[PATCH 21/30] panic: Introduce the panic pre-reboot notifier list

Corey Minyard
2022-04-28T16:26:16Z

On Wed, Apr 27, 2022 at 07:49:15PM -0300, Guilherme G. Piccoli wrote:
> This patch renames the panic_notifier_list to panic_pre_reboot_list;
> the idea is that a subsequent patch will refactor the panic path
> in order to better split the notifiers, running some of them very
> early, some of them not so early [but still before kmsg_dump()] and
> finally, the rest should execute late, after kdump. The latter ones
> are now in the panic pre-reboot list - the name comes from the idea
> that these notifiers execute before panic() attempts rebooting the
> machine (if that option is set).
>
> We also took the opportunity to clean-up useless header inclusions,
> improve some notifier block declarations (e.g. in ibmasm/heartbeat.c)
> and more important, change some priorities - we hereby set 2 notifiers
> to run late in the list [iss_panic_event() and the IPMI panic_event()]
> due to the risks they offer (may not return, for example).
> Proper documentation is going to be provided in a subsequent patch,
> that effectively refactors the panic path.

For the IPMI portion:

Acked-by: Corey Minyard <cminyard@mvista.com>

Note that the IPMI panic_event() should always return, but it may take
some time, especially if the IPMI controller is no longer functional.
So the risk of a long delay is there and it makes sense to move it very
late.

-corey

>
> Cc: Alex Elder <elder@kernel.org>
> Cc: Alexander Gordeev <agordeev@linux.ibm.com>
> Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com>
> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
> Cc: Chris Zankel <chris@zankel.net>
> Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
> Cc: Corey Minyard <minyard@acm.org>
> Cc: Dexuan Cui <decui@microsoft.com>
> Cc: "H. Peter Anvin" <hpa@zytor.com>
> Cc: Haiyang Zhang <haiyangz@microsoft.com>
> Cc: Heiko Carstens <hca@linux.ibm.com>
> Cc: Helge Deller <deller@gmx.de>
> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
> Cc: James Morse <james.morse@arm.com>
> Cc: Johannes Berg <johannes@sipsolutions.net>
> Cc: Juergen Gross <jgross@suse.com>
> Cc: "K. Y. Srinivasan" <kys@microsoft.com>
> Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
> Cc: Matt Turner <mattst88@gmail.com>
> Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
> Cc: Max Filippov <jcmvbkbc@gmail.com>
> Cc: Michael Ellerman <mpe@ellerman.id.au>
> Cc: Paul Mackerras <paulus@samba.org>
> Cc: Pavel Machek <pavel@ucw.cz>
> Cc: Richard Henderson <rth@twiddle.net>
> Cc: Richard Weinberger <richard@nod.at>
> Cc: Robert Richter <rric@kernel.org>
> Cc: Stefano Stabellini <sstabellini@kernel.org>
> Cc: Stephen Hemminger <sthemmin@microsoft.com>
> Cc: Sven Schnelle <svens@linux.ibm.com>
> Cc: Tony Luck <tony.luck@intel.com>
> Cc: Vasily Gorbik <gor@linux.ibm.com>
> Cc: Wei Liu <wei.liu@kernel.org>
> Signed-off-by: Guilherme G. Piccoli <gpiccoli@igalia.com>
> ---
>
> Notice that, with this name change, out-of-tree code that relies in the global
> exported "panic_notifier_list" will fail to build. We could easily keep the
> retro-compatibility by making the old symbol to still exist and point to the
> pre_reboot list (or even, keep the old naming).
>
> But our design choice was to allow the breakage, making users rethink their
> notifiers, adding them in the list that fits best. If that wasn't a good
> decision, we're open to change it, of course.
> Thanks in advance for the review!
