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-rw-r--r--meta/recipes-kernel/lttng/lttng-modules/0006-fix-removal-of-smp_-read_barrier_depends-v5.9.patch391
1 files changed, 0 insertions, 391 deletions
diff --git a/meta/recipes-kernel/lttng/lttng-modules/0006-fix-removal-of-smp_-read_barrier_depends-v5.9.patch b/meta/recipes-kernel/lttng/lttng-modules/0006-fix-removal-of-smp_-read_barrier_depends-v5.9.patch
deleted file mode 100644
index 0970dd30aa..0000000000
--- a/meta/recipes-kernel/lttng/lttng-modules/0006-fix-removal-of-smp_-read_barrier_depends-v5.9.patch
+++ /dev/null
@@ -1,391 +0,0 @@
1From 57ccbfa6a8a79c7b84394c2097efaf7935607aa5 Mon Sep 17 00:00:00 2001
2From: Michael Jeanson <mjeanson@efficios.com>
3Date: Tue, 25 Aug 2020 10:56:29 -0400
4Subject: [PATCH 06/10] fix: removal of [smp_]read_barrier_depends (v5.9)
5
6See upstream commits:
7
8 commit 76ebbe78f7390aee075a7f3768af197ded1bdfbb
9 Author: Will Deacon <will@kernel.org>
10 Date: Tue Oct 24 11:22:47 2017 +0100
11
12 locking/barriers: Add implicit smp_read_barrier_depends() to READ_ONCE()
13
14 In preparation for the removal of lockless_dereference(), which is the
15 same as READ_ONCE() on all architectures other than Alpha, add an
16 implicit smp_read_barrier_depends() to READ_ONCE() so that it can be
17 used to head dependency chains on all architectures.
18
19 commit 76ebbe78f7390aee075a7f3768af197ded1bdfbb
20 Author: Will Deacon <will.deacon@arm.com>
21 Date: Tue Oct 24 11:22:47 2017 +0100
22
23 locking/barriers: Add implicit smp_read_barrier_depends() to READ_ONCE()
24
25 In preparation for the removal of lockless_dereference(), which is the
26 same as READ_ONCE() on all architectures other than Alpha, add an
27 implicit smp_read_barrier_depends() to READ_ONCE() so that it can be
28 used to head dependency chains on all architectures.
29
30Upstream-Status: Backport
31
32Change-Id: Ife8880bd9378dca2972da8838f40fc35ccdfaaac
33Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
34Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
35---
36 instrumentation/events/lttng-module/i2c.h | 4 ++--
37 lib/ringbuffer/backend.h | 2 +-
38 lib/ringbuffer/backend_internal.h | 2 +-
39 lib/ringbuffer/frontend.h | 4 ++--
40 lib/ringbuffer/ring_buffer_frontend.c | 4 ++--
41 lib/ringbuffer/ring_buffer_iterator.c | 2 +-
42 lttng-events.c | 8 ++++----
43 probes/lttng-kprobes.c | 6 +++---
44 probes/lttng-kretprobes.c | 6 +++---
45 probes/lttng-tracepoint-event-impl.h | 12 ++++++------
46 probes/lttng-uprobes.c | 6 +++---
47 wrapper/compiler.h | 18 ++++++++++++++++++
48 wrapper/trace-clock.h | 15 +++++----------
49 13 files changed, 51 insertions(+), 38 deletions(-)
50
51diff --git a/instrumentation/events/lttng-module/i2c.h b/instrumentation/events/lttng-module/i2c.h
52index dcbabf6..131d134 100644
53--- a/instrumentation/events/lttng-module/i2c.h
54+++ b/instrumentation/events/lttng-module/i2c.h
55@@ -23,7 +23,7 @@ LTTNG_TRACEPOINT_EVENT_CODE(i2c_write,
56
57 TP_code_pre(
58 tp_locvar->extract_sensitive_payload =
59- READ_ONCE(extract_sensitive_payload);
60+ LTTNG_READ_ONCE(extract_sensitive_payload);
61 ),
62
63 TP_FIELDS(
64@@ -78,7 +78,7 @@ LTTNG_TRACEPOINT_EVENT_CODE(i2c_reply,
65
66 TP_code_pre(
67 tp_locvar->extract_sensitive_payload =
68- READ_ONCE(extract_sensitive_payload);
69+ LTTNG_READ_ONCE(extract_sensitive_payload);
70 ),
71
72 TP_FIELDS(
73diff --git a/lib/ringbuffer/backend.h b/lib/ringbuffer/backend.h
74index da937f2..43e1d47 100644
75--- a/lib/ringbuffer/backend.h
76+++ b/lib/ringbuffer/backend.h
77@@ -156,7 +156,7 @@ size_t lib_ring_buffer_do_strcpy(const struct lib_ring_buffer_config *config,
78 * Only read source character once, in case it is
79 * modified concurrently.
