On 08:19 Thu 25 Jul, shuah wrote: > On 7/25/19 7:22 AM, Liu, Changcheng wrote: > > GCC8 started emitting warning about using strncpy with number of bytes > > exactly equal destination size which could lead to non-zero terminated > > string being copied. Use "SYSFS_PATH_MAX - 1" & "SYSFS_BUS_ID_SIZE - 1" > > as number of bytes to ensure name is always zero-terminated. > > > > Signed-off-by: Changcheng Liu <changcheng.liu@xxxxxxxxxx> > > --- > > v1 -> v2: > > * Correct array tail index > > --- > > tools/usb/usbip/libsrc/usbip_common.c | 6 ++++-- > > tools/usb/usbip/libsrc/usbip_device_driver.c | 6 ++++-- > > 2 files changed, 8 insertions(+), 4 deletions(-) > > > > diff --git a/tools/usb/usbip/libsrc/usbip_common.c b/tools/usb/usbip/libsrc/usbip_common.c > > index bb424638d75b..b8d7d480595a 100644 > > --- a/tools/usb/usbip/libsrc/usbip_common.c > > +++ b/tools/usb/usbip/libsrc/usbip_common.c > > @@ -226,8 +226,10 @@ int read_usb_device(struct udev_device *sdev, struct usbip_usb_device *udev) > > path = udev_device_get_syspath(sdev); > > name = udev_device_get_sysname(sdev); > > - strncpy(udev->path, path, SYSFS_PATH_MAX); > > - strncpy(udev->busid, name, SYSFS_BUS_ID_SIZE); > > + strncpy(udev->path, path, SYSFS_PATH_MAX - 1); > > + udev->path[SYSFS_PATH_MAX - 1] = '\0'; > > + strncpy(udev->busid, name, SYSFS_BUS_ID_SIZE - 1); > > + udev->busid[SYSFS_BUS_ID_SIZE - 1] = '\0'; > > strlcpy() would be better choice here. Any reason to not use that? > @Shuah: linux tools link with libc which doesn't implment strlcpy yet. So tools source code can't use strlcpy function like other kernel source code. > > sscanf(name, "%u-%u", &busnum, &devnum); > > udev->busnum = busnum; > > diff --git a/tools/usb/usbip/libsrc/usbip_device_driver.c b/tools/usb/usbip/libsrc/usbip_device_driver.c > > index 5a3726eb44ab..051d7d3f443b 100644 > > --- a/tools/usb/usbip/libsrc/usbip_device_driver.c > > +++ b/tools/usb/usbip/libsrc/usbip_device_driver.c > > @@ -91,7 +91,8 @@ int read_usb_vudc_device(struct udev_device *sdev, struct usbip_usb_device *dev) > > copy_descr_attr16(dev, &descr, idProduct); > > copy_descr_attr16(dev, &descr, bcdDevice); > > - strncpy(dev->path, path, SYSFS_PATH_MAX); > > + strncpy(dev->path, path, SYSFS_PATH_MAX - 1); > > + dev->path[SYSFS_PATH_MAX - 1] = '\0'; > > dev->speed = USB_SPEED_UNKNOWN; > > speed = udev_device_get_sysattr_value(sdev, "current_speed"); > > @@ -110,7 +111,8 @@ int read_usb_vudc_device(struct udev_device *sdev, struct usbip_usb_device *dev) > > dev->busnum = 0; > > name = udev_device_get_sysname(plat); > > - strncpy(dev->busid, name, SYSFS_BUS_ID_SIZE); > > + strncpy(dev->busid, name, SYSFS_BUS_ID_SIZE - 1); > > + dev->busid[SYSFS_BUS_ID_SIZE - 1] = '\0'; > > strlcpy() would be better choice here. Any reason to not use that? > > > return 0; > > err: > > fclose(fd); > > > > thanks, > -- Shuah
