linux-stable/arch
Josh Poimboeuf 37251c7114 powerpc/module_64: Fix "expected nop" error on module re-patching
When a module with a livepatched function is unloaded and then reloaded,
klp attempts to dynamically re-patch it.  On ppc64, that fails with the
following error:

  module_64: livepatch_nfsd: Expected nop after call, got e8410018 at e_show+0x60/0x548 [livepatch_nfsd]
  livepatch: failed to initialize patch 'livepatch_nfsd' for module 'nfsd' (-8)
  livepatch: patch 'livepatch_nfsd' failed for module 'nfsd', refusing to load module 'nfsd'

The error happens because the restore r2 instruction had already
previously been written into the klp module's replacement function when
the original function was patched the first time.  So the instruction
wasn't a nop as expected.

When the restore r2 instruction has already been patched in, detect that
and skip the warning and the instruction write.

Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Acked-by: Song Liu <song@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/2f6329ffd9674df6ff57e03edeb2ca54414770ab.1674617130.git.jpoimboe@kernel.org
2023-01-26 21:08:04 +11:00
..
alpha MM patches for 6.2-rc1. 2022-12-13 19:29:45 -08:00
arc MM patches for 6.2-rc1. 2022-12-13 19:29:45 -08:00
arm ARM: SoC fixes for 6.2 2022-12-19 16:07:59 -06:00
arm64 remoteproc updates for v6.2 2022-12-21 09:37:14 -08:00
csky arch/csky patches for 6.2-rc1 2022-12-19 07:51:30 -06:00
hexagon MM patches for 6.2-rc1. 2022-12-13 19:29:45 -08:00
ia64 - Add the call depth tracking mitigation for Retbleed which has 2022-12-14 15:03:00 -08:00
loongarch LoongArch changes for v6.2 2022-12-19 08:23:27 -06:00
m68k m68k: remove broken strcmp implementation 2022-12-21 08:56:43 -08:00
microblaze MM patches for 6.2-rc1. 2022-12-13 19:29:45 -08:00
mips Fixes due to DT changes 2022-12-23 10:49:45 -08:00
nios2 MM patches for 6.2-rc1. 2022-12-13 19:29:45 -08:00
openrisc MM patches for 6.2-rc1. 2022-12-13 19:29:45 -08:00
parisc parisc architecture fixes for kernel v6.2-rc1: 2022-12-20 08:43:53 -06:00
powerpc powerpc/module_64: Fix "expected nop" error on module re-patching 2023-01-26 21:08:04 +11:00
riscv KVM/riscv changes for 6.2 2022-12-21 18:52:15 -08:00
s390 random: do not include <asm/archrandom.h> from random.h 2022-12-20 03:13:45 +01:00
sh treewide: Convert del_timer*() to timer_shutdown*() 2022-12-25 13:38:09 -08:00
sparc MM patches for 6.2-rc1. 2022-12-13 19:29:45 -08:00
um New Feature: 2022-12-17 14:06:53 -06:00
x86 - Pass only an initialized perf event attribute to the LSM hook 2023-01-01 11:27:00 -08:00
xtensa MM patches for 6.2-rc1. 2022-12-13 19:29:45 -08:00
.gitignore
Kconfig arm64 fixes for -rc1 2022-12-16 13:46:41 -06:00