diff options
| author | Josh Poimboeuf <jpoimboe@redhat.com> | 2017-11-16 11:45:37 -0600 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2017-12-11 13:03:29 +1100 |
| commit | b9eab08d012fa093947b230f9a87257c27fb829b (patch) | |
| tree | fa5f33c519c97d9cbbf59b4598a8fdf8e8f4d273 /arch/powerpc/lib | |
| parent | a443bf6e8a7674b86221f4922cae82d67dc9e8ad (diff) | |
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 <jpoimboe@redhat.com>
Acked-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Reviewed-and-tested-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch/powerpc/lib')
| -rw-r--r-- | arch/powerpc/lib/code-patching.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/arch/powerpc/lib/code-patching.c b/arch/powerpc/lib/code-patching.c index d469224c4ada..096d4e4d31e6 100644 --- a/arch/powerpc/lib/code-patching.c +++ b/arch/powerpc/lib/code-patching.c @@ -302,6 +302,11 @@ int instr_is_relative_branch(unsigned int instr) return instr_is_branch_iform(instr) || instr_is_branch_bform(instr); } +int instr_is_relative_link_branch(unsigned int instr) +{ + return instr_is_relative_branch(instr) && (instr & BRANCH_SET_LINK); +} + static unsigned long branch_iform_target(const unsigned int *instr) { signed long imm; |