Use safe_strerror instead of strerror where possible

This provides threadsafety. Unfortunately, since libinproctrace.so
does not link to gnulib, we can't use it there, especially since it
still includes the gnulib headers (so it is difficult to directly
call the system strerror_r).

gdb/ChangeLog:

2019-11-26  Christian Biesinger  <cbiesinger@google.com>

	* linux-nat.c (detach_one_lwp): Call safe_strerror instead of
	strerror.
	* nto-procfs.c (nto_procfs_target::create_inferior): Likewise.
	* windows-nat.c (windows_nat_target::create_inferior): Likewise.

gdb/gdbserver/ChangeLog:

2019-11-26  Christian Biesinger  <cbiesinger@google.com>

	* debug.c (debug_set_output): Call safe_strerror instead of
	strerror.
	* linux-low.c (attach_proc_task_lwp_callback): Likewise.
	(linux_kill_one_lwp): Likewise.
	(linux_detach_one_lwp): Likewise.
	(linux_wait_for_event_filtered): Likewise.
	(store_register): Likewise.
	* lynx-low.c (lynx_attach): Likewise.
	* mem-break.c (insert_memory_breakpoint): Likewise.
	(remove_memory_breakpoint): Likewise.
	(delete_fast_tracepoint_jump): Likewise.
	(set_fast_tracepoint_jump): Likewise.
	(uninsert_fast_tracepoint_jumps_at): Likewise.
	(reinsert_fast_tracepoint_jumps_at): Likewise.
	* nto-low.c (nto_xfer_memory): Likewise.
	(nto_resume): Likewise.

Change-Id: I9e259cdcaa6e11bbcc4ee6bdc5b7127d73e11abe

6 files changed, 38 insertions, 19 deletions

diff --git a/gdb/gdbserver/ChangeLog b/gdb/gdbserver/ChangeLog
index a5da6b5..7b22cfd 100644
--- a/gdb/gdbserver/ChangeLog
+++ b/gdb/gdbserver/ChangeLog
@@ -1,3 +1,22 @@
+2019-11-26  Christian Biesinger  <cbiesinger@google.com>
+
+	* debug.c (debug_set_output): Call safe_strerror instead of
+	strerror.
+	* linux-low.c (attach_proc_task_lwp_callback): Likewise.
+	(linux_kill_one_lwp): Likewise.
+	(linux_detach_one_lwp): Likewise.
+	(linux_wait_for_event_filtered): Likewise.
+	(store_register): Likewise.
+	* lynx-low.c (lynx_attach): Likewise.
+	* mem-break.c (insert_memory_breakpoint): Likewise.
+	(remove_memory_breakpoint): Likewise.
+	(delete_fast_tracepoint_jump): Likewise.
+	(set_fast_tracepoint_jump): Likewise.
+	(uninsert_fast_tracepoint_jumps_at): Likewise.
+	(reinsert_fast_tracepoint_jumps_at): Likewise.
+	* nto-low.c (nto_xfer_memory): Likewise.
+	(nto_resume): Likewise.
+
 2019-11-20  Luis Machado  <luis.machado@linaro.org>
 
 	* linux-aarch64-low.c (is_sve_tdesc): Check against target feature
diff --git a/gdb/gdbserver/debug.c b/gdb/gdbserver/debug.c
index a764df7..d299b93 100644
--- a/gdb/gdbserver/debug.c
+++ b/gdb/gdbserver/debug.c
@@ -55,7 +55,7 @@ debug_set_output (const char *new_debug_file)
   if (fptr == nullptr)
     {
       debug_printf ("Cannot open %s for writing. %s. Switching to stderr.\n",
-		    new_debug_file, strerror (errno));
+		    new_debug_file, safe_strerror (errno));
       return;
     }
 
