From: Yao Qi <yao.qi@linaro.org>
Date: Tue, 16 Jan 2018 09:05:39 +0000 (+0000)
Subject: Mark register unavailable when PTRACE_PEEKUSER fails
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=9a70f35c8d872bb5542e98e34b8b044228dcb844;p=binutils-gdb.git

Mark register unavailable when PTRACE_PEEKUSER fails

As described in PR 18749, GDB/GDBserver may get an error on accessing
memory or register because the thread may disappear.  However, some
path doesn't expect the error.  This patch fixes this problem by
marking the register unavailable when PTRACE_PEEKUSER fails instead
of throwing error.

gdb/gdbserver:

2018-01-16  Yao Qi  <yao.qi@linaro.org>

	PR gdb/18749
	* linux-low.c (fetch_register): Call supply_register instead of
	error.
---

diff --git a/gdb/gdbserver/ChangeLog b/gdb/gdbserver/ChangeLog
index 32a515728f3..be8c48f0f79 100644
--- a/gdb/gdbserver/ChangeLog
+++ b/gdb/gdbserver/ChangeLog
@@ -1,3 +1,9 @@
+2018-01-16  Yao Qi  <yao.qi@linaro.org>
+
+	PR gdb/18749
+	* linux-low.c (fetch_register): Call supply_register instead of
+	error.
+
 2018-01-08  Yao Qi  <yao.qi@linaro.org>
 	    Simon Marchi  <simon.marchi@ericsson.com>
 
diff --git a/gdb/gdbserver/linux-low.c b/gdb/gdbserver/linux-low.c
index cfb2b56a089..d8e122603cb 100644
--- a/gdb/gdbserver/linux-low.c
+++ b/gdb/gdbserver/linux-low.c
@@ -5555,7 +5555,11 @@ fetch_register (const struct usrregs_info *usrregs,
 		(PTRACE_TYPE_ARG3) (uintptr_t) regaddr, (PTRACE_TYPE_ARG4) 0);
       regaddr += sizeof (PTRACE_XFER_TYPE);
       if (errno != 0)
-	error ("reading register %d: %s", regno, strerror (errno));
+	{
+	  /* Mark register REGNO unavailable.  */
+	  supply_register (regcache, regno, NULL);
+	  return;
+	}
     }
 
   if (the_low_target.supply_ptrace_register)