From: Mark Wielaard <mark@klomp.org>
Date: Sat, 25 May 2019 14:25:19 +0000 (+0200)
Subject: vgdb: Fix read check in report_pid.
X-Git-Tag: VALGRIND_3_16_0~282
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f7f48f91b046751def38326f8a8547bb8c98d4f2;p=thirdparty%2Fvalgrind.git

vgdb: Fix read check in report_pid.

When read fails it will return -1. In which case we might assign
cmdline[sz] = 0 and print a garbage cmdline. Fix the test to check
the return value is > 0.
---

diff --git a/coregrind/vgdb.c b/coregrind/vgdb.c
index 075c737fd1..e678eac2db 100644
--- a/coregrind/vgdb.c
+++ b/coregrind/vgdb.c
@@ -1090,7 +1090,7 @@ void report_pid(int pid, Bool on_stdout)
    } else {
       char cmdline[100];
       ssize_t sz;
-      while ((sz = read(fd, cmdline, sizeof cmdline - 1)) != 0) {
+      while ((sz = read(fd, cmdline, sizeof cmdline - 1)) > 0) {
          for (i = 0; i < sz; i++)
             if (cmdline[i] == 0)
                cmdline[i] = ' ';