Implement base-address-state tracing

[lttng-ust.git] / liblttng-ust-baddr / lttng-ust-baddr.c

diff --git a/liblttng-ust-baddr/lttng-ust-baddr.c b/liblttng-ust-baddr/lttng-ust-baddr.c
index f24a1717277ab99c2c81f1aa6b47bc290fb9c5fd..a8569656bce804de5ea1369012ba42b3a4b0d19d 100644 (file)
--- a/liblttng-ust-baddr/lttng-ust-baddr.c
+++ b/liblttng-ust-baddr/lttng-ust-baddr.c
@@ -34,6 +34,7 @@
 
 #define TRACEPOINT_DEFINE
 #include "ust_baddr.h"
+#include "ust_baddr_statedump.h"
 
 int
 lttng_ust_push_baddr(void *so_base, const char *so_name)
@@ -62,3 +63,74 @@ lttng_ust_pop_baddr(void *so_base)
        tracepoint(ust_baddr, pop, so_base);
        return 0;
 }
+
+static int
+extract_soinfo_events(struct dl_phdr_info *info, size_t size, void *data)
+{
+       int j;
+       int num_loadable_segment = 0;
+
+       for (j = 0; j < info->dlpi_phnum; j++) {
+               char resolved_path[PATH_MAX];
+               struct stat sostat;
+               void *base_addr_ptr;
+
+               if (info->dlpi_phdr[j].p_type != PT_LOAD)
+                       continue;
+
+               /* Calculate virtual memory address of the loadable segment */
+               base_addr_ptr = (void *) info->dlpi_addr
+                       + info->dlpi_phdr[j].p_vaddr;
+
+               num_loadable_segment += 1;
+               if ((info->dlpi_name == NULL || info->dlpi_name[0] == 0)
+                               && num_loadable_segment == 1) {
+                       /*
+                        * If the iterated element is the executable itself we
+                        * have to use Dl_info to determine its full path
+                        */
+                       Dl_info dl_info = { 0 };
+                       if (!dladdr(base_addr_ptr, &dl_info))
+                               return 0;
+                       if (!realpath(dl_info.dli_fname, resolved_path))
+                               return 0;
+               } else {
+                       /*
+                        * For regular dl_phdr_info entries we have to check if
+                        * the path to the shared object really exists
+                        */
+                       if (!realpath(info->dlpi_name, resolved_path)) {
+                               /* Found vDSO, put the 'path' into brackets */
+                               snprintf(resolved_path, PATH_MAX - 1, "[%s]",
+                                               info->dlpi_name);
+                       }
+               }
+
+               if (stat(resolved_path, &sostat)) {
+                       sostat.st_size = 0;
+                       sostat.st_mtime = -1;
+               }
+
+               tracepoint(ust_baddr_statedump, soinfo,
+                               (struct lttng_session *) data, base_addr_ptr,
+                               resolved_path, sostat.st_size, sostat.st_mtime);
+
+               /*
+                * We are only interested in the base address (lowest virtual
+                * address associated with the memory image), skip the rest
+                */
+               break;
+       }
+       return 0;
+}
+
+int
+lttng_ust_baddr_statedump(struct lttng_session *session)
+{
+       /*
+        * Iterate through the list of currently loaded shared objects and
+        * generate events for loadable segments using extract_soinfo_events
+        */
+       dl_iterate_phdr(extract_soinfo_events, session);
+       return 0;
+}