tty: mxser: improve error handling in mxser_probe() and mxser_module_init()

1. Currently mxser_probe() and mxser_module_init() ignore errors
that can happen in tty_port_register_device().
2. mxser_module_init() does not deallocate resources allocated in mxser_get_ISA_conf()
if mxser_initbrd() failed.

The patch adds proper error handling in all the cases.
Also it moves free_irq() from mxser_release_ISA_res() to mxser_board_remove(),
since it makes mxser_release_ISA_res() a counterpart for mxser_get_ISA_conf(),
while free_irq() is relevant to both ISA and PCI boards.

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/mxser.c b/drivers/tty/mxser.c
index ad34a202a34dc06aeaa241cf134fcd1c9079afcb..484b6a3c9b03714a3eae559e061f3767cdc3af72 100644 (file)
--- a/drivers/tty/mxser.c
+++ b/drivers/tty/mxser.c
@@ -2364,7 +2364,6 @@ static void mxser_release_vector(struct mxser_board *brd)
 
 static void mxser_release_ISA_res(struct mxser_board *brd)
 {
-       free_irq(brd->irq, brd);
        release_region(brd->ports[0].ioaddr, 8 * brd->info->nports);
        mxser_release_vector(brd);
 }
@@ -2430,6 +2429,7 @@ static void mxser_board_remove(struct mxser_board *brd)
                tty_unregister_device(mxvar_sdriver, brd->idx + i);
                tty_port_destroy(&brd->ports[i].port);
        }
+       free_irq(brd->irq, brd);
 }
 
 static int __init mxser_get_ISA_conf(int cap, struct mxser_board *brd)
@@ -2554,6 +2554,7 @@ static int mxser_probe(struct pci_dev *pdev,
        struct mxser_board *brd;
        unsigned int i, j;
        unsigned long ioaddress;
+       struct device *tty_dev;
        int retval = -EINVAL;
 
        for (i = 0; i < MXSER_BOARDS; i++)
@@ -2637,13 +2638,25 @@ static int mxser_probe(struct pci_dev *pdev,
        if (retval)
                goto err_rel3;
 
-       for (i = 0; i < brd->info->nports; i++)
-               tty_port_register_device(&brd->ports[i].port, mxvar_sdriver,
-                               brd->idx + i, &pdev->dev);
+       for (i = 0; i < brd->info->nports; i++) {
+               tty_dev = tty_port_register_device(&brd->ports[i].port,
+                               mxvar_sdriver, brd->idx + i, &pdev->dev);
+               if (IS_ERR(tty_dev)) {
+                       retval = PTR_ERR(tty_dev);
+                       for (i--; i >= 0; i--)
+                               tty_unregister_device(mxvar_sdriver,
+                                       brd->idx + i);
+                       goto err_relbrd;
+               }
+       }
 
        pci_set_drvdata(pdev, brd);
 
        return 0;
+err_relbrd:
+       for (i = 0; i < brd->info->nports; i++)
+               tty_port_destroy(&brd->ports[i].port);
+       free_irq(brd->irq, brd);
 err_rel3:
        pci_release_region(pdev, 3);
 err_zero:
@@ -2665,7 +2678,6 @@ static void mxser_remove(struct pci_dev *pdev)
 
        mxser_board_remove(brd);
 
-       free_irq(pdev->irq, brd);
        pci_release_region(pdev, 2);
        pci_release_region(pdev, 3);
        pci_disable_device(pdev);
@@ -2683,6 +2695,7 @@ static struct pci_driver mxser_driver = {
 static int __init mxser_module_init(void)
 {
        struct mxser_board *brd;
+       struct device *tty_dev;
        unsigned int b, i, m;
        int retval;
 
@@ -2728,14 +2741,29 @@ static int __init mxser_module_init(void)
 
                /* mxser_initbrd will hook ISR. */
                if (mxser_initbrd(brd, NULL) < 0) {
+                       mxser_release_ISA_res(brd);
                        brd->info = NULL;
                        continue;
                }
 
                brd->idx = m * MXSER_PORTS_PER_BOARD;
-               for (i = 0; i < brd->info->nports; i++)
-                       tty_port_register_device(&brd->ports[i].port,
+               for (i = 0; i < brd->info->nports; i++) {
+                       tty_dev = tty_port_register_device(&brd->ports[i].port,
                                        mxvar_sdriver, brd->idx + i, NULL);
+                       if (IS_ERR(tty_dev)) {
+                               for (i--; i >= 0; i--)
+                                       tty_unregister_device(mxvar_sdriver,
+                                               brd->idx + i);
+                               for (i = 0; i < brd->info->nports; i++)
+                                       tty_port_destroy(&brd->ports[i].port);
+                               free_irq(brd->irq, brd);
+                               mxser_release_ISA_res(brd);
+                               brd->info = NULL;
+                               break;
+                       }
+               }
+               if (brd->info == NULL)
+                       continue;
 
                m++;
        }