From b999e2038dbc54e2c8b1c390f8b8fe50d0f1d10a Mon Sep 17 00:00:00 2001 From: John Baldwin Date: Tue, 9 Jan 2018 13:35:17 -0800 Subject: [PATCH] Don't return stale data from fbsd_pid_to_exec_file for kernel processes. For processes without an associated executable (such as kernel processes), the kern.proc.pathname. system control node returns a length of zero without modifying the user's buffer. Detect this case and return NULL rather than the previous contents of the static buffer 'buf'. gdb/ChangeLog: * fbsd-nat.c (fbsd_pid_to_exec_file) [KERN_PROC_PATHNAME]: Return NULL for an empty pathname. --- gdb/ChangeLog | 5 +++++ gdb/fbsd-nat.c | 5 ++++- 2 files changed, 9 insertions(+), 1 deletion(-) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index e7f3cc2052..3752a3b1a1 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,8 @@ +2018-01-09 John Baldwin + + * fbsd-nat.c (fbsd_pid_to_exec_file) [KERN_PROC_PATHNAME]: Return + NULL for an empty pathname. + 2018-01-09 John Baldwin * fbsd-tdep.c (KVE_STRUCTSIZE, KVE_START, KVE_END, KVE_OFFSET) diff --git a/gdb/fbsd-nat.c b/gdb/fbsd-nat.c index ec4eed9abe..d0aaf89145 100644 --- a/gdb/fbsd-nat.c +++ b/gdb/fbsd-nat.c @@ -63,7 +63,10 @@ fbsd_pid_to_exec_file (struct target_ops *self, int pid) mib[3] = pid; buflen = sizeof buf; if (sysctl (mib, 4, buf, &buflen, NULL, 0) == 0) - return buf; + /* The kern.proc.pathname. sysctl returns a length of zero + for processes without an associated executable such as kernel + processes. */ + return buflen == 0 ? NULL : buf; #endif xsnprintf (name, PATH_MAX, "/proc/%d/exe", pid); -- 2.34.1