80 */
81- c = READ_ONCE(src[count]);
82+ c = LTTNG_READ_ONCE(src[count]);
83 if (!c)
84 break;
85 lib_ring_buffer_do_copy(config, &dest[count], &c, 1);
86diff --git a/lib/ringbuffer/backend_internal.h b/lib/ringbuffer/backend_internal.h
87index 2d6a345..1226fd8 100644
88--- a/lib/ringbuffer/backend_internal.h
89+++ b/lib/ringbuffer/backend_internal.h
90@@ -367,7 +367,7 @@ void lib_ring_buffer_clear_noref(const struct lib_ring_buffer_config *config,
91 * Performing a volatile access to read the sb_pages, because we want to
92 * read a coherent version of the pointer and the associated noref flag.
93 */
94- id = READ_ONCE(bufb->buf_wsb[idx].id);
95+ id = LTTNG_READ_ONCE(bufb->buf_wsb[idx].id);
96 for (;;) {
97 /* This check is called on the fast path for each record. */
98 if (likely(!subbuffer_id_is_noref(config, id))) {
99diff --git a/lib/ringbuffer/frontend.h b/lib/ringbuffer/frontend.h
100index 6f516d9..41382fe 100644
101--- a/lib/ringbuffer/frontend.h
102+++ b/lib/ringbuffer/frontend.h
103@@ -79,7 +79,7 @@ void *channel_destroy(struct channel *chan);
104 #define for_each_channel_cpu(cpu, chan) \
105 for ((cpu) = -1; \
106 ({ (cpu) = cpumask_next(cpu, (chan)->backend.cpumask); \
107- smp_read_barrier_depends(); (cpu) < nr_cpu_ids; });)
108+ smp_rmb(); (cpu) < nr_cpu_ids; });)
109
110 extern struct lib_ring_buffer *channel_get_ring_buffer(
111 const struct lib_ring_buffer_config *config,
112@@ -155,7 +155,7 @@ static inline
113 int lib_ring_buffer_is_finalized(const struct lib_ring_buffer_config *config,
114 struct lib_ring_buffer *buf)
115 {
116- int finalized = READ_ONCE(buf->finalized);
117+ int finalized = LTTNG_READ_ONCE(buf->finalized);
118 /*
119 * Read finalized before counters.
120 */
121diff --git a/lib/ringbuffer/ring_buffer_frontend.c b/lib/ringbuffer/ring_buffer_frontend.c
122index 3cab365..4980d20 100644
123--- a/lib/ringbuffer/ring_buffer_frontend.c
124+++ b/lib/ringbuffer/ring_buffer_frontend.c
125@@ -1074,7 +1074,7 @@ int lib_ring_buffer_snapshot(struct lib_ring_buffer *buf,
126 int finalized;
127
128 retry:
129- finalized = READ_ONCE(buf->finalized);
130+ finalized = LTTNG_READ_ONCE(buf->finalized);
131 /*
132 * Read finalized before counters.
133 */
134@@ -1245,7 +1245,7 @@ int lib_ring_buffer_get_subbuf(struct lib_ring_buffer *buf,
135 return -EBUSY;
136 }
137 retry:
138- finalized = READ_ONCE(buf->finalized);
139+ finalized = LTTNG_READ_ONCE(buf->finalized);
140 /*
141 * Read finalized before counters.