diff --git a/gdb/gdbserver/linux-low.c b/gdb/gdbserver/linux-low.c
index d6b6ce7..f34811c 100644
--- a/gdb/gdbserver/linux-low.c
+++ b/gdb/gdbserver/linux-low.c
@@ -1159,7 +1159,7 @@ attach_proc_task_lwp_callback (ptid_t ptid)
 	    {
 	      debug_printf ("Cannot attach to lwp %d: "
 			    "thread is gone (%d: %s)\n",
-			    lwpid, err, strerror (err));
+			    lwpid, err, safe_strerror (err));
 	    }
 	}
       else if (err != 0)
@@ -1303,7 +1303,7 @@ linux_kill_one_lwp (struct lwp_info *lwp)
 
       debug_printf ("LKL:  kill_lwp (SIGKILL) %s, 0, 0 (%s)\n",
 		    target_pid_to_str (ptid_of (thr)),
-		    save_errno ? strerror (save_errno) : "OK");
+		    save_errno ? safe_strerror (save_errno) : "OK");
     }
 
   errno = 0;
@@ -1314,7 +1314,7 @@ linux_kill_one_lwp (struct lwp_info *lwp)
 
       debug_printf ("LKL:  PTRACE_KILL %s, 0, 0 (%s)\n",
 		    target_pid_to_str (ptid_of (thr)),
-		    save_errno ? strerror (save_errno) : "OK");
+		    save_errno ? safe_strerror (save_errno) : "OK");
     }
 }
 
@@ -1560,7 +1560,7 @@ linux_detach_one_lwp (struct lwp_info *lwp)
 	  if (ret == -1)
 	    {
 	      warning (_("Couldn't reap LWP %d while detaching: %s"),
-		       lwpid, strerror (errno));
+		       lwpid, safe_strerror (errno));
 	    }
 	  else if (!WIFEXITED (status) && !WIFSIGNALED (status))
 	    {
@@ -1573,7 +1573,7 @@ linux_detach_one_lwp (struct lwp_info *lwp)
 	{
 	  error (_("Can't detach %s: %s"),
 		 target_pid_to_str (ptid_of (thread)),
-		 strerror (save_errno));
+		 safe_strerror (save_errno));
 	}
     }
   else if (debug_threads)
@@ -2715,7 +2715,7 @@ linux_wait_for_event_filtered (ptid_t wait_ptid, ptid_t filter_ptid,
 
       if (debug_threads)
 	debug_printf ("LWFE: waitpid(-1, ...) returned %d, %s\n",
-		      ret, errno ? strerror (errno) : "ERRNO-OK");
+		      ret, errno ? safe_strerror (errno) : "ERRNO-OK");
 
       if (ret > 0)
 	{
@@ -5593,7 +5593,7 @@ store_register (const struct usrregs_info *usrregs,
 	    return;
 
 	  if ((*the_low_target.cannot_store_register) (regno) == 0)
-	    error ("writing register %d: %s", regno, strerror (errno));
+	    error ("writing register %d: %s", regno, safe_strerror (errno));
 	}
       regaddr += sizeof (PTRACE_XFER_TYPE);
     }
diff --git a/gdb/gdbserver/lynx-low.c b/gdb/gdbserver/lynx-low.c
index 2bd24e7..dd4cdd8 100644
--- a/gdb/gdbserver/lynx-low.c
+++ b/gdb/gdbserver/lynx-low.c
@@ -316,7 +316,7 @@ lynx_attach (unsigned long pid)
 
   if (lynx_ptrace (PTRACE_ATTACH, ptid, 0, 0, 0) != 0)
     error ("Cannot attach to process %lu: %s (%d)\n", pid,
-	   strerror (errno), errno);
+	   safe_strerror (errno), errno);
 
