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diff --git a/lib/libsys/ptrace.2 b/lib/libsys/ptrace.2
--- a/lib/libsys/ptrace.2
+++ b/lib/libsys/ptrace.2
@@ -468,6 +468,20 @@
apply.)
The tracing process will see the newly-traced process stop and may
then control it as if it had been traced all along.
+.It Dv PT_ATTACH_PD
+The request attaches to the process specified by the process
+descriptor passed in the
+.Fa data
+argument.
+Otherwise, it is identical to
+.Dv PT_ATTACH .
+.Pp
+See
+.Xr pdfork 2
+for description of the process descriptors.
+The
+.Fa pid
+argument must be set to zero.
.It Dv PT_DETACH
This request is like PT_CONTINUE, except that it does not allow
specifying an alternate place to continue execution, and after it
diff --git a/sys/kern/subr_capability.c b/sys/kern/subr_capability.c
--- a/sys/kern/subr_capability.c
+++ b/sys/kern/subr_capability.c
@@ -93,6 +93,8 @@
const cap_rights_t cap_pdkill_rights = CAP_RIGHTS_INITIALIZER(CAP_PDKILL);
const cap_rights_t cap_pdwait_rights = CAP_RIGHTS_INITIALIZER(CAP_PDWAIT);
const cap_rights_t cap_pread_rights = CAP_RIGHTS_INITIALIZER(CAP_PREAD);
+const cap_rights_t cap_ptrace_attach_rights =
+ CAP_RIGHTS_INITIALIZER(CAP_PTRACE_ATTACH);
const cap_rights_t cap_pwrite_rights = CAP_RIGHTS_INITIALIZER(CAP_PWRITE);
const cap_rights_t cap_read_rights = CAP_RIGHTS_INITIALIZER(CAP_READ);
const cap_rights_t cap_recv_rights = CAP_RIGHTS_INITIALIZER(CAP_RECV);
diff --git a/sys/kern/sys_procdesc.c b/sys/kern/sys_procdesc.c
--- a/sys/kern/sys_procdesc.c
+++ b/sys/kern/sys_procdesc.c
@@ -704,44 +704,72 @@
return (kern_pdopenpid(td, args->pid, args->flags));
}
+int
+fget_procdesc(struct thread *td, int pdfd, const cap_rights_t *cap_rights,
+ struct file **pfp, struct procdesc **pdp, struct proc **pp)
+{
+ struct file *fp;
+ struct procdesc *pd;
+ struct proc *p;
+ int error;
+
+ sx_assert(&proctree_lock, SX_LOCKED);
+
+ error = fget(td, pdfd, cap_rights, &fp);
+ if (error != 0)
+ return (error);
+ if (fp->f_type != DTYPE_PROCDESC) {
+ fdrop(fp, td);
+ return (EBADF);
+ }
+ pd = fp->f_data;
+ if (pp != NULL) {
+ p = pd->pd_proc;
+ if (p == NULL) {
+ fdrop(fp, td);
+ return (ESRCH);
+ } else {
+ PROC_LOCK(p);
+ *pp = p;
+ }
+ }
+ *pfp = fp;
+ if (pdp != NULL)
+ *pdp = pd;
+ return (0);
+}
+
static int
kern_pddupfd(struct thread *td, int pdfd, int fd, int flags)
{
struct proc *p;
struct file *fp, *pfp;
- struct procdesc *pd;
struct filecaps fcaps;
uint8_t fd_flags;
int error, fdr;
- error = fget(td, pdfd, &cap_pddupfd_rights, &pfp);
+ sx_slock(&proctree_lock);
+ error = fget_procdesc(td, pdfd, &cap_pddupfd_rights, &pfp, NULL, &p);
+ sx_sunlock(&proctree_lock);
if (error != 0)
return (error);
- if (pfp->f_type != DTYPE_PROCDESC) {
- error = EBADF;
- goto out;
- }
- pd = pfp->f_data;
-again:
- sx_slock(&proctree_lock);
- p = pd->pd_proc;
- if (p != NULL) {
- AUDIT_ARG_PROCESS(p);
- PROC_LOCK(p);
- sx_sunlock(&proctree_lock);
+ AUDIT_ARG_PROCESS(p);
+ for (;;) {
+ PROC_LOCK_ASSERT(p, MA_OWNED);
if ((p->p_flag & P_WEXIT) != 0) {
error = ESRCH;
} else {
/*
- * Block the target process from entering
- * execve(). We need to ensure that the
- * p_candebug() predicate is stable until the
- * fget_remote() call ends even after the
- * process lock is dropped. For that, the
+ * Block the target process from entering execve().
