[PATCH 4.4 28/63] watchdog: hpwdt: Check source of NMI

From: Greg Kroah-Hartman
Date: Fri Mar 16 2018 - 11:27:56 EST


4.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: Jerry Hoemann <jerry.hoemann@xxxxxxx>

commit 838534e50e2e5c1e644e30ab6cb28da88eb31368 upstream.

Do not claim the NMI (i.e. return NMI_DONE) if the source of
the NMI isn't the iLO watchdog or debug.

Signed-off-by: Jerry Hoemann <jerry.hoemann@xxxxxxx>
Reviewed-by: Guenter Roeck <linux@xxxxxxxxxxxx>
Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx>
Signed-off-by: Wim Van Sebroeck <wim@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/watchdog/hpwdt.c | 10 ++++++++++
1 file changed, 10 insertions(+)

--- a/drivers/watchdog/hpwdt.c
+++ b/drivers/watchdog/hpwdt.c
@@ -51,6 +51,7 @@ static char expect_release;
static unsigned long hpwdt_is_open;

static void __iomem *pci_mem_addr; /* the PCI-memory address */
+static unsigned long __iomem *hpwdt_nmistat;
static unsigned long __iomem *hpwdt_timer_reg;
static unsigned long __iomem *hpwdt_timer_con;

@@ -473,6 +474,11 @@ static int hpwdt_time_left(void)
return TICKS_TO_SECS(ioread16(hpwdt_timer_reg));
}

+static int hpwdt_my_nmi(void)
+{
+ return ioread8(hpwdt_nmistat) & 0x6;
+}
+
#ifdef CONFIG_HPWDT_NMI_DECODING
/*
* NMI Handler
@@ -485,6 +491,9 @@ static int hpwdt_pretimeout(unsigned int
if (!hpwdt_nmi_decoding)
goto out;

+ if ((ulReason == NMI_UNKNOWN) && !hpwdt_my_nmi())
+ return NMI_DONE;
+
spin_lock_irqsave(&rom_lock, rom_pl);
if (!die_nmi_called && !is_icru && !is_uefi)
asminline_call(&cmn_regs, cru_rom_addr);
@@ -840,6 +849,7 @@ static int hpwdt_init_one(struct pci_dev
retval = -ENOMEM;
goto error_pci_iomap;
}
+ hpwdt_nmistat = pci_mem_addr + 0x6e;
hpwdt_timer_reg = pci_mem_addr + 0x70;
hpwdt_timer_con = pci_mem_addr + 0x72;