On Thu, 1 Nov 2012 15:03:00 -0400
Nick Bowler wrote:
> There is absolutely no reason to crash the kernel when we have a
> perfectly good return value already available to use for conveying
> failure status.
Yes, I suppose that's true. I don't see a case for BUGging the kernel
> Let's return an error code instead of crashing the kernel: that sounds
> like a much better plan.
> Signed-off-by: Nick Bowler
> lib/scatterlist.c | 3 ++-
> 1 files changed, 2 insertions(+), 1 deletions(-)
> diff --git a/lib/scatterlist.c b/lib/scatterlist.c
> index 3675452b23ca..11ecaf000696 100644
> --- a/lib/scatterlist.c
> +++ b/lib/scatterlist.c
> @@ -248,7 +248,8 @@ int __sg_alloc_table(struct sg_table *table, unsigned
> unsigned int left;
> #ifndef ARCH_HAS_SG_CHAIN
> - BUG_ON(nents > max_ents);
> + if (WARN_ON_ONCE(nents > max_ents))
> + return -E2BIG;
OK, pet peeve: if this E2BIG gets returned to userspace, our poor user
will look it up and see "Argument list too long; used when the
arguments passed to a new program being executed with one of the exec
functions occupy too much memory space". He then gets to spend half a
day reviewing his code's exec() callsites!
See? Although the error's name sounds like a nice match to the
internal state, it isn't really a match at all and our use of it is
Unfortunately there is no EKERNELSCREWEDUP, so we usually use EINVAL.