Re: Change 28183 has broken 64-bit builds?

Message-ID: <446B7757.8030301@gmail.com>

p4raw-id: //depot/perl@28216

diff --git a/perl.h b/perl.h
index 91e1b58..2cf5a46 100644 (file)
--- a/perl.h
+++ b/perl.h
@@ -348,11 +348,17 @@ register struct op *Perl_op asm(stringify(OP_IN_REGISTER));
 #endif
 
 #if defined(PERL_GCC_PEDANTIC)
-#  if !defined(PERL_GCC_BRACE_GROUPS_FORBIDDEN)
+#  ifndef PERL_GCC_BRACE_GROUPS_FORBIDDEN
 #    define PERL_GCC_BRACE_GROUPS_FORBIDDEN
 #  endif
 #endif
 
+#if defined(__GNUC__) && !defined(PERL_GCC_BRACE_GROUPS_FORBIDDEN) && !defined(__cplusplus)
+#  ifndef PERL_USE_GCC_BRACE_GROUPS
+#    define PERL_USE_GCC_BRACE_GROUPS
+#  endif
+#endif
+
 /*
  * STMT_START { statements; } STMT_END;
  * can be used as a single statement, as in
@@ -361,7 +367,7 @@ register struct op *Perl_op asm(stringify(OP_IN_REGISTER));
  * Trying to select a version that gives no warnings...
  */
 #if !(defined(STMT_START) && defined(STMT_END))
-# if defined(__GNUC__) && !defined(PERL_GCC_BRACE_GROUPS_FORBIDDEN) && !defined(__cplusplus)
+# ifdef PERL_USE_GCC_BRACE_GROUPS
 #   define STMT_START  (void)( /* gcc supports "({ STATEMENTS; })" */
 #   define STMT_END    )
 # else
@@ -1439,18 +1445,38 @@ int sockatmark(int);
 */
 #ifdef SPRINTF_RETURNS_STRLEN
 #  define my_sprintf sprintf
-#  ifdef HAS_SNPRINTF
-#    define USE_SNPRINTF
-#  endif
-#  ifdef HAS_VSNPRINTF
-#    define USE_VSNPRINTF
-#  endif
 #else
 #  define my_sprintf Perl_my_sprintf
 #endif
 
-#define my_snprintf  Perl_my_snprintf
-#define my_vsnprintf Perl_my_vsnprintf
+/*
+ * If we have v?snprintf() and the C99 variadic macros, we can just
+ * use just the v?snprintf().  It is nice to try to trap the buffer
+ * overflow, however, so if we are DEBUGGING, and we cannot use the
+ * gcc brace groups, then use the function wrappers which try to trap
+ * the overflow.  If we can use the gcc brace groups, we can try that
+ * even with the version that uses the C99 variadic macros.
+ */
+
+#if defined(HAS_C99_VARIADIC_MACROS) && !(defined(DEBUGGING) && !defined(PERL_USE_GCC_BRACE_GROUPS))
+#  ifdef PERL_USE_GCC_BRACE_GROUPS
+#      define my_snprintf(buffer, len, ...) ({ int __len__ = snprintf(buffer, len, __VA_ARGS__); if (__len__ >= len) Perl_croak(aTHX_ "panic: snprintf buffer overflow"); __len__; })
+#  else
+#    define my_snprintf(buffer, len, ...) snprintf(buffer, len, __VA_ARGS__)
+#  endif
+#else
+#  define my_snprintf  Perl_my_snprintf
+#endif
+
+#if defined(HAS_C99_VARIADIC_MACROS)
+#  ifdef PERL_USE_GCC_BRACE_GROUPS
+#      define my_vsnprintf(buffer, len, ...) ({ int __len__ = vsnprintf(buffer, len, __VA_ARGS__); if (__len__ >= len) Perl_croak(aTHX_ "panic: vsnprintf buffer overflow"); __len__; })
+#  else
+#    define my_vsnprintf(buffer, len, ...) vsnprintf(buffer, len, __VA_ARGS__)
+#  endif
+#else
+#  define my_vsnprintf Perl_my_vsnprintf
+#endif
 
