Wire up the system call tracepoints with Tasks Trace RCU to allow the ftrace, perf, and eBPF tracers to handle page faults. This series does the initial wire-up allowing tracers to handle page faults, but leaves out the actual handling of said page faults as future work. This series was compile and runtime tested with ftrace and perf syscall tracing and raw syscall tracing, adding a WARN_ON_ONCE() in the generated code to validate that the intended probes are used for raw syscall tracing. The might_fault() added within those probes validate that they are called from a context where handling a page fault is OK. The eBPF people have been needing this feature for quite a while: https://lore.kernel.org/lkml/c323bce9-a04e-b1c3-580a-783fde259d60@xxxxxx/ This series replaces the "Faultable Tracepoints v6" series found at [1]. This has been rebased on v6.12-rc1 on top of two patches from Steven: tracing: Remove definition of trace_*_rcuidle() tracepoint: Remove SRCU protection The main change since v2 is removal of remapping from trace_sys_enter/exit to trace_syscall_sys_enter/exit (likewise for register/unregister), which caused arch-specific code churn needlessly. Thanks, Mathieu Link: https://lore.kernel.org/lkml/20240828144153.829582-1-mathieu.desnoyers@xxxxxxxxxxxx/ # [1] Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Alexei Starovoitov <ast@xxxxxxxxxx> Cc: Yonghong Song <yhs@xxxxxx> Cc: Paul E. McKenney <paulmck@xxxxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxxxxx> Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx> Cc: Mark Rutland <mark.rutland@xxxxxxx> Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx> Cc: Namhyung Kim <namhyung@xxxxxxxxxx> Cc: Andrii Nakryiko <andrii.nakryiko@xxxxxxxxx> Cc: bpf@xxxxxxxxxxxxxxx Cc: Joel Fernandes <joel@xxxxxxxxxxxxxxxxx> Cc: linux-trace-kernel@xxxxxxxxxxxxxxx Mathieu Desnoyers (8): tracing: Declare system call tracepoints with TRACE_EVENT_SYSCALL tracing/ftrace: guard syscall probe with preempt_notrace tracing/perf: guard syscall probe with preempt_notrace tracing/bpf: guard syscall probe with preempt_notrace tracing: Allow system call tracepoints to handle page faults tracing/ftrace: Add might_fault check to syscall probes tracing/perf: Add might_fault check to syscall probes tracing/bpf: Add might_fault check to syscall probes include/linux/tracepoint.h | 65 +++++++++++++++++++++++++-------- include/trace/bpf_probe.h | 13 +++++++ include/trace/define_trace.h | 5 +++ include/trace/events/syscalls.h | 4 +- include/trace/perf.h | 43 ++++++++++++++++++++-- include/trace/trace_events.h | 61 +++++++++++++++++++++++++++++-- init/Kconfig | 1 + kernel/trace/trace_syscalls.c | 28 ++++++++++++++ 8 files changed, 196 insertions(+), 24 deletions(-) -- 2.39.2
