Attachment 67625 Details for Bug 55213 – Working (less ugly) fix of early boot vsnprintf/vasprintf segfault

Working (less ugly) fix of early boot vsnprintf/vasprintf segfault

03-systemd-191-varargs-segfault.02.patch (text/plain), 4.75 KB, created by jpsinthemix on 2012-09-24 11:22:19 UTC

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Creator: jpsinthemix

Created: 2012-09-24 11:22:19 UTC

Size: 4.75 KB

patch

obsolete

>--- systemd-191.old/src/shared/log.c	2012-09-21 06:07:41.885429447 -0400
>+++ systemd-191.new/src/shared/log.c	2012-09-24 07:03:24.430017040 -0400
>@@ -649,6 +649,68 @@ int log_oom_internal(const char *file, i
>         return -ENOMEM;
> }
> 
>+const char *next_format(
>+                const char *format,
>+                va_list *ap) {
>+
>+        char lm, *cs, *fc, *format_copy, *format_ptr;
>+
>+        if ( (fc = strchr(format, '%')) ) {
>+
>+                format_copy = strndup(fc, LINE_MAX);
>+
>+                // remove any non-format spec % chars
>+                while ( (fc = strstr(format_copy, "%%")) )
>+                        *(fc+1) = *fc = ' ';
>+
>+                cs = strtok_r(format_copy, "%", &format_ptr);
>+                // no need to worry about 'h' or 'hh' length modifiers as these will promoted to ints
>+                do {
>+                        lm = 0;
>+
>+                        while (*cs) {
>+                                switch(*cs++) {
>+                                   case 'l':
>+                                           lm = (lm == 'l') ? 'L' : 'l';
>+                                           break;
>+                                   case 'L':
>+                                           lm = 'l';
>+                                           break;
>+                                   case 's':
>+                                           va_arg(*ap, char *);
>+                                           *cs = 0;
>+                                           break;
>+                                   case 'u': case 'd': case 'i': case 'x': case 'X': case 'c': case 'o':
>+                                           if (!lm)
>+                                                   va_arg(*ap, int);
>+                                           else if (lm == 'l')
>+                                                   va_arg(*ap, long);
>+                                           else if (lm == 'L')
>+                                                   va_arg(*ap, long long);
>+                                           else
>+                                                   va_arg(*ap, int);
>+                                           *cs = 0;
>+                                           break;
>+                                   case 'e': case 'f': case 'g': case 'E': case 'F': case 'G':
>+                                           if (lm != 'l')
>+                                                   va_arg(*ap, double);
>+                                           else
>+                                                   va_arg(*ap, long double);
>+                                           *cs = 0;
>+                                           break;
>+                                   case 'p':
>+                                           va_arg(*ap, void *);
>+                                           *cs = 0;
>+                                           break;
>+                                }
>+                        }
>+                } while( (cs = strtok_r(NULL, "%", &format_ptr)) );
>+
>+                free(format_copy);
>+        }
>+        return va_arg(*ap, char *);
>+}
>+
> int log_struct_internal(
>                 int level,
>                 const char *file,
>@@ -657,7 +719,7 @@ int log_struct_internal(
>                 const char *format, ...) {
> 
>         int saved_errno;
>-        va_list ap;
>+        va_list ap, app;
>         int r;
> 
>         if (_likely_(LOG_PRI(level) > log_max_level))
>@@ -706,7 +768,9 @@ int log_struct_internal(
>                 while (format && n + 1 < ELEMENTSOF(iovec)) {
>                         char *buf;
> 
>-                        if (vasprintf(&buf, format, ap) < 0) {
>+                        va_copy(app, ap);
>+
>+                        if (vasprintf(&buf, format, app) < 0) {
>                                 r = -ENOMEM;
>                                 goto finish;
>                         }
>@@ -717,7 +781,7 @@ int log_struct_internal(
>                         iovec[n].iov_len = 1;
>                         n++;
> 
>-                        format = va_arg(ap, char *);
>+                        format = next_format(format, &ap);
>                 }
> 
>                 zero(mh);
>@@ -743,7 +807,9 @@ int log_struct_internal(
>                 va_start(ap, format);
>                 while (format) {
> 
>-                        vsnprintf(buf, sizeof(buf), format, ap);
>+                        va_copy(app, ap);
>+
>+                        vsnprintf(buf, sizeof(buf), format, app);
>                         char_array_0(buf);
> 
>                         if (startswith(buf, "MESSAGE=")) {
>@@ -751,7 +817,7 @@ int log_struct_internal(
>                                 break;
>                         }
> 
>-                        format = va_arg(ap, char *);
>+                        format = next_format(format, &ap);
>                 }
>                 va_end(ap);
>

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Attachments on bug 55213: 67533 | 67625

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