>
> arch/alpha/kernel/setup.c | 4 ++--
> arch/parisc/kernel/pdc_chassis.c | 3 +--
> arch/powerpc/kernel/setup-common.c | 2 +-
> arch/s390/kernel/ipl.c | 4 ++--
> arch/um/drivers/mconsole_kern.c | 2 +-
> arch/um/kernel/um_arch.c | 2 +-
> arch/x86/xen/enlighten.c | 2 +-
> arch/xtensa/platforms/iss/setup.c | 4 ++--
> drivers/char/ipmi/ipmi_msghandler.c | 12 +++++++-----
> drivers/edac/altera_edac.c | 3 +--
> drivers/hv/vmbus_drv.c | 4 ++--
> drivers/leds/trigger/ledtrig-panic.c | 3 +--
> drivers/misc/ibmasm/heartbeat.c | 16 +++++++++-------
> drivers/net/ipa/ipa_smp2p.c | 5 ++---
> drivers/parisc/power.c | 4 ++--
> drivers/remoteproc/remoteproc_core.c | 6 ++++--
> drivers/s390/char/con3215.c | 2 +-
> drivers/s390/char/con3270.c | 2 +-
> drivers/s390/char/sclp_con.c | 2 +-
> drivers/s390/char/sclp_vt220.c | 2 +-
> drivers/staging/olpc_dcon/olpc_dcon.c | 6 ++++--
> drivers/video/fbdev/hyperv_fb.c | 4 ++--
> include/linux/panic_notifier.h | 2 +-
> kernel/panic.c | 9 ++++-----
> 24 files changed, 54 insertions(+), 51 deletions(-)
>
> diff --git a/arch/alpha/kernel/setup.c b/arch/alpha/kernel/setup.c
> index d88bdf852753..8ace0d7113b6 100644
> --- a/arch/alpha/kernel/setup.c
> +++ b/arch/alpha/kernel/setup.c
> @@ -472,8 +472,8 @@ setup_arch(char **cmdline_p)
> }
>
> /* Register a call for panic conditions. */
> - atomic_notifier_chain_register(&panic_notifier_list,
> - &alpha_panic_block);
> + atomic_notifier_chain_register(&panic_pre_reboot_list,
> + &alpha_panic_block);
>
> #ifndef alpha_using_srm
> /* Assume that we've booted from SRM if we haven't booted from MILO.
> diff --git a/arch/parisc/kernel/pdc_chassis.c b/arch/parisc/kernel/pdc_chassis.c
> index da154406d368..0fd8d87fb4f9 100644
> --- a/arch/parisc/kernel/pdc_chassis.c
> +++ b/arch/parisc/kernel/pdc_chassis.c
> @@ -22,7 +22,6 @@
> #include <linux/kernel.h>
> #include <linux/panic_notifier.h>
> #include <linux/reboot.h>
> -#include <linux/notifier.h>
> #include <linux/cache.h>
> #include <linux/proc_fs.h>
> #include <linux/seq_file.h>
> @@ -135,7 +134,7 @@ void __init parisc_pdc_chassis_init(void)
> PDC_CHASSIS_VER);
>
> /* initialize panic notifier chain */
> - atomic_notifier_chain_register(&panic_notifier_list,
> + atomic_notifier_chain_register(&panic_pre_reboot_list,
> &pdc_chassis_panic_block);
>
> /* initialize reboot notifier chain */
> diff --git a/arch/powerpc/kernel/setup-common.c b/arch/powerpc/kernel/setup-common.c
> index d04b8bf8dbc7..3518bebc10ad 100644
> --- a/arch/powerpc/kernel/setup-common.c
> +++ b/arch/powerpc/kernel/setup-common.c
> @@ -762,7 +762,7 @@ void __init setup_panic(void)
>
> /* Low-level platform-specific routines that should run on panic */
> if (ppc_md.panic)
> - atomic_notifier_chain_register(&panic_notifier_list,
> + atomic_notifier_chain_register(&panic_pre_reboot_list,
> &ppc_panic_block);
> }
>
> diff --git a/arch/s390/kernel/ipl.c b/arch/s390/kernel/ipl.c
> index 1cc85b8ff42e..4a88c5bb6e15 100644
> --- a/arch/s390/kernel/ipl.c
> +++ b/arch/s390/kernel/ipl.c
> @@ -2034,7 +2034,7 @@ static int on_panic_notify(struct notifier_block *self,
> unsigned long event, void *data)
> {
> do_panic();
> - return NOTIFY_OK;
> + return NOTIFY_DONE;
> }
>
> static struct notifier_block on_panic_nb = {
