Messages in this thread | | | Subject | Re: [PATCH 3/3] hpwdt: Use nmi_panic() when kernel panics in NMI handler | From | Guenter Roeck <> | Date | Mon, 29 Feb 2016 18:55:24 -0800 |
| |
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.
> + goto handled;
The goto is unnecessary. Just return NMI_HANDLED.
> } > } > - 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.
> + 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;"
> return NMI_DONE; > } > > >
| |