[PATCH] PCI: rcar-host: Free MSI IRQs on error

[PATCH] PCI: rcar-host: Free MSI IRQs on error

[Marek Vasut]

The rcar_pcie_get_resources() calls irq_of_parse_and_map() on both IRQs.
The rcar_pcie_enable_msi() called afterward calls devm_request_irq() on
both IRQs. In case a failure occurs after rcar_pcie_enable_msi() was
already called, the invocation of irq_dispose_mapping() on those two
IRQs triggers a WARNING:

remove_proc_entry: removing non-empty directory 'irq/96', leaking at least 'R-Car MSI'

Fix this by calling devm_free_irq() on those two IRQs before invocation
of irq_dispose_mapping(), this way the IRQ is free'd before it is
unmapped. Fix matching issue in rcar_pcie_enable_msi() fail path too.

Fixes: 290c1fb35860 ("PCI: rcar: Add MSI support for PCIe")
Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
---
Cc: "Krzysztof Wilczyński" <kwilczynski@kernel.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Cc: Lorenzo Pieralisi <lpieralisi@kernel.org>
Cc: Magnus Damm <magnus.damm@gmail.com>
Cc: Manivannan Sadhasivam <mani@kernel.org>
Cc: Rob Herring <robh@kernel.org>
Cc: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Cc: linux-kernel@vger.kernel.org
Cc: linux-pci@vger.kernel.org
Cc: linux-renesas-soc@vger.kernel.org
---
 remove_proc_entry: removing non-empty directory 'irq/96', leaking at least 'R-Car MSI'
 WARNING: fs/proc/generic.c:747 at remove_proc_entry+0x120/0x144, CPU#3: kworker/u33:6/81
 CPU: 3 UID: 0 PID: 81 Comm: kworker/u33:6 Not tainted 7.3.0-rc7-next-20261016-00042-g33a3dc2a3ff4-dirty #2134 PREEMPT
 Hardware name: Renesas Salvator-X 2nd version board based on r8a77951 (DT)
 Workqueue: events_unbound deferred_probe_work_func
 pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
 pc : remove_proc_entry+0x120/0x144
 lr : remove_proc_entry+0x120/0x144
 sp : ffffffc0804238a0
 x29: ffffffc0804238c0 x28: 0000000000000000 x27: 0000000000000000
 x26: ffffff84c01db20d x25: ffffffe1678941eb x24: 0000000000000061
 x23: 0000000000000001 x22: ffffff84c016e000 x21: ffffffe167f639b0
 x20: ffffffc08042390d x19: ffffff84c0de1d00 x18: 00000000ffffffff
 x17: 6e696b61656c202c x16: 2736392f71726927 x15: 0720072007200720
 x14: 0720072007200720 x13: 0720072007200720 x12: 0720072007200720
 x11: 000000000000018a x10: ffffffe167ea7878 x9 : ffffffe167eff930
 x8 : 3fffffffffffefff x7 : ffffffc0804235c0 x6 : 0000000000000000
 x5 : 0000000000057fa8 x4 : 0000000000000000 x3 : 0000000000000000
 x2 : 0000000000000000 x1 : 0000000000000000 x0 : ffffff84c110e300
 Call trace:
  remove_proc_entry+0x120/0x144 (P)
  unregister_irq_proc+0xd4/0x100
  free_desc+0x3c/0x18c
  irq_free_descs+0x70/0x74
  irq_domain_free_irqs+0xb0/0x11c
  irq_dispose_mapping+0x64/0x138
  rcar_pcie_probe+0x254/0x5ac
  platform_probe+0x68/0x8c
  really_probe+0x1ac/0x388
  __driver_probe_device+0x160/0x170
  driver_probe_device+0x44/0xec
  __device_attach_driver+0x10c/0x124
  bus_for_each_drv+0xa8/0xd0
  __device_attach+0x98/0x174
  device_initial_probe+0x34/0x48
  bus_probe_device+0x30/0x90
  deferred_probe_work_func+0xd8/0xf0
  process_scheduled_works+0x300/0x4ac
  worker_thread+0x13c/0x1cc
  kthread+0x108/0x118
  ret_from_fork+0x10/0x20
 irq event stamp: 8926
 hardirqs last  enabled at (8925): [<ffffffe1666b840c>] __up_console_sem+0x50/0x64
 hardirqs last disabled at (8926): [<ffffffe1672c5908>] el1_brk64+0x1c/0x4c
 softirqs last  enabled at (8920): [<ffffffe166610214>] __do_softirq+0x10/0x18
 softirqs last disabled at (8899): [<ffffffe166610214>] __do_softirq+0x10/0x18
---
 drivers/pci/controller/pcie-rcar-host.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/pci/controller/pcie-rcar-host.c b/drivers/pci/controller/pcie-rcar-host.c
index 5856861922599..aedfb283826b5 100644
--- a/drivers/pci/controller/pcie-rcar-host.c
+++ b/drivers/pci/controller/pcie-rcar-host.c
@@ -768,7 +768,7 @@ static int rcar_pcie_enable_msi(struct rcar_pcie_host *host)
 			       rcar_msi_bottom_chip.name, host);
 	if (err < 0) {
 		dev_err(dev, "failed to request IRQ: %d\n", err);
-		goto err;
+		goto err_irq2;
 	}
 
 	/* Disable all MSIs */
@@ -783,6 +783,9 @@ static int rcar_pcie_enable_msi(struct rcar_pcie_host *host)
 
 	return 0;
 
+err_irq2:
+	devm_free_irq(dev, host->msi.irq1, host);
+
 err:
 	rcar_free_domains(msi);
 	return err;
@@ -791,6 +794,7 @@ static int rcar_pcie_enable_msi(struct rcar_pcie_host *host)
 static void rcar_pcie_teardown_msi(struct rcar_pcie_host *host)
 {
 	struct rcar_pcie *pcie = &host->pcie;
+	struct device *dev = pcie->dev;
 
 	/* Disable all MSI interrupts */
 	rcar_pci_write_reg(pcie, 0, PCIEMSIIER);
@@ -798,6 +802,8 @@ static void rcar_pcie_teardown_msi(struct rcar_pcie_host *host)
 	/* Disable address decoding of the MSI interrupt, MSIFE */
 	rcar_pci_write_reg(pcie, 0, PCIEMSIALR);
 
+	devm_free_irq(dev, host->msi.irq2, host);
+	devm_free_irq(dev, host->msi.irq1, host);
 	rcar_free_domains(&host->msi);
 }
 
-- 
2.53.0

Re: [PATCH] PCI: rcar-host: Free MSI IRQs on error

[sashiko-bot]

> The rcar_pcie_get_resources() calls irq_of_parse_and_map() on both IRQs.
> The rcar_pcie_enable_msi() called afterward calls devm_request_irq() on
> both IRQs. In case a failure occurs after rcar_pcie_enable_msi() was
> already called, the invocation of irq_dispose_mapping() on those two
> IRQs triggers a WARNING:
> 
> remove_proc_entry: removing non-empty directory 'irq/96', leaking at least 'R-Car MSI'
> 
> Fix this by calling devm_free_irq() on those two IRQs before invocation
> of irq_dispose_mapping(), this way the IRQ is free'd before it is
> unmapped. Fix matching issue in rcar_pcie_enable_msi() fail path too.
> 
> Fixes: 290c1fb35860 ("PCI: rcar: Add MSI support for PCIe")
> Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>

Sashiko has reviewed this patch and found no issues.

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20261017172122.225861-1-marek.vasut+renesas@mailbox.org?part=1