   lynx_add_process (pid, 1);
   lynx_add_threads_after_attach (pid);
diff --git a/gdb/gdbserver/mem-break.c b/gdb/gdbserver/mem-break.c
index 582fcac..e943915 100644
--- a/gdb/gdbserver/mem-break.c
+++ b/gdb/gdbserver/mem-break.c
@@ -374,7 +374,7 @@ insert_memory_breakpoint (struct raw_breakpoint *bp)
       if (debug_threads)
 	debug_printf ("Failed to read shadow memory of"
 		      " breakpoint at 0x%s (%s).\n",
-		      paddress (bp->pc), strerror (err));
+		      paddress (bp->pc), safe_strerror (err));
     }
   else
     {
@@ -386,7 +386,7 @@ insert_memory_breakpoint (struct raw_breakpoint *bp)
 	{
 	  if (debug_threads)
 	    debug_printf ("Failed to insert breakpoint at 0x%s (%s).\n",
-			  paddress (bp->pc), strerror (err));
+			  paddress (bp->pc), safe_strerror (err));
 	}
     }
   return err != 0 ? -1 : 0;
@@ -415,7 +415,7 @@ remove_memory_breakpoint (struct raw_breakpoint *bp)
       if (debug_threads)
 	debug_printf ("Failed to uninsert raw breakpoint "
 		      "at 0x%s (%s) while deleting it.\n",
-		      paddress (bp->pc), strerror (err));
+		      paddress (bp->pc), safe_strerror (err));
     }
   return err != 0 ? -1 : 0;
 }
@@ -597,7 +597,7 @@ delete_fast_tracepoint_jump (struct fast_tracepoint_jump *todel)
 		  if (debug_threads)
 		    debug_printf ("Failed to uninsert fast tracepoint jump "
 				  "at 0x%s (%s) while deleting it.\n",
-				  paddress (bp->pc), strerror (ret));
+				  paddress (bp->pc), safe_strerror (ret));
 		  return ret;
 		}
 
@@ -660,7 +660,7 @@ set_fast_tracepoint_jump (CORE_ADDR where,
       if (debug_threads)
 	debug_printf ("Failed to read shadow memory of"
 		      " fast tracepoint at 0x%s (%s).\n",
-		      paddress (where), strerror (err));
+		      paddress (where), safe_strerror (err));
       free (jp);
       return NULL;
     }
@@ -684,7 +684,7 @@ set_fast_tracepoint_jump (CORE_ADDR where,
     {
       if (debug_threads)
 	debug_printf ("Failed to insert fast tracepoint jump at 0x%s (%s).\n",
-		      paddress (where), strerror (err));
+		      paddress (where), safe_strerror (err));
 
       /* Unlink it.  */
       proc->fast_tracepoint_jumps = jp->next;
@@ -739,7 +739,7 @@ uninsert_fast_tracepoint_jumps_at (CORE_ADDR pc)
 	  if (debug_threads)
 	    debug_printf ("Failed to uninsert fast tracepoint jump at"
 			  " 0x%s (%s).\n",
-			  paddress (pc), strerror (err));
+			  paddress (pc), safe_strerror (err));
 	}
     }
 }
@@ -786,7 +786,7 @@ reinsert_fast_tracepoint_jumps_at (CORE_ADDR where)
       if (debug_threads)
 	debug_printf ("Failed to reinsert fast tracepoint jump at"
 		      " 0x%s (%s).\n",
-		      paddress (where), strerror (err));
+		      paddress (where), safe_strerror (err));
     }
 }
 
diff --git a/gdb/gdbserver/nto-low.c b/gdb/gdbserver/nto-low.c
index d77fda5..f267a9d 100644
--- a/gdb/gdbserver/nto-low.c
+++ b/gdb/gdbserver/nto-low.c
@@ -247,7 +247,7 @@ nto_xfer_memory (off_t memaddr, unsigned char *myaddr, int len,
   if (nbytes == 0)
     {
       int e = errno;
-      TRACE ("Error in %s : errno=%d (%s)\n", __func__, e, strerror (e));
+      TRACE ("Error in %s : errno=%d (%s)\n", __func__, e, safe_strerror (e));
     }
   return nbytes;
 }
@@ -505,7 +505,7 @@ nto_resume (struct thread_resume *resume_info, size_t n)
 
   err = devctl (nto_inferior.ctl_fd, DCMD_PROC_RUN, &run, sizeof (run), 0);
   if (err != EOK)
-    TRACE ("Error: %d \"%s\"\n", err, strerror (err));
+    TRACE ("Error: %d \"%s\"\n", err, safe_strerror (err));
 }
 
 /* Wait for inferior's event.