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Subject[PATCH v3 0/3] ftrace: Introduce PERMANENT ftrace_ops flag
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Livepatch uses ftrace for redirection to new patched functions. It means
that if ftrace is disabled, all live patched functions are disabled as
well. Toggling global 'ftrace_enabled' sysctl thus affect it directly.
It is not a problem per se, because only administrator can set sysctl
values, but it still may be surprising.

Introduce PERMANENT ftrace_ops flag to amend this. If the
FTRACE_OPS_FL_PERMANENT is set on any ftrace ops, the tracing cannot be
disabled by disabling ftrace_enabled. Equally, a callback with the flag
set cannot be registered if ftrace_enabled is disabled.

v2->v3:
- ftrace_enabled explicitly set to true
- selftest from Joe Lawrence (I just split it to two patches)
- typo fix

v1->v2:
- different logic, proposed by Joe Lawrence

Joe Lawrence (2):
selftests/livepatch: Make dynamic debug setup and restore generic
selftests/livepatch: Test interaction with ftrace_enabled

Miroslav Benes (1):
ftrace: Introduce PERMANENT ftrace_ops flag

Documentation/trace/ftrace-uses.rst | 8 +++
Documentation/trace/ftrace.rst | 4 +-
include/linux/ftrace.h | 3 +
kernel/livepatch/patch.c | 3 +-
kernel/trace/ftrace.c | 23 ++++++-
tools/testing/selftests/livepatch/Makefile | 3 +-
.../testing/selftests/livepatch/functions.sh | 34 +++++++---
.../selftests/livepatch/test-callbacks.sh | 2 +-
.../selftests/livepatch/test-ftrace.sh | 65 +++++++++++++++++++
.../selftests/livepatch/test-livepatch.sh | 2 +-
.../selftests/livepatch/test-shadow-vars.sh | 2 +-
11 files changed, 132 insertions(+), 17 deletions(-)
create mode 100755 tools/testing/selftests/livepatch/test-ftrace.sh

--
2.23.0

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