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From: david.laight.linux@gmail.com
To: linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org
Cc: Bjorn Helgaas <bhelgaas@google.com>,
	David Laight <david.laight.linux@gmail.com>
Subject: [PATCH 25/44] drivers/pci: use min() instead of min_t()
Date: Wed, 19 Nov 2025 22:41:21 +0000	[thread overview]
Message-ID: <20251119224140.8616-26-david.laight.linux@gmail.com> (raw)
In-Reply-To: <20251119224140.8616-1-david.laight.linux@gmail.com>

From: David Laight <david.laight.linux@gmail.com>

min_t(unsigned int, a, b) casts an 'unsigned long' to 'unsigned int'.
Use min(a, b) instead as it promotes any 'unsigned int' to 'unsigned long'
and so cannot discard significant bits.

In this case although pci_hotplug_bus_size is 'long' it is constrained
to be <= 255.

Detected by an extra check added to min_t().

Signed-off-by: David Laight <david.laight.linux@gmail.com>
---
 drivers/pci/probe.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 0ce98e18b5a8..0f0d1b44d8c2 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -3163,8 +3163,7 @@ static unsigned int pci_scan_child_bus_extend(struct pci_bus *bus,
 	 * bus number if there is room.
 	 */
 	if (bus->self && bus->self->is_hotplug_bridge) {
-		used_buses = max_t(unsigned int, available_buses,
-				   pci_hotplug_bus_size - 1);
+		used_buses = max(available_buses, pci_hotplug_bus_size - 1);
 		if (max - start < used_buses) {
 			max = start + used_buses;
 
-- 
2.39.5


  reply	other threads:[~2025-11-19 22:42 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-11-19 22:40 [PATCH 00/44] Change a lot of min_t() that might mask high bits david.laight.linux
2025-11-19 22:41 ` david.laight.linux [this message]
2025-11-24 21:04   ` [PATCH 25/44] drivers/pci: use min() instead of min_t() Bjorn Helgaas
2025-11-24 21:42     ` David Laight
2025-11-20  1:47 ` [PATCH 00/44] Change a lot of min_t() that might mask high bits Jakub Kicinski
2025-11-20  9:38 ` Lorenzo Stoakes
2025-11-20 14:52 ` (subset) " Jens Axboe
2025-11-24  9:49 ` Herbert Xu

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