Re: [PATCH] [WATCHDOG] [hpwdt] Set the mapped BIOS address space as executable

From: Wim Van Sebroeck
Date: Thu Nov 20 2008 - 15:25:09 EST


Hi All,

> I tested changing the return value to NOTIFY_OK always.

Splendid. I changed the patch (see below).
Can you check if all is ok now, so that I can sent them off for mainline inclusion?

Kind regards,
Wim.
-----------------------------------------------------------------------------------------
commit 1adecc3d59d01ac7ffe9ab695cbd7311ab50198e
Author: Bernhard Walle <bwalle@xxxxxxx>
Date: Sun Oct 26 15:59:37 2008 +0100

[WATCHDOG] hpwdt: Fix kdump when using hpwdt

When the "hpwdt" module is loaded (even if the /dev/watchdog device is not
opened), then kdump does not work. The panic kernel either does not start at
all or crash in various places.

The problem is that hpwdt_pretimeout is registered with register_die_notifier()
with the highest possible priority. Because it returns NOTIFY_STOP, the
crash_nmi_callback which is also registered with register_die_notifier()
is never executed. This causes the shutdown of other CPUs to fail.

Reverting the order is no option: The crash_nmi_callback executes HLT
and so never returns normally. Because of that, it must be executed as
last notifier, which currently is done.

So, this patch returns NOTIFY_OK instead of NOTIFY_STOP.
Also, it changes the default of allow_kdump to 1.
Kdump is quite common and should be working as default.

Signed-off-by: Bernhard Walle <bwalle@xxxxxxx>
Signed-off-by: Wim Van Sebroeck <wim@xxxxxxxxx>
Signed-off-by: Thomas Mingarelli <thomas.mingarelli@xxxxxx>
Cc: Vivek Goyal <vgoyal@xxxxxxxxxx>

diff --git a/drivers/watchdog/hpwdt.c b/drivers/watchdog/hpwdt.c
index f6cff7b..8900989 100644
--- a/drivers/watchdog/hpwdt.c
+++ b/drivers/watchdog/hpwdt.c
@@ -117,7 +117,7 @@ static unsigned int reload; /* the computed soft_margin */
static int nowayout = WATCHDOG_NOWAYOUT;
static char expect_release;
static unsigned long hpwdt_is_open;
-static unsigned int allow_kdump;
+static unsigned int allow_kdump = 1;

static void __iomem *pci_mem_addr; /* the PCI-memory address */
static unsigned long __iomem *hpwdt_timer_reg;
@@ -485,7 +485,7 @@ static int hpwdt_pretimeout(struct notifier_block *nb, unsigned long ulReason,
"Management Log for details.\n");
}

- return NOTIFY_STOP;
+ return NOTIFY_OK;
}

/*
--
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