[Bug gdb/10783] New: search_simple_memory miscalculates its read address for multiple search chunks

[Bug gdb/10783] New: search_simple_memory miscalculates its read address for multiple search chunks

[chris at cmears dot id dot au]

The search_simple_memory function in gdb/target.c has an error that leads to
incorrect reporting of found patterns.  The problem occurs only when the search
space length is larger than the chunk size.  I believe the cause is a simple
mixup of variables.

I think the following change should fix it.

--- orig/gdb-7.0/gdb/target.c	2009-09-16 02:16:40.000000000 +1000
+++ fixed/gdb-7.0/gdb/target.c	2009-10-16 02:10:35.000000000 +1100
@@ -2302,7 +2302,7 @@ simple_search_memory (struct target_ops 
       if (search_space_len >= pattern_len)
 	{
 	  unsigned keep_len = search_buf_size - chunk_size;
-	  CORE_ADDR read_addr = start_addr + keep_len;
+	  CORE_ADDR read_addr = start_addr + chunk_size;
 	  int nr_to_read;
 
 	  /* Copy the trailing part of the previous iteration to the front

-- 
           Summary: search_simple_memory miscalculates its read address for
                    multiple search chunks
           Product: gdb
           Version: 7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: gdb
        AssignedTo: unassigned at sourceware dot org
        ReportedBy: chris at cmears dot id dot au
                CC: gdb-prs at sourceware dot org


http://sourceware.org/bugzilla/show_bug.cgi?id=10783

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[Bug gdb/10783] search_simple_memory miscalculates its read address for multiple search chunks

[pedro at codesourcery dot com]

------- Additional Comments From pedro at codesourcery dot com  2009-10-15 15:45 -------
Thanks.  Pasting here the example you showed on IRC:

(gdb) find /b 0xcaa6000, 0x0caa7000, 'B', 'u', 'r', 'n', 'e', 'r'
0xcaa6324    <--- this one is correct
1 pattern found.
(gdb) find /b 0xbaa6000, 0x0caa7000, 'B', 'u', 'r', 'n', 'e', 'r'
              ^^^^^^^^^--- lowered the start address
0xc9197d2   \
0xc91985c    \_ no mention of 0xcaa6324 anymore ):
0xc91993c    /
0xca98fac   /  
4 patterns found.

-- 


http://sourceware.org/bugzilla/show_bug.cgi?id=10783

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[Bug gdb/10783] search_simple_memory miscalculates its read address for multiple search chunks

[cvs-commit at gcc dot gnu dot org]

------- Additional Comments From cvs-commit at gcc dot gnu dot org  2009-10-29 20:12 -------
Subject: Bug 10783

CVSROOT:	/cvs/src
Module name:	src
Changes by:	sandra@sourceware.org	2009-10-29 20:12:26

Modified files:
	gdb            : ChangeLog target.c 
	gdb/gdbserver  : ChangeLog server.c 

Log message:
	2009-10-29  Sandra Loosemore  <sandra@codesourcery.com>
	
	PR gdb/10783
	
	gdb/
	* target.c (simple_search_memory): Correct read_addr initialization
	in loop for searching subsequent chunks.
	
	gdb/gdbserver/
	* server.c (handle_search_memory_1): Correct read_addr initialization
	in loop for searching subsequent chunks.

Patches:
http://sources.redhat.com/cgi-bin/cvsweb.cgi/src/gdb/ChangeLog.diff?cvsroot=src&r1=1.11014&r2=1.11015
http://sources.redhat.com/cgi-bin/cvsweb.cgi/src/gdb/target.c.diff?cvsroot=src&r1=1.230&r2=1.231
http://sources.redhat.com/cgi-bin/cvsweb.cgi/src/gdb/gdbserver/ChangeLog.diff?cvsroot=src&r1=1.294&r2=1.295
http://sources.redhat.com/cgi-bin/cvsweb.cgi/src/gdb/gdbserver/server.c.diff?cvsroot=src&r1=1.103&r2=1.104



-- 


http://sourceware.org/bugzilla/show_bug.cgi?id=10783

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[Bug gdb/10783] search_simple_memory miscalculates its read address for multiple search chunks

[sandra at codesourcery dot com]

------- Additional Comments From sandra at codesourcery dot com  2009-10-29 20:15 -------
I've checked in the patch attached to this message.  As noted, the bug was also
present in the target-side gdbserver logic.

http://sourceware.org/ml/gdb-patches/2009-10/msg00691.html

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
         Resolution|                            |FIXED


http://sourceware.org/bugzilla/show_bug.cgi?id=10783

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