forked from mirrors/linux
cdb537ac41
Add a might_fault() check to validate that the perf sys_enter/sys_exit probe callbacks are indeed called from a context where page faults can be handled. Cc: Michael Jeanson <mjeanson@efficios.com> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Yonghong Song <yhs@fb.com> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Andrii Nakryiko <andrii.nakryiko@gmail.com> Cc: bpf@vger.kernel.org Cc: Joel Fernandes <joel@joelfernandes.org> Link: https://lore.kernel.org/20241009010718.2050182-8-mathieu.desnoyers@efficios.com Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
114 lines
3.5 KiB
C
114 lines
3.5 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#undef TRACE_SYSTEM_VAR
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#ifdef CONFIG_PERF_EVENTS
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#include "stages/stage6_event_callback.h"
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#undef __perf_count
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#define __perf_count(c) (__count = (c))
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#undef __perf_task
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#define __perf_task(t) (__task = (t))
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#undef __DECLARE_EVENT_CLASS
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#define __DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print) \
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static notrace void \
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do_perf_trace_##call(void *__data, proto) \
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{ \
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struct trace_event_call *event_call = __data; \
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struct trace_event_data_offsets_##call __maybe_unused __data_offsets;\
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struct trace_event_raw_##call *entry; \
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struct pt_regs *__regs; \
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u64 __count = 1; \
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struct task_struct *__task = NULL; \
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struct hlist_head *head; \
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int __entry_size; \
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int __data_size; \
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int rctx; \
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\
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__data_size = trace_event_get_offsets_##call(&__data_offsets, args); \
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\
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head = this_cpu_ptr(event_call->perf_events); \
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if (!bpf_prog_array_valid(event_call) && \
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__builtin_constant_p(!__task) && !__task && \
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hlist_empty(head)) \
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return; \
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\
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__entry_size = ALIGN(__data_size + sizeof(*entry) + sizeof(u32),\
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sizeof(u64)); \
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__entry_size -= sizeof(u32); \
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\
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entry = perf_trace_buf_alloc(__entry_size, &__regs, &rctx); \
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if (!entry) \
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return; \
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\
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perf_fetch_caller_regs(__regs); \
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\
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tstruct \
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\
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{ assign; } \
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\
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perf_trace_run_bpf_submit(entry, __entry_size, rctx, \
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event_call, __count, __regs, \
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head, __task); \
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}
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/*
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* Define unused __count and __task variables to use @args to pass
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* arguments to do_perf_trace_##call. This is needed because the
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* macros __perf_count and __perf_task introduce the side-effect to
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* store copies into those local variables.
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*/
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#undef DECLARE_EVENT_CLASS
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#define DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print) \
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__DECLARE_EVENT_CLASS(call, PARAMS(proto), PARAMS(args), PARAMS(tstruct), \
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PARAMS(assign), PARAMS(print)) \
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static notrace void \
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perf_trace_##call(void *__data, proto) \
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{ \
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u64 __count __attribute__((unused)); \
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struct task_struct *__task __attribute__((unused)); \
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\
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do_perf_trace_##call(__data, args); \
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}
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#undef DECLARE_EVENT_SYSCALL_CLASS
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#define DECLARE_EVENT_SYSCALL_CLASS(call, proto, args, tstruct, assign, print) \
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__DECLARE_EVENT_CLASS(call, PARAMS(proto), PARAMS(args), PARAMS(tstruct), \
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PARAMS(assign), PARAMS(print)) \
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static notrace void \
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perf_trace_##call(void *__data, proto) \
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{ \
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u64 __count __attribute__((unused)); \
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struct task_struct *__task __attribute__((unused)); \
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\
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might_fault(); \
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preempt_disable_notrace(); \
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do_perf_trace_##call(__data, args); \
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preempt_enable_notrace(); \
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}
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/*
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* This part is compiled out, it is only here as a build time check
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* to make sure that if the tracepoint handling changes, the
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* perf probe will fail to compile unless it too is updated.
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*/
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#undef DEFINE_EVENT
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#define DEFINE_EVENT(template, call, proto, args) \
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static inline void perf_test_probe_##call(void) \
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{ \
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check_trace_callback_type_##call(perf_trace_##template); \
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}
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#undef DEFINE_EVENT_PRINT
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#define DEFINE_EVENT_PRINT(template, name, proto, args, print) \
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DEFINE_EVENT(template, name, PARAMS(proto), PARAMS(args))
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#include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
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#undef __DECLARE_EVENT_CLASS
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#endif /* CONFIG_PERF_EVENTS */
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