[lttng-dev] [PATCH lttng-ust] Fix: Dump executable base-address with readlink
Mathieu Desnoyers
mathieu.desnoyers at efficios.com
Tue Feb 25 05:18:04 EST 2014
merged with small style updates.
Thanks!
Mathieu
----- Original Message -----
> From: "Paul Woegerer" <paul_woegerer at mentor.com>
> To: lttng-dev at lists.lttng.org, "mathieu desnoyers" <mathieu.desnoyers at efficios.com>
> Sent: Tuesday, February 25, 2014 4:47:00 AM
> Subject: [PATCH lttng-ust] Fix: Dump executable base-address with readlink
>
> The previous approach only worked if the traced executable was invoked
> via its fully qualified path. Using readlink to determine the full
> qualified path of the traced executable works reliably even when the
> traced executable is started via PATH lookup.
>
> Signed-off-by: Paul Woegerer <paul_woegerer at mentor.com>
> ---
> liblttng-ust/lttng-ust-baddr.c | 14 +++++++-------
> 1 file changed, 7 insertions(+), 7 deletions(-)
>
> diff --git a/liblttng-ust/lttng-ust-baddr.c b/liblttng-ust/lttng-ust-baddr.c
> index 42ae630..3ae4e03 100644
> --- a/liblttng-ust/lttng-ust-baddr.c
> +++ b/liblttng-ust/lttng-ust-baddr.c
> @@ -154,21 +154,21 @@ static
> void dump_exec_baddr(struct extract_data *data)
> {
> void *owner = data->owner;
> - Dl_info dl_info = { 0 };
> void *base_addr_ptr;
> - char resolved_path[PATH_MAX];
> + char exe_path[PATH_MAX];
> + ssize_t exe_len;
>
> base_addr_ptr = data->exec_baddr;
> if (!base_addr_ptr)
> return;
> /*
> - * We have to use Dl_info to determine the executable full path.
> + * We have to use /proc/self/exe to determine the executable full path.
> */
> - if (!dladdr(base_addr_ptr, &dl_info))
> + exe_len = readlink("/proc/self/exe", exe_path, sizeof(exe_path)-1);
> + if (exe_len <= 0)
> return;
> - if (!realpath(dl_info.dli_fname, resolved_path))
> - return;
> - trace_baddr(base_addr_ptr, resolved_path, 0, owner);
> + exe_path[exe_len] = '\0';
> + trace_baddr(base_addr_ptr, exe_path, 0, owner);
> }
>
> int lttng_ust_baddr_statedump(void *owner)
> --
> 1.8.5.2
>
>
--
Mathieu Desnoyers
EfficiOS Inc.
http://www.efficios.com
More information about the lttng-dev
mailing list