 /* Configure gets this right but the UTS compiler gets it wrong.
    -- Hal Morris <hom00@utsglobal.com> */

diff --git a/perlio.c b/perlio.c
index ad2570e..9e06ef1 100644 (file)
--- a/perlio.c
+++ b/perlio.c
@@ -5142,7 +5142,7 @@ vfprintf(FILE *fd, char *pat, char *args)
 int
 PerlIO_vsprintf(char *s, int n, const char *fmt, va_list ap)
 {
-    dVAR;
+    dTHX;
     const int val = my_vsnprintf(s, n > 0 ? n : 0, fmt, ap);
     if (n >= 0) {
        if (strlen(s) >= (STRLEN) n) {

diff --git a/pod/perlapi.pod b/pod/perlapi.pod
index 400b329..b9eb329 100644 (file)
--- a/pod/perlapi.pod
+++ b/pod/perlapi.pod
@@ -2249,9 +2249,11 @@ Found in file util.c
 X<my_snprintf>
 
 The C library C<snprintf> functionality, if available and
-standards-compliant (uses C<vsnprintf>, actually).  If the
+standards-compliant (uses C<vsnprintf>, actually).  However, if the
 C<vsnprintf> is not available, will unfortunately use the unsafe
-C<vsprintf>.  Consider using C<sv_vcatpvf> instead.
+C<vsprintf> which can overrun the buffer (there is an overrun check,
+but that may be too late).  Consider using C<sv_vcatpvf> instead, or
+getting C<vsnprintf>.
 
        int     my_snprintf(char *buffer, const Size_t len, const char *format, ...)
 
@@ -2273,9 +2275,11 @@ Found in file util.c
 =item my_vsnprintf
 X<my_vsnprintf>
 
-The C library C<vsnprintf> if available and standards-compliant,
-but if the C<vsnprintf> is not available, will unfortunately use
-the unsafe C<vsprintf>.  Consider using C<sv_vcatpvf> instead.
+The C library C<vsnprintf> if available and standards-compliant.
+However, if if the C<vsnprintf> is not available, will unfortunately
+use the unsafe C<vsprintf> which can overrun the buffer (there is an
+overrun check, but that may be too late).  Consider using
+C<sv_vcatpvf> instead, or getting C<vsnprintf>.
 
        int     my_vsnprintf(char *buffer, const Size_t len, const char *format, va_list ap)
 

