Messages in this thread | | | Subject | Re: [PATCH] net: xfrm: use preempt-safe this_cpu_read() in ipcomp_alloc_tfms() | From | Eric Dumazet <> | Date | Thu, 8 Mar 2018 08:31:47 -0800 |
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On 03/07/2018 11:33 PM, Herbert Xu wrote: > On Wed, Mar 07, 2018 at 11:24:16AM -0800, Greg Hackmann wrote: >> f7c83bcbfaf5 ("net: xfrm: use __this_cpu_read per-cpu helper") added a >> __this_cpu_read() call inside ipcomp_alloc_tfms(). Since this call was >> introduced, the rules around per-cpu accessors have been tightened and >> __this_cpu_read() cannot be used in a preemptible context. >> >> syzkaller reported this leading to the following kernel BUG while >> fuzzing sendmsg: > > How about reverting f7c83bcbfaf5 instead? > > Thanks, >
Because that would not be nice.
this_cpu_read() is faster than going through raw_smp_processor_id() and per_cpu_ptr()
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