[PATCH v2 0/7] powerpc/ftrace: Patch out -mprofile-kernel instructions

Naveen N. Rao naveen.n.rao at linux.vnet.ibm.com
Thu Jun 27 21:23:48 AEST 2019


Changes since v1 
(https://patchwork.ozlabs.org/project/linuxppc-dev/list/?series=114556):
- Patches 1,2,3 and 6: No changes
- Patch 4: Add smp_call_function() to flush icache on all cpus after 
  patching in the 'mflr r0' instruction.
- Patch 5: Changes as per Steven Rostedt's suggestions.
- Patch 7: Changes as per Masami and Joe Perches.

--
On powerpc64, -mprofile-kernel results in two instructions being 
emitted: 'mflr r0' and 'bl _mcount'. So far, we were only nop'ing out 
the branch to _mcount(). This series implements an approach to also nop 
out the preceding mflr.


- Naveen


Naveen N. Rao (7):
  ftrace: Expose flags used for ftrace_replace_code()
  x86/ftrace: Fix use of flags in ftrace_replace_code()
  ftrace: Expose __ftrace_replace_code()
  powerpc/ftrace: Additionally nop out the preceding mflr with
    -mprofile-kernel
  ftrace: Update ftrace_location() for powerpc -mprofile-kernel
  kprobes/ftrace: Use ftrace_location() when [dis]arming probes
  powerpc/kprobes: Allow probing on any ftrace address

 arch/powerpc/include/asm/ftrace.h    |   8 +
 arch/powerpc/kernel/kprobes-ftrace.c |  32 +++-
 arch/powerpc/kernel/trace/ftrace.c   | 258 ++++++++++++++++++++++++---
 arch/x86/kernel/ftrace.c             |   3 +-
 include/linux/ftrace.h               |  15 ++
 kernel/kprobes.c                     |  10 +-
 kernel/trace/ftrace.c                |  15 +-
 7 files changed, 302 insertions(+), 39 deletions(-)

-- 
2.22.0



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