From: Michael Ellerman <mpe@ellerman•id.au>
To: Gavin Shan <gwshan@linux•vnet.ibm.com>, linuxppc-dev@lists•ozlabs.org
Subject: Re: [PATCH] powerpc/eeh: Fix wrong flag passed to eeh_unfreeze_pe()
Date: Wed, 18 Jan 2017 16:49:58 +1100 [thread overview]
Message-ID: <87wpdsapdl.fsf@concordia.ellerman.id.au> (raw)
In-Reply-To: <1484104609-22129-1-git-send-email-gwshan@linux.vnet.ibm.com>
Gavin Shan <gwshan@linux•vnet.ibm.com> writes:
> In __eeh_clear_pe_frozen_state(), we should pass the flag's value
> instead of its address to eeh_unfreeze_pe(). This doesn't introduce
> any problems, but the code is just wrong.
It means any caller that passes false, will be getting the wrong
behaviour. eg. I see at least one call in eeh_reset_device() which
passes false to eeh_clear_pe_frozen_state(), which is then passed to
__eeh_clear_pe_frozen_state().
But I guess you're saying that caller doesn't actually see a bug because
of this?
> This fixes the code by passing flag's value to eeh_unfreeze_pe().
>
> Cc: stable@vger•kernel.org #3.18+
> Fixes: 5cfb20b96f6 ("powerpc/eeh: Emulate EEH recovery for VFIO devices")
> Signed-off-by: Gavin Shan <gwshan@linux•vnet.ibm.com>
>
> diff --git a/arch/powerpc/kernel/eeh_driver.c b/arch/powerpc/kernel/eeh_driver.c
> index d88573b..fa15fa6 100644
> --- a/arch/powerpc/kernel/eeh_driver.c
> +++ b/arch/powerpc/kernel/eeh_driver.c
> @@ -549,7 +549,7 @@ static void *__eeh_clear_pe_frozen_state(void *data, void *flag)
bool *clear_sw_state = flag;
> int i, rc = 1;
>
> for (i = 0; rc && i < 3; i++)
> - rc = eeh_unfreeze_pe(pe, clear_sw_state);
> + rc = eeh_unfreeze_pe(pe, *clear_sw_state);
I think it would be better to just do the dereference once:
bool clear_sw_state = *(bool *)flag;
int i, rc = 1;
for (i = 0; rc && i < 3; i++)
rc = eeh_unfreeze_pe(pe, clear_sw_state);
cheers
next prev parent reply other threads:[~2017-01-18 5:50 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-01-11 3:16 [PATCH] powerpc/eeh: Fix wrong flag passed to eeh_unfreeze_pe() Gavin Shan
2017-01-18 5:49 ` Michael Ellerman [this message]
2017-01-18 22:50 ` Gavin Shan
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