jca and I converted %n to a syslog warning about a year ago, and the ports

ecosystem experienced a very good cleanup.  Time has arrived to switch (as
planned) to syslog + abort, which will result in a coredump thus identifying
the remaining culprits in a more visible fashion.
vfprintf(3) and vfwprintf(3) man pages still require documentation changes.
with jca

diff --git a/lib/libc/stdio/vfprintf.c b/lib/libc/stdio/vfprintf.c
index 53f59e6..527de41 100644 (file)
--- a/lib/libc/stdio/vfprintf.c
+++ b/lib/libc/stdio/vfprintf.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: vfprintf.c,v 1.79 2020/10/27 21:06:57 deraadt Exp $   */
+/*     $OpenBSD: vfprintf.c,v 1.80 2021/08/30 11:16:49 deraadt Exp $   */
 /*-
  * Copyright (c) 1990 The Regents of the University of California.
  * All rights reserved.
@@ -56,9 +56,6 @@
 #include "local.h"
 #include "fvwrite.h"
 
-static const char n_msg[] = ": *printf used %n: ";
-static int n_report;
-
 union arg {
        int                     intarg;
        unsigned int            uintarg;
@@ -801,63 +798,29 @@ fp_common:
                        }
                        break;
 #endif /* FLOATING_POINT */
-#ifndef NO_PRINTF_PERCENT_N
                case 'n': {
-                       int maxprot = 0;
-
-#ifdef notyet
-                       if (mprotections(fmt0, strlen(fmt0) + 1,
-                           &maxprot) == -1)
-                               maxprot = 0;
-                       maxprot &= ~PROT_READ;
-#endif
+                       static const char n_msg[] = ": *printf used %n, aborting: ";
+                       char buf[1024], *p;
 
-                       if (n_report == 0 || maxprot) {
-                               char buf[1024], *p;
+                       /* <10> is LOG_CRIT */
+                       strlcpy(buf, "<10>", sizeof buf);
 
-                               /* <10> is LOG_CRIT */
-                               strlcpy(buf, "<10>", sizeof buf);
-
-                               /* XXX */
-                               if ((p = getenv("_THIS_PORT")) != NULL) {
-                                       strlcat(buf, p, sizeof buf);
-                                       strlcat(buf, " ", sizeof buf);
-                               }
-
-                               /* Make sure progname does not fill the whole buffer */
-                               strlcat(buf, __progname, sizeof(buf) - sizeof n_msg);
-                               strlcat(buf, n_msg, sizeof buf);
-                               strlcat(buf, fmt0, sizeof buf);
-                               if ((p = strchr(buf, '\n')))
-                                       *p = '\0';
-                               if (maxprot)
-                                       strlcat(buf, ": aborting", sizeof buf);
-                               sendsyslog(buf, strlen(buf), LOG_CONS);
-                               n_report = 1;
+                       /* XXX */
+                       if ((p = getenv("_THIS_PORT")) != NULL) {
+                               strlcat(buf, p, sizeof buf);
+                               strlcat(buf, " ", sizeof buf);
                        }
 
-                       if (maxprot)
-                               abort();
-
-                       if (flags & LLONGINT)
-                               *GETARG(long long *) = ret;
-                       else if (flags & LONGINT)
-                               *GETARG(long *) = ret;
-                       else if (flags & SHORTINT)
-                               *GETARG(short *) = ret;
-                       else if (flags & CHARINT)
-                               *GETARG(signed char *) = ret;
-                       else if (flags & PTRINT)
-                               *GETARG(ptrdiff_t *) = ret;
-                       else if (flags & SIZEINT)
-                               *GETARG(ssize_t *) = ret;
-                       else if (flags & MAXINT)
-                               *GETARG(intmax_t *) = ret;
-                       else
-                               *GETARG(int *) = ret;
-                       continue;       /* no output */
+                       /* Make sure progname does not fill the whole buffer */
+                       strlcat(buf, __progname, sizeof(buf) - sizeof n_msg);
+                       strlcat(buf, n_msg, sizeof buf);
+                       strlcat(buf, fmt0, sizeof buf);
+                       if ((p = strchr(buf, '\n')))
+                               *p = '\0';
+                       sendsyslog(buf, strlen(buf), LOG_CONS);
+                       abort();
+                       break;
                        }
-#endif /* NO_PRINTF_PERCENT_N */
                case 'O':
                        flags |= LONGINT;
                        /*FALLTHROUGH*/
@@ -1350,7 +1313,6 @@ reswitch: switch (ch) {
                                ADDTYPE(T_DOUBLE);
                        break;
 #endif /* FLOATING_POINT */
-#ifndef NO_PRINTF_PERCENT_N
                case 'n':
                        if (flags & LLONGINT)
                                ADDTYPE(TP_LLONG);
@@ -1367,7 +1329,6 @@ reswitch: switch (ch) {
                        else
                                ADDTYPE(TP_INT);
                        continue;       /* no output */
-#endif /* NO_PRINTF_PERCENT_N */
                case 'O':
                        flags |= LONGINT;
                        /*FALLTHROUGH*/

