X-Git-Url: http://git.liburcu.org/?a=blobdiff_plain;f=liblttng-ust-libc-wrapper%2Flttng-ust-malloc.c;h=f3e1e19e28e52d8d5fe07d399f6c4741d0d87282;hb=09434f96935202d1e6cf64a74d4da4b95d06246d;hp=06e0efe8679a4a24d635715f01e1130eb0d1ea20;hpb=8c06ba6ffeeb1196fa96dfbdd0b1c9937496f70f;p=lttng-ust.git

diff --git a/liblttng-ust-libc-wrapper/lttng-ust-malloc.c b/liblttng-ust-libc-wrapper/lttng-ust-malloc.c
index 06e0efe8..f3e1e19e 100644
--- a/liblttng-ust-libc-wrapper/lttng-ust-malloc.c
+++ b/liblttng-ust-libc-wrapper/lttng-ust-malloc.c
@@ -9,7 +9,7 @@
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	 See the GNU
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public
@@ -18,6 +18,11 @@
  */
 
 #define _GNU_SOURCE
+/*
+ * Do _not_ define _LGPL_SOURCE because we don't want to create a
+ * circular dependency loop between this malloc wrapper, liburcu and
+ * libc.
+ */
 #include <lttng/ust-dlfcn.h>
 #include <sys/types.h>
 #include <stdio.h>
@@ -26,10 +31,13 @@
 #include <urcu/uatomic.h>
 #include <urcu/compiler.h>
 #include <urcu/tls-compat.h>
+#include <urcu/arch.h>
 #include <lttng/align.h>
+#include <helper.h>
 
 #define TRACEPOINT_DEFINE
 #define TRACEPOINT_CREATE_PROBES
+#define TP_IP_PARAM ip
 #include "ust_libc.h"
 
 #define STATIC_CALLOC_LEN 4096
@@ -56,8 +64,40 @@ struct alloc_functions cur_alloc;
 static
 void *static_calloc(size_t nmemb, size_t size);
 
+/*
+ * pthread mutex replacement for URCU tls compat layer.
+ */
+static int ust_malloc_lock;
+
+static __attribute__((unused))
+void ust_malloc_spin_lock(pthread_mutex_t *lock)
+{
+	/*
+	 * The memory barrier within cmpxchg takes care of ordering
+	 * memory accesses with respect to the start of the critical
+	 * section.
+	 */
+	while (uatomic_cmpxchg(&ust_malloc_lock, 0, 1) != 0)
+		caa_cpu_relax();
+}
+
+static __attribute__((unused))
+void ust_malloc_spin_unlock(pthread_mutex_t *lock)
+{
+	/*
+	 * Ensure memory accesses within the critical section do not
+	 * leak outside.
+	 */
+	cmm_smp_mb();
+	uatomic_set(&ust_malloc_lock, 0);
+}
+
 #define calloc static_calloc
+#define pthread_mutex_lock ust_malloc_spin_lock
+#define pthread_mutex_unlock ust_malloc_spin_unlock
 static DEFINE_URCU_TLS(int, malloc_nesting);
+#undef ust_malloc_spin_unlock
+#undef ust_malloc_spin_lock
 #undef calloc
 
 /*
@@ -227,7 +267,8 @@ void *malloc(size_t size)
 	}
 	retval = cur_alloc.malloc(size);
 	if (URCU_TLS(malloc_nesting) == 1) {
-		tracepoint(ust_libc, malloc, size, retval);
+		tracepoint(lttng_ust_libc, malloc,
+			size, retval, LTTNG_UST_CALLER_IP());
 	}
 	URCU_TLS(malloc_nesting)--;
 	return retval;
@@ -246,7 +287,8 @@ void free(void *ptr)
 	}
 
 	if (URCU_TLS(malloc_nesting) == 1) {
-		tracepoint(ust_libc, free, ptr);
+		tracepoint(lttng_ust_libc, free,
+			ptr, LTTNG_UST_CALLER_IP());
 	}
 
 	if (cur_alloc.free == NULL) {
@@ -275,7 +317,8 @@ void *calloc(size_t nmemb, size_t size)
 	}
 	retval = cur_alloc.calloc(nmemb, size);
 	if (URCU_TLS(malloc_nesting) == 1) {
-		tracepoint(ust_libc, calloc, nmemb, size, retval);
+		tracepoint(lttng_ust_libc, calloc,
+			nmemb, size, retval, LTTNG_UST_CALLER_IP());
 	}
 	URCU_TLS(malloc_nesting)--;
 	return retval;
@@ -327,7 +370,8 @@ void *realloc(void *ptr, size_t size)
 	retval = cur_alloc.realloc(ptr, size);
 end:
 	if (URCU_TLS(malloc_nesting) == 1) {
-		tracepoint(ust_libc, realloc, ptr, size, retval);
+		tracepoint(lttng_ust_libc, realloc,
+			ptr, size, retval, LTTNG_UST_CALLER_IP());
 	}
 	URCU_TLS(malloc_nesting)--;
 	return retval;
@@ -347,7 +391,9 @@ void *memalign(size_t alignment, size_t size)
 	}
 	retval = cur_alloc.memalign(alignment, size);
 	if (URCU_TLS(malloc_nesting) == 1) {
-		tracepoint(ust_libc, memalign, alignment, size, retval);
+		tracepoint(lttng_ust_libc, memalign,
+			alignment, size, retval,
+			LTTNG_UST_CALLER_IP());
 	}
 	URCU_TLS(malloc_nesting)--;
 	return retval;
@@ -367,13 +413,20 @@ int posix_memalign(void **memptr, size_t alignment, size_t size)
 	}
 	retval = cur_alloc.posix_memalign(memptr, alignment, size);
 	if (URCU_TLS(malloc_nesting) == 1) {
-		tracepoint(ust_libc, posix_memalign, *memptr, alignment, size,
-			retval);
+		tracepoint(lttng_ust_libc, posix_memalign,
+			*memptr, alignment, size,
+			retval, LTTNG_UST_CALLER_IP());
 	}
 	URCU_TLS(malloc_nesting)--;
 	return retval;
 }
 
+static
+void lttng_ust_fixup_malloc_nesting_tls(void)
+{
+	asm volatile ("" : : "m" (URCU_TLS(malloc_nesting)));
+}
+
 __attribute__((constructor))
 void lttng_ust_malloc_wrapper_init(void)
 {
@@ -381,6 +434,7 @@ void lttng_ust_malloc_wrapper_init(void)
 	if (cur_alloc.calloc) {
 		return;
 	}
+	lttng_ust_fixup_malloc_nesting_tls();
 	/*
 	 * Ensure the allocator is in place before the process becomes
 	 * multithreaded.