From: Grant Likely <grant.likely@secretlab.ca>
Commit 4f9a58d75bfe82ab2b8ba5b8506dfb190a267834 changes the size of

AT_VECTOR_SIZE from hard coded '44' to a calculation based on the value

of AT_VECTOR_SIZE_ARCH and AT_VECTOR_SIZE_BASE.  The change works for

arch/powerpc, but it breaks arch/ppc because the needed

AT_VECTOR_SIZE_ARCH is not present in include/asm-ppc/system.h and a

default value of 0 is used instead.  This results in AT_VECTOR_SIZE

being too small and it causes a kernel crash on loading init.
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

---
I think this bug fix needs to go in ASAP.  I cannot boot my Virtex ppc405

platform without it.
Olaf, do I have the correct solution here?
Thanks,

g.
 include/asm-ppc/system.h |    1 +

 1 files changed, 1 insertions(+), 0 deletions(-)
diff --git a/include/asm-ppc/system.h b/include/asm-ppc/system.h

index cc45780..51df94c 100644

--- a/include/asm-ppc/system.h

+++ b/include/asm-ppc/system.h

@@ -33,6 +33,7 @@
 #define set_mb(var, value)	do { var = value; mb(); } while (0)
+#define AT_VECTOR_SIZE_ARCH 6 /* entries in ARCH_DLINFO */

 #ifdef CONFIG_SMP

 #define smp_mb()	mb()

 #define smp_rmb()	rmb()
-

Sure.

-

Side note: I already applied that patch, but take a look at the commit

message.
That's right: I had to edit the message provided to make it readable. So

I'll just take this opportunity to ask people that when they send

bug-fixes, please try to make the subject line and message make sense for

a *reader*, not for yourself (or even to me, although if it's readable to

some generic person, it's hopefully readable to me too!).
So a subject line of "Bugfix to commit <commit-sha-goes-here>" is

obviously not a very nice one, if you're looking at the kernel commit

history in gitk or some other visualizer that shows the first line as the

subject for the whole commit. It just doesn't make any sense to the

reader!
Related to that, another thing that also happens is that people write

subject lines (and the description) as if everybody realized that

something is particular to that architecture or driver. It may be true

that that particular developer (or development list) is only about ppc,

and then people write subject lines like "Fix execve() argument handling",

but again, when a *generic* person reads that, it now reads totally wrong,

since it wasn't execve() in general, it was a particular architecture that

it went wrong for.
So the rule should be:
 - if it's not fairly generic, specify the area (architecture, subsystem,

   driver) that the fix is for in the subject line. Even if you end up

   initially sending the fix out to just a list that handles that

   particular subsystem anyway.
 - don't use commit names in the subject line - and while it's great to

   use them in the body of the explanation, even there you don't want to

   assume that people read it from within git. People see patches and

   commit changelogs on the web or the commit mailing lists, so when

   specifying an exact version, also specify the human-readable name of

   that version.
 - write the commit message for an outsider, and use whitespace. The

   third-most common fi...
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