[PATCH -tip 0/5] kprobes: Fix stacktrace in kretprobes

[Masami Hiramatsu <mhiramat@kernel.org>]

Hello,

Here is a series of patches for kprobes and stacktracer to fix the kretprobe
entries in the kernel stack. This was reported by Daniel Xu. I thought that
was in the bpftrace, but it is actually more generic issue.
So I decided to fix the issue in arch independent part.

While fixing the issue, I found a bug in ia64 related to kretprobe, which is
fixed by [1/5]. [2/5] and [3/5] is a kind of cleanup before fixing the main
issue. [4/5] is the patch to fix the stacktrace, which involves kretprobe
internal change. And [5/5] removing the stacktrace kretprobe fixup code in
ftrace. 

Daniel, can you also check that this fixes your issue too? I hope it is.

Note that this doesn't fixup all cases. Unfortunately, stacktracing the
other tasks (non current task) on the arch which doesn't support ARCH_STACKWALK,
I can not fix it in the arch independent code. Maybe each arch dependent
stacktrace implementation must fixup by themselves.

Thank you,

---

Masami Hiramatsu (5):
      ia64: kprobes: Fix to pass correct trampoline address to the handler
      kprobes: treewide: Replace arch_deref_entry_point() with dereference_function_descriptor()
      kprobes: treewide: Remove trampoline_address from kretprobe_trampoline_handler()
      kprobes: stacktrace: Recover the address changed by kretprobe
      tracing: Remove kretprobe unknown indicator from stacktrace


 arch/arc/kernel/kprobes.c          |    2 -
 arch/arm/probes/kprobes/core.c     |    3 -
 arch/arm64/kernel/probes/kprobes.c |    3 -
 arch/csky/kernel/probes/kprobes.c  |    2 -
 arch/ia64/kernel/kprobes.c         |   15 ++----
 arch/mips/kernel/kprobes.c         |    3 -
 arch/parisc/kernel/kprobes.c       |    4 +-
 arch/powerpc/kernel/kprobes.c      |   13 -----
 arch/riscv/kernel/probes/kprobes.c |    2 -
 arch/s390/kernel/kprobes.c         |    2 -
 arch/sh/kernel/kprobes.c           |    2 -
 arch/sparc/kernel/kprobes.c        |    2 -
 arch/x86/kernel/kprobes/core.c     |    2 -
 include/linux/kprobes.h            |   32 +++++++++++--
 kernel/kprobes.c                   |   89 ++++++++++++++++++++++--------------
 kernel/stacktrace.c                |   21 ++++++++
 kernel/trace/trace_output.c        |   27 ++---------
 lib/error-inject.c                 |    3 +
 18 files changed, 126 insertions(+), 101 deletions(-)

--
Masami Hiramatsu (Linaro) <mhiramat@kernel.org>