Comment 1 for bug 1865858

Looks like commit 657480d9c015 "s390: support KPROBES_ON_FTRACE" is in since 5.6-rc1

I tried to cherry pick (on top of focal master-next) but it failed:

$ git cherry-pick -x -s -e 657480d9c015
Auto-merging arch/s390/kernel/mcount.S
CONFLICT (content): Merge conflict in arch/s390/kernel/mcount.S
Auto-merging arch/s390/Kconfig
warning: inexact rename detection was skipped due to too many files.
warning: you may want to set your merge.renamelimit variable to at least 1670 and retry the command.
error: could not apply 657480d9c015... s390: support KPROBES_ON_FTRACE
hint: after resolving the conflicts, mark the corrected paths
hint: with 'git add <paths>' or 'git rm <paths>'
hint: and commit the result with 'git commit'

 git status
On branch master-next
Your branch is up to date with 'origin/master-next'.

You are currently cherry-picking commit 657480d9c015.
  (fix conflicts and run "git cherry-pick --continue")
  (use "git cherry-pick --skip" to skip this patch)
  (use "git cherry-pick --abort" to cancel the cherry-pick operation)

Changes to be committed:
 modified: Documentation/features/debug/kprobes-on-ftrace/arch-support.txt
 modified: arch/s390/Kconfig
 modified: arch/s390/include/asm/kprobes.h
 modified: arch/s390/kernel/ftrace.c
 modified: arch/s390/kernel/kprobes.c

Unmerged paths:
  (use "git add <file>..." to mark resolution)
 both modified: arch/s390/kernel/mcount.S

$ git difftool
diff --cc arch/s390/kernel/mcount.S
index 3431b2d5e334,7458dcfd6464..000000000000
--- a/arch/s390/kernel/mcount.S
+++ b/arch/s390/kernel/mcount.S
@@@ -41,6 -41,10 +41,13 @@@ EXPORT_SYMBOL(_mcount
  ENTRY(ftrace_caller)
   .globl ftrace_regs_caller
   .set ftrace_regs_caller,ftrace_caller
++<<<<<<< HEAD
++=======
+ stg %r14,(__SF_GPRS+8*8)(%r15) # save traced function caller
+ lghi %r14,0 # save condition code
+ ipm %r14 # don't put any instructions
+ sllg %r14,%r14,16 # clobbering CC before this point
++>>>>>>> 657480d9c015... s390: support KPROBES_ON_FTRACE
   lgr %r1,%r15
  #if !(defined(CC_USING_HOTPATCH) || defined(CC_USING_NOP_MCOUNT))
   aghi %r0,MCOUNT_RETURN_FIXUP

The conflict is in "arch/s390/kernel/mcount.S" assembler code.
Are there add. commits needed as pre-reqs? Or a backport?

Please can you check on top of focal master-next?
$ git clone https://git.launchpad.net/~ubuntu-kernel/ubuntu/+source/linux/+git/focal --branch master-next --single-branch