On 14/02/2021 19:00, Linus Torvalds wrote: > On Sun, Feb 14, 2021 at 10:42 AM Ramsay Jones > <ramsay@xxxxxxxxxxxxxxxxxxxx> wrote: >> >>> >>> I looked around but didn't find any hints how to fix this. Any pointers >>> I missed (added the sparse list to cc:)? >> >> This is a limitation of sparse; when using the 'stringize' pre-processor >> operator #, the maximum size of the resulting string is about 8k (if I >> remember correctly). > > Well, yes and no. > > The C89 standard actually says that a string literal can be at most > 509 characters to be portable. C99 increased it to 4095 characters. > > Sparse makes the limit higher, and the limit could easily be expanded > way past 8kB - but the point is that large string literals are > actually not guaranteed to be valid C. > > So honestly, it really sounds like that TRACE_EVENT() thing is doing > something it shouldn't be doing. Yep, as I said, I didn't submit the patch - rather I changed the source so as not to need such a long string. > I don't think there's any fundamental limit why sparse does 8kB as a > limit (just a few random buffers). Making sparse accept larger ones > should be as simple as just increasing MAX_STRING, but I really don't > think the kernel should encourage that kind of excessive string sizes. I agree, but I wiggled my patch (which doesn't increase MAX_STRING) to apply to the current codebase, and ... it now fails two tests! ;-) (It seems, in the intervening 9 years, the show_token_sequence() function fixed the quoting of double-quotes in the resulting strings, which my patch fails to do). Sorry for the noise. ATB, Ramsay Jones
