125 lines
3.4 KiB
Diff
125 lines
3.4 KiB
Diff
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From: Maarten ter Huurne <maarten@treewalker.org>
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Date: Sat, 13 Sep 2014 11:37:59 +0200
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Subject: Do not use memcpy as an alternative for bcopy/memmove
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The configure script runs a small test program to check whether
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memcpy can handle overlapping memory areas. However, it is not valid
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to conclude that if a single case of overlapping memory is handled
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correctly, all cases will be handled correctly.
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Since screen already has its own bcopy implementation as a fallback
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for the case that bcopy and memmove are unusable, removing the memcpy
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option should not break any systems.
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Signed-off-by: Maarten ter Huurne <maarten@treewalker.org>
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[Ricardo: rebase on top of 4.3.1]
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Signed-off-by: Ricardo Martincoski <ricardo.martincoski@gmail.com>
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---
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acconfig.h | 3 +--
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configure.ac | 18 +-----------------
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os.h | 8 ++------
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osdef.h.in | 10 +---------
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4 files changed, 5 insertions(+), 34 deletions(-)
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diff --git a/acconfig.h b/acconfig.h
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index 2e46985..9b0b9d4 100644
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--- a/acconfig.h
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+++ b/acconfig.h
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@@ -476,7 +476,7 @@
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#undef GETTTYENT
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/*
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- * Define USEBCOPY if the bcopy/memcpy from your system's C library
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+ * Define USEBCOPY if the bcopy from your system's C library
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* supports the overlapping of source and destination blocks. When
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* undefined, screen uses its own (probably slower) version of bcopy().
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*
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@@ -487,7 +487,6 @@
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* Their memove fails the test in the configure script. Sigh. (Juergen)
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*/
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#undef USEBCOPY
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-#undef USEMEMCPY
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#undef USEMEMMOVE
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/*
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diff --git a/configure.ac b/configure.ac
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index 27690a6..b8e3bec 100644
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--- a/configure.ac
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+++ b/configure.ac
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@@ -1145,7 +1145,7 @@ AC_TRY_LINK(,[getttyent();], AC_DEFINE(GETTTYENT))
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AC_CHECKING(fdwalk)
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AC_TRY_LINK([#include <stdlib.h>], [fdwalk(NULL, NULL);],AC_DEFINE(HAVE_FDWALK))
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-AC_CHECKING(whether memcpy/memmove/bcopy handles overlapping arguments)
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+AC_CHECKING(whether memmove/bcopy handles overlapping arguments)
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AC_TRY_RUN([
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main() {
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char buf[10];
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@@ -1175,22 +1175,6 @@ main() {
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exit(0); /* libc version works properly. */
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}], AC_DEFINE(USEMEMMOVE))
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-
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-AC_TRY_RUN([
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-#define bcopy(s,d,l) memcpy(d,s,l)
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-main() {
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- char buf[10];
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- strcpy(buf, "abcdefghi");
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- bcopy(buf, buf + 2, 3);
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- if (strncmp(buf, "ababcf", 6))
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- exit(1);
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- strcpy(buf, "abcdefghi");
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- bcopy(buf + 2, buf, 3);
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- if (strncmp(buf, "cdedef", 6))
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- exit(1);
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- exit(0); /* libc version works properly. */
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-}], AC_DEFINE(USEMEMCPY))
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-
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AC_SYS_LONG_FILE_NAMES
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AC_MSG_CHECKING(for vsprintf)
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diff --git a/os.h b/os.h
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index e827ac9..0b41fb9 100644
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--- a/os.h
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+++ b/os.h
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@@ -142,12 +142,8 @@ extern int errno;
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# ifdef USEMEMMOVE
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# define bcopy(s,d,len) memmove(d,s,len)
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# else
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-# ifdef USEMEMCPY
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-# define bcopy(s,d,len) memcpy(d,s,len)
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-# else
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-# define NEED_OWN_BCOPY
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-# define bcopy xbcopy
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-# endif
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+# define NEED_OWN_BCOPY
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+# define bcopy xbcopy
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# endif
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#endif
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diff --git a/osdef.h.in b/osdef.h.in
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index 8687b60..e4057a0 100644
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--- a/osdef.h.in
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+++ b/osdef.h.in
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@@ -58,16 +58,8 @@ extern int bcmp __P((char *, char *, int));
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extern int killpg __P((int, int));
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#endif
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-#ifndef USEBCOPY
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-# ifdef USEMEMCPY
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-extern void memcpy __P((char *, char *, int));
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-# else
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-# ifdef USEMEMMOVE
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+#if defined(USEMEMMOVE) && !defined(USEBCOPY)
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extern void memmove __P((char *, char *, int));
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-# else
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-extern void bcopy __P((char *, char *, int));
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-# endif
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-# endif
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#else
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extern void bcopy __P((char *, char *, int));
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#endif
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--
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1.8.4.5
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