diff options
Diffstat (limited to 'meta/recipes-kernel/lttng/lttng-modules/0006-fix-removal-of-smp_-read_barrier_depends-v5.9.patch')
-rw-r--r-- | meta/recipes-kernel/lttng/lttng-modules/0006-fix-removal-of-smp_-read_barrier_depends-v5.9.patch | 391 |
1 files changed, 391 insertions, 0 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 new file mode 100644 index 0000000000..0970dd30aa --- /dev/null +++ b/meta/recipes-kernel/lttng/lttng-modules/0006-fix-removal-of-smp_-read_barrier_depends-v5.9.patch @@ -0,0 +1,391 @@ +From 57ccbfa6a8a79c7b84394c2097efaf7935607aa5 Mon Sep 17 00:00:00 2001 +From: Michael Jeanson <mjeanson@efficios.com> +Date: Tue, 25 Aug 2020 10:56:29 -0400 +Subject: [PATCH 06/10] fix: removal of [smp_]read_barrier_depends (v5.9) + +See upstream commits: + + commit 76ebbe78f7390aee075a7f3768af197ded1bdfbb + Author: Will Deacon <will@kernel.org> + Date: Tue Oct 24 11:22:47 2017 +0100 + + locking/barriers: Add implicit smp_read_barrier_depends() to READ_ONCE() + + In preparation for the removal of lockless_dereference(), which is the + same as READ_ONCE() on all architectures other than Alpha, add an + implicit smp_read_barrier_depends() to READ_ONCE() so that it can be + used to head dependency chains on all architectures. + + commit 76ebbe78f7390aee075a7f3768af197ded1bdfbb + Author: Will Deacon <will.deacon@arm.com> + Date: Tue Oct 24 11:22:47 2017 +0100 + + locking/barriers: Add implicit smp_read_barrier_depends() to READ_ONCE() + + In preparation for the removal of lockless_dereference(), which is the + same as READ_ONCE() on all architectures other than Alpha, add an + implicit smp_read_barrier_depends() to READ_ONCE() so that it can be + used to head dependency chains on all architectures. + +Upstream-Status: Backport + +Change-Id: Ife8880bd9378dca2972da8838f40fc35ccdfaaac +Signed-off-by: Michael Jeanson <mjeanson@efficios.com> +Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> +--- + instrumentation/events/lttng-module/i2c.h | 4 ++-- + lib/ringbuffer/backend.h | 2 +- + lib/ringbuffer/backend_internal.h | 2 +- + lib/ringbuffer/frontend.h | 4 ++-- + lib/ringbuffer/ring_buffer_frontend.c | 4 ++-- + lib/ringbuffer/ring_buffer_iterator.c | 2 +- + lttng-events.c | 8 ++++---- + probes/lttng-kprobes.c | 6 +++--- + probes/lttng-kretprobes.c | 6 +++--- + probes/lttng-tracepoint-event-impl.h | 12 ++++++------ + probes/lttng-uprobes.c | 6 +++--- + wrapper/compiler.h | 18 ++++++++++++++++++ + wrapper/trace-clock.h | 15 +++++---------- + 13 files changed, 51 insertions(+), 38 deletions(-) + +diff --git a/instrumentation/events/lttng-module/i2c.h b/instrumentation/events/lttng-module/i2c.h +index dcbabf6..131d134 100644 +--- a/instrumentation/events/lttng-module/i2c.h ++++ b/instrumentation/events/lttng-module/i2c.h +@@ -23,7 +23,7 @@ LTTNG_TRACEPOINT_EVENT_CODE(i2c_write, + + TP_code_pre( + tp_locvar->extract_sensitive_payload = +- READ_ONCE(extract_sensitive_payload); ++ LTTNG_READ_ONCE(extract_sensitive_payload); + ), + + TP_FIELDS( +@@ -78,7 +78,7 @@ LTTNG_TRACEPOINT_EVENT_CODE(i2c_reply, + + TP_code_pre( + tp_locvar->extract_sensitive_payload = +- READ_ONCE(extract_sensitive_payload); ++ LTTNG_READ_ONCE(extract_sensitive_payload); + ), + + TP_FIELDS( +diff --git a/lib/ringbuffer/backend.h b/lib/ringbuffer/backend.h +index da937f2..43e1d47 100644 +--- a/lib/ringbuffer/backend.h ++++ b/lib/ringbuffer/backend.h +@@ -156,7 +156,7 @@ size_t lib_ring_buffer_do_strcpy(const struct lib_ring_buffer_config *config, + * Only read source character once, in case it is + * modified concurrently. + */ +- c = READ_ONCE(src[count]); ++ c = LTTNG_READ_ONCE(src[count]); + if (!c) + break; + lib_ring_buffer_do_copy(config, &dest[count], &c, 1); +diff --git a/lib/ringbuffer/backend_internal.h b/lib/ringbuffer/backend_internal.h +index 2d6a345..1226fd8 100644 +--- a/lib/ringbuffer/backend_internal.h ++++ b/lib/ringbuffer/backend_internal.h +@@ -367,7 +367,7 @@ void lib_ring_buffer_clear_noref(const struct lib_ring_buffer_config *config, + * Performing a volatile access to read the sb_pages, because we want to + * read a coherent version of the pointer and the associated noref flag. + */ +- id = READ_ONCE(bufb->buf_wsb[idx].id); ++ id = LTTNG_READ_ONCE(bufb->buf_wsb[idx].id); + for (;;) { + /* This check is called on the fast path for each record. */ + if (likely(!subbuffer_id_is_noref(config, id))) { +diff --git a/lib/ringbuffer/frontend.h b/lib/ringbuffer/frontend.h +index 6f516d9..41382fe 100644 +--- a/lib/ringbuffer/frontend.h ++++ b/lib/ringbuffer/frontend.h +@@ -79,7 +79,7 @@ void *channel_destroy(struct channel *chan); + #define for_each_channel_cpu(cpu, chan) \ + for ((cpu) = -1; \ + ({ (cpu) = cpumask_next(cpu, (chan)->backend.cpumask); \ +- smp_read_barrier_depends(); (cpu) < nr_cpu_ids; });) ++ smp_rmb(); (cpu) < nr_cpu_ids; });) + + extern struct lib_ring_buffer *channel_get_ring_buffer( + const struct lib_ring_buffer_config *config, +@@ -155,7 +155,7 @@ static inline + int lib_ring_buffer_is_finalized(const struct lib_ring_buffer_config *config, + struct lib_ring_buffer *buf) + { +- int finalized = READ_ONCE(buf->finalized); ++ int finalized = LTTNG_READ_ONCE(buf->finalized); + /* + * Read finalized before counters. + */ +diff --git a/lib/ringbuffer/ring_buffer_frontend.c b/lib/ringbuffer/ring_buffer_frontend.c +index 3cab365..4980d20 100644 +--- a/lib/ringbuffer/ring_buffer_frontend.c ++++ b/lib/ringbuffer/ring_buffer_frontend.c +@@ -1074,7 +1074,7 @@ int lib_ring_buffer_snapshot(struct lib_ring_buffer *buf, + int finalized; + + retry: +- finalized = READ_ONCE(buf->finalized); ++ finalized = LTTNG_READ_ONCE(buf->finalized); + /* + * Read finalized before counters. + */ +@@ -1245,7 +1245,7 @@ int lib_ring_buffer_get_subbuf(struct lib_ring_buffer *buf, + return -EBUSY; + } + retry: +- finalized = READ_ONCE(buf->finalized); ++ finalized = LTTNG_READ_ONCE(buf->finalized); + /* + * Read finalized before counters. + */ +diff --git a/lib/ringbuffer/ring_buffer_iterator.c b/lib/ringbuffer/ring_buffer_iterator.c +index d25db72..7b4f20a 100644 +--- a/lib/ringbuffer/ring_buffer_iterator.c ++++ b/lib/ringbuffer/ring_buffer_iterator.c +@@ -46,7 +46,7 @@ restart: + switch (iter->state) { + case ITER_GET_SUBBUF: + ret = lib_ring_buffer_get_next_subbuf(buf); +- if (ret && !READ_ONCE(buf->finalized) ++ if (ret && !LTTNG_READ_ONCE(buf->finalized) + && config->alloc == RING_BUFFER_ALLOC_GLOBAL) { + /* + * Use "pull" scheme for global buffers. The reader +diff --git a/lttng-events.c b/lttng-events.c +index be7e389..d719294 100644 +--- a/lttng-events.c ++++ b/lttng-events.c +@@ -1719,7 +1719,7 @@ int lttng_metadata_printf(struct lttng_session *session, + size_t len; + va_list ap; + +- WARN_ON_ONCE(!READ_ONCE(session->active)); ++ WARN_ON_ONCE(!LTTNG_READ_ONCE(session->active)); + + va_start(ap, fmt); + str = kvasprintf(GFP_KERNEL, fmt, ap); +@@ -2305,7 +2305,7 @@ int _lttng_event_metadata_statedump(struct lttng_session *session, + { + int ret = 0; + +- if (event->metadata_dumped || !READ_ONCE(session->active)) ++ if (event->metadata_dumped || !LTTNG_READ_ONCE(session->active)) + return 0; + if (chan->channel_type == METADATA_CHANNEL) + return 0; +@@ -2377,7 +2377,7 @@ int _lttng_channel_metadata_statedump(struct lttng_session *session, + { + int ret = 0; + +- if (chan->metadata_dumped || !READ_ONCE(session->active)) ++ if (chan->metadata_dumped || !LTTNG_READ_ONCE(session->active)) + return 0; + + if (chan->channel_type == METADATA_CHANNEL) +@@ -2604,7 +2604,7 @@ int _lttng_session_metadata_statedump(struct lttng_session *session) + struct lttng_event *event; + int ret = 0; + +- if (!READ_ONCE(session->active)) ++ if (!LTTNG_READ_ONCE(session->active)) + return 0; + + lttng_metadata_begin(session); +diff --git a/probes/lttng-kprobes.c b/probes/lttng-kprobes.c +index a44eaa1..38fb72e 100644 +--- a/probes/lttng-kprobes.c ++++ b/probes/lttng-kprobes.c +@@ -31,11 +31,11 @@ int lttng_kprobes_handler_pre(struct kprobe *p, struct pt_regs *regs) + int ret; + unsigned long data = (unsigned long) p->addr; + +- if (unlikely(!READ_ONCE(chan->session->active))) ++ if (unlikely(!LTTNG_READ_ONCE(chan->session->active))) + return 0; +- if (unlikely(!READ_ONCE(chan->enabled))) ++ if (unlikely(!LTTNG_READ_ONCE(chan->enabled))) + return 0; +- if (unlikely(!READ_ONCE(event->enabled))) ++ if (unlikely(!LTTNG_READ_ONCE(event->enabled))) + return 0; + + lib_ring_buffer_ctx_init(&ctx, chan->chan, <tng_probe_ctx, sizeof(data), +diff --git a/probes/lttng-kretprobes.c b/probes/lttng-kretprobes.c +index ab98ff2..a6bcd21 100644 +--- a/probes/lttng-kretprobes.c ++++ b/probes/lttng-kretprobes.c +@@ -51,11 +51,11 @@ int _lttng_kretprobes_handler(struct kretprobe_instance *krpi, + unsigned long parent_ip; + } payload; + +- if (unlikely(!READ_ONCE(chan->session->active))) ++ if (unlikely(!LTTNG_READ_ONCE(chan->session->active))) + return 0; +- if (unlikely(!READ_ONCE(chan->enabled))) ++ if (unlikely(!LTTNG_READ_ONCE(chan->enabled))) + return 0; +- if (unlikely(!READ_ONCE(event->enabled))) ++ if (unlikely(!LTTNG_READ_ONCE(event->enabled))) + return 0; + + payload.ip = (unsigned long) krpi->rp->kp.addr; +diff --git a/probes/lttng-tracepoint-event-impl.h b/probes/lttng-tracepoint-event-impl.h +index 77b8638..72a669e 100644 +--- a/probes/lttng-tracepoint-event-impl.h ++++ b/probes/lttng-tracepoint-event-impl.h +@@ -1132,11 +1132,11 @@ static void __event_probe__##_name(void *__data, _proto) \ + \ + if (!_TP_SESSION_CHECK(session, __session)) \ + return; \ +- if (unlikely(!READ_ONCE(__session->active))) \ ++ if (unlikely(!LTTNG_READ_ONCE(__session->active))) \ + return; \ +- if (unlikely(!READ_ONCE(__chan->enabled))) \ ++ if (unlikely(!LTTNG_READ_ONCE(__chan->enabled))) \ + return; \ +- if (unlikely(!READ_ONCE(__event->enabled))) \ ++ if (unlikely(!LTTNG_READ_ONCE(__event->enabled))) \ + return; \ + __lf = lttng_rcu_dereference(__session->pid_tracker.p); \ + if (__lf && likely(!lttng_id_tracker_lookup(__lf, current->tgid))) \ +@@ -1225,11 +1225,11 @@ static void __event_probe__##_name(void *__data) \ + \ + if (!_TP_SESSION_CHECK(session, __session)) \ + return; \ +- if (unlikely(!READ_ONCE(__session->active))) \ ++ if (unlikely(!LTTNG_READ_ONCE(__session->active))) \ + return; \ +- if (unlikely(!READ_ONCE(__chan->enabled))) \ ++ if (unlikely(!LTTNG_READ_ONCE(__chan->enabled))) \ + return; \ +- if (unlikely(!READ_ONCE(__event->enabled))) \ ++ if (unlikely(!LTTNG_READ_ONCE(__event->enabled))) \ + return; \ + __lf = lttng_rcu_dereference(__session->pid_tracker.p); \ + if (__lf && likely(!lttng_id_tracker_lookup(__lf, current->tgid))) \ +diff --git a/probes/lttng-uprobes.c b/probes/lttng-uprobes.c +index bc10128..bda1d9b 100644 +--- a/probes/lttng-uprobes.c ++++ b/probes/lttng-uprobes.c +@@ -40,11 +40,11 @@ int lttng_uprobes_handler_pre(struct uprobe_consumer *uc, struct pt_regs *regs) + unsigned long ip; + } payload; + +- if (unlikely(!READ_ONCE(chan->session->active))) ++ if (unlikely(!LTTNG_READ_ONCE(chan->session->active))) + return 0; +- if (unlikely(!READ_ONCE(chan->enabled))) ++ if (unlikely(!LTTNG_READ_ONCE(chan->enabled))) + return 0; +- if (unlikely(!READ_ONCE(event->enabled))) ++ if (unlikely(!LTTNG_READ_ONCE(event->enabled))) + return 0; + + lib_ring_buffer_ctx_init(&ctx, chan->chan, <tng_probe_ctx, +diff --git a/wrapper/compiler.h b/wrapper/compiler.h +index 1496f33..b9f8c51 100644 +--- a/wrapper/compiler.h ++++ b/wrapper/compiler.h +@@ -9,6 +9,7 @@ + #define _LTTNG_WRAPPER_COMPILER_H + + #include <linux/compiler.h> ++#include <linux/version.h> + + /* + * Don't allow compiling with buggy compiler. +@@ -39,4 +40,21 @@ + # define WRITE_ONCE(x, val) ({ ACCESS_ONCE(x) = val; }) + #endif + ++/* ++ * In v4.15 a smp read barrier was added to READ_ONCE to replace ++ * lockless_dereference(), replicate this behavior on prior kernels ++ * and remove calls to smp_read_barrier_depends which was dropped ++ * in v5.9. ++ */ ++#if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,15,0)) ++#define LTTNG_READ_ONCE(x) READ_ONCE(x) ++#else ++#define LTTNG_READ_ONCE(x) \ ++({ \ ++ typeof(x) __val = READ_ONCE(x); \ ++ smp_read_barrier_depends(); \ ++ __val; \ ++}) ++#endif ++ + #endif /* _LTTNG_WRAPPER_COMPILER_H */ +diff --git a/wrapper/trace-clock.h b/wrapper/trace-clock.h +index 9f4e366..187fc82 100644 +--- a/wrapper/trace-clock.h ++++ b/wrapper/trace-clock.h +@@ -160,33 +160,30 @@ static inline void put_trace_clock(void) + + static inline u64 trace_clock_read64(void) + { +- struct lttng_trace_clock *ltc = READ_ONCE(lttng_trace_clock); ++ struct lttng_trace_clock *ltc = LTTNG_READ_ONCE(lttng_trace_clock); + + if (likely(!ltc)) { + return trace_clock_read64_monotonic(); + } else { +- read_barrier_depends(); /* load ltc before content */ + return ltc->read64(); + } + } + + static inline u64 trace_clock_freq(void) + { +- struct lttng_trace_clock *ltc = READ_ONCE(lttng_trace_clock); ++ struct lttng_trace_clock *ltc = LTTNG_READ_ONCE(lttng_trace_clock); + + if (!ltc) { + return trace_clock_freq_monotonic(); + } else { +- read_barrier_depends(); /* load ltc before content */ + return ltc->freq(); + } + } + + static inline int trace_clock_uuid(char *uuid) + { +- struct lttng_trace_clock *ltc = READ_ONCE(lttng_trace_clock); ++ struct lttng_trace_clock *ltc = LTTNG_READ_ONCE(lttng_trace_clock); + +- read_barrier_depends(); /* load ltc before content */ + /* Use default UUID cb when NULL */ + if (!ltc || !ltc->uuid) { + return trace_clock_uuid_monotonic(uuid); +@@ -197,24 +194,22 @@ static inline int trace_clock_uuid(char *uuid) + + static inline const char *trace_clock_name(void) + { +- struct lttng_trace_clock *ltc = READ_ONCE(lttng_trace_clock); ++ struct lttng_trace_clock *ltc = LTTNG_READ_ONCE(lttng_trace_clock); + + if (!ltc) { + return trace_clock_name_monotonic(); + } else { +- read_barrier_depends(); /* load ltc before content */ + return ltc->name(); + } + } + + static inline const char *trace_clock_description(void) + { +- struct lttng_trace_clock *ltc = READ_ONCE(lttng_trace_clock); ++ struct lttng_trace_clock *ltc = LTTNG_READ_ONCE(lttng_trace_clock); + + if (!ltc) { + return trace_clock_description_monotonic(); + } else { +- read_barrier_depends(); /* load ltc before content */ + return ltc->description(); + } + } +-- +2.19.1 + |