> @@ -2069,7 +2069,7 @@ void __init setup_ipl(void)
> /* We have no info to copy */
> break;
> }
> - atomic_notifier_chain_register(&panic_notifier_list, &on_panic_nb);
> + atomic_notifier_chain_register(&panic_pre_reboot_list, &on_panic_nb);
> }
>
> void s390_reset_system(void)
> diff --git a/arch/um/drivers/mconsole_kern.c b/arch/um/drivers/mconsole_kern.c
> index 2ea0421bcc3f..21c13b4e24a3 100644
> --- a/arch/um/drivers/mconsole_kern.c
> +++ b/arch/um/drivers/mconsole_kern.c
> @@ -855,7 +855,7 @@ static struct notifier_block panic_exit_notifier = {
>
> static int add_notifier(void)
> {
> - atomic_notifier_chain_register(&panic_notifier_list,
> + atomic_notifier_chain_register(&panic_pre_reboot_list,
> &panic_exit_notifier);
> return 0;
> }
> diff --git a/arch/um/kernel/um_arch.c b/arch/um/kernel/um_arch.c
> index 4485b1a7c8e4..fc6e443299da 100644
> --- a/arch/um/kernel/um_arch.c
> +++ b/arch/um/kernel/um_arch.c
> @@ -257,7 +257,7 @@ static struct notifier_block panic_exit_notifier = {
>
> void uml_finishsetup(void)
> {
> - atomic_notifier_chain_register(&panic_notifier_list,
> + atomic_notifier_chain_register(&panic_pre_reboot_list,
> &panic_exit_notifier);
>
> uml_postsetup();
> diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
> index 30c6e986a6cd..d4f4de239a21 100644
> --- a/arch/x86/xen/enlighten.c
> +++ b/arch/x86/xen/enlighten.c
> @@ -290,7 +290,7 @@ static struct notifier_block xen_panic_block = {
>
> int xen_panic_handler_init(void)
> {
> - atomic_notifier_chain_register(&panic_notifier_list, &xen_panic_block);
> + atomic_notifier_chain_register(&panic_pre_reboot_list, &xen_panic_block);
> return 0;
> }
>
> diff --git a/arch/xtensa/platforms/iss/setup.c b/arch/xtensa/platforms/iss/setup.c
> index d3433e1bb94e..eeeeb6cff6bd 100644
> --- a/arch/xtensa/platforms/iss/setup.c
> +++ b/arch/xtensa/platforms/iss/setup.c
> @@ -13,7 +13,6 @@
> */
> #include <linux/init.h>
> #include <linux/kernel.h>
> -#include <linux/notifier.h>
> #include <linux/panic_notifier.h>
> #include <linux/printk.h>
> #include <linux/string.h>
> @@ -53,6 +52,7 @@ iss_panic_event(struct notifier_block *this, unsigned long event, void *ptr)
>
> static struct notifier_block iss_panic_block = {
> .notifier_call = iss_panic_event,
> + .priority = INT_MIN, /* run as late as possible, may not return */
> };
>
> void __init platform_setup(char **p_cmdline)
> @@ -81,5 +81,5 @@ void __init platform_setup(char **p_cmdline)
> }
> }
>
> - atomic_notifier_chain_register(&panic_notifier_list, &iss_panic_block);
> + atomic_notifier_chain_register(&panic_pre_reboot_list, &iss_panic_block);
> }
> diff --git a/drivers/char/ipmi/ipmi_msghandler.c b/drivers/char/ipmi/ipmi_msghandler.c
> index c59265146e9c..6c4770949c01 100644
> --- a/drivers/char/ipmi/ipmi_msghandler.c
> +++ b/drivers/char/ipmi/ipmi_msghandler.c
> @@ -25,7 +25,6 @@
> #include <linux/slab.h>
> #include <linux/ipmi.h>
> #include <linux/ipmi_smi.h>
> -#include <linux/notifier.h>
> #include <linux/init.h>
> #include <linux/proc_fs.h>
> #include <linux/rcupdate.h>
> @@ -5375,10 +5374,13 @@ static int ipmi_register_driver(void)
> return rv;
> }
>
> +/*
> + * we should execute this panic callback late, since it involves
> + * a complex call-chain and panic() runs in atomic context.
