> > > commit 6784beada631800f2c5afd567e5628c843362cee upstream. > > > > > > Fix the event trigger to accept redundant spaces in > > > the trigger input. > > > > > > For example, these return -EINVAL > > > > > > echo " traceon" > events/ftrace/print/trigger > > > echo "traceon if common_pid == 0" > events/ftrace/print/trigger > > > echo "disable_event:kmem:kmalloc " > events/ftrace/print/trigger > > > > > > But these are hard to find what is wrong. > > > > > > To fix this issue, use skip_spaces() to remove spaces > > > in front of actual tokens, and set NULL if there is no > > > token. > > > > For the record, I'm not fan of this one. It is ABI change, not a > > bugfix. > > > > Yes, it makes kernel interface "easier to use". It also changes > > interface in the middle of stable series, and if people start relying > > on new interface and start putting extra spaces, they'll get nasty > > surprise when they move code to the older kernel. > > If an interface changes anywhere that breaks userspace, it needs to be > not done, stable kernels are not an issue here or not. I'm not saying it is a regression; I'd scream way more if that was the case. I'm saying it is nowhere near a fix. We really don't want userspace doing: > > > echo " traceon" > events/ftrace/print/trigger Because it does not work on older kernels. It will work on 4.19.131 and break on 5.6.19. Best regards, Pavel -- DENX Software Engineering GmbH, Managing Director: Wolfgang Denk HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
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