| 1 | # SPDX-License-Identifier: GPL-2.0-or-later |
| 2 | |
| 3 | """ |
| 4 | DTrace/SystemTAP backend. |
| 5 | """ |
| 6 | |
| 7 | __author__ = "Lluís Vilanova <vilanova@ac.upc.edu>" |
| 8 | __copyright__ = "Copyright 2012-2017, Lluís Vilanova <vilanova@ac.upc.edu>" |
| 9 | __license__ = "GPL version 2 or (at your option) any later version" |
| 10 | |
| 11 | __maintainer__ = "Stefan Hajnoczi" |
| 12 | __email__ = "stefanha@redhat.com" |
| 13 | |
| 14 | |
| 15 | from tracetool import out |
| 16 | |
| 17 | |
| 18 | PUBLIC = True |
| 19 | |
| 20 | |
| 21 | PROBEPREFIX = None |
| 22 | |
| 23 | def probeprefix(): |
| 24 | if PROBEPREFIX is None: |
| 25 | raise ValueError("you must set PROBEPREFIX") |
| 26 | return PROBEPREFIX |
| 27 | |
| 28 | |
| 29 | BINARY = None |
| 30 | |
| 31 | def binary(): |
| 32 | if BINARY is None: |
| 33 | raise ValueError("you must set BINARY") |
| 34 | return BINARY |
| 35 | |
| 36 | |
| 37 | def generate_h_begin(events, group): |
| 38 | if group == "root": |
| 39 | header = "trace-dtrace-root.h" |
| 40 | else: |
| 41 | header = "trace-dtrace-%s.h" % group |
| 42 | |
| 43 | # Workaround for ust backend, which also includes <sys/sdt.h> and may |
| 44 | # require SDT_USE_VARIADIC to be defined. If dtrace includes <sys/sdt.h> |
| 45 | # first without defining SDT_USE_VARIADIC then ust breaks because the |
| 46 | # STAP_PROBEV() macro is not defined. |
| 47 | out('#ifndef SDT_USE_VARIADIC') |
| 48 | out('#define SDT_USE_VARIADIC 1') |
| 49 | out('#endif') |
| 50 | |
| 51 | out('#include "%s"' % header, |
| 52 | '') |
| 53 | |
| 54 | out('#undef SDT_USE_VARIADIC') |
| 55 | |
| 56 | # SystemTap defines <provider>_<name>_ENABLED() but other DTrace |
| 57 | # implementations might not. |
| 58 | for e in events: |
| 59 | out('#ifndef QEMU_%(uppername)s_ENABLED', |
| 60 | '#define QEMU_%(uppername)s_ENABLED() true', |
| 61 | '#endif', |
| 62 | uppername=e.name.upper()) |
| 63 | |
| 64 | def generate_h(event, group): |
| 65 | out(' QEMU_%(uppername)s(%(argnames)s);', |
| 66 | uppername=event.name.upper(), |
| 67 | argnames=", ".join(event.args.names())) |
| 68 | |
| 69 | |
| 70 | def generate_h_backend_dstate(event, group): |
| 71 | out(' QEMU_%(uppername)s_ENABLED() || \\', |
| 72 | uppername=event.name.upper()) |
| 73 | |
| 74 | |
| 75 | def generate_rs_begin(events, group): |
| 76 | out('use std::cell::UnsafeCell;', |
| 77 | '', |
| 78 | 'extern "C" {') |
| 79 | # These are the Rust declarations of the .probes section semaphores |
| 80 | # generated by dtrace(1) in its .o file output. |
| 81 | for e in events: |
| 82 | if 'disable' in e.properties: |
| 83 | continue |
| 84 | out(' #[allow(dead_code)]', |
| 85 | f' static qemu_{e.name}_semaphore: UnsafeCell<u16>;') |
| 86 | out('}', |
| 87 | '') |
| 88 | |
| 89 | |
| 90 | def generate_rs(event, group): |
| 91 | args = event.args.rust_call_extern() |
| 92 | if args: |
| 93 | args = ', ' + args |
| 94 | |
| 95 | out(f' ::trace::probe!(qemu, {event.name}{args});') |
| 96 | |
| 97 | |
| 98 | def generate_rs_backend_dstate(event, group): |
| 99 | # Rust does not have access to the <provider>_<name>_ENABLED() macro from |
| 100 | # the dtrace(1) generated .h file. Use the matching semaphore declarations |
| 101 | # generated by generate_rs_begin() instead. |
| 102 | out(' (unsafe {qemu_%(n)s_semaphore.get().read_volatile()}) != 0 ||', |
| 103 | n=event.name) |