Jens Axboe <[email protected]> writes: > On Wed, Feb 27 2013, Rusty Russell wrote: >> Aurelien Jarno <[email protected]> writes: >> > Hi, >> > >> > I have noticed that virtio-rng only returns zero for kernels >= 2.6.33 >> > built with CONFIG_HW_RANDOM=m. This is a bit much too predictable for a >> > random generator ;-). >> >> Wow. Fortunately, all of SLES, RHEL, Ubuntu or Fedora set >> CONFIG_HW_RANDOM=y. What do they know that we don't? >> >> Oops, looks like Debian testing: config-3.2.0-4-amd64:CONFIG_HW_RANDOM=m >> >> > The reason for that is virtio expects guest real addresses, while >> > rng_core.ko (ie when built as a module) is passing a vmalloced buffer >> > to the virtio-rng read function, declared as such: >> > >> > static u8 rng_buffer[SMP_CACHE_BYTES < 32 ? 32 : SMP_CACHE_BYTES] >> > __cacheline_aligned; >> >> Yuck... It would be nice if this has oopsed. Jens, what about this patch? >> >> Cheers, >> Rusty. >> >> Subject: scatterlist: sg_set_buf() argument must be in linear mapping. >> >> Signed-off-by: Rusty Russell <[email protected]> >> >> diff --git a/include/linux/scatterlist.h b/include/linux/scatterlist.h >> index 4bd6c06..9365375 100644 >> --- a/include/linux/scatterlist.h >> +++ b/include/linux/scatterlist.h >> @@ -111,6 +111,9 @@ static inline struct page *sg_page(struct scatterlist >> *sg) >> static inline void sg_set_buf(struct scatterlist *sg, const void *buf, >> unsigned int buflen) >> { >> +#ifdef CONFIG_DEBUG_SG >> + BUG_ON(!virt_addr_valid(buf)); >> +#endif >> sg_set_page(sg, virt_to_page(buf), buflen, offset_in_page(buf)); >> } > > Looks good to me, in lieu of being able to return an error. Want me to > queue it up? > > -- > Jens Axboe
Ping? I haven't seen this go into Linus' tree... Subject: scatterlist: sg_set_buf() argument must be in linear mapping. Signed-off-by: Rusty Russell <[email protected]> diff --git a/include/linux/scatterlist.h b/include/linux/scatterlist.h index 4bd6c06..9365375 100644 --- a/include/linux/scatterlist.h +++ b/include/linux/scatterlist.h @@ -111,6 +111,9 @@ static inline struct page *sg_page(struct scatterlist *sg) static inline void sg_set_buf(struct scatterlist *sg, const void *buf, unsigned int buflen) { +#ifdef CONFIG_DEBUG_SG + BUG_ON(!virt_addr_valid(buf)); +#endif sg_set_page(sg, virt_to_page(buf), buflen, offset_in_page(buf)); } -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