diff --git a/util.c b/util.c
index 82f7f82..3474660 100644 (file)
--- a/util.c
+++ b/util.c
@@ -5206,27 +5206,30 @@ Perl_mem_log_alloc(const UV n, const UV typesize, const char *typename, Malloc_t
        /* We can't use SVs or PerlIO for obvious reasons,
         * so we'll use stdio and low-level IO instead. */
        char buf[PERL_MEM_LOG_SPRINTF_BUF_SIZE];
-# if defined(PERL_MEM_LOG_TIMESTAMP) && defined(HAS_GETTIMEOFDAY)
+# ifdef PERL_MEM_LOG_TIMESTAMP
        struct timeval tv;
+#   ifdef HAS_GETTIMEOFDAY
        gettimeofday(&tv, 0);
+#   endif
+       /* If there are other OS specific ways of hires time than
+        * gettimeofday() (see ext/Time/HiRes), the easiest way is
+        * probably that they would be used to fill in the struct
+        * timeval. */
+# endif
        {
            const STRLEN len =
                my_snprintf(buf,
                            PERL_MEM_LOG_SPRINTF_BUF_SIZE,
-                           "%10d.%06d: alloc: %s:%d:%s: %"IVdf" %"UVuf
-                           " %s = %"IVdf": %"UVxf"\n",
-                           (int)tv.tv_sec, (int)tv.tv_usec,
-                           filename, linenumber, funcname, n, typesize,
-                           typename, n * typesize, PTR2UV(newalloc));
-# else
-           const STRLEN len =
-               my_snprintf(buf,
-                           PERL_MEM_LOG_SPRINTF_BUF_SIZE,
+#  ifdef PERL_MEM_LOG_TIMESTAMP
+                           "%10d.%06d: "
+# endif
                            "alloc: %s:%d:%s: %"IVdf" %"UVuf
                            " %s = %"IVdf": %"UVxf"\n",
+#  ifdef PERL_MEM_LOG_TIMESTAMP
+                           (int)tv.tv_sec, (int)tv.tv_usec,
+# endif
                            filename, linenumber, funcname, n, typesize,
                            typename, n * typesize, PTR2UV(newalloc));
-# endif
 # ifdef PERL_MEM_LOG_ENV_FD
            s = PerlEnv_getenv("PERL_MEM_LOG_FD");
            PerlLIO_write(s ? atoi(s) : PERL_MEM_LOG_FD, buf, len);
@@ -5254,29 +5257,25 @@ Perl_mem_log_realloc(const UV n, const UV typesize, const char *typename, Malloc
        /* We can't use SVs or PerlIO for obvious reasons,
         * so we'll use stdio and low-level IO instead. */
        char buf[PERL_MEM_LOG_SPRINTF_BUF_SIZE];
-# if defined(PERL_MEM_LOG_TIMESTAMP) && defined(HAS_GETTIMEOFDAY)
+#  ifdef PERL_MEM_LOG_TIMESTAMP
        struct timeval tv;
        gettimeofday(&tv, 0);
+# endif
        {
            const STRLEN len =
                my_snprintf(buf,
                            PERL_MEM_LOG_SPRINTF_BUF_SIZE,
-                           "%10d.%06d: realloc: %s:%d:%s: %"IVdf" %"UVuf
-                           " %s = %"IVdf": %"UVxf" -> %"UVxf"\n",
-                           (int)tv.tv_sec, (int)tv.tv_usec,
-                           filename, linenumber, funcname, n, typesize,
-                           typename, n * typesize, PTR2UV(oldalloc),
-                           PTR2UV(newalloc));
-# else
-           const STRLEN len =
-               my_snprintf(buf,
-                           PERL_MEM_LOG_SPRINTF_BUF_SIZE,
+#  ifdef PERL_MEM_LOG_TIMESTAMP
+                           "%10d.%06d: "
+# endif
                            "realloc: %s:%d:%s: %"IVdf" %"UVuf
                            " %s = %"IVdf": %"UVxf" -> %"UVxf"\n",
+#  ifdef PERL_MEM_LOG_TIMESTAMP
+                           (int)tv.tv_sec, (int)tv.tv_usec,
+# endif
                            filename, linenumber, funcname, n, typesize,
                            typename, n * typesize, PTR2UV(oldalloc),
                            PTR2UV(newalloc));
-# endif
 # ifdef PERL_MEM_LOG_ENV_FD
            s = PerlEnv_getenv("PERL_MEM_LOG_FD");
            PerlLIO_write(s ? atoi(s) : PERL_MEM_LOG_FD, buf, len);
@@ -5304,24 +5303,23 @@ Perl_mem_log_free(Malloc_t oldalloc, const char *filename, const int linenumber,
        /* We can't use SVs or PerlIO for obvious reasons,
         * so we'll use stdio and low-level IO instead. */
        char buf[PERL_MEM_LOG_SPRINTF_BUF_SIZE];
-# if defined(PERL_MEM_LOG_TIMESTAMP) && defined(HAS_GETTIMEOFDAY)
+#  ifdef PERL_MEM_LOG_TIMESTAMP
        struct timeval tv;
        gettimeofday(&tv, 0);
+# endif
        {
            const STRLEN len =
                my_snprintf(buf,
                            PERL_MEM_LOG_SPRINTF_BUF_SIZE,
-                           "%10d.%06d: free: %s:%d:%s: %"UVxf"\n",
+#  ifdef PERL_MEM_LOG_TIMESTAMP
+                           "%10d.%06d: "
+# endif
+                           "free: %s:%d:%s: %"UVxf"\n",
+#  ifdef PERL_MEM_LOG_TIMESTAMP
                            (int)tv.tv_sec, (int)tv.tv_usec,
+# endif
                            filename, linenumber, funcname,
                            PTR2UV(oldalloc));
-# else
-           const STRLEN len =
-               my_sprintf(buf,
-                          "free: %s:%d:%s: %"UVxf"\n",
-                          filename, linenumber, funcname,
-                          PTR2UV(oldalloc));
-# endif
 # ifdef PERL_MEM_LOG_ENV_FD
            s = PerlEnv_getenv("PERL_MEM_LOG_FD");
            PerlLIO_write(s ? atoi(s) : PERL_MEM_LOG_FD, buf, len);
@@ -5361,65 +5359,65 @@ Perl_my_sprintf(char *buffer, const char* pat, ...)
 =for apidoc my_snprintf
 
