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Date:      Wed, 20 Feb 2019 20:17:55 +0000 (UTC)
From:      Dimitry Andric <dim@FreeBSD.org>
To:        src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org
Subject:   svn commit: r344381 - head/usr.bin/top
Message-ID:  <201902202017.x1KKHtGZ062412@repo.freebsd.org>
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Author: dim
Date: Wed Feb 20 20:17:54 2019
New Revision: 344381
URL: https://svnweb.freebsd.org/changeset/base/344381

Log:
  Fix more AddressSanitizer violations in usr.bin/top
  
  In line_update(), set lastcol correctly after moving to any non-zero
  column, so the "overwrite old stuff" part does not attempt to address
  negative offsets in the current line.
  
  Rewrite setup_buffer() to always allocate at least 80 characters,
  otherwise various calls to summary_format() will overwrite the end of
  the buffers, if the screen width gets small enough.
  
  MFC after:	1 week

Modified:
  head/usr.bin/top/display.c

Modified: head/usr.bin/top/display.c
==============================================================================
--- head/usr.bin/top/display.c	Wed Feb 20 20:09:59 2019	(r344380)
+++ head/usr.bin/top/display.c	Wed Feb 20 20:17:54 2019	(r344381)
@@ -378,13 +378,13 @@ u_procstates(int total, int *brkdn)
     if (ltotal != total)
     {
 	/* move and overwrite */
-if (x_procstate == 0) {
-	Move_to(x_procstate, y_procstate);
-}
-else {
-	/* cursor is already there...no motion needed */
-	assert(lastline == 1);
-}
+	if (x_procstate == 0) {
+	    Move_to(x_procstate, y_procstate);
+	}
+	else {
+	    /* cursor is already there...no motion needed */
+	    assert(lastline == 1);
+	}
 	printf("%d", total);
 
 	/* if number of digits differs, rewrite the label */
@@ -1205,7 +1205,7 @@ line_update(char *old, char *new, int start, int line)
 	cursor_on_line = true;
 	putchar(ch);
 	*old = ch;
-	lastcol = 1;
+	lastcol = start + 1;
     }
     old++;
 
@@ -1341,33 +1341,27 @@ i_uptime(struct timeval *bt, time_t *tod)
     }
 }
 
+#define SETUPBUFFER_MIN_SCREENWIDTH 80
 #define SETUPBUFFER_REQUIRED_ADDBUFSIZ 2
 
 static char *
 setup_buffer(char *buffer, int addlen)
 {
-	char *b = NULL;
+    size_t len;
 
-	if (NULL == buffer) {
-		setup_buffer_bufsiz = screen_width;
-		b = calloc(setup_buffer_bufsiz + addlen +
-				SETUPBUFFER_REQUIRED_ADDBUFSIZ,
-				sizeof(char));
-	} else {
-		if (screen_width > setup_buffer_bufsiz) {
-			setup_buffer_bufsiz = screen_width;
-			free(buffer);
-			b = calloc(setup_buffer_bufsiz + addlen +
-					SETUPBUFFER_REQUIRED_ADDBUFSIZ,
-					sizeof(char));
-		} else {
-			b = buffer;
-		}	
-	}
+    setup_buffer_bufsiz = screen_width;
+    if (setup_buffer_bufsiz < SETUPBUFFER_MIN_SCREENWIDTH)
+    {
+	setup_buffer_bufsiz = SETUPBUFFER_MIN_SCREENWIDTH;
+    }
 
-	if (NULL == b) {
-		errx(4, "can't allocate sufficient memory");
-	}
+    free(buffer);
+    len = setup_buffer_bufsiz + addlen + SETUPBUFFER_REQUIRED_ADDBUFSIZ;
+    buffer = calloc(len, sizeof(char));
+    if (buffer == NULL)
+    {
+	errx(4, "can't allocate sufficient memory");
+    }
 
-	return b;
+    return buffer;
 }

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