James Bottomley <jbottom...@odin.com> writes: > On Fri, 2015-10-30 at 01:32 +0200, Andy Shevchenko wrote: >> 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). > > The standard signal for a drive error in capacity is zero size and zero > block size. We have to take that case as standard without emitting > scary warnings.
Ok, but what if size != 0? Is WARN_ON() justified in this case? -- Vitaly -- 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/