> + */
> static struct notifier_block panic_block = {
> .notifier_call = panic_event,
> - .next = NULL,
> - .priority = 200 /* priority: INT_MAX >= x >= 0 */
> + .priority = INT_MIN + 1,
> };
>
> static int ipmi_init_msghandler(void)
> @@ -5406,7 +5408,7 @@ static int ipmi_init_msghandler(void)
> timer_setup(&ipmi_timer, ipmi_timeout, 0);
> mod_timer(&ipmi_timer, jiffies + IPMI_TIMEOUT_JIFFIES);
>
> - atomic_notifier_chain_register(&panic_notifier_list, &panic_block);
> + atomic_notifier_chain_register(&panic_pre_reboot_list, &panic_block);
>
> initialized = true;
>
> @@ -5438,7 +5440,7 @@ static void __exit cleanup_ipmi(void)
> if (initialized) {
> destroy_workqueue(remove_work_wq);
>
> - atomic_notifier_chain_unregister(&panic_notifier_list,
> + atomic_notifier_chain_unregister(&panic_pre_reboot_list,
> &panic_block);
>
> /*
> diff --git a/drivers/edac/altera_edac.c b/drivers/edac/altera_edac.c
> index e7e8e624a436..4890e9cba6fb 100644
> --- a/drivers/edac/altera_edac.c
> +++ b/drivers/edac/altera_edac.c
> @@ -16,7 +16,6 @@
> #include <linux/kernel.h>
> #include <linux/mfd/altera-sysmgr.h>
> #include <linux/mfd/syscon.h>
> -#include <linux/notifier.h>
> #include <linux/of_address.h>
> #include <linux/of_irq.h>
> #include <linux/of_platform.h>
> @@ -2163,7 +2162,7 @@ static int altr_edac_a10_probe(struct platform_device *pdev)
> int dberror, err_addr;
>
> edac->panic_notifier.notifier_call = s10_edac_dberr_handler;
> - atomic_notifier_chain_register(&panic_notifier_list,
> + atomic_notifier_chain_register(&panic_pre_reboot_list,
> &edac->panic_notifier);
>
> /* Printout a message if uncorrectable error previously. */
> diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c
> index 901b97034308..3717c323aa36 100644
> --- a/drivers/hv/vmbus_drv.c
> +++ b/drivers/hv/vmbus_drv.c
> @@ -1622,7 +1622,7 @@ static int vmbus_bus_init(void)
> * Always register the vmbus unload panic notifier because we
> * need to shut the VMbus channel connection on panic.
> */
> - atomic_notifier_chain_register(&panic_notifier_list,
> + atomic_notifier_chain_register(&panic_pre_reboot_list,
> &hyperv_panic_vmbus_unload_block);
>
> vmbus_request_offers();
> @@ -2851,7 +2851,7 @@ static void __exit vmbus_exit(void)
> * The vmbus panic notifier is always registered, hence we should
> * also unconditionally unregister it here as well.
> */
> - atomic_notifier_chain_unregister(&panic_notifier_list,
> + atomic_notifier_chain_unregister(&panic_pre_reboot_list,
> &hyperv_panic_vmbus_unload_block);
>
> free_page((unsigned long)hv_panic_page);
> diff --git a/drivers/leds/trigger/ledtrig-panic.c b/drivers/leds/trigger/ledtrig-panic.c
> index 64abf2e91608..34fd5170723f 100644
> --- a/drivers/leds/trigger/ledtrig-panic.c
> +++ b/drivers/leds/trigger/ledtrig-panic.c
> @@ -7,7 +7,6 @@
>
> #include <linux/kernel.h>
> #include <linux/init.h>
> -#include <linux/notifier.h>
> #include <linux/panic_notifier.h>
> #include <linux/leds.h>
> #include "../leds.h"
> @@ -64,7 +63,7 @@ static long led_panic_blink(int state)
>
> static int __init ledtrig_panic_init(void)
> {
> - atomic_notifier_chain_register(&panic_notifier_list,
> + atomic_notifier_chain_register(&panic_pre_reboot_list,
> &led_trigger_panic_nb);
>
> led_trigger_register_simple("panic", &trigger);
> diff --git a/drivers/misc/ibmasm/heartbeat.c b/drivers/misc/ibmasm/heartbeat.c
> index 59c9a0d95659..d6acae88b722 100644
> --- a/drivers/misc/ibmasm/heartbeat.c
> +++ b/drivers/misc/ibmasm/heartbeat.c
> @@ -8,7 +8,6 @@
> * Author: Max Asb?ck <amax@us.ibm.com>
> */
>
> -#include <linux/notifier.h>
> #include <linux/panic_notifier.h>
> #include "ibmasm.h"
> #include "dot_command.h"
> @@ -24,7 +23,7 @@ static int suspend_heartbeats = 0;
> * In the case of a panic the interrupt handler continues to work and thus
> * continues to respond to heartbeats, making the service processor believe
> * the OS is still running and thus preventing a reboot.
