Messages in this thread | | | From | 河合英宏 / KAWAI,HIDEHIRO <> | Subject | RE: [PATCH 3/3] hpwdt: Use nmi_panic() when kernel panics in NMI handler | Date | Tue, 1 Mar 2016 03:54:37 +0000 |
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Hi Guenter,
Thanks for the review.
> On 02/29/2016 05:50 PM, Hidehiro Kawai wrote: > > commit 58c5661f2144 ("panic, x86: Allow CPUs to save registers even > > if looping in NMI context") introduced nmi_panic() which prevents > > concurrent/recursive execution of panic(). It also saves registers > > for the crash dump on x86. > > > > hpwdt driver can call panic() from NMI handler, so replace it with > > nmi_panic(). > > > > Signed-off-by: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com> > > Cc: Thomas Mingarelli <thomas.mingarelli@hpe.com> > > Cc: Wim Van Sebroeck <wim@iguana.be> > > Cc: Guenter Roeck <linux@roeck-us.net> > > Cc: linux-watchdog@vger.kernel.org > > --- > > drivers/watchdog/hpwdt.c | 12 ++++++++++-- > > 1 file changed, 10 insertions(+), 2 deletions(-) > > > > diff --git a/drivers/watchdog/hpwdt.c b/drivers/watchdog/hpwdt.c > > index 92443c3..fd0486f 100644 > > --- a/drivers/watchdog/hpwdt.c > > +++ b/drivers/watchdog/hpwdt.c > > @@ -496,11 +496,12 @@ static int hpwdt_pretimeout(unsigned int ulReason, struct pt_regs *regs) > > > > if (!is_icru && !is_uefi) { > > if (cmn_regs.u1.ral == 0) { > > - panic("An NMI occurred, " > > + nmi_panic(regs, "An NMI occurred, " > > "but unable to determine source.\n"); > > This message should really be in a single line. > Sure, strictly speaking that should be done in a separate patch, > but since you touch the line you might as well fix it.
OK, I'll combine them.
> > + goto handled; > > The goto is unnecessary. Just return NMI_HANDLED.
Sure, I'll do that.
> > > } > > } > > - panic("An NMI occurred. Depending on your system the reason " > > + nmi_panic(regs, "An NMI occurred. Depending on your system the reason " > > "for the NMI is logged in any one of the following " > > "resources:\n" > > "1. Integrated Management Log (IML)\n" > > @@ -508,6 +509,13 @@ static int hpwdt_pretimeout(unsigned int ulReason, struct pt_regs *regs) > > "3. OA Forward Progress Log\n" > > "4. iLO Event Log"); > > > > +handled: > > + /* > > + * Returning from nmi_panic() means this CPU was processing panic() > > + * before NMI. Return NMI_HANDLED and go back to panic routines. > > + */ > > I don't think this comment adds much if any value.
So, I remove this comment. NMI_HANDLED would be self-explanatory.
> > + return NMI_HANDLED; > > + > > out: > > Any goto to this label does no longer serve a useful purpose (if it ever served one), > and should be replaced with "return NMI_DONE;"
I'll fix it. It will become a bit simpler.
Thanks,
-- Hidehiro Kawai Hitachi, Ltd. Research & Development Group
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