0007-fix-kprobes-Use-rethook-for-kretprobe-if-possible-v5.patch

   1 From 3c46ddc134621dba65030263aa321dd6bdae3ba3 Mon Sep 17 00:00:00 2001
   2 From: Michael Jeanson <mjeanson@efficios.com>
   3 Date: Mon, 4 Apr 2022 15:02:10 -0400
   4 Subject: [PATCH 07/13] fix: kprobes: Use rethook for kretprobe if possible
   5  (v5.18)
   6
   7 See upstream commit :
   8
   9   commit 73f9b911faa74ac5107879de05c9489c419f41bb
  10   Author: Masami Hiramatsu <mhiramat@kernel.org>
  11   Date:   Sat Mar 26 11:27:05 2022 +0900
  12
  13     kprobes: Use rethook for kretprobe if possible
  14
  15     Use rethook for kretprobe function return hooking if the arch sets
  16     CONFIG_HAVE_RETHOOK=y. In this case, CONFIG_KRETPROBE_ON_RETHOOK is
  17     set to 'y' automatically, and the kretprobe internal data fields
  18     switches to use rethook. If not, it continues to use kretprobe
  19     specific function return hooks.
  20
  21 Change-Id: I2b7670dc04e4769c1e3c372582ad2f555f6d7a66
  22 Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
  23 Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
  24 ---
  25  include/wrapper/kprobes.h     | 17 +++++++++++++++++
  26  src/probes/lttng-kretprobes.c |  2 +-
  27  2 files changed, 18 insertions(+), 1 deletion(-)
  28
  29 diff --git a/include/wrapper/kprobes.h b/include/wrapper/kprobes.h
  30 index b546d615..51d32b7c 100644
  31 --- a/include/wrapper/kprobes.h
  32 +++ b/include/wrapper/kprobes.h
  33 @@ -29,4 +29,21 @@ struct kretprobe *lttng_get_kretprobe(struct kretprobe_instance *ri)
  34
  35  #endif /* LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(5,11,0) */
  36
  37 +
  38 +#if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(5,18,0))
  39 +static inline
  40 +unsigned long lttng_get_kretprobe_retaddr(struct kretprobe_instance *ri)
  41 +{
  42 +       return get_kretprobe_retaddr(ri);
  43 +}
  44 +
  45 +#else
  46 +
  47 +static inline
  48 +unsigned long lttng_get_kretprobe_retaddr(struct kretprobe_instance *ri)
  49 +{
  50 +       return (unsigned long) ri->ret_addr;
  51 +}
  52 +#endif
  53 +
  54  #endif /* _LTTNG_WRAPPER_KPROBES_H */
  55 diff --git a/src/probes/lttng-kretprobes.c b/src/probes/lttng-kretprobes.c
  56 index 5cb2e953..565df739 100644
  57 --- a/src/probes/lttng-kretprobes.c
  58 +++ b/src/probes/lttng-kretprobes.c
  59 @@ -81,7 +81,7 @@ int _lttng_kretprobes_handler(struct kretprobe_instance *krpi,
  60                 int ret;
  61
  62                 payload.ip = (unsigned long) lttng_get_kretprobe(krpi)->kp.addr;
  63 -               payload.parent_ip = (unsigned long) krpi->ret_addr;
  64 +               payload.parent_ip = lttng_get_kretprobe_retaddr(krpi);
  65
  66                 lib_ring_buffer_ctx_init(&ctx, event_recorder, sizeof(payload),
  67                                          lttng_alignof(payload), &lttng_probe_ctx);
  68 --
  69 2.36.1
  70