> - * To prevent this from happening a callback is added the panic_notifier_list.
> + * To prevent this from happening a callback is added in a panic notifier list.
> * Before responding to a heartbeat the driver checks if a panic has happened,
> * if yes it suspends heartbeat, causing the service processor to reboot as
> * expected.
> @@ -32,20 +31,23 @@ static int suspend_heartbeats = 0;
> static int panic_happened(struct notifier_block *n, unsigned long val, void *v)
> {
> suspend_heartbeats = 1;
> - return 0;
> + return NOTIFY_DONE;
> }
>
> -static struct notifier_block panic_notifier = { panic_happened, NULL, 1 };
> +static struct notifier_block panic_notifier = {
> + .notifier_call = panic_happened,
> +};
>
> void ibmasm_register_panic_notifier(void)
> {
> - atomic_notifier_chain_register(&panic_notifier_list, &panic_notifier);
> + atomic_notifier_chain_register(&panic_pre_reboot_list,
> + &panic_notifier);
> }
>
> void ibmasm_unregister_panic_notifier(void)
> {
> - atomic_notifier_chain_unregister(&panic_notifier_list,
> - &panic_notifier);
> + atomic_notifier_chain_unregister(&panic_pre_reboot_list,
> + &panic_notifier);
> }
>
>
> diff --git a/drivers/net/ipa/ipa_smp2p.c b/drivers/net/ipa/ipa_smp2p.c
> index 211233612039..92cdf6e0637c 100644
> --- a/drivers/net/ipa/ipa_smp2p.c
> +++ b/drivers/net/ipa/ipa_smp2p.c
> @@ -7,7 +7,6 @@
> #include <linux/types.h>
> #include <linux/device.h>
> #include <linux/interrupt.h>
> -#include <linux/notifier.h>
> #include <linux/panic_notifier.h>
> #include <linux/pm_runtime.h>
> #include <linux/soc/qcom/smem.h>
> @@ -138,13 +137,13 @@ static int ipa_smp2p_panic_notifier_register(struct ipa_smp2p *smp2p)
> smp2p->panic_notifier.notifier_call = ipa_smp2p_panic_notifier;
> smp2p->panic_notifier.priority = INT_MAX; /* Do it early */
>
> - return atomic_notifier_chain_register(&panic_notifier_list,
> + return atomic_notifier_chain_register(&panic_pre_reboot_list,
> &smp2p->panic_notifier);
> }
>
> static void ipa_smp2p_panic_notifier_unregister(struct ipa_smp2p *smp2p)
> {
> - atomic_notifier_chain_unregister(&panic_notifier_list,
> + atomic_notifier_chain_unregister(&panic_pre_reboot_list,
> &smp2p->panic_notifier);
> }
>
> diff --git a/drivers/parisc/power.c b/drivers/parisc/power.c
> index 8512884de2cf..5bb0868f5f08 100644
> --- a/drivers/parisc/power.c
> +++ b/drivers/parisc/power.c
> @@ -233,7 +233,7 @@ static int __init power_init(void)
> }
>
> /* Register a call for panic conditions. */
> - atomic_notifier_chain_register(&panic_notifier_list,
> + atomic_notifier_chain_register(&panic_pre_reboot_list,
> &parisc_panic_block);
>
> return 0;
> @@ -243,7 +243,7 @@ static void __exit power_exit(void)
> {
> kthread_stop(power_task);
>
> - atomic_notifier_chain_unregister(&panic_notifier_list,
> + atomic_notifier_chain_unregister(&panic_pre_reboot_list,
> &parisc_panic_block);
>
> pdc_soft_power_button(0);
> diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
> index c510125769b9..24799ff239e6 100644
> --- a/drivers/remoteproc/remoteproc_core.c
> +++ b/drivers/remoteproc/remoteproc_core.c
