On 08/02/2013 09:18 PM, Mathieu Desnoyers wrote:
[...]
> Then, I recommend porting the code from memleak-finder.c to UST
> liblttng-ust-libc-wrapper. The approach I used in memleak-finder.c seems
> to work quite well, and is clearly more complete that what we find in
> liblttng-ust-libc-wrapper currently.
...and here is a revised patch to add calloc and realloc
instrumentation, using the same technique as memleak-finder.
I've ran the patch through the checkpatch.pl script, and made some minor
adjustments to other code to fix coding style errors.
Regards,
Stefan
--
Stefan Seefeld
CodeSourcery / Mentor Graphics
http://www.mentor.com/embedded-software/
>From 93da5d2be5ec3a3680449e186780ff7a08cec6d9 Mon Sep 17 00:00:00 2001
From: Stefan Seefeld <[email protected]>
Date: Sat, 27 Jul 2013 01:10:23 -0400
Subject: [PATCH] Add trace support for calloc and realloc.
Signed-off-by: Stefan Seefeld <[email protected]>
---
liblttng-ust-libc-wrapper/lttng-ust-malloc.c | 68 +++++++++++++++++++++++++++-
liblttng-ust-libc-wrapper/ust_libc.h | 18 ++++++++
2 files changed, 84 insertions(+), 2 deletions(-)
diff --git a/liblttng-ust-libc-wrapper/lttng-ust-malloc.c b/liblttng-ust-libc-wrapper/lttng-ust-malloc.c
index 3212ff0..81beb78 100644
--- a/liblttng-ust-libc-wrapper/lttng-ust-malloc.c
+++ b/liblttng-ust-libc-wrapper/lttng-ust-malloc.c
@@ -26,9 +26,25 @@
#define TRACEPOINT_CREATE_PROBES
#include "ust_libc.h"
+#define STATIC_CALLOC_LEN 4096
+static char static_calloc_buf[STATIC_CALLOC_LEN];
+static size_t static_calloc_buf_offset;
+
+static void *static_calloc(size_t nmemb, size_t size)
+{
+ size_t prev_offset;
+
+ if (nmemb * size > sizeof(static_calloc_buf) - static_calloc_buf_offset) {
+ return NULL;
+ }
+ prev_offset = static_calloc_buf_offset;
+ static_calloc_buf_offset += nmemb * size;
+ return &static_calloc_buf[prev_offset];
+}
+
void *malloc(size_t size)
{
- static void *(*plibc_malloc)(size_t size) = NULL;
+ static void *(*plibc_malloc)(size_t size);
void *retval;
if (plibc_malloc == NULL) {
@@ -45,7 +61,16 @@ void *malloc(size_t size)
void free(void *ptr)
{
- static void *(*plibc_free)(void *ptr) = NULL;
+ static void (*plibc_free)(void *ptr);
+
+ /* Check whether the memory was allocated with
+ * static_calloc, in which case there is nothing
+ * to free.
+ */
+ if ((char *)ptr >= static_calloc_buf &&
+ (char *)ptr < static_calloc_buf + STATIC_CALLOC_LEN) {
+ return;
+ }
if (plibc_free == NULL) {
plibc_free = dlsym(RTLD_NEXT, "free");
@@ -57,3 +82,42 @@ void free(void *ptr)
tracepoint(ust_libc, free, ptr);
plibc_free(ptr);
}
+
+void *calloc(size_t nmemb, size_t size)
+{
+ static void *(*volatile plibc_calloc)(size_t nmemb, size_t size);
+ void *retval;
+
+ if (plibc_calloc == NULL) {
+ /*
+ * Temporarily redirect to static_calloc,
+ * until the dlsym lookup has completed.
+ */
+ plibc_calloc = static_calloc;
+ plibc_calloc = dlsym(RTLD_NEXT, "calloc");
+ if (plibc_calloc == NULL) {
+ fprintf(stderr, "callocwrap: unable to find calloc\n");
+ return NULL;
+ }
+ }
+ retval = plibc_calloc(nmemb, size);
+ tracepoint(ust_libc, calloc, nmemb, size, retval);
+ return retval;
+}
+
+void *realloc(void *ptr, size_t size)
+{
+ static void *(*plibc_realloc)(void *ptr, size_t size);
+ void *retval;
+
+ if (plibc_realloc == NULL) {
+ plibc_realloc = dlsym(RTLD_NEXT, "realloc");
+ if (plibc_realloc == NULL) {
+ fprintf(stderr, "reallocwrap: unable to find realloc\n");
+ return NULL;
+ }
+ }
+ retval = plibc_realloc(ptr, size);
+ tracepoint(ust_libc, realloc, ptr, size, retval);
+ return retval;
+}
diff --git a/liblttng-ust-libc-wrapper/ust_libc.h b/liblttng-ust-libc-wrapper/ust_libc.h
index af705aa..6b03a4d 100644
--- a/liblttng-ust-libc-wrapper/ust_libc.h
+++ b/liblttng-ust-libc-wrapper/ust_libc.h
@@ -47,6 +47,24 @@ TRACEPOINT_EVENT(ust_libc, free,
)
)
+TRACEPOINT_EVENT(ust_libc, calloc,
+ TP_ARGS(size_t, nmemb, size_t, size, void *, ptr),
+ TP_FIELDS(
+ ctf_integer(size_t, nmemb, nmemb)
+ ctf_integer(size_t, size, size)
+ ctf_integer_hex(unsigned long, ptr, (unsigned long) ptr)
+ )
+)
+
+TRACEPOINT_EVENT(ust_libc, realloc,
+ TP_ARGS(void *, in_ptr, size_t, size, void *, ptr),
+ TP_FIELDS(
+ ctf_integer_hex(unsigned long, in_ptr, (unsigned long) in_ptr)
+ ctf_integer(size_t, size, size)
+ ctf_integer_hex(unsigned long, ptr, (unsigned long) ptr)
+ )
+)
+
#endif /* _TRACEPOINT_UST_LIBC_H */
#undef TRACEPOINT_INCLUDE
--
1.8.3.1
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