Date: Mon, 3 Nov 2014 12:02:05 +0800 From: Tiwei Bie <btw@mail.ustc.edu.cn> To: mjg@freebsd.org Cc: freebsd-hackers@freebsd.org Subject: [PATCH] Finish the task 'sysctl reporting current working directory' Message-ID: <1414987325-23280-1-git-send-email-btw@mail.ustc.edu.cn>
next in thread | raw e-mail | index | archive | help
Hi, Mateusz!
I have finished the task: sysctl reporting current working directory [1].
The patch for tmux is against tmux-1.9a [2].
#1. Patch for FreeBSD:
diff --git a/sys/kern/kern_descrip.c b/sys/kern/kern_descrip.c
index 11ab4ba..4652cb9 100644
--- a/sys/kern/kern_descrip.c
+++ b/sys/kern/kern_descrip.c
@@ -3409,6 +3409,72 @@ static SYSCTL_NODE(_kern_proc, KERN_PROC_FILEDESC, filedesc,
CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_filedesc,
"Process filedesc entries");
+/*
+ * Store a process current working directory information to sbuf.
+ *
+ * Takes a locked proc as argument, and returns with the proc unlocked.
+ */
+int
+kern_proc_cwd_out(struct proc *p, struct sbuf *sb, ssize_t maxlen)
+{
+ struct filedesc *fdp;
+ struct export_fd_buf *efbuf;
+ int error = 0;
+
+ PROC_LOCK_ASSERT(p, MA_OWNED);
+
+ fdp = fdhold(p);
+ PROC_UNLOCK(p);
+
+ if (fdp == NULL)
+ return (error);
+
+ efbuf = malloc(sizeof(*efbuf), M_TEMP, M_WAITOK);
+ efbuf->fdp = fdp;
+ efbuf->sb = sb;
+ efbuf->remainder = maxlen;
+
+ FILEDESC_SLOCK(fdp);
+ /* working directory */
+ if (fdp->fd_cdir != NULL) {
+ vref(fdp->fd_cdir);
+ export_vnode_to_sb(fdp->fd_cdir, KF_FD_TYPE_CWD, FREAD, efbuf);
+ }
+ FILEDESC_SUNLOCK(fdp);
+ fddrop(fdp);
+ free(efbuf, M_TEMP);
+ return (error);
+}
+
+/*
+ * Get per-process current working directory.
+ */
+static int
+sysctl_kern_proc_cwd(SYSCTL_HANDLER_ARGS)
+{
+ struct sbuf sb;
+ struct proc *p;
+ ssize_t maxlen;
+ int error, error2, *name;
+
+ name = (int *)arg1;
+
+ sbuf_new_for_sysctl(&sb, NULL, sizeof(struct kinfo_file), req);
+ error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p);
+ if (error != 0) {
+ sbuf_delete(&sb);
+ return (error);
+ }
+ maxlen = req->oldptr != NULL ? req->oldlen : -1;
+ error = kern_proc_cwd_out(p, &sb, maxlen);
+ error2 = sbuf_finish(&sb);
+ sbuf_delete(&sb);
+ return (error != 0 ? error : error2);
+}
+
+static SYSCTL_NODE(_kern_proc, KERN_PROC_CWD, cwd, CTLFLAG_RD|CTLFLAG_MPSAFE,
+ sysctl_kern_proc_cwd, "Process current working directory");
+
#ifdef DDB
/*
* For the purposes of debugging, generate a human-readable string for the
diff --git a/sys/sys/sysctl.h b/sys/sys/sysctl.h
index d782375..f3173c2 100644
--- a/sys/sys/sysctl.h
+++ b/sys/sys/sysctl.h
@@ -657,6 +657,7 @@ TAILQ_HEAD(sysctl_ctx_list, sysctl_ctx_entry);
#define KERN_PROC_UMASK 39 /* process umask */
#define KERN_PROC_OSREL 40 /* osreldate for process binary */
#define KERN_PROC_SIGTRAMP 41 /* signal trampoline location */
+#define KERN_PROC_CWD 42 /* process current working directory */
/*
* KERN_IPC identifiers
diff --git a/sys/sys/user.h b/sys/sys/user.h
index f0d059e..c3b3bc5 100644
--- a/sys/sys/user.h
+++ b/sys/sys/user.h
@@ -530,6 +530,7 @@ struct sbuf;
*/
int kern_proc_filedesc_out(struct proc *p, struct sbuf *sb, ssize_t maxlen);
+int kern_proc_cwd_out(struct proc *p, struct sbuf *sb, ssize_t maxlen);
int kern_proc_out(struct proc *p, struct sbuf *sb, int flags);
int kern_proc_vmmap_out(struct proc *p, struct sbuf *sb);
--
2.1.0
#2. Patch for tmux:
diff --git a/osdep-freebsd.c b/osdep-freebsd.c
index d596eab..f2443b7 100644
--- a/osdep-freebsd.c
+++ b/osdep-freebsd.c
@@ -136,26 +136,39 @@ char *
osdep_get_cwd(int fd)
{
static char wd[PATH_MAX];
- struct kinfo_file *info = NULL;
pid_t pgrp;
- int nrecords, i;
+ int mib[4];
+ size_t len;
+ struct kinfo_file *info;
+ char *buf;
+ int error;
if ((pgrp = tcgetpgrp(fd)) == -1)
return (NULL);
- if ((info = kinfo_getfile(pgrp, &nrecords)) == NULL)
+ mib[0] = CTL_KERN;
+ mib[1] = KERN_PROC;
+ mib[2] = KERN_PROC_CWD;
+ mib[3] = pgrp;
+
+ error = sysctl(mib, 4, NULL, &len, NULL, 0);
+ if (error)
return (NULL);
- for (i = 0; i < nrecords; i++) {
- if (info[i].kf_fd == KF_FD_TYPE_CWD) {
- strlcpy(wd, info[i].kf_path, sizeof wd);
- free(info);
- return (wd);
- }
+ buf = malloc(len);
+ if (buf == NULL)
+ return (NULL);
+ error = sysctl(mib, 4, buf, &len, NULL, 0);
+ if (error) {
+ free(buf);
+ return (NULL);
}
- free(info);
- return (NULL);
+ info = (struct kinfo_file *)buf;
+ strlcpy(wd, info->kf_path, sizeof wd);
+
+ free(buf);
+ return (wd);
}
struct event_base *
--
2.1.0
[1] https://wiki.freebsd.org/JuniorJobs#sysctl_reporting_current_working_directory
[2] http://cznic.dl.sourceforge.net/project/tmux/tmux/tmux-1.9/tmux-1.9a.tar.gz
Tiwei Bie
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?1414987325-23280-1-git-send-email-btw>