From: Maciej W. Rozycki <macro@linux-mips.org>
Date: Tue, 22 May 2012 23:17:51 +0000 (+0000)
Subject: 	* linux-low.c (linux_store_registers): Avoid the copying sequence
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=8d409d16dd8660cfca6c32f3feed3eca36d55c20;p=binutils-gdb.git

	* linux-low.c (linux_store_registers): Avoid the copying sequence
	when no data has been retrieved by ptrace.
---

diff --git a/gdb/gdbserver/ChangeLog b/gdb/gdbserver/ChangeLog
index 5017bc600f5..1976a42efdd 100644
--- a/gdb/gdbserver/ChangeLog
+++ b/gdb/gdbserver/ChangeLog
@@ -1,3 +1,8 @@
+2012-05-22  Maciej W. Rozycki  <macro@codesourcery.com>
+
+	* linux-low.c (linux_store_registers): Avoid the copying sequence
+	when no data has been retrieved by ptrace.
+
 2012-05-22  Will Deacon  <will.deacon@arm.com>
 
 	* linux-low (__UCLIBC__ && !(__UCLIBC_HAS_MMU__ || __ARCH_HAS_MMU__)):
diff --git a/gdb/gdbserver/linux-low.c b/gdb/gdbserver/linux-low.c
index 19f7be64170..5fe19fdf72c 100644
--- a/gdb/gdbserver/linux-low.c
+++ b/gdb/gdbserver/linux-low.c
@@ -4449,11 +4449,14 @@ linux_read_memory (CORE_ADDR memaddr, unsigned char *myaddr, int len)
   ret = errno;
 
   /* Copy appropriate bytes out of the buffer.  */
-  i *= sizeof (PTRACE_XFER_TYPE);
-  i -= memaddr & (sizeof (PTRACE_XFER_TYPE) - 1);
-  memcpy (myaddr,
-	  (char *) buffer + (memaddr & (sizeof (PTRACE_XFER_TYPE) - 1)),
-	  i < len ? i : len);
+  if (i > 0)
+    {
+      i *= sizeof (PTRACE_XFER_TYPE);
+      i -= memaddr & (sizeof (PTRACE_XFER_TYPE) - 1);
+      memcpy (myaddr,
+	      (char *) buffer + (memaddr & (sizeof (PTRACE_XFER_TYPE) - 1)),
+	      i < len ? i : len);
+    }
 
   return ret;
 }