On Fri, Oct 30, 2015 at 1:00 AM, James Bottomley <jbottom...@odin.com> wrote: > On Thu, 2015-10-29 at 17:30 +0100, Vitaly Kuznetsov wrote: >> Division by zero happens if blk_size=0 is supplied to string_get_size(). >> Add WARN_ON() and set size to 0 to report '0 B'. >> >> Signed-off-by: Vitaly Kuznetsov <vkuzn...@redhat.com> >> --- >> lib/string_helpers.c | 5 +++++ >> 1 file changed, 5 insertions(+) >> >> diff --git a/lib/string_helpers.c b/lib/string_helpers.c >> index f6c27dc..ff3575b 100644 >> --- a/lib/string_helpers.c >> +++ b/lib/string_helpers.c >> @@ -50,6 +50,11 @@ void string_get_size(u64 size, u32 blk_size, const enum >> string_size_units units, >> >> tmp[0] = '\0'; >> i = 0; >> + >> + /* Calling string_get_size() with blk_size=0 is wrong! */ >> + if (WARN_ON(!blk_size)) > > Get rid of the WARN_ON; it's the standard thing to do for a partially > connected device. Seeing zero is standard in a whole variety of > situations. SCSI shims the zero but most other drivers don't.
For *block* size? It will crash the kernel. I've checked, it wasn't changed from the beginning (b9f28d863594). + exp = divisor[units] / (u32)blk_size; -- With Best Regards, Andy Shevchenko -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
