From 539b54f03dd082c572308246e610e516ff96b5b1 Mon Sep 17 00:00:00 2001 From: Alan Modra Date: Fri, 18 Jun 2021 18:24:43 +0930 Subject: [PATCH] dwarf.c: string_fortify.h strncpy error In function 'strncpy', inlined from 'display_debug_lines_decoded' at /home/alan/src/binutils-gdb/binutils/dwarf.c:5434:5, inlined from 'display_debug_lines' at /home/alan/src/binutils-gdb/binutils/dwarf.c:5567:21: /usr/include/bits/string_fortified.h:95:10: error: '__builtin_strncpy' specified bound 36 equals destination size [-Werror=stringop-truncation] No need for strncpy here, the string being copied always fits the destination buffer. * dwarf.c (display_debug_lines_decoded): Use memcpy rather than strncpy when trimming file name length to MAX_FILENAME_LENGTH. Don't make an unnecessary copy when length is good. --- binutils/ChangeLog | 6 ++++++ binutils/dwarf.c | 24 ++++++++---------------- 2 files changed, 14 insertions(+), 16 deletions(-) diff --git a/binutils/ChangeLog b/binutils/ChangeLog index 125dd2e1a31..c6a05ca6b3e 100644 --- a/binutils/ChangeLog +++ b/binutils/ChangeLog @@ -1,3 +1,9 @@ +2021-06-19 Alan Modra + + * dwarf.c (display_debug_lines_decoded): Use memcpy rather than + strncpy when trimming file name length to MAX_FILENAME_LENGTH. + Don't make an unnecessary copy when length is good. + 2021-06-18 H.J. Lu * readelf.c (print_gnu_property_note): Handle diff --git a/binutils/dwarf.c b/binutils/dwarf.c index ebc7b023e3b..a57f0dab6b2 100644 --- a/binutils/dwarf.c +++ b/binutils/dwarf.c @@ -5426,31 +5426,22 @@ display_debug_lines_decoded (struct dwarf_section * section, fileName = _(""); fileNameLength = strlen (fileName); - - if ((fileNameLength > MAX_FILENAME_LENGTH) && (!do_wide)) + newFileName = fileName; + if (fileNameLength > MAX_FILENAME_LENGTH && !do_wide) { newFileName = (char *) xmalloc (MAX_FILENAME_LENGTH + 1); /* Truncate file name */ - strncpy (newFileName, - fileName + fileNameLength - MAX_FILENAME_LENGTH, - MAX_FILENAME_LENGTH + 1); - /* FIXME: This is to pacify gcc-10 which can warn that the - strncpy above might leave a non-NUL terminated string - in newFileName. It won't, but gcc's analysis doesn't - quite go far enough to discover this. */ + memcpy (newFileName, + fileName + fileNameLength - MAX_FILENAME_LENGTH, + MAX_FILENAME_LENGTH); newFileName[MAX_FILENAME_LENGTH] = 0; } - else - { - newFileName = (char *) xmalloc (fileNameLength + 1); - strncpy (newFileName, fileName, fileNameLength + 1); - } /* A row with end_seq set to true has a meaningful address, but the other information in the same row is not significant. In such a row, print line as "-", and don't print view/is_stmt. */ - if (!do_wide || (fileNameLength <= MAX_FILENAME_LENGTH)) + if (!do_wide || fileNameLength <= MAX_FILENAME_LENGTH) { if (linfo.li_max_ops_per_insn == 1) { @@ -5525,7 +5516,8 @@ display_debug_lines_decoded (struct dwarf_section * section, putchar ('\n'); } - free (newFileName); + if (newFileName != fileName) + free (newFileName); } } -- 2.30.2