From: Geert Uytterhoeven geert+renesas@glider.be
[ Upstream commit 9d8ba74a181b1c81def21168795ed96cbe6f05ed ]
On r8a7791/koelsch:
kmemleak: 1 new suspected memory leaks (see /sys/kernel/debug/kmemleak) # cat /sys/kernel/debug/kmemleak unreferenced object 0xc3a34e00 (size 64): comm "swapper/0", pid 1, jiffies 4294937460 (age 199.080s) hex dump (first 32 bytes): b4 5d 81 f0 b4 5d 81 f0 c0 b0 a2 c3 00 00 00 00 .]...].......... 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [<fe3aa979>] __kmalloc+0xf0/0x140 [<34bd6bc0>] resource_list_create_entry+0x18/0x38 [<767046bc>] pci_add_resource_offset+0x20/0x68 [<b3f3edf2>] devm_of_pci_get_host_bridge_resources.constprop.0+0xb0/0x390
When coalescing two resources for a contiguous aperture, the second resource is enlarged to cover the full contiguous range, while the first resource is marked invalid. This invalidation is done by clearing the flags, start, and end members.
When adding the initial resources to the bus later, invalid resources are skipped. Unfortunately, the check for an invalid resource considers only the end member, causing false positives.
E.g. on r8a7791/koelsch, root bus resource 0 ("bus 00") is skipped, and no longer registered with pci_bus_insert_busn_res() (causing the memory leak), nor printed:
pci-rcar-gen2 ee090000.pci: host bridge /soc/pci@ee090000 ranges: pci-rcar-gen2 ee090000.pci: MEM 0x00ee080000..0x00ee08ffff -> 0x00ee080000 pci-rcar-gen2 ee090000.pci: PCI: revision 11 pci-rcar-gen2 ee090000.pci: PCI host bridge to bus 0000:00 -pci_bus 0000:00: root bus resource [bus 00] pci_bus 0000:00: root bus resource [mem 0xee080000-0xee08ffff]
Fix this by only skipping resources where all of the flags, start, and end members are zero.
Fixes: 7c3855c423b17f6c ("PCI: Coalesce host bridge contiguous apertures") Link: https://lore.kernel.org/r/da0fcd5e86c74239be79c7cb03651c0fce31b515.167603667... Tested-by: Niklas Schnelle schnelle@linux.ibm.com Signed-off-by: Geert Uytterhoeven geert+renesas@glider.be Signed-off-by: Bjorn Helgaas bhelgaas@google.com Acked-by: Kai-Heng Feng kai.heng.feng@canonical.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/pci/probe.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index 1d6f7b502020d..90e676439170b 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -994,7 +994,7 @@ static int pci_register_host_bridge(struct pci_host_bridge *bridge) resource_list_for_each_entry_safe(window, n, &resources) { offset = window->offset; res = window->res; - if (!res->end) + if (!res->flags && !res->start && !res->end) continue;
list_move_tail(&window->node, &bridge->windows);