> @@ -2795,12 +2795,14 @@ static int rproc_panic_handler(struct notifier_block *nb, unsigned long event,
> static void __init rproc_init_panic(void)
> {
> rproc_panic_nb.notifier_call = rproc_panic_handler;
> - atomic_notifier_chain_register(&panic_notifier_list, &rproc_panic_nb);
> + atomic_notifier_chain_register(&panic_pre_reboot_list,
> + &rproc_panic_nb);
> }
>
> static void __exit rproc_exit_panic(void)
> {
> - atomic_notifier_chain_unregister(&panic_notifier_list, &rproc_panic_nb);
> + atomic_notifier_chain_unregister(&panic_pre_reboot_list,
> + &rproc_panic_nb);
> }
>
> static int __init remoteproc_init(void)
> diff --git a/drivers/s390/char/con3215.c b/drivers/s390/char/con3215.c
> index 192198bd3dc4..07379dd3f1f3 100644
> --- a/drivers/s390/char/con3215.c
> +++ b/drivers/s390/char/con3215.c
> @@ -867,7 +867,7 @@ static int __init con3215_init(void)
> raw3215[0] = NULL;
> return -ENODEV;
> }
> - atomic_notifier_chain_register(&panic_notifier_list, &on_panic_nb);
> + atomic_notifier_chain_register(&panic_pre_reboot_list, &on_panic_nb);
> register_reboot_notifier(&on_reboot_nb);
> register_console(&con3215);
> return 0;
> diff --git a/drivers/s390/char/con3270.c b/drivers/s390/char/con3270.c
> index 476202f3d8a0..e79bf3e7bde3 100644
> --- a/drivers/s390/char/con3270.c
> +++ b/drivers/s390/char/con3270.c
> @@ -645,7 +645,7 @@ con3270_init(void)
> condev->cline->len = 0;
> con3270_create_status(condev);
> condev->input = alloc_string(&condev->freemem, 80);
> - atomic_notifier_chain_register(&panic_notifier_list, &on_panic_nb);
> + atomic_notifier_chain_register(&panic_pre_reboot_list, &on_panic_nb);
> register_reboot_notifier(&on_reboot_nb);
> register_console(&con3270);
> return 0;
> diff --git a/drivers/s390/char/sclp_con.c b/drivers/s390/char/sclp_con.c
> index e5d947c763ea..7ca9d4c45d60 100644
> --- a/drivers/s390/char/sclp_con.c
> +++ b/drivers/s390/char/sclp_con.c
> @@ -288,7 +288,7 @@ sclp_console_init(void)
> timer_setup(&sclp_con_timer, sclp_console_timeout, 0);
>
> /* enable printk-access to this driver */
> - atomic_notifier_chain_register(&panic_notifier_list, &on_panic_nb);
> + atomic_notifier_chain_register(&panic_pre_reboot_list, &on_panic_nb);
> register_reboot_notifier(&on_reboot_nb);
> register_console(&sclp_console);
> return 0;
> diff --git a/drivers/s390/char/sclp_vt220.c b/drivers/s390/char/sclp_vt220.c
> index a32f34a1c6d2..97cf9e290c28 100644
> --- a/drivers/s390/char/sclp_vt220.c
> +++ b/drivers/s390/char/sclp_vt220.c
> @@ -838,7 +838,7 @@ sclp_vt220_con_init(void)
> if (rc)
> return rc;
> /* Attach linux console */
> - atomic_notifier_chain_register(&panic_notifier_list, &on_panic_nb);
> + atomic_notifier_chain_register(&panic_pre_reboot_list, &on_panic_nb);
> register_reboot_notifier(&on_reboot_nb);
> register_console(&sclp_vt220_console);
> return 0;
> diff --git a/drivers/staging/olpc_dcon/olpc_dcon.c b/drivers/staging/olpc_dcon/olpc_dcon.c
> index 7284cb4ac395..cb50471f2246 100644
> --- a/drivers/staging/olpc_dcon/olpc_dcon.c
> +++ b/drivers/staging/olpc_dcon/olpc_dcon.c
> @@ -653,7 +653,8 @@ static int dcon_probe(struct i2c_client *client, const struct i2c_device_id *id)