142 */
143diff --git a/lib/ringbuffer/ring_buffer_iterator.c b/lib/ringbuffer/ring_buffer_iterator.c
144index d25db72..7b4f20a 100644
145--- a/lib/ringbuffer/ring_buffer_iterator.c
146+++ b/lib/ringbuffer/ring_buffer_iterator.c
147@@ -46,7 +46,7 @@ restart:
148 switch (iter->state) {
149 case ITER_GET_SUBBUF:
150 ret = lib_ring_buffer_get_next_subbuf(buf);
151- if (ret && !READ_ONCE(buf->finalized)
152+ if (ret && !LTTNG_READ_ONCE(buf->finalized)
153 && config->alloc == RING_BUFFER_ALLOC_GLOBAL) {
154 /*
155 * Use "pull" scheme for global buffers. The reader
156diff --git a/lttng-events.c b/lttng-events.c
157index be7e389..d719294 100644
158--- a/lttng-events.c
159+++ b/lttng-events.c
160@@ -1719,7 +1719,7 @@ int lttng_metadata_printf(struct lttng_session *session,
161 size_t len;
162 va_list ap;
163
164- WARN_ON_ONCE(!READ_ONCE(session->active));
165+ WARN_ON_ONCE(!LTTNG_READ_ONCE(session->active));
166
167 va_start(ap, fmt);
168 str = kvasprintf(GFP_KERNEL, fmt, ap);
169@@ -2305,7 +2305,7 @@ int _lttng_event_metadata_statedump(struct lttng_session *session,
170 {
171 int ret = 0;
172
173- if (event->metadata_dumped || !READ_ONCE(session->active))
174+ if (event->metadata_dumped || !LTTNG_READ_ONCE(session->active))
175 return 0;
176 if (chan->channel_type == METADATA_CHANNEL)
177 return 0;
178@@ -2377,7 +2377,7 @@ int _lttng_channel_metadata_statedump(struct lttng_session *session,
179 {
180 int ret = 0;
181
182- if (chan->metadata_dumped || !READ_ONCE(session->active))
183+ if (chan->metadata_dumped || !LTTNG_READ_ONCE(session->active))
184 return 0;
185
186 if (chan->channel_type == METADATA_CHANNEL)
187@@ -2604,7 +2604,7 @@ int _lttng_session_metadata_statedump(struct lttng_session *session)
188 struct lttng_event *event;
189 int ret = 0;
190
191- if (!READ_ONCE(session->active))
192+ if (!LTTNG_READ_ONCE(session->active))
193 return 0;
194
195 lttng_metadata_begin(session);
196diff --git a/probes/lttng-kprobes.c b/probes/lttng-kprobes.c
197index a44eaa1..38fb72e 100644
198--- a/probes/lttng-kprobes.c
199+++ b/probes/lttng-kprobes.c
200@@ -31,11 +31,11 @@ int lttng_kprobes_handler_pre(struct kprobe *p, struct pt_regs *regs)
201 int ret;
202 unsigned long data = (unsigned long) p->addr;
203
204- if (unlikely(!READ_ONCE(chan->session->active)))
205+ if (unlikely(!LTTNG_READ_ONCE(chan->session->active)))
206 return 0;
207- if (unlikely(!READ_ONCE(chan->enabled)))
208+ if (unlikely(!LTTNG_READ_ONCE(chan->enabled)))
209 return 0;
210- if (unlikely(!READ_ONCE(event->enabled)))
211+ if (unlikely(!LTTNG_READ_ONCE(event->enabled)))
212 return 0;
213
214 lib_ring_buffer_ctx_init(&ctx, chan->chan, &lttng_probe_ctx, sizeof(data),
215diff --git a/probes/lttng-kretprobes.c b/probes/lttng-kretprobes.c
216index ab98ff2..a6bcd21 100644
217--- a/probes/lttng-kretprobes.c
218+++ b/probes/lttng-kretprobes.c
219@@ -51,11 +51,11 @@ int _lttng_kretprobes_handler(struct kretprobe_instance *krpi,
220 unsigned long parent_ip;
221 } payload;
222
