02-10 12:51 ` Ben Hutchings [this message]
2017-02-10 13:19 ` Greg Kroah-Hartman
2017-02-10 13:26 ` Greg Kroah-Hartman
2017-01-31 5:37 ` [PATCH 4.4 13/23] parisc: Dont use BITS_PER_LONG in userspace-exported swab.h header Greg Kroah-Hartman
2017-01-31 5:37 ` [PATCH 4.4 14/23] nfs: Dont increment lock sequence ID after NFS4ERR_MOVED Greg Kroah-Hartman
2017-01-31 5:37 ` [PATCH 4.4 15/23] NFSv4.0: always send mode in SETATTR after EXCLUSIVE4 Greg Kroah-Hartman
2017-01-31 5:37 ` [PATCH 4.4 16/23] SUNRPC: cleanup ida information when removing sunrpc module Greg Kroah-Hartman
2017-01-31 5:37 ` [PATCH 4.4 18/23] IB/ipoib: move back IB LL address into the hard header Greg Kroah-Hartman
2017-01-31 5:37 ` [PATCH 4.4 19/23] IB/umem: Release pid in error and ODP flow Greg Kroah-Hartman
2017-01-31 5:37 ` [PATCH 4.4 20/23] [media] s5k4ecgx: select CRC32 helper Greg Kroah-Hartman
2017-01-31 5:37 ` [PATCH 4.4 21/23] pinctrl: broxton: Use correct PADCFGLOCK offset Greg Kroah-Hartman
2017-01-31 5:37 ` [PATCH 4.4 22/23] platform/x86: intel_mid_powerbtn: Set IRQ_ONESHOT Greg Kroah-Hartman
2017-01-31 5:37 ` [PATCH 4.4 23/23] mm, memcg: do not retry precharge charges Greg Kroah-Hartman
2017-01-31 17:23 ` [PATCH 4.4 00/23] 4.4.46-stable review Guenter Roeck
2017-01-31 22:06 ` Shuah Khan
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