1 files changed, 98 insertions, 0 deletions
diff --git a/src/third_party/unwind/dist/src/coredump/_UCD_access_mem.c b/src/third_party/unwind/dist/src/coredump/_UCD_access_mem.c
new file mode 100644
index 00000000000..1fdbd128ffc
--- /dev/null
+++ b/src/third_party/unwind/dist/src/coredump/_UCD_access_mem.c
@@ -0,0 +1,98 @@
+/* libunwind - a platform-independent unwind library
+
+This file is part of libunwind.
+
+Permission is hereby granted, free of charge, to any person obtaining
+a copy of this software and associated documentation files (the
+"Software"), to deal in the Software without restriction, including
+without limitation the rights to use, copy, modify, merge, publish,
+distribute, sublicense, and/or sell copies of the Software, and to
+permit persons to whom the Software is furnished to do so, subject to
+the following conditions:
+
+The above copyright notice and this permission notice shall be
+included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.  */
+
+#include "_UCD_lib.h"
+#include "_UCD_internal.h"
+
+int
+_UCD_access_mem(unw_addr_space_t as, unw_word_t addr, unw_word_t *val,
+                 int write, void *arg)
+{
+  if (write)
+    {
+      Debug(0, "write is not supported\n");
+      return -UNW_EINVAL;
+    }
+
+  struct UCD_info *ui = arg;
+
+  unw_word_t addr_last = addr + sizeof(*val)-1;
+  coredump_phdr_t *phdr;
+  unsigned i;
+  for (i = 0; i < ui->phdrs_count; i++)
+    {
+      phdr = &ui->phdrs[i];
+      if (phdr->p_vaddr <= addr && addr_last < phdr->p_vaddr + phdr->p_memsz)
+        {
+          goto found;
+        }
+    }
+  Debug(1, "addr 0x%llx is unmapped\n", (unsigned long long)addr);
+  return -UNW_EINVAL;
+
+ found: ;
+
+  const char *filename UNUSED;
+  off_t fileofs;
+  int fd;
+  if (addr_last >= phdr->p_vaddr + phdr->p_filesz)
+    {
+      /* This part of mapped address space is not present in coredump file */
+      /* Do we have it in the backup file? */
+      if (phdr->backing_fd < 0)
+        {
+          Debug(1, "access to not-present data in phdr[%d]: addr:0x%llx\n",
+                                i, (unsigned long long)addr
+                        );
+          return -UNW_EINVAL;
+        }
+      filename = phdr->backing_filename;
+      fileofs = addr - phdr->p_vaddr;
+      fd = phdr->backing_fd;
+      goto read;
+    }
+
+  filename = ui->coredump_filename;
+  fileofs = phdr->p_offset + (addr - phdr->p_vaddr);
+  fd = ui->coredump_fd;
+ read:
+  if (lseek(fd, fileofs, SEEK_SET) != fileofs)
+    goto read_error;
+  if (read(fd, val, sizeof(*val)) != sizeof(*val))
+    goto read_error;
+
+  Debug(1, "0x%llx <- [addr:0x%llx fileofs:0x%llx]\n",
+        (unsigned long long)(*val),
+        (unsigned long long)addr,
+        (unsigned long long)fileofs
+  );
+  return 0;
+
+ read_error:
+  Debug(1, "access out of file: addr:0x%llx fileofs:%llx file:'%s'\n",
+        (unsigned long long)addr,
+        (unsigned long long)fileofs,
+        filename
+  );
+  return -UNW_EINVAL;
+}