223- if (unlikely(!READ_ONCE(chan->session->active)))
224+ if (unlikely(!LTTNG_READ_ONCE(chan->session->active)))
225 return 0;
226- if (unlikely(!READ_ONCE(chan->enabled)))
227+ if (unlikely(!LTTNG_READ_ONCE(chan->enabled)))
228 return 0;
229- if (unlikely(!READ_ONCE(event->enabled)))
230+ if (unlikely(!LTTNG_READ_ONCE(event->enabled)))
231 return 0;
232
233 payload.ip = (unsigned long) krpi->rp->kp.addr;
234diff --git a/probes/lttng-tracepoint-event-impl.h b/probes/lttng-tracepoint-event-impl.h
235index 77b8638..72a669e 100644
236--- a/probes/lttng-tracepoint-event-impl.h
237+++ b/probes/lttng-tracepoint-event-impl.h
238@@ -1132,11 +1132,11 @@ static void __event_probe__##_name(void *__data, _proto) \
239 \
240 if (!_TP_SESSION_CHECK(session, __session)) \
241 return; \
242- if (unlikely(!READ_ONCE(__session->active))) \
243+ if (unlikely(!LTTNG_READ_ONCE(__session->active))) \
244 return; \
245- if (unlikely(!READ_ONCE(__chan->enabled))) \
246+ if (unlikely(!LTTNG_READ_ONCE(__chan->enabled))) \
247 return; \
248- if (unlikely(!READ_ONCE(__event->enabled))) \
249+ if (unlikely(!LTTNG_READ_ONCE(__event->enabled))) \
250 return; \
251 __lf = lttng_rcu_dereference(__session->pid_tracker.p); \
252 if (__lf && likely(!lttng_id_tracker_lookup(__lf, current->tgid))) \
253@@ -1225,11 +1225,11 @@ static void __event_probe__##_name(void *__data) \
254 \
255 if (!_TP_SESSION_CHECK(session, __session)) \
256 return; \
257- if (unlikely(!READ_ONCE(__session->active))) \
258+ if (unlikely(!LTTNG_READ_ONCE(__session->active))) \
259 return; \
260- if (unlikely(!READ_ONCE(__chan->enabled))) \
261+ if (unlikely(!LTTNG_READ_ONCE(__chan->enabled))) \
262 return; \
263- if (unlikely(!READ_ONCE(__event->enabled))) \
264+ if (unlikely(!LTTNG_READ_ONCE(__event->enabled))) \
265 return; \
266 __lf = lttng_rcu_dereference(__session->pid_tracker.p); \
267 if (__lf && likely(!lttng_id_tracker_lookup(__lf, current->tgid))) \
268diff --git a/probes/lttng-uprobes.c b/probes/lttng-uprobes.c
269index bc10128..bda1d9b 100644
270--- a/probes/lttng-uprobes.c
271+++ b/probes/lttng-uprobes.c
272@@ -40,11 +40,11 @@ int lttng_uprobes_handler_pre(struct uprobe_consumer *uc, struct pt_regs *regs)
273 unsigned long ip;
274 } payload;
275
276- if (unlikely(!READ_ONCE(chan->session->active)))
277+ if (unlikely(!LTTNG_READ_ONCE(chan->session->active)))
278 return 0;
279- if (unlikely(!READ_ONCE(chan->enabled)))
280+ if (unlikely(!LTTNG_READ_ONCE(chan->enabled)))
281 return 0;
282- if (unlikely(!READ_ONCE(event->enabled)))
283+ if (unlikely(!LTTNG_READ_ONCE(event->enabled)))
284 return 0;
285
286 lib_ring_buffer_ctx_init(&ctx, chan->chan, &lttng_probe_ctx,
287diff --git a/wrapper/compiler.h b/wrapper/compiler.h
288index 1496f33..b9f8c51 100644
289--- a/wrapper/compiler.h
290+++ b/wrapper/compiler.h
291@@ -9,6 +9,7 @@
292 #define _LTTNG_WRAPPER_COMPILER_H
293
294 #include <linux/compiler.h>
295+#include <linux/version.h>
296
297 /*
298 * Don't allow compiling with buggy compiler.