diff --git a/lib/libc/stdio/vfwprintf.c b/lib/libc/stdio/vfwprintf.c
index cadbed1..15312c2 100644 (file)
--- a/lib/libc/stdio/vfwprintf.c
+++ b/lib/libc/stdio/vfwprintf.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: vfwprintf.c,v 1.20 2020/10/27 21:06:57 deraadt Exp $ */
+/*     $OpenBSD: vfwprintf.c,v 1.21 2021/08/30 11:16:49 deraadt Exp $ */
 /*-
  * Copyright (c) 1990 The Regents of the University of California.
  * All rights reserved.
@@ -55,9 +55,6 @@
 #include "local.h"
 #include "fvwrite.h"
 
-static const char n_msg[] = ": *wprintf used %n";
-static int n_report;
-
 union arg {
        int                     intarg;
        unsigned int            uintarg;
@@ -785,62 +782,32 @@ fp_common:
                        }
                        break;
 #endif /* FLOATING_POINT */
-#ifndef NO_PRINTF_PERCENT_N
                case 'n': {
-                       int maxprot = 0;
-
-#ifdef notyet
-                       if (mprotections(fmt0, wcslen(fmt0) + 1,
-                           &maxprot) == -1)
-                               maxprot = 0;
-                       maxprot &= ~PROT_READ;
-#endif
+                       static const char n_msg[] = ": *wprintf used %n, aborting";
+                       char buf[1024], *p;
 
-                       if (n_report == 0 || maxprot) {
-                               char buf[1024], *p;
+                       /* <10> is LOG_CRIT */
+                       strlcpy(buf, "<10>", sizeof buf);
 
-                               /* <10> is LOG_CRIT */
-                               strlcpy(buf, "<10>", sizeof buf);
-
-                               /* XXX */
-                               if ((p = getenv("_THIS_PORT")) != NULL) {
-                                       strlcat(buf, p, sizeof buf);
-                                       strlcat(buf, " ", sizeof buf);
-                               }
-
-                               /* Make sure progname does not fill the whole buffer */
-                               strlcat(buf, __progname, sizeof(buf) - sizeof n_msg);
-                               strlcat(buf, n_msg, sizeof buf);
-                               /* XXX should we include the wide string? */
-                               if ((p = strchr(buf, '\n')))
-                                       *p = '\0';
-                               if (maxprot)
-                                       strlcat(buf, ": aborting", sizeof buf);
-                               sendsyslog(buf, strlen(buf), LOG_CONS);
-                               n_report = 1;
+                       /* XXX */
+                       if ((p = getenv("_THIS_PORT")) != NULL) {
+                               strlcat(buf, p, sizeof buf);
+                               strlcat(buf, " ", sizeof buf);
                        }
-                       if (maxprot)
-                               abort();
 
-                       if (flags & LLONGINT)
-                               *GETARG(long long *) = ret;
-                       else if (flags & LONGINT)
-                               *GETARG(long *) = ret;
-                       else if (flags & SHORTINT)
-                               *GETARG(short *) = ret;
-                       else if (flags & CHARINT)
-                               *GETARG(signed char *) = ret;
-                       else if (flags & PTRINT)
-                               *GETARG(ptrdiff_t *) = ret;
-                       else if (flags & SIZEINT)
-                               *GETARG(ssize_t *) = ret;
-                       else if (flags & MAXINT)
-                               *GETARG(intmax_t *) = ret;
-                       else
-                               *GETARG(int *) = ret;
-                       continue;       /* no output */
+                       /* Make sure progname does not fill the whole buffer */
+                       strlcat(buf, __progname, sizeof(buf) - sizeof n_msg);
+                       strlcat(buf, n_msg, sizeof buf);
+                       /*
+                        * vfprintf sends fmt0 via syslog, but this is not
+                        * good behaviour for wide strings.
+                        */
+                       if ((p = strchr(buf, '\n')))
+                               *p = '\0';
+                       sendsyslog(buf, strlen(buf), LOG_CONS);
+                       abort();
+                       break;
                        }
-#endif /* NO_PRINTF_PERCENT_N */
                case 'O':
                        flags |= LONGINT;
                        /*FALLTHROUGH*/
@@ -1347,7 +1314,6 @@ reswitch: switch (ch) {
                                ADDTYPE(T_DOUBLE);
                        break;
 #endif /* FLOATING_POINT */
-#ifndef NO_PRINTF_PERCENT_N
                case 'n':
                        if (flags & LLONGINT)
                                ADDTYPE(TP_LLONG);
@@ -1364,7 +1330,6 @@ reswitch: switch (ch) {
                        else
                                ADDTYPE(TP_INT);
                        continue;       /* no output */
-#endif /* NO_PRINTF_PERCENT_N */
                case 'O':
                        flags |= LONGINT;
                        /*FALLTHROUGH*/