[Git][ghc/ghc][master] 3 commits: rts/EventLog: Place eliminate duplicate strlens
Marge Bot (@marge-bot)
gitlab at gitlab.haskell.org
Wed Feb 14 19:28:15 UTC 2024
Marge Bot pushed to branch master at Glasgow Haskell Compiler / GHC
Commits:
325b7613 by Ben Gamari at 2024-02-14T14:27:45-05:00
rts/EventLog: Place eliminate duplicate strlens
Previously many of the `post*` implementations would first compute the
length of the event's strings in order to determine the event length.
Later we would then end up computing the length yet again in
`postString`. Now we instead pass the string length to `postStringLen`,
avoiding the repeated work.
- - - - -
8aafa51c by Ben Gamari at 2024-02-14T14:27:46-05:00
rts/eventlog: Place upper bound on IPE string field lengths
The strings in IPE events may be of unbounded length. Limit the lengths
of these fields to 64k characters to ensure that we don't exceed the
maximum event length.
- - - - -
0e60d52c by Zubin Duggal at 2024-02-14T14:27:46-05:00
rts: drop unused postString function
- - - - -
1 changed file:
- rts/eventlog/EventLog.c
Changes:
=====================================
rts/eventlog/EventLog.c
=====================================
@@ -27,6 +27,8 @@
#include <unistd.h>
#endif
+#define MIN(x,y) ((x) < (y) ? (x) : (y))
+
Mutex state_change_mutex;
bool eventlog_enabled; // protected by state_change_mutex to ensure
// serialisation of calls to
@@ -85,6 +87,14 @@ bool eventlog_enabled; // protected by state_change_mutex to ensure
* case is that we must ensure that the buffers of any disabled capabilities are
* flushed, lest their events are stuck in limbo. This is achieved with a call to
* flushLocalEventsBuf in traceCapDisable.
+ *
+ *
+ * Note [Maximum event length]
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ * The maximum length of an eventlog event is determined by the maximum event
+ * buffer size, EVENT_LOG_SIZE. We must ensure that no variable-length event
+ * exceeds this limit. For this reason we impose maximum length limits on
+ * fields which may have unbounded values.
*/
static const EventLogWriter *event_log_writer = NULL;
@@ -93,6 +103,7 @@ static const EventLogWriter *event_log_writer = NULL;
// eventlog is restarted
static eventlog_init_func_t *eventlog_header_funcs = NULL;
+// See Note [Maximum event length]
#define EVENT_LOG_SIZE 2 * (1024 * 1024) // 2MB
static int flushCount = 0;
@@ -172,14 +183,13 @@ static inline void postBuf(EventsBuf *eb, const StgWord8 *buf, uint32_t size)
eb->pos += size;
}
-/* Post a null-terminated string to the event log.
- * It is the caller's responsibility to ensure that there is
- * enough room for strlen(buf)+1 bytes.
+/* Post a null-terminated string up to a given length to the event log. It is
+ * the caller's responsibility to ensure that there is enough room for
+ * len+1 bytes.
*/
-static inline void postString(EventsBuf *eb, const char *buf)
+static inline void postStringLen(EventsBuf *eb, const char *buf, StgWord len)
{
if (buf) {
- const int len = strlen(buf);
ASSERT(eb->begin + eb->size > eb->pos + len + 1);
memcpy(eb->pos, buf, len);
eb->pos += len;
@@ -1228,13 +1238,13 @@ void postHeapProfBegin(StgWord8 profile_id)
postWord8(&eventBuf, profile_id);
postWord64(&eventBuf, TimeToNS(flags->heapProfileInterval));
postWord32(&eventBuf, getHeapProfBreakdown());
- postString(&eventBuf, flags->modSelector);
- postString(&eventBuf, flags->descrSelector);
- postString(&eventBuf, flags->typeSelector);
- postString(&eventBuf, flags->ccSelector);
- postString(&eventBuf, flags->ccsSelector);
- postString(&eventBuf, flags->retainerSelector);
- postString(&eventBuf, flags->bioSelector);
+ postStringLen(&eventBuf, flags->modSelector, modSelector_len);
+ postStringLen(&eventBuf, flags->descrSelector, descrSelector_len);
+ postStringLen(&eventBuf, flags->typeSelector, typeSelector_len);
+ postStringLen(&eventBuf, flags->ccSelector, ccSelector_len);
+ postStringLen(&eventBuf, flags->ccsSelector, ccsSelector_len);
+ postStringLen(&eventBuf, flags->retainerSelector, retainerSelector_len);
+ postStringLen(&eventBuf, flags->bioSelector, bioSelector_len);
RELEASE_LOCK(&eventBufMutex);
}
@@ -1279,7 +1289,7 @@ void postHeapProfSampleString(StgWord8 profile_id,
