On Wed, 16 Oct 2019 13:33:12 +0200 Miroslav Benes <mbenes@xxxxxxx> wrote: > 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 > Would you like me to take all three patches through my tree? -- Steve
