This is a note to let you know that I've just added the patch titled
PCI/MSI: Prevent MSI hardware interrupt number truncation
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
pci-msi-prevent-msi-hardware-interrupt-number-truncation.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From db744ddd59be798c2627efbfc71f707f5a935a40 Mon Sep 17 00:00:00 2001
From: Vidya Sagar <vidyas@xxxxxxxxxx>
Date: Mon, 15 Jan 2024 19:26:49 +0530
Subject: PCI/MSI: Prevent MSI hardware interrupt number truncation
From: Vidya Sagar <vidyas@xxxxxxxxxx>
commit db744ddd59be798c2627efbfc71f707f5a935a40 upstream.
While calculating the hardware interrupt number for a MSI interrupt, the
higher bits (i.e. from bit-5 onwards a.k.a domain_nr >= 32) of the PCI
domain number gets truncated because of the shifted value casting to return
type of pci_domain_nr() which is 'int'. This for example is resulting in
same hardware interrupt number for devices 0019:00:00.0 and 0039:00:00.0.
To address this cast the PCI domain number to 'irq_hw_number_t' before left
shifting it to calculate the hardware interrupt number.
Please note that this fixes the issue only on 64-bit systems and doesn't
change the behavior for 32-bit systems i.e. the 32-bit systems continue to
have the issue. Since the issue surfaces only if there are too many PCIe
controllers in the system which usually is the case in modern server
systems and they don't tend to run 32-bit kernels.
Fixes: 3878eaefb89a ("PCI/MSI: Enhance core to support hierarchy irqdomain")
Signed-off-by: Vidya Sagar <vidyas@xxxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Tested-by: Shanker Donthineni <sdonthineni@xxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Link: https://lore.kernel.org/r/20240115135649.708536-1-vidyas@xxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/pci/msi.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -1311,7 +1311,7 @@ static irq_hw_number_t pci_msi_domain_ca
return (irq_hw_number_t)desc->msi_attrib.entry_nr |
pci_dev_id(dev) << 11 |
- (pci_domain_nr(dev->bus) & 0xFFFFFFFF) << 27;
+ ((irq_hw_number_t)(pci_domain_nr(dev->bus) & 0xFFFFFFFF)) << 27;
}
static inline bool pci_msi_desc_is_multi_msi(struct msi_desc *desc)
Patches currently in stable-queue which might be from vidyas@xxxxxxxxxx are
queue-5.15/pci-msi-prevent-msi-hardware-interrupt-number-truncation.patch
