From: Paul Woegerer Date: Tue, 25 Feb 2014 09:47:00 +0000 (+0100) Subject: Fix: Dump executable base-address with readlink X-Git-Tag: v2.4.0~11 X-Git-Url: https://git.lttng.org./?a=commitdiff_plain;h=6d0c2f84f1ec7f09ecfc2da1bb6145c0b7b71e26;p=lttng-ust.git 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 Signed-off-by: Mathieu Desnoyers --- diff --git a/liblttng-ust/lttng-ust-baddr.c b/liblttng-ust/lttng-ust-baddr.c index 42ae630d..922899b4 100644 --- a/liblttng-ust/lttng-ust-baddr.c +++ b/liblttng-ust/lttng-ust-baddr.c @@ -154,21 +154,22 @@ 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)