> }
>
> register_reboot_notifier(&dcon->reboot_nb);
> - atomic_notifier_chain_register(&panic_notifier_list, &dcon_panic_nb);
> + atomic_notifier_chain_register(&panic_pre_reboot_list,
> + &dcon_panic_nb);
>
> return 0;
>
> @@ -676,7 +677,8 @@ static int dcon_remove(struct i2c_client *client)
> struct dcon_priv *dcon = i2c_get_clientdata(client);
>
> unregister_reboot_notifier(&dcon->reboot_nb);
> - atomic_notifier_chain_unregister(&panic_notifier_list, &dcon_panic_nb);
> + atomic_notifier_chain_unregister(&panic_pre_reboot_list,
> + &dcon_panic_nb);
>
> free_irq(DCON_IRQ, dcon);
>
> diff --git a/drivers/video/fbdev/hyperv_fb.c b/drivers/video/fbdev/hyperv_fb.c
> index f3494b868a64..ec21e63592be 100644
> --- a/drivers/video/fbdev/hyperv_fb.c
> +++ b/drivers/video/fbdev/hyperv_fb.c
> @@ -1253,7 +1253,7 @@ static int hvfb_probe(struct hv_device *hdev,
> */
> par->hvfb_panic_nb.notifier_call = hvfb_on_panic;
> par->hvfb_panic_nb.priority = INT_MIN + 10,
> - atomic_notifier_chain_register(&panic_notifier_list,
> + atomic_notifier_chain_register(&panic_pre_reboot_list,
> &par->hvfb_panic_nb);
>
> return 0;
> @@ -1276,7 +1276,7 @@ static int hvfb_remove(struct hv_device *hdev)
> struct fb_info *info = hv_get_drvdata(hdev);
> struct hvfb_par *par = info->par;
>
> - atomic_notifier_chain_unregister(&panic_notifier_list,
> + atomic_notifier_chain_unregister(&panic_pre_reboot_list,
> &par->hvfb_panic_nb);
>
> par->update = false;
> diff --git a/include/linux/panic_notifier.h b/include/linux/panic_notifier.h
> index 7364a346bcb0..7912aacbc0e5 100644
> --- a/include/linux/panic_notifier.h
> +++ b/include/linux/panic_notifier.h
> @@ -5,9 +5,9 @@
> #include <linux/notifier.h>
> #include <linux/types.h>
>
> -extern struct atomic_notifier_head panic_notifier_list;
> extern struct atomic_notifier_head panic_hypervisor_list;
> extern struct atomic_notifier_head panic_info_list;
> +extern struct atomic_notifier_head panic_pre_reboot_list;
>
> extern bool crash_kexec_post_notifiers;
>
> diff --git a/kernel/panic.c b/kernel/panic.c
> index 73ca1bc44e30..a9d43b98b05b 100644
> --- a/kernel/panic.c
> +++ b/kernel/panic.c
> @@ -69,16 +69,15 @@ EXPORT_SYMBOL_GPL(panic_timeout);
> #define PANIC_PRINT_ALL_CPU_BT 0x00000040
> unsigned long panic_print;
>
> -ATOMIC_NOTIFIER_HEAD(panic_notifier_list);
> -
> -EXPORT_SYMBOL(panic_notifier_list);
> -
> ATOMIC_NOTIFIER_HEAD(panic_hypervisor_list);
> EXPORT_SYMBOL(panic_hypervisor_list);
>
> ATOMIC_NOTIFIER_HEAD(panic_info_list);
> EXPORT_SYMBOL(panic_info_list);
>
> +ATOMIC_NOTIFIER_HEAD(panic_pre_reboot_list);
> +EXPORT_SYMBOL(panic_pre_reboot_list);
> +
> static long no_blink(int state)
> {
> return 0;
> @@ -295,7 +294,7 @@ void panic(const char *fmt, ...)
> */
> atomic_notifier_call_chain(&panic_hypervisor_list, PANIC_NOTIFIER, buf);
> atomic_notifier_call_chain(&panic_info_list, PANIC_NOTIFIER, buf);
> - atomic_notifier_call_chain(&panic_notifier_list, PANIC_NOTIFIER, buf);
> + atomic_notifier_call_chain(&panic_pre_reboot_list, PANIC_NOTIFIER, buf);
>
> panic_print_sys_info(false);
>
> --
> 2.36.0
>