Parse /proc/pid/maps

1 files changed, 77 insertions, 0 deletions

diff --git a/src/vm.c b/src/vm.c
new file mode 100644
index 0000000..8e62426
--- /dev/null
+++ b/src/vm.c
@@ -0,0 +1,77 @@
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <ctype.h>
+#include <stdint.h>
+#include "vm.h"
+#include "util.h"
+
+static void strtrim (char *str)
+{
+  char *begin = str;
+  while (isspace(*begin)) {
+    begin++;
+  }
+  size_t len = strlen(begin);
+  char *end = begin + len;
+  while (end > begin && isspace(*end)) {
+    end++;
+  }
+
+  memmove(str, begin, end - begin + 1);
+}
+
+VMMapping* parse_vmmap (int pid)
+{
+  char fmaps_path[128];
+  sprintf(fmaps_path, "/proc/%d/maps", pid);
+  FILE *fmaps;
+
+  if ((fmaps = fopen(fmaps_path, "r")) == NULL) {
+    perror("fopen");
+    exit(1);
+  }
+
+  uint64_t begin, end;
+  char perms[16];
+  char filename[1024];
+  VMMapping *head = NULL;
+  VMMapping *cur = NULL;
+
+  while(
+    fscanf(fmaps, "%lx-%lx %15s %*x %*x:%*x %*u%1023[^\n]",
+           &begin, &end, perms, filename) != EOF) {
+    strtrim(filename);
+
+    VMMapping *new_mapping = xmalloc(sizeof(VMMapping));
+    *new_mapping = (VMMapping) {
+      .begin = begin,
+      .end = end,
+      .r = perms[0] == 'r',
+      .w = perms[1] == 'w',
+      .x = perms[2] == 'x',
+      .s = perms[3] == 's',
+      .p = perms[3] == 'p',
+      .name = strdup(filename),
+      .next = NULL,
+    };
+
+    if (head) {
+      cur->next = new_mapping;
+      cur = new_mapping;
+    } else {
+      head = cur = new_mapping;
+    }
+
+    LOG("%lx-%lx %c%c%c%c %s\n",
+        cur->begin,
+        cur->end,
+        cur->r ? 'r' : '-',
+        cur->w ? 'w' : '-',
+        cur->x ? 'x' : '-',
+        cur->s ? 's' : 'p',
+        cur->name);
+  }
+
+  return head;
+}