[binutils-gdb] Throw NOT_AVAILABLE_ERROR in read_stack and read_code

[Yao Qi <qiyao at sourceware dot org>]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=edf689f02787121a49ea0e36cfaa051b06852c8b

commit edf689f02787121a49ea0e36cfaa051b06852c8b
Author: Yao Qi <yao.qi@linaro.org>
Date:   Wed May 4 15:04:01 2016 +0100

    Throw NOT_AVAILABLE_ERROR in read_stack and read_code
    
    Nowadays, read_memory may throw NOT_AVAILABLE_ERROR (it is done by
    patch http://sourceware.org/ml/gdb-patches/2013-08/msg00625.html)
    however, read_stack and read_code still throws MEMORY_ERROR only.  This
    causes PR 19947, that is prologue unwinder is unable unwind because
    code memory isn't available, but MEMORY_ERROR is thrown, while unwinder
    catches NOT_AVAILABLE_ERROR.
    
     #0  memory_error (err=err@entry=TARGET_XFER_E_IO, memaddr=memaddr@entry=140737349781158) at /home/yao/SourceCode/gnu/gdb/git/gdb/corefile.c:217
     #1  0x000000000065f5ba in read_code (memaddr=memaddr@entry=140737349781158, myaddr=myaddr@entry=0x7fffffffd7b0 "\340\023<\001", len=len@entry=1)
         at /home/yao/SourceCode/gnu/gdb/git/gdb/corefile.c:288
     #2  0x000000000065f7b5 in read_code_unsigned_integer (memaddr=memaddr@entry=140737349781158, len=len@entry=1, byte_order=byte_order@entry=BFD_ENDIAN_LITTLE)
         at /home/yao/SourceCode/gnu/gdb/git/gdb/corefile.c:363
     #3  0x00000000004717e0 in amd64_analyze_prologue (gdbarch=gdbarch@entry=0x13c13e0, pc=140737349781158, current_pc=140737349781165, cache=cache@entry=0xda0cb0)
         at /home/yao/SourceCode/gnu/gdb/git/gdb/amd64-tdep.c:2267
     #4  0x0000000000471f6d in amd64_frame_cache_1 (cache=0xda0cb0, this_frame=0xda0bf0) at /home/yao/SourceCode/gnu/gdb/git/gdb/amd64-tdep.c:2437
     #5  amd64_frame_cache (this_frame=0xda0bf0, this_cache=<optimised out>) at /home/yao/SourceCode/gnu/gdb/git/gdb/amd64-tdep.c:2508
     #6  0x000000000047214d in amd64_frame_this_id (this_frame=<optimised out>, this_cache=<optimised out>, this_id=0xda0c50)
         at /home/yao/SourceCode/gnu/gdb/git/gdb/amd64-tdep.c:2541
     #7  0x00000000006b94c4 in compute_frame_id (fi=0xda0bf0) at /home/yao/SourceCode/gnu/gdb/git/gdb/frame.c:481
     #8  get_prev_frame_if_no_cycle (this_frame=this_frame@entry=0xda0b20) at /home/yao/SourceCode/gnu/gdb/git/gdb/frame.c:1809
     #9  0x00000000006bb6c9 in get_prev_frame_always_1 (this_frame=0xda0b20) at /home/yao/SourceCode/gnu/gdb/git/gdb/frame.c:1983
     #10 get_prev_frame_always (this_frame=this_frame@entry=0xda0b20) at /home/yao/SourceCode/gnu/gdb/git/gdb/frame.c:1999
     #11 0x00000000006bbe11 in get_prev_frame (this_frame=this_frame@entry=0xda0b20) at /home/yao/SourceCode/gnu/gdb/git/gdb/frame.c:2241
     #12 0x00000000006bc13c in unwind_to_current_frame (ui_out=<optimised out>, args=args@entry=0xda0b20) at /home/yao/SourceCode/gnu/gdb/git/gdb/frame.c:1485
    
    The fix is to let read_stack and read_code throw NOT_AVAILABLE_ERROR too,
    in order to align with read_memory.
    
    gdb:
    
    2016-05-04  Yao Qi  <yao.qi@linaro.org>
    
    	PR gdb/19947
    	* corefile.c (read_memory): Rename it to ...
    	(read_memory_object): ... it.  Add parameter object.
    	(read_memory): Call read_memory_object.
    	(read_stack): Likewise.
    	(read_code): Likewise.

