[SRU][P][PATCH 0/1] UBUNTU: SAUCE: powerpc64/ftrace: fail to load i40e driver at boot time (LP: #2104297)

[Massimiliano Pellizzer]

BugLink: https://bugs.launchpad.net/bugs/2104297

[ Impact ]

In ppc64el kernels, loading modules without any
__patchable_function_entries section would fail due to a
zero size allocation of executable memory for ftrace trampolines.
This causes boot failures when trying to boot the kernel on IBM Power 9
systems. In particular becasue IBM Power 9 tries to load i40e at boot
time, which fails.

The bug was introduced by commit eec37961a56a which landed in v6.13-rc1,
which assumed all modules have traceable functions.

[ Fix ]

Apply the following patch:
- https://lore.kernel.org/all/wlscshbqan2svtqkz5xc6v47tzndfnsvge7h4lbfn67zoplekl@elt2oxwhrp6f/T/
which has not landed in linux-next yet.

[ Test Plan ]

Compile and boot test the kernel on a Power 9 bare metal machine.

[ Where problems could occur ]

The patch simply removes an if branch which handles (incorrectly) errors during
module loading on ppc64 systems. The regression potential therefore is
very low.


Massimiliano Pellizzer (1):
  UBUNTU: SAUCE: powerpc64/ftrace: fix module loading without patchable
    function entries

 arch/powerpc/kernel/module_64.c | 4 ----
 1 file changed, 4 deletions(-)

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2.43.0