Re: [RFC][PATCHES] constifying ftrace globs

[Steven Rostedt]

Seems that this series fell through the cracks. Is it worth
resurrecting?

-- Steve


On Thu, 5 Feb 2015 19:49:14 +0000
Al Viro <viro@xxxxxxxxxxxxxxxxxx> wrote:

> 	We don't really need to NUL-terminate the substring we are
> matching against; all it takes is introducing memmem(3) and using it
> instead of str[n]str().
> 
> 	It's not that much work - see vfs.git#ftrace_glob.  The reason
> I went there is rather amusing; it all started with making do_execve()
> take arrays of const strings for argv and envp.  After all, we never
> change them *and* we often enough pass arrays of string literals that
> way.  It exploded into a series ofÂ75 commits, with the final ripple
> being argv_split() and argv_free().  OK, turns out that ftrace is
> using those as well, fortunately it's done to get arrays of regexes,
> so it should be trivial to constify as well, right?  Imagine the amount of
> swearing when I noticed that it *does* modify the resulting strings...
> 
> 	This series deals with that problem, providing the missing prereq for
> the patchbomb from hell...
> 
> 	Could you review #ftrace_glob?  It's not large - seven commits,
> boiling down to
>  include/linux/ftrace.h             |  8 ++---
>  include/linux/string.h             |  1 +
>  kernel/trace/ftrace.c              | 68 ++++++++++++++++++--------------------
>  kernel/trace/trace.h               |  2 +-
>  kernel/trace/trace_events_filter.c | 26 +++++++++------
>  lib/string.c                       | 34 ++++++++++++-------
>  6 files changed, 75 insertions(+), 64 deletions(-)
> 
> Patches in followups.