Re: 3.5+: yaboot, Invalid memory access

On Tue, 4 Sep 2012 at 16:51, Michael Ellerman wrote:

My guess would be we're calling that quite early and the __put_user()
check is getting confused and failing. That means we'll have left some
code unpatched, which then fails.

Can you try with the patch applied, but instead of returning if the
__put_user() fails, just continue on anyway.

You mean, like this?

------

diff --git a/arch/powerpc/lib/code-patching.c 

b/arch/powerpc/lib/code-patching.c
index dd223b3..755b623 100644

--- a/arch/powerpc/lib/code-patching.c
+++ b/arch/powerpc/lib/code-patching.c

@@ -21,8 +21,8 @@ int patch_instruction(unsigned int *addr, unsigned int 

instr)
        int err;
 
        err = __put_user(instr, addr);
-       if (err)
-               return err;
+//     if (err)
+//             return err;
        asm ("dcbst 0, %0; sync; icbi 0,%0; sync; isync" : : "r" (addr));
        return 0;
 }
------


Thanks,
Christian.

That will isolate if it's something in the __put_user() (I doubt it), or
just that the __put_user() is failing and leaving the code unpatched.

cheers

-- 
BOFH excuse #361:

Communist revolutionaries taking over the server room and demanding all the computers in the building or they shoot the sysadmin. Poor misguided fools.