initial commit

Change-Id: I8f7a7eeece0e516efa486b77e9d97805c0e65d3e
Signed-off-by: Iliyan Malchev <malchev@google.com>

1 files changed, 106 insertions, 0 deletions

diff --git a/mapinfo.c b/mapinfo.c
new file mode 100644
index 0000000..7f4250f
--- /dev/null
+++ b/mapinfo.c
@@ -0,0 +1,106 @@
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+
+#include "mapinfo.h"
+
+extern void *__real_malloc(size_t size);
+extern void __real_free(void *ptr);
+
+#if 0
+    while (p <= end) {
+         data = ptrace(PTRACE_PEEKTEXT, pid, (void*)p, NULL);
+         _LOG(tfd, (sp_depth > 2) || only_in_tombstone,
+              "    %08x  %08x  %s\n", p, data,
+              map_to_name(map, data, ""));
+         p += 4;
+    }
+#endif
+
+// 6f000000-6f01e000 rwxp 00000000 00:0c 16389419   /system/lib/libcomposer.so
+// 012345678901234567890123456789012345678901234567890123456789
+// 0         1         2         3         4         5
+
+static mapinfo *parse_maps_line(char *line)
+{
+    mapinfo *mi;
+    int len = strlen(line);
+
+    if(len < 1) return 0;
+    line[--len] = 0;
+
+    if(len < 50) return 0;
+    if(line[20] != 'x') return 0;
+
+    mi = __real_malloc(sizeof(mapinfo) + (len - 47));
+    if(mi == 0) return 0;
+
+    mi->start = strtoul(line, 0, 16);
+    mi->end = strtoul(line + 9, 0, 16);
+    /* To be filled in parse_elf_info if the mapped section starts with
+     * elf_header
+     */
+    mi->next = 0;
+    strcpy(mi->name, line + 49);
+
+    return mi;
+}
+
+mapinfo *init_mapinfo(int pid)
+{
+    struct mapinfo *milist = NULL;
+    char data[1024];
+    sprintf(data, "/proc/%d/maps", pid);
+    FILE *fp = fopen(data, "r");
+    if(fp) {
+        while(fgets(data, sizeof(data), fp)) {
+            mapinfo *mi = parse_maps_line(data);
+            if(mi) {
+                mi->next = milist;
+                milist = mi;
+            }
+        }
+        fclose(fp);
+    }
+
+    return milist;
+}
+
+void deinit_mapinfo(mapinfo *mi)
+{
+   mapinfo *del;
+   while(mi) {
+       del = mi;
+       mi = mi->next;
+       __real_free(del);
+   }
+}
+
+/* Map a pc address to the name of the containing ELF file */
+const char *map_to_name(mapinfo *mi, unsigned pc, const char* def)
+{
+    while(mi) {
+        if((pc >= mi->start) && (pc < mi->end)){
+            return mi->name;
+        }
+        mi = mi->next;
+    }
+    return def;
+}
+
+/* Find the containing map info for the pc */
+const mapinfo *pc_to_mapinfo(mapinfo *mi, unsigned pc, unsigned *rel_pc)
+{
+    *rel_pc = pc;
+    while(mi) {
+        if((pc >= mi->start) && (pc < mi->end)){
+            // Only calculate the relative offset for shared libraries
+            if (strstr(mi->name, ".so")) {
+                *rel_pc -= mi->start;
+            }
+            return mi;
+        }
+        mi = mi->next;
+    }
+    return NULL;
+}