Diff:
---
 gdb/ChangeLog  |  9 +++++++++
 gdb/corefile.c | 29 +++++++++++++++--------------
 2 files changed, 24 insertions(+), 14 deletions(-)

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index faf2304..8f1b4a4 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,12 @@
+2016-05-04  Yao Qi  <yao.qi@linaro.org>
+
+	PR gdb/19947
+	* corefile.c (read_memory): Rename it to ...
+	(read_memory_object): ... it.  Add parameter object.
+	(read_memory): Call read_memory_object.
+	(read_stack): Likewise.
+	(read_code): Likewise.
+
 2016-05-03  Yunlian Jiang <yunlian@google.com>
 	    Doug Evans  <dje@google.com>
 
diff --git a/gdb/corefile.c b/gdb/corefile.c
index 5ad4d40..6cc2afc 100644
--- a/gdb/corefile.c
+++ b/gdb/corefile.c
@@ -237,10 +237,11 @@ memory_error (enum target_xfer_status err, CORE_ADDR memaddr)
   throw_error (exception, ("%s"), str);
 }
 
-/* Same as target_read_memory, but report an error if can't read.  */
+/* Helper function.  */
 
-void
-read_memory (CORE_ADDR memaddr, gdb_byte *myaddr, ssize_t len)
+static void
+read_memory_object (enum target_object object, CORE_ADDR memaddr,
+		    gdb_byte *myaddr, ssize_t len)
 {
   ULONGEST xfered = 0;
 
@@ -250,7 +251,7 @@ read_memory (CORE_ADDR memaddr, gdb_byte *myaddr, ssize_t len)
       ULONGEST xfered_len;
 
       status = target_xfer_partial (current_target.beneath,
-				    TARGET_OBJECT_MEMORY, NULL,
+				    object, NULL,
 				    myaddr + xfered, NULL,
 				    memaddr + xfered, len - xfered,
 				    &xfered_len);
@@ -264,16 +265,20 @@ read_memory (CORE_ADDR memaddr, gdb_byte *myaddr, ssize_t len)
     }
 }
 
+/* Same as target_read_memory, but report an error if can't read.  */
+
+void
+read_memory (CORE_ADDR memaddr, gdb_byte *myaddr, ssize_t len)
+{
+  read_memory_object (TARGET_OBJECT_MEMORY, memaddr, myaddr, len);
+}
+
 /* Same as target_read_stack, but report an error if can't read.  */
 
 void
 read_stack (CORE_ADDR memaddr, gdb_byte *myaddr, ssize_t len)
 {
-  int status;
-
-  status = target_read_stack (memaddr, myaddr, len);
-  if (status != 0)
-    memory_error (TARGET_XFER_E_IO, memaddr);
+  read_memory_object (TARGET_OBJECT_STACK_MEMORY, memaddr, myaddr, len);
 }
 
 /* Same as target_read_code, but report an error if can't read.  */
@@ -281,11 +286,7 @@ read_stack (CORE_ADDR memaddr, gdb_byte *myaddr, ssize_t len)
 void
 read_code (CORE_ADDR memaddr, gdb_byte *myaddr, ssize_t len)
 {
-  int status;
-
-  status = target_read_code (memaddr, myaddr, len);
-  if (status != 0)
-    memory_error (TARGET_XFER_E_IO, memaddr);
+  read_memory_object (TARGET_OBJECT_CODE_MEMORY, memaddr, myaddr, len);
 }
 
 /* Read memory at MEMADDR of length LEN and put the contents in