Bug 189021
| Summary: | Function eni_do_init() does not set the error code when the call to ioremap_nocache() fails | ||
|---|---|---|---|
| Product: | Drivers | Reporter: | bianpan (bianpan2010) |
| Component: | Network | Assignee: | drivers_network (drivers_network) |
| Status: | RESOLVED CODE_FIX | ||
| Severity: | normal | ||
| Priority: | P1 | ||
| Hardware: | All | ||
| OS: | Linux | ||
| Kernel Version: | linux-4.9-rc6 | Subsystem: | |
| Regression: | No | Bisected commit-id: | |
| Attachments: | The patch fixes the bug | ||
Created attachment 256449 [details]
The patch fixes the bug
The patch has been merged into the latest version of the Linux kernel. So I will close the bug.
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Function ioremap_nocache() returns a NULL pointer if there is no enough memory. It is called in the function eni_do_init() defined in file drivers/atm/eni.c. Its return value is checked against NULL at line 1726. And if the return value is NULL, it returns variable error. Because variable error is checked at line 1717, the value of error must be 0 here. As a result, eni_do_init() returns 0 (indicates success) even if ioremap_nocache() fails. Though this error may occur rarely, I think it is better to return a correct error code (e.g. -ENOMEM) on the failure. Codes related to this bug are summarised as follows. eni_do_init @@ drivers/atm/eni.c 1700 static int eni_do_init(struct atm_dev *dev) 1701 { ... 1707 int error,i,last; ... 1717 if ((error = pci_write_config_word(pci_dev,PCI_COMMAND, 1718 PCI_COMMAND_MEMORY | 1719 (eni_dev->asic ? PCI_COMMAND_PARITY | PCI_COMMAND_SERR : 0)))) { 1720 printk(KERN_ERR DEV_LABEL "(itf %d): can't enable memory " 1721 "(0x%02x)\n",dev->number,error); 1722 return -EIO; 1723 } 1724 printk(KERN_NOTICE DEV_LABEL "(itf %d): rev.%d,base=0x%lx,irq=%d,", 1725 dev->number,pci_dev->revision,real_base,eni_dev->irq); 1726 if (!(base = ioremap_nocache(real_base,MAP_MAX_SIZE))) { 1727 printk("\n"); 1728 printk(KERN_ERR DEV_LABEL "(itf %d): can't set up page " 1729 "mapping\n",dev->number); // The value of error is 0. Insert "error = -ENOMEM;" ? 1730 return error; 1731 } ... 1787 out: 1788 return error; 1789 unmap: 1790 iounmap(base); 1791 goto out; 1792 } Thanks very much!