[PATCH 2/2] msi: Add sanity check if more than MAX_DEV_MSIS MSIs are requested

[Julian Vetter]

If a device requests more than MAX_DEV_MSIS the MSI index will collide with
the devid and might cause Linux to compute twice the same virtual interrupt
number for two different devices.

Signed-off-by: Julian Vetter <jvetter@xxxxxxxxxxxxx>
Reviewed-by: Yann Sionneau <ysionneau@xxxxxxxxxxxxx>
---
 drivers/base/platform-msi.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/base/platform-msi.c b/drivers/base/platform-msi.c
index 4b0b2fe3a7ff..627d8f6b83ea 100644
--- a/drivers/base/platform-msi.c
+++ b/drivers/base/platform-msi.c
@@ -40,6 +40,8 @@ static irq_hw_number_t platform_msi_calc_hwirq(struct msi_desc *desc)
 {
 	u32 devid = desc->dev->msi.data->platform_data->devid;
 
+	WARN_ON(desc->msi_index >= MAX_DEV_MSIS);
+
 	return (devid << (32 - DEV_ID_SHIFT)) | desc->msi_index;
 }
 
-- 
2.17.1