Sumit Saxena 8e781506a7 scsi: megaraid_sas: Fix concurrent access to ISR between IRQ polling and real interrupt ... [ Upstream commit e7dcc514a4 ] IRQ polling thread calls ISR after enable_irq() to handle any missed I/O completion. The atomic flag "in_used" was added to have the synchronization between the IRQ polling thread and the interrupt context. There is a bug around it leading to a race condition. Below is the sequence: - IRQ polling thread accesses ISR, fetches the reply descriptor. - Real interrupt arrives and pre-empts polling thread (enable_irq() is already called). - Interrupt context picks the same reply descriptor as fetched by polling thread, processes it, and exits. - Polling thread resumes and processes the descriptor which is already processed by interrupt thread leads to kernel crash. Setting the "in_used" flag before fetching the reply descriptor ensures synchronized access to ISR. Link: https://www.spinics.net/lists/linux-scsi/msg159440.html Link: https://lore.kernel.org/r/20210929124022.24605-2-sumit.saxena@broadcom.com Fixes: 9bedd36e91 ("scsi: megaraid_sas: Handle missing interrupts while re-enabling IRQs") Signed-off-by: Sumit Saxena <sumit.saxena@broadcom.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Sasha Levin <sashal@kernel.org>		2021-11-18 19:16:50 +01:00
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Kconfig.megaraid
Makefile
mbox_defs.h	treewide: remove editor modelines and cruft	2021-05-07 00:26:34 -07:00
mega_common.h	treewide: remove editor modelines and cruft	2021-05-07 00:26:34 -07:00
megaraid_ioctl.h
megaraid_mbox.c	scsi: megaraid_mbox: Use DEVICE_ATTR_ADMIN_RO() macro	2021-06-22 23:00:02 -04:00
megaraid_mbox.h	treewide: remove editor modelines and cruft	2021-05-07 00:26:34 -07:00
megaraid_mm.c	scsi: megaraid_mm: Fix end of loop tests for list_for_each_entry()	2021-07-28 23:29:09 -04:00
megaraid_mm.h
megaraid_sas.h	scsi: megaraid_sas: Update driver version to 07.717.02.00-rc1	2021-06-02 01:06:33 -04:00
megaraid_sas_base.c	scsi: megaraid: Clean up some inconsistent indenting	2021-09-13 22:15:50 -04:00
megaraid_sas_debugfs.c
megaraid_sas_fp.c	scsi: megaraid_sas: Early detection of VD deletion through RaidMap update	2021-06-02 01:06:33 -04:00
megaraid_sas_fusion.c	scsi: megaraid_sas: Fix concurrent access to ISR between IRQ polling and real interrupt	2021-11-18 19:16:50 +01:00
megaraid_sas_fusion.h	scsi: megaraid_sas: mq_poll support	2021-03-04 17:37:03 -05:00