Re: [PATCH v2 2/2] pinctrl: pinmux: Add pinmux-select debugfs file

From: Dan Carpenter
Date: Wed Feb 10 2021 - 13:34:56 EST

Hi Drew,

url: https://github.com/0day-ci/linux/commits/Drew-Fustini/pinctrl-pinmux-Add-pinmux-select-debugfs-file/20210210-160108
base: https://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl.git devel
config: i386-randconfig-m021-20210209 (attached as .config)
compiler: gcc-9 (Debian 9.3.0-15) 9.3.0

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@xxxxxxxxx>
Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>

smatch warnings:
drivers/pinctrl/pinmux.c:762 pinmux_select() error: uninitialized symbol 'gname'.

vim +/gname +762 drivers/pinctrl/pinmux.c

99b2f99aa41aa7 Drew Fustini 2021-02-09 678 static ssize_t pinmux_select(struct file *file, const char __user *user_buf,
99b2f99aa41aa7 Drew Fustini 2021-02-09 679 size_t len, loff_t *ppos)
99b2f99aa41aa7 Drew Fustini 2021-02-09 680 {
99b2f99aa41aa7 Drew Fustini 2021-02-09 681 struct seq_file *sfile = file->private_data;
99b2f99aa41aa7 Drew Fustini 2021-02-09 682 struct pinctrl_dev *pctldev = sfile->private;
99b2f99aa41aa7 Drew Fustini 2021-02-09 683 const struct pinmux_ops *pmxops = pctldev->desc->pmxops;
99b2f99aa41aa7 Drew Fustini 2021-02-09 684 const char *const *groups;
99b2f99aa41aa7 Drew Fustini 2021-02-09 685 char *buf, *fname, *gname;
99b2f99aa41aa7 Drew Fustini 2021-02-09 686 unsigned int num_groups;
99b2f99aa41aa7 Drew Fustini 2021-02-09 687 int fsel, gsel, ret;
99b2f99aa41aa7 Drew Fustini 2021-02-09 688
99b2f99aa41aa7 Drew Fustini 2021-02-09 689 if (len > (PINMUX_MAX_NAME * 2)) {
99b2f99aa41aa7 Drew Fustini 2021-02-09 690 dev_err(pctldev->dev, "write too big for buffer");
99b2f99aa41aa7 Drew Fustini 2021-02-09 691 return -EINVAL;
99b2f99aa41aa7 Drew Fustini 2021-02-09 692 }
99b2f99aa41aa7 Drew Fustini 2021-02-09 693
99b2f99aa41aa7 Drew Fustini 2021-02-09 694 buf = devm_kzalloc(pctldev->dev, PINMUX_MAX_NAME * 2, GFP_KERNEL);
99b2f99aa41aa7 Drew Fustini 2021-02-09 695 if (!buf)
99b2f99aa41aa7 Drew Fustini 2021-02-09 696 return -ENOMEM;
99b2f99aa41aa7 Drew Fustini 2021-02-09 697
99b2f99aa41aa7 Drew Fustini 2021-02-09 698 fname = devm_kzalloc(pctldev->dev, PINMUX_MAX_NAME, GFP_KERNEL);
99b2f99aa41aa7 Drew Fustini 2021-02-09 699 if (!fname) {
99b2f99aa41aa7 Drew Fustini 2021-02-09 700 ret = -ENOMEM;
99b2f99aa41aa7 Drew Fustini 2021-02-09 701 goto free_buf;

The gotos are out of order. They should be in mirror/reverse order of
the allocations:

free_gmane:
devm_kfree(pctldev->dev, gname);
free_fname:
devm_kfree(pctldev->dev, fname);
free_buf:
devm_kfree(pctldev->dev, buf);

But also why do we need to use devm_kfree() at all? I thought the whole
point of devm_ functions was that they are garbage collected
automatically for you. Can we not just delete all error handling and
return -ENOMEM here?

