1 files changed, 12 insertions, 7 deletions

diff --git a/runit/svlogd.c b/runit/svlogd.c
index 4458bd787..db3d4c540 100644
--- a/runit/svlogd.c
+++ b/runit/svlogd.c
@@ -206,17 +206,22 @@ static void fmt_time_bernstein_25(char *s)
         bin2hex(s, (char*)pack, 12);
 }
 
-static unsigned processorstart(struct logdir *ld)
+static void processorstart(struct logdir *ld)
 {
+        char sv_ch;
         int pid;
 
-        if (!ld->processor) return 0;
+        if (!ld->processor) return;
         if (ld->ppid) {
                 warnx("processor already running", ld->name);
-                return 0;
+                return;
         }
-        while ((pid = fork()) == -1)
-                pause2cannot("fork for processor", ld->name);
+
+        /* vfork'ed child trashes this byte, save... */
+        sv_ch = ld->fnsave[26];
+
+        while ((pid = vfork()) == -1)
+                pause2cannot("vfork for processor", ld->name);
         if (!pid) {
                 char *prog[4];
                 int fd;
@@ -235,7 +240,7 @@ static unsigned processorstart(struct logdir *ld)
                         bb_error_msg(INFO"processing: %s/%s", ld->name, ld->fnsave);
                 fd = xopen(ld->fnsave, O_RDONLY|O_NDELAY);
                 xmove_fd(fd, 0);
-                ld->fnsave[26] = 't';
+                ld->fnsave[26] = 't'; /* <- that's why we need sv_ch! */
                 fd = xopen(ld->fnsave, O_WRONLY|O_NDELAY|O_TRUNC|O_CREAT);
                 xmove_fd(fd, 1);
                 fd = open_read("state");
@@ -257,8 +262,8 @@ static unsigned processorstart(struct logdir *ld)
                 execv("/bin/sh", prog);
                 bb_perror_msg_and_die(FATAL"cannot %s processor %s", "run", ld->name);
         }
+        ld->fnsave[26] = sv_ch; /* ...restore */
         ld->ppid = pid;
-        return 1;
 }
 
 static unsigned processorstop(struct logdir *ld)