postPayloadSize(&eventBuf, len);
postWord8(&eventBuf, profile_id);
postWord64(&eventBuf, residency);
- postString(&eventBuf, label);
+ postStringLen(&eventBuf, label, label_len);
RELEASE_LOCK(&eventBufMutex);
}
@@ -1299,9 +1309,9 @@ void postHeapProfCostCentre(StgWord32 ccID,
postEventHeader(&eventBuf, EVENT_HEAP_PROF_COST_CENTRE);
postPayloadSize(&eventBuf, len);
postWord32(&eventBuf, ccID);
- postString(&eventBuf, label);
- postString(&eventBuf, module);
- postString(&eventBuf, srcloc);
+ postStringLen(&eventBuf, label, label_len);
+ postStringLen(&eventBuf, module, module_len);
+ postStringLen(&eventBuf, srcloc, srcloc_len);
postWord8(&eventBuf, is_caf);
RELEASE_LOCK(&eventBufMutex);
}
@@ -1373,17 +1383,20 @@ void postProfBegin(void)
#if defined(TICKY_TICKY)
static void postTickyCounterDef(EventsBuf *eb, StgEntCounter *p)
{
- StgWord len = 8 + 2 + strlen(p->arg_kinds)+1 + strlen(p->str)+1 + 8 + strlen(p->ticky_json)+1;
+ StgWord arg_kinds_len = strlen(p->arg_kinds);
+ StgWord str_len = strlen(p->str);
+ StgWord ticky_json_len = strlen(p->ticky_json);
+ StgWord len = 8 + 2 + arg_kinds_len+1 + str_len+1 + 8 + ticky_json_len+1;
CHECK(!ensureRoomForVariableEvent(eb, len));
postEventHeader(eb, EVENT_TICKY_COUNTER_DEF);
postPayloadSize(eb, len);
postWord64(eb, (uint64_t)((uintptr_t) p));
postWord16(eb, (uint16_t) p->arity);
- postString(eb, p->arg_kinds);
- postString(eb, p->str);
+ postStringLen(eb, p->arg_kinds, arg_kinds_len);
+ postStringLen(eb, p->str, str_len);
postWord64(eb, (W_) (INFO_PTR_TO_STRUCT(p->info)));
- postString(eb, p->ticky_json);
+ postStringLen(eb, p->ticky_json, ticky_json_len);
}
@@ -1428,14 +1441,16 @@ void postTickyCounterSamples(StgEntCounter *counters)
#endif /* TICKY_TICKY */
void postIPE(const InfoProvEnt *ipe)
{
+ // See Note [Maximum event length].
+ const StgWord MAX_IPE_STRING_LEN = 65535;
ACQUIRE_LOCK(&eventBufMutex);
- StgWord table_name_len = strlen(ipe->prov.table_name);
- StgWord closure_desc_len = strlen(ipe->prov.closure_desc);
- StgWord ty_desc_len = strlen(ipe->prov.ty_desc);
- StgWord label_len = strlen(ipe->prov.label);
- StgWord module_len = strlen(ipe->prov.module);
- StgWord src_file_len = strlen(ipe->prov.src_file);
- StgWord src_span_len = strlen(ipe->prov.src_span);
+ StgWord table_name_len = MIN(strlen(ipe->prov.table_name), MAX_IPE_STRING_LEN);
+ StgWord closure_desc_len = MIN(strlen(ipe->prov.closure_desc), MAX_IPE_STRING_LEN);
+ StgWord ty_desc_len = MIN(strlen(ipe->prov.ty_desc), MAX_IPE_STRING_LEN);
+ StgWord label_len = MIN(strlen(ipe->prov.label), MAX_IPE_STRING_LEN);
+ StgWord module_len = MIN(strlen(ipe->prov.module), MAX_IPE_STRING_LEN);
+ StgWord src_file_len = MIN(strlen(ipe->prov.src_file), MAX_IPE_STRING_LEN);
+ StgWord src_span_len = MIN(strlen(ipe->prov.src_span), MAX_IPE_STRING_LEN);
// 8 for the info word
// 1 null after each string
@@ -1446,17 +1461,17 @@ void postIPE(const InfoProvEnt *ipe)
postEventHeader(&eventBuf, EVENT_IPE);
postPayloadSize(&eventBuf, len);
postWord64(&eventBuf, (StgWord) INFO_PTR_TO_STRUCT(ipe->info));
- postString(&eventBuf, ipe->prov.table_name);
- postString(&eventBuf, ipe->prov.closure_desc);
- postString(&eventBuf, ipe->prov.ty_desc);
- postString(&eventBuf, ipe->prov.label);
- postString(&eventBuf, ipe->prov.module);
+ postStringLen(&eventBuf, ipe->prov.table_name, table_name_len);
+ postStringLen(&eventBuf, ipe->prov.closure_desc, closure_desc_len);
+ postStringLen(&eventBuf, ipe->prov.ty_desc, ty_desc_len);
+ postStringLen(&eventBuf, ipe->prov.label, label_len);
+ postStringLen(&eventBuf, ipe->prov.module, module_len);
// Manually construct the location field: "<file>:<span>\0"
postBuf(&eventBuf, (const StgWord8*) ipe->prov.src_file, src_file_len);
StgWord8 colon = ':';
postBuf(&eventBuf, &colon, 1);
- postString(&eventBuf, ipe->prov.src_span);
+ postStringLen(&eventBuf, ipe->prov.src_span, src_span_len);
RELEASE_LOCK(&eventBufMutex);
}
View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/de589554386fc173a9019922851c05bb727e3450...0e60d52cc7e261da11c37bd649511584d92a688b
--
View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/de589554386fc173a9019922851c05bb727e3450...0e60d52cc7e261da11c37bd649511584d92a688b
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