----- Original Message -----

> From: "Olivier Delbeke" <Olivier.Delbeke@awtce.be>
> To: lttng-dev@lists.lttng.org
> Sent: Tuesday, January 13, 2015 10:50:38 AM
> Subject: [lttng-dev] Addition of the return address to
> liblttng-ust-libc-wrapper

> Hi guys,

> I am using liblttng-ust-libc-wrapper to detect memory leaks in my
> applications.
> In order to identify not only the thread where the unfreed allocations are
> done, but also the calling function, I extended the
> liblttng-ust-libc-wrapper to log the "return address"
> (__builtin_return_address(0)) in addition to the parameters of malloc(). It
> solves my problem and does not affect Trace Compass.
> Was this the right thing to do ?
You should be able to achieve the same thing with the "ip" context, e.g.: 

lttng create 
lttng enable-event -u -a 
lttng add-context -u -t ip 
lttng start 
.... 

All this dynamically without changing the instrumentation. 

Thanks, 

Mathieu 

> If it is, then I guess that it might interest other people too.

> diff -Nurd b/liblttng-ust-libc-wrapper/lttng-ust-malloc.c
> c/liblttng-ust-libc-wrapper/lttng-ust-malloc.c
> --- b/liblttng-ust-libc-wrapper/lttng-ust-malloc.c 2015-01-06
> 17:14:34.000000000 +0100
> +++ c/liblttng-ust-libc-wrapper/lttng-ust-malloc.c 2015-01-06
> 17:16:40.811145106 +0100
> @@ -260,7 +260,7 @@
> }
> retval = cur_alloc.malloc(size);
> if (URCU_TLS(malloc_nesting) == 1) {
> - tracepoint(ust_libc, malloc, size, retval);
> + tracepoint(ust_libc, malloc, size, retval, __builtin_return_address(0) );
> }
> URCU_TLS(malloc_nesting)--;
> return retval;
> @@ -279,7 +279,7 @@
> }

> if (URCU_TLS(malloc_nesting) == 1) {
> - tracepoint(ust_libc, free, ptr);
> + tracepoint(ust_libc, free, ptr, __builtin_return_address(0) );
> }

> if (cur_alloc.free == NULL) {
> @@ -308,7 +308,7 @@
> }
> retval = cur_alloc.calloc(nmemb, size);
> if (URCU_TLS(malloc_nesting) == 1) {
> - tracepoint(ust_libc, calloc, nmemb, size, retval);
> + tracepoint(ust_libc, calloc, nmemb, size, retval,
> __builtin_return_address(0) );
> }
> URCU_TLS(malloc_nesting)--;
> return retval;
> @@ -360,7 +360,7 @@
> retval = cur_alloc.realloc(ptr, size);
> end:
> if (URCU_TLS(malloc_nesting) == 1) {
> - tracepoint(ust_libc, realloc, ptr, size, retval);
> + tracepoint(ust_libc, realloc, ptr, size, retval,
> __builtin_return_address(0) );
> }
> URCU_TLS(malloc_nesting)--;
> return retval;
> @@ -380,7 +380,7 @@
> }
> retval = cur_alloc.memalign(alignment, size);
> if (URCU_TLS(malloc_nesting) == 1) {
> - tracepoint(ust_libc, memalign, alignment, size, retval);
> + tracepoint(ust_libc, memalign, alignment, size, retval,
> __builtin_return_address(0) );
> }
> URCU_TLS(malloc_nesting)--;
> return retval;
> @@ -401,7 +401,7 @@
> retval = cur_alloc.posix_memalign(memptr, alignment, size);
> if (URCU_TLS(malloc_nesting) == 1) {
> tracepoint(ust_libc, posix_memalign, *memptr, alignment, size,
> - retval);
> + retval, __builtin_return_address(0) );
> }
> URCU_TLS(malloc_nesting)--;
> return retval;
> diff -Nurd b/liblttng-ust-libc-wrapper/ust_libc.h
> c/liblttng-ust-libc-wrapper/ust_libc.h
> --- b/liblttng-ust-libc-wrapper/ust_libc.h 2015-01-06 17:14:34.000000000
> +0100
> +++ c/liblttng-ust-libc-wrapper/ust_libc.h 2015-01-06 17:16:40.811145106
> +0100
> @@ -33,54 +33,60 @@
> #include <lttng/tracepoint.h>

> TRACEPOINT_EVENT(ust_libc, malloc,
> - TP_ARGS(size_t, size, void *, ptr),
> + TP_ARGS(size_t, size, void *, ptr, void *, ra),
> TP_FIELDS(
> ctf_integer(size_t, size, size)
> ctf_integer_hex(void *, ptr, ptr)
> + ctf_integer_hex(void *, ra, ra)
> )
> )

> TRACEPOINT_EVENT(ust_libc, free,
> - TP_ARGS(void *, ptr),
> + TP_ARGS(void *, ptr, void *, ra),
> TP_FIELDS(
> ctf_integer_hex(void *, ptr, ptr)
> + ctf_integer_hex(void *, ra, ra)
> )
> )

> TRACEPOINT_EVENT(ust_libc, calloc,
> - TP_ARGS(size_t, nmemb, size_t, size, void *, ptr),
> + TP_ARGS(size_t, nmemb, size_t, size, void *, ptr, void *, ra),
> TP_FIELDS(
> ctf_integer(size_t, nmemb, nmemb)
> ctf_integer(size_t, size, size)
> ctf_integer_hex(void *, ptr, ptr)
> + ctf_integer_hex(void *, ra, ra)
> )
> )

> TRACEPOINT_EVENT(ust_libc, realloc,
> - TP_ARGS(void *, in_ptr, size_t, size, void *, ptr),
> + TP_ARGS(void *, in_ptr, size_t, size, void *, ptr, void *, ra),
> TP_FIELDS(
> ctf_integer_hex(void *, in_ptr, in_ptr)
> ctf_integer(size_t, size, size)
> ctf_integer_hex(void *, ptr, ptr)
> + ctf_integer_hex(void *, ra, ra)
> )
> )

> TRACEPOINT_EVENT(ust_libc, memalign,
> - TP_ARGS(size_t, alignment, size_t, size, void *, ptr),
> + TP_ARGS(size_t, alignment, size_t, size, void *, ptr, void *, ra),
> TP_FIELDS(
> ctf_integer(size_t, alignment, alignment)
> ctf_integer(size_t, size, size)
> ctf_integer_hex(void *, ptr, ptr)
> + ctf_integer_hex(void *, ra, ra)
> )
> )

> TRACEPOINT_EVENT(ust_libc, posix_memalign,
> - TP_ARGS(void *, out_ptr, size_t, alignment, size_t, size, int, result),
> + TP_ARGS(void *, out_ptr, size_t, alignment, size_t, size, int, result, void
> *, ra),
> TP_FIELDS(
> ctf_integer_hex(void *, out_ptr, out_ptr)
> ctf_integer(size_t, alignment, alignment)
> ctf_integer(size_t, size, size)
> ctf_integer(int, result, result)
> + ctf_integer_hex(void *, ra, ra)
> )
> )

> Best regards,
> 
> Olivier Delbeke Senior Software Engineer
> Olivier.Delbeke@awtce.be / T. +32 2 389 25 53
> AWTC Europe S.A. - Avenue de l’Industrie, 19 - 1420 Braine-l’Alleud - Belgium
> - www.aweurope.eu - www.aisin-aw.co.jp
> VAT : BE 0474.474.114 - RPM Nivelles

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-- 
Mathieu Desnoyers 
EfficiOS Inc. 
http://www.efficios.com