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[binutils-gdb] Don't return stale data from fbsd_pid_to_exec_file for kernel processes.
- From: John Baldwin <jhb at sourceware dot org>
- To: gdb-cvs at sourceware dot org
- Date: 9 Jan 2018 21:57:14 -0000
- Subject: [binutils-gdb] Don't return stale data from fbsd_pid_to_exec_file for kernel processes.
https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=b999e2038dbc54e2c8b1c390f8b8fe50d0f1d10a
commit b999e2038dbc54e2c8b1c390f8b8fe50d0f1d10a
Author: John Baldwin <jhb@FreeBSD.org>
Date: Tue Jan 9 13:35:17 2018 -0800
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.<pid> 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.
Diff:
---
gdb/ChangeLog | 5 +++++
gdb/fbsd-nat.c | 5 ++++-
2 files changed, 9 insertions(+), 1 deletion(-)
diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index e7f3cc2..3752a3b 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,5 +1,10 @@
2018-01-09 John Baldwin <jhb@FreeBSD.org>
+ * fbsd-nat.c (fbsd_pid_to_exec_file) [KERN_PROC_PATHNAME]: Return
+ NULL for an empty pathname.
+
+2018-01-09 John Baldwin <jhb@FreeBSD.org>
+
* fbsd-tdep.c (KVE_STRUCTSIZE, KVE_START, KVE_END, KVE_OFFSET)
(KVE_FLAGS, KVE_PROTECTION, KVE_PATH, KINFO_VME_PROT_READ)
(KINFO_VME_PROT_WRITE, KINFO_VME_PROT_EXEC, KINFO_VME_FLAG_COW)
diff --git a/gdb/fbsd-nat.c b/gdb/fbsd-nat.c
index ec4eed9..d0aaf89 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.<pid> 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);