runtime: print pkey of target memory range for forbidden operations

runtime/memory-map/src/lib.rs

@@ -337,6 +337,28 @@ pub extern "C" fn memory_map_region_get_prot(map: &MemoryMap, needle: Range) ->
 /** memory_map_region_get_prot found no or multiple protections in the given range */
 pub const PROT_INDETERMINATE: u32 = 0xFFFFFFFFu32;
 
+const PKEY_MULTIPLE: u8 = 255;
+const PKEY_NONE: u8 = 254;
+
+/// return the pkey (0-15) that covers the given range, or PKEY_MULTIPLE or
+/// PKEY_NONE if the entire range is not protected by exactly one pkey
+#[no_mangle]
+pub extern "C" fn memory_map_region_get_owner_pkey(map: &MemoryMap, needle: Range) -> u8 {
+    let mut pkey = None;
+    let same = map.all_overlapping_regions(needle, |region| match pkey {
+        None => {
+            pkey = Some(region.state.owner_pkey);
+            true
+        }
+        Some(pkey) => region.state.owner_pkey == pkey,
+    });
+    if same {
+        pkey.unwrap_or(PKEY_NONE) // all same (return pkey) or no pkey
+    } else {
+        PKEY_MULTIPLE // multiple pkeys
+    }
+}
+
 #[no_mangle]
 pub extern "C" fn memory_map_unmap_region(map: &mut MemoryMap, needle: Range) -> bool {
     map.split_out_region(needle).is_some()

runtime/memory_map.h

@@ -43,6 +43,8 @@ bool memory_map_all_overlapping_regions_mprotected(const struct memory_map *map,
 
 uint32_t memory_map_region_get_prot(const struct memory_map *map, struct range needle);
 
+uint8_t memory_map_region_get_owner_pkey(const struct memory_map *map, struct range needle);
+
 bool memory_map_unmap_region(struct memory_map *map, struct range needle);
 
 bool memory_map_add_region(struct memory_map *map,

runtime/mmap_event.h

@@ -78,4 +78,28 @@ static const char *event_name(enum mmap_event event) {
   return event_names[event];
 }
 
+static inline const struct range *event_target_range(enum mmap_event event, const union event_info *info) {
+  switch (event) {
+  case EVENT_MMAP:
+    return &info->mmap.range;
+  case EVENT_MUNMAP:
+    return &info->munmap.range;
+  case EVENT_MREMAP:
+    return &info->mremap.old_range;
+  case EVENT_MADVISE:
+    return &info->madvise.range;
+  case EVENT_MPROTECT:
+    return &info->mprotect.range;
+  case EVENT_PKEY_MPROTECT:
+    return &info->pkey_mprotect.range;
+  case EVENT_CLONE:
+    return NULL;
+  case EVENT_EXEC:
+    return NULL;
+  case EVENT_NONE:
+    return NULL;
+    break;
+  }
+}
+
 enum mmap_event event_from_syscall(uint64_t rax);

runtime/track_memory_map.c

@@ -839,6 +839,10 @@ bool track_memory_map(pid_t pid, int *exit_status_out, enum trace_mode mode) {
     } else if (!is_op_permitted(map, event, &event_info)) {
       fprintf(stderr, "forbidden operation requested: ");
       print_event(event, &event_info);
+      const struct range *range = event_target_range(event, &event_info);
+      if (range != NULL) {
+        printf("region pkey: %d\n", memory_map_region_get_owner_pkey(map, *range));
+      }
       return_syscall_eperm(waited_pid);
       if (ptrace(continue_request, waited_pid, 0, 0) < 0) {
         perror("could not PTRACE_SYSCALL");