299@@ -39,4 +40,21 @@
300 # define WRITE_ONCE(x, val) ({ ACCESS_ONCE(x) = val; })
301 #endif
302
303+/*
304+ * In v4.15 a smp read barrier was added to READ_ONCE to replace
305+ * lockless_dereference(), replicate this behavior on prior kernels
306+ * and remove calls to smp_read_barrier_depends which was dropped
307+ * in v5.9.
308+ */
309+#if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,15,0))
310+#define LTTNG_READ_ONCE(x) READ_ONCE(x)
311+#else
312+#define LTTNG_READ_ONCE(x) \
313+({ \
314+ typeof(x) __val = READ_ONCE(x); \
315+ smp_read_barrier_depends(); \
316+ __val; \
317+})
318+#endif
319+
320 #endif /* _LTTNG_WRAPPER_COMPILER_H */
321diff --git a/wrapper/trace-clock.h b/wrapper/trace-clock.h
322index 9f4e366..187fc82 100644
323--- a/wrapper/trace-clock.h
324+++ b/wrapper/trace-clock.h
325@@ -160,33 +160,30 @@ static inline void put_trace_clock(void)
326
327 static inline u64 trace_clock_read64(void)
328 {
329- struct lttng_trace_clock *ltc = READ_ONCE(lttng_trace_clock);
330+ struct lttng_trace_clock *ltc = LTTNG_READ_ONCE(lttng_trace_clock);
331
332 if (likely(!ltc)) {
333 return trace_clock_read64_monotonic();
334 } else {
335- read_barrier_depends(); /* load ltc before content */
336 return ltc->read64();
337 }
338 }
339
340 static inline u64 trace_clock_freq(void)
341 {
342- struct lttng_trace_clock *ltc = READ_ONCE(lttng_trace_clock);
343+ struct lttng_trace_clock *ltc = LTTNG_READ_ONCE(lttng_trace_clock);
344
345 if (!ltc) {
346 return trace_clock_freq_monotonic();
347 } else {
348- read_barrier_depends(); /* load ltc before content */
349 return ltc->freq();
350 }
351 }
352
353 static inline int trace_clock_uuid(char *uuid)
354 {
355- struct lttng_trace_clock *ltc = READ_ONCE(lttng_trace_clock);
356+ struct lttng_trace_clock *ltc = LTTNG_READ_ONCE(lttng_trace_clock);
357
358- read_barrier_depends(); /* load ltc before content */
359 /* Use default UUID cb when NULL */
360 if (!ltc || !ltc->uuid) {
361 return trace_clock_uuid_monotonic(uuid);
362@@ -197,24 +194,22 @@ static inline int trace_clock_uuid(char *uuid)
363
364 static inline const char *trace_clock_name(void)
365 {
366- struct lttng_trace_clock *ltc = READ_ONCE(lttng_trace_clock);
367+ struct lttng_trace_clock *ltc = LTTNG_READ_ONCE(lttng_trace_clock);
368
369 if (!ltc) {
370 return trace_clock_name_monotonic();
371 } else {
372- read_barrier_depends(); /* load ltc before content */
373 return ltc->name();
374 }
375 }
376
377 static inline const char *trace_clock_description(void)
378 {
379- struct lttng_trace_clock *ltc = READ_ONCE(lttng_trace_clock);
380+ struct lttng_trace_clock *ltc = LTTNG_READ_ONCE(lttng_trace_clock);
381
382 if (!ltc) {
383 return trace_clock_description_monotonic();
384 } else {
385- read_barrier_depends(); /* load ltc before content */
386 return ltc->description();
387 }
388 }
389--
3902.19.1
391
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