Re: [v4.2] powerpc/modules: Don't try to restore r2 after a sibling call
From: Michael Ellerman <hidden>
Date: 2017-12-12 11:39:42
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On Thu, 2017-11-16 at 17:45:37 UTC, Josh Poimboeuf wrote:
From: Josh Poimboeuf <redacted>
Subject: [PATCH v4.2] powerpc/modules: Don't try to restore r2 after a sibling call
When attempting to load a livepatch module, I got the following error:
module_64: patch_module: Expect noop after relocate, got 3c820000
The error was triggered by the following code in
unregister_netdevice_queue():
14c: 00 00 00 48 b 14c <unregister_netdevice_queue+0x14c>
14c: R_PPC64_REL24 net_set_todo
150: 00 00 82 3c addis r4,r2,0
GCC didn't insert a nop after the branch to net_set_todo() because it's
a sibling call, so it never returns. The nop isn't needed after the
branch in that case.
Signed-off-by: Josh Poimboeuf <redacted>
Acked-by: Naveen N. Rao <redacted>Applied to powerpc next, thanks. https://git.kernel.org/powerpc/c/b9eab08d012fa093947b230f9a8725 cheers