libdwfl: linux-core-attach.c handle possible unaligned data access.

Use libdw/memory-access.h macros read_4ubyte_unaligned_noncvt and
read_8ubyte_unaligned_noncvt to access possibly unaligned data in
core files.

Signed-off-by: Mark Wielaard <mjw@redhat.com>

diff --git a/libdwfl/ChangeLog b/libdwfl/ChangeLog
index ac92a219dcb7f25b090745a7ae64e9f77ad5b70f..f1bc1a796094725c1c4d5a9b852ff42bd1421b4c 100644 (file)
--- a/libdwfl/ChangeLog
+++ b/libdwfl/ChangeLog
@@ -1,3 +1,12 @@
+2014-06-15  Mark Wielaard  <mjw@redhat.com>
+
+       * linux-core-attach.c (core_memory_read): Use libdw/memory-access.h
+       macros read_4ubyte_unaligned_noncvt and read_8ubyte_unaligned_noncvt
+       to read possibly unaligned data.
+       (core_next_thread): Likewise.
+       (core_set_initial_registers): Likewise.
+       (dwfl_core_file_attach): Likewise.
+
 2014-06-11  Mark Wielaard  <mjw@redhat.com>
 
        * dwfl_frame.c (__libdwfl_process_free): Reset dwfl->attacherr.

diff --git a/libdwfl/linux-core-attach.c b/libdwfl/linux-core-attach.c
index 7ef3f256073fbd961e8e25509c443895e7ff3770..5a7b3b3daad76d149c7241c817750280106a6353 100644 (file)
--- a/libdwfl/linux-core-attach.c
+++ b/libdwfl/linux-core-attach.c
@@ -30,6 +30,8 @@
 #include <fcntl.h>
 #include "system.h"
 
+#include "../libdw/memory-access.h"
+
 #ifndef MIN
 # define MIN(a, b) ((a) < (b) ? (a) : (b))
 #endif
@@ -83,12 +85,10 @@ core_memory_read (Dwfl *dwfl, Dwarf_Addr addr, Dwarf_Word *result,
          return false;
        }
       assert (data->d_size == bytes);
-      /* FIXME: Currently any arch supported for unwinding supports
-        unaligned access.  */
       if (bytes == 8)
-       *result = *(const uint64_t *) data->d_buf;
+       *result = read_8ubyte_unaligned_noncvt (data->d_buf);
       else
-       *result = *(const uint32_t *) data->d_buf;
+       *result = read_4ubyte_unaligned_noncvt (data->d_buf);
       return true;
     }
   __libdwfl_seterrno (DWFL_E_ADDR_OUTOFRANGE);
@@ -150,7 +150,7 @@ core_next_thread (Dwfl *dwfl __attribute__ ((unused)), void *dwfl_arg,
          break;
       if (item == items + nitems)
        continue;
-      uint32_t val32 = *(const uint32_t *) (desc + item->offset);
+      uint32_t val32 = read_4ubyte_unaligned_noncvt (desc + item->offset);
       val32 = (elf_getident (core, NULL)[EI_DATA] == ELFDATA2MSB
                ? be32toh (val32) : le32toh (val32));
       pid_t tid = (int32_t) val32;
@@ -201,7 +201,7 @@ core_set_initial_registers (Dwfl_Thread *thread, void *thread_arg_voidp)
   assert (item < items + nitems);
   pid_t tid;
   {
-    uint32_t val32 = *(const uint32_t *) (desc + item->offset);
+    uint32_t val32 = read_4ubyte_unaligned_noncvt (desc + item->offset);
     val32 = (elf_getident (core, NULL)[EI_DATA] == ELFDATA2MSB
             ? be32toh (val32) : le32toh (val32));
     tid = (int32_t) val32;
@@ -218,14 +218,14 @@ core_set_initial_registers (Dwfl_Thread *thread, void *thread_arg_voidp)
       switch (gelf_getclass (core) == ELFCLASS32 ? 32 : 64)
       {
        case 32:;
-         uint32_t val32 = *(const uint32_t *) (desc + item->offset);
+         uint32_t val32 = read_4ubyte_unaligned_noncvt (desc + item->offset);
          val32 = (elf_getident (core, NULL)[EI_DATA] == ELFDATA2MSB
                   ? be32toh (val32) : le32toh (val32));
          /* Do a host width conversion.  */
          pc = val32;
          break;
        case 64:;
-         uint64_t val64 = *(const uint64_t *) (desc + item->offset);
+         uint64_t val64 = read_8ubyte_unaligned_noncvt (desc + item->offset);
          val64 = (elf_getident (core, NULL)[EI_DATA] == ELFDATA2MSB
                   ? be64toh (val64) : le64toh (val64));
          pc = val64;
@@ -259,7 +259,7 @@ core_set_initial_registers (Dwfl_Thread *thread, void *thread_arg_voidp)
          switch (regloc->bits)
          {
            case 32:;
-             uint32_t val32 = *(const uint32_t *) reg_desc;
+             uint32_t val32 = read_4ubyte_unaligned_noncvt (reg_desc);
              reg_desc += sizeof val32;
              val32 = (elf_getident (core, NULL)[EI_DATA] == ELFDATA2MSB
                       ? be32toh (val32) : le32toh (val32));
@@ -267,7 +267,7 @@ core_set_initial_registers (Dwfl_Thread *thread, void *thread_arg_voidp)
              val = val32;
              break;
            case 64:;
-             uint64_t val64 = *(const uint64_t *) reg_desc;
+             uint64_t val64 = read_8ubyte_unaligned_noncvt (reg_desc);
              reg_desc += sizeof val64;
              val64 = (elf_getident (core, NULL)[EI_DATA] == ELFDATA2MSB
                       ? be64toh (val64) : le64toh (val64));
@@ -392,7 +392,7 @@ dwfl_core_file_attach (Dwfl *dwfl, Elf *core)
          break;
       if (item == items + nitems)
        continue;
-      uint32_t val32 = *(const uint32_t *) (desc + item->offset);
+      uint32_t val32 = read_4ubyte_unaligned_noncvt (desc + item->offset);
       val32 = (elf_getident (core, NULL)[EI_DATA] == ELFDATA2MSB
                ? be32toh (val32) : le32toh (val32));
       pid = (int32_t) val32;