The altera_edac panic notifier performs some data collection with regards errors detected; such code relies in the regmap layer to perform reads/writes, so the code is abstracted and there is some risk level to execute that, since the panic path runs in atomic context, with interrupts/preemption and secondary CPUs disabled. Users want the information collected in this panic notifier though, so in order to balance the risk/benefit, let's skip the altera panic notifier if kdump is loaded. While at it, remove a useless header and encompass a macro inside the sole ifdef block it is used. Cc: Borislav Petkov <bp@xxxxxxxxx> Cc: Petr Mladek <pmladek@xxxxxxxx> Cc: Tony Luck <tony.luck@xxxxxxxxx> Acked-by: Dinh Nguyen <dinguyen@xxxxxxxxxx> Signed-off-by: Guilherme G. Piccoli <gpiccoli@xxxxxxxxxx> --- V3: - added the ack tag from Dinh - thanks! - had a good discussion with Boris about that in V2 [0], hopefully we can continue and reach a consensus in this V3. [0] https://lore.kernel.org/lkml/46137c67-25b4-6657-33b7-cffdc7afc0d7@xxxxxxxxxx/ V2: - new patch, based on the discussion in [1]. [1] https://lore.kernel.org/lkml/62a63fc2-346f-f375-043a-fa21385279df@xxxxxxxxxx/ drivers/edac/altera_edac.c | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-) diff --git a/drivers/edac/altera_edac.c b/drivers/edac/altera_edac.c index e7e8e624a436..741fe5539154 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> @@ -24,6 +23,7 @@ #include <linux/platform_device.h> #include <linux/regmap.h> #include <linux/types.h> +#include <linux/kexec.h> #include <linux/uaccess.h> #include "altera_edac.h" @@ -2063,22 +2063,30 @@ static const struct irq_domain_ops a10_eccmgr_ic_ops = { }; /************** Stratix 10 EDAC Double Bit Error Handler ************/ -#define to_a10edac(p, m) container_of(p, struct altr_arria10_edac, m) - #ifdef CONFIG_64BIT /* panic routine issues reboot on non-zero panic_timeout */ extern int panic_timeout; +#define to_a10edac(p, m) container_of(p, struct altr_arria10_edac, m) + /* * The double bit error is handled through SError which is fatal. This is * called as a panic notifier to printout ECC error info as part of the panic. + * + * Notice that if kdump is set, we take the risk avoidance approach and + * skip the notifier, given that users are expected to have access to a + * full vmcore. */ static int s10_edac_dberr_handler(struct notifier_block *this, unsigned long event, void *ptr) { - struct altr_arria10_edac *edac = to_a10edac(this, panic_notifier); + struct altr_arria10_edac *edac; int err_addr, dberror; + if (kexec_crash_loaded()) + return NOTIFY_DONE; + + edac = to_a10edac(this, panic_notifier); regmap_read(edac->ecc_mgr_map, S10_SYSMGR_ECC_INTSTAT_DERR_OFST, &dberror); regmap_write(edac->ecc_mgr_map, S10_SYSMGR_UE_VAL_OFST, dberror); -- 2.37.2