99b2f99aa41aa7 Drew Fustini 2021-02-09 702 }
99b2f99aa41aa7 Drew Fustini 2021-02-09 703
99b2f99aa41aa7 Drew Fustini 2021-02-09 704 gname = devm_kzalloc(pctldev->dev, PINMUX_MAX_NAME, GFP_KERNEL);
99b2f99aa41aa7 Drew Fustini 2021-02-09 705 if (!buf) {
99b2f99aa41aa7 Drew Fustini 2021-02-09 706 ret = -ENOMEM;
99b2f99aa41aa7 Drew Fustini 2021-02-09 707 goto free_fname;
99b2f99aa41aa7 Drew Fustini 2021-02-09 708 }
99b2f99aa41aa7 Drew Fustini 2021-02-09 709
99b2f99aa41aa7 Drew Fustini 2021-02-09 710 ret = strncpy_from_user(buf, user_buf, PINMUX_MAX_NAME * 2);
99b2f99aa41aa7 Drew Fustini 2021-02-09 711 if (ret < 0) {
99b2f99aa41aa7 Drew Fustini 2021-02-09 712 dev_err(pctldev->dev, "failed to copy buffer from userspace");
99b2f99aa41aa7 Drew Fustini 2021-02-09 713 goto free_gname;
99b2f99aa41aa7 Drew Fustini 2021-02-09 714 }
99b2f99aa41aa7 Drew Fustini 2021-02-09 715 buf[len-1] = '\0';
99b2f99aa41aa7 Drew Fustini 2021-02-09 716
99b2f99aa41aa7 Drew Fustini 2021-02-09 717 ret = sscanf(buf, "%s %s", fname, gname);
99b2f99aa41aa7 Drew Fustini 2021-02-09 718 if (ret != 2) {
99b2f99aa41aa7 Drew Fustini 2021-02-09 719 dev_err(pctldev->dev, "expected format: <function-name> <group-name>");
99b2f99aa41aa7 Drew Fustini 2021-02-09 720 goto free_gname;
99b2f99aa41aa7 Drew Fustini 2021-02-09 721 }
99b2f99aa41aa7 Drew Fustini 2021-02-09 722
99b2f99aa41aa7 Drew Fustini 2021-02-09 723 fsel = pinmux_func_name_to_selector(pctldev, fname);
99b2f99aa41aa7 Drew Fustini 2021-02-09 724 if (fsel < 0) {
99b2f99aa41aa7 Drew Fustini 2021-02-09 725 dev_err(pctldev->dev, "invalid function %s in map table\n", fname);
99b2f99aa41aa7 Drew Fustini 2021-02-09 726 ret = -EINVAL;
99b2f99aa41aa7 Drew Fustini 2021-02-09 727 goto free_gname;
99b2f99aa41aa7 Drew Fustini 2021-02-09 728 }
99b2f99aa41aa7 Drew Fustini 2021-02-09 729
99b2f99aa41aa7 Drew Fustini 2021-02-09 730 ret = pmxops->get_function_groups(pctldev, fsel, &groups, &num_groups);
99b2f99aa41aa7 Drew Fustini 2021-02-09 731 if (ret) {
99b2f99aa41aa7 Drew Fustini 2021-02-09 732 dev_err(pctldev->dev, "no groups for function %d (%s)", fsel, fname);
99b2f99aa41aa7 Drew Fustini 2021-02-09 733 goto free_gname;
99b2f99aa41aa7 Drew Fustini 2021-02-09 734
99b2f99aa41aa7 Drew Fustini 2021-02-09 735 }
99b2f99aa41aa7 Drew Fustini 2021-02-09 736
99b2f99aa41aa7 Drew Fustini 2021-02-09 737 ret = match_string(groups, num_groups, gname);
99b2f99aa41aa7 Drew Fustini 2021-02-09 738 if (ret < 0) {
99b2f99aa41aa7 Drew Fustini 2021-02-09 739 dev_err(pctldev->dev, "invalid group %s", gname);
99b2f99aa41aa7 Drew Fustini 2021-02-09 740 goto free_gname;
99b2f99aa41aa7 Drew Fustini 2021-02-09 741 }
99b2f99aa41aa7 Drew Fustini 2021-02-09 742
99b2f99aa41aa7 Drew Fustini 2021-02-09 743 ret = pinctrl_get_group_selector(pctldev, gname);
99b2f99aa41aa7 Drew Fustini 2021-02-09 744 if (ret < 0) {
99b2f99aa41aa7 Drew Fustini 2021-02-09 745 dev_err(pctldev->dev, "failed to get group selectorL %s", gname);
99b2f99aa41aa7 Drew Fustini 2021-02-09 746 goto free_gname;
99b2f99aa41aa7 Drew Fustini 2021-02-09 747 }
99b2f99aa41aa7 Drew Fustini 2021-02-09 748 gsel = ret;
99b2f99aa41aa7 Drew Fustini 2021-02-09 749
99b2f99aa41aa7 Drew Fustini 2021-02-09 750 ret = pmxops->set_mux(pctldev, fsel, gsel);
99b2f99aa41aa7 Drew Fustini 2021-02-09 751 if (ret) {
99b2f99aa41aa7 Drew Fustini 2021-02-09 752 dev_err(pctldev->dev, "set_mux() failed: %d", ret);
99b2f99aa41aa7 Drew Fustini 2021-02-09 753 goto free_gname;
99b2f99aa41aa7 Drew Fustini 2021-02-09 754 }
99b2f99aa41aa7 Drew Fustini 2021-02-09 755
99b2f99aa41aa7 Drew Fustini 2021-02-09 756 return len;
99b2f99aa41aa7 Drew Fustini 2021-02-09 757 free_buf:
99b2f99aa41aa7 Drew Fustini 2021-02-09 758 devm_kfree(pctldev->dev, buf);
99b2f99aa41aa7 Drew Fustini 2021-02-09 759 free_fname:
99b2f99aa41aa7 Drew Fustini 2021-02-09 760 devm_kfree(pctldev->dev, fname);
99b2f99aa41aa7 Drew Fustini 2021-02-09 761 free_gname:
99b2f99aa41aa7 Drew Fustini 2021-02-09 @762 devm_kfree(pctldev->dev, gname);
99b2f99aa41aa7 Drew Fustini 2021-02-09 763 return ret;
99b2f99aa41aa7 Drew Fustini 2021-02-09 764 }

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@xxxxxxxxxxxx

Attachment: .config.gz
Description: application/gzip