 The C library C<snprintf> functionality, if available and
-standards-compliant (uses C<vsnprintf>, actually).  If the
+standards-compliant (uses C<vsnprintf>, actually).  However, if the
 C<vsnprintf> is not available, will unfortunately use the unsafe
-C<vsprintf>.  Consider using C<sv_vcatpvf> instead.
+C<vsprintf> which can overrun the buffer (there is an overrun check,
+but that may be too late).  Consider using C<sv_vcatpvf> instead, or
+getting C<vsnprintf>.
 
 =cut
 */
 int
 Perl_my_snprintf(char *buffer, const Size_t len, const char *format, ...)
-/* Cannot do this using variadic macros because that is too unportable. */
 {
     dTHX;
     int retval;
     va_list ap;
-#ifndef USE_VSNPRINTF
-    PERL_UNUSED_ARG(len);
-#endif
     va_start(ap, format);
-#ifdef USE_VSNPRINTF
+#ifdef HAS_VSNPRINTF
     retval = vsnprintf(buffer, len, format, ap);
 #else
     retval = vsprintf(buffer, format, ap);
 #endif
     va_end(ap);
+    if (retval >= len)
+       Perl_croak(aTHX_ "panic: my_snprintf buffer overflow");
     return retval;
 }
 
 /*
 =for apidoc my_vsnprintf
 
-The C library C<vsnprintf> if available and standards-compliant,
-but if the C<vsnprintf> is not available, will unfortunately use
-the unsafe C<vsprintf>.  Consider using C<sv_vcatpvf> instead.
+The C library C<vsnprintf> if available and standards-compliant.
+However, if if the C<vsnprintf> is not available, will unfortunately
+use the unsafe C<vsprintf> which can overrun the buffer (there is an
+overrun check, but that may be too late).  Consider using
+C<sv_vcatpvf> instead, or getting C<vsnprintf>.
 
 =cut
 */
 int
 Perl_my_vsnprintf(char *buffer, const Size_t len, const char *format, va_list ap)
-/* Cannot do this using variadic macros because that is too unportable. */
 {
     dTHX;
     int retval;
-#ifndef USE_VSNPRINTF
-    PERL_UNUSED_ARG(len);
-#endif
 #ifdef NEED_VA_COPY
     va_list apc;
     Perl_va_copy(apc);
-# ifdef USE_VSNPRINTF
+# ifdef HAS_VSNPRINTF
     retval = vsnprintf(buffer, len, format, apc);
 # else
     retval = vsprintf(buffer, format, apc);
 # endif
 #else
-# ifdef USE_VSNPRINTF
+# ifdef HAS_VSNPRINTF
     retval = vsnprintf(buffer, len, format, ap);
 # else
     retval = vsprintf(buffer, format, ap);
 # endif
-#endif
+#endif /* #ifdef NEED_VA_COPY */
+    if (retval >= len)
+       Perl_croak(aTHX_ "panic: my_vsnprintf buffer overflow");
     return retval;
 }