Messages in this thread Patch in this message | | | Date | Thu, 6 Aug 2009 18:47:02 -0400 (EDT) | From | Steven Rostedt <> | Subject | Re: drivers/staging/meilhaus build broken with ftrace |
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On Thu, 6 Aug 2009, Greg KH wrote:
> On Thu, Aug 06, 2009 at 05:46:57PM -0400, Steven Rostedt wrote: > > > > Hi Roland, > > > > On Thu, 6 Aug 2009, Roland Dreier wrote: > > > > > Commit fc4c7355 ("ftrace: Fix the conditional that updates $ref_func") > > > breaks the build of drivers/staging/meilhaus with ftrace enabled: > > > > > > CC [M] drivers/staging/meilhaus/me0600_device.o > > > No function to reference at scripts/recordmcount.pl line 339, <IN> line 258. > > > make[4]: *** [drivers/staging/meilhaus/me0600_device.o] Error 9 > > > > > > Yes, that's crazy, but the situation is the following: > > > > > > - for some reason I can't fathom, the meilhaus driver declares > > > me0600_pci_constructor() as weak in drivers/staging/meilhaus/me0600_device.h > > > > > > - me0600_pci_constructor() is the only function in .text in > > > drivers/staging/meilhaus/me0600_device.c > > > > > > so recordmcount.pl ends up finding only one weak function in .text, and > > > so it never sets $ref_func before calling update_funcs(). > > > > Ug, I figured this would happen. I think I have a patch somewhere that can > > handle this. > > Don't make ftrace do a lot of work if it's a bug in the staging driver. > Odds are the code in there should be fixed instead, I'll gladly take a > patch to do that.
Yes the module did something funky, but what broke recordmcount.pl was not something that is not allowed. The code broke because a weak function was the only function in a section. This patch keeps it from crashing.
Hmm, maybe I should make it warn, because a weak function by itself in a section will not be traced.
-- Steve
diff --git a/scripts/recordmcount.pl b/scripts/recordmcount.pl index d29baa2..979da4b 100755 --- a/scripts/recordmcount.pl +++ b/scripts/recordmcount.pl @@ -393,7 +393,7 @@ while (<IN>) { $read_function = 0; } # print out any recorded offsets - update_funcs() if ($text_found); + update_funcs() if (defined($ref_func)); # reset all markers and arrays $text_found = 0; @@ -441,7 +441,7 @@ while (<IN>) { } # dump out anymore offsets that may have been found -update_funcs() if ($text_found); +update_funcs() if (defined($ref_func)); # If we did not find any mcount callers, we are done (do nothing). if (!$opened) {
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