+ * We need to ensure that the p_candebug() predicate
+ * is stable until the fget_remote() call ends even
+ * after the process lock is dropped. For that, the
* process must not change uid/suid.
*/
- if (!execve_block(td, p))
- goto again;
+ if (!execve_block(td, p)) {
+ PROC_LOCK(p);
+ continue;
+ }
error = p_candebug(td, p);
if (error == 0)
_PHOLD(p);
@@ -749,9 +777,9 @@
execve_unblock(td, p);
}
PROC_UNLOCK(p);
- if (error != 0)
- goto out;
-
+ break;
+ }
+ if (error == 0) {
error = fget_remote(td, p, fd, &fcaps, &fd_flags, &fp);
PROC_LOCK(p);
execve_unblock(td, p);
@@ -768,11 +796,7 @@
td->td_retval[0] = fdr;
}
}
- } else {
- sx_sunlock(&proctree_lock);
- error = ESRCH;
}
-out:
fdrop(pfp, td);
return (error);
}
diff --git a/sys/kern/sys_process.c b/sys/kern/sys_process.c
--- a/sys/kern/sys_process.c
+++ b/sys/kern/sys_process.c
@@ -43,6 +43,7 @@
#include <sys/mutex.h>
#include <sys/priv.h>
#include <sys/proc.h>
+#include <sys/procdesc.h>
#include <sys/ptrace.h>
#include <sys/reg.h>
#include <sys/rwlock.h>
@@ -978,6 +979,7 @@
struct ptrace_coredump *pc;
struct thr_coredump_req *tcq;
struct thr_syscall_req *tsr;
+ struct file *pfp;
int error, num, tmp;
lwpid_t tid = 0, *buf;
#ifdef COMPAT_FREEBSD32
@@ -988,11 +990,13 @@
curp = td->td_proc;
proctree_locked = false;
p2_req_set = false;
+ pfp = NULL;
/* Lock proctree before locking the process. */
switch (req) {
case PT_TRACE_ME:
case PT_ATTACH:
+ case PT_ATTACH_PD:
case PT_STEP:
case PT_CONTINUE:
case PT_TO_SCE:
@@ -1015,7 +1019,19 @@
p = td->td_proc;
PROC_LOCK(p);
} else {
- if (pid <= PID_MAX) {
+ if (req == PT_ATTACH_PD) {
+ if (pid != 0) {
+ sx_xunlock(&proctree_lock);
+ return (EINVAL);
+ }
+ error = fget_procdesc(td, data,
+ &cap_ptrace_attach_rights, &pfp, NULL, &p);
+ if (error != 0) {
+ sx_xunlock(&proctree_lock);
+ return (error);
+ }
+ tid = pid = p->p_pid;
+ } else if (pid <= PID_MAX) {
if ((p = pfind(pid)) == NULL) {
if (proctree_locked)
sx_xunlock(&proctree_lock);
@@ -1092,6 +1108,7 @@
break;
case PT_ATTACH:
+ case PT_ATTACH_PD:
/* Self */
if (p == td->td_proc) {
error = EINVAL;
@@ -1183,6 +1200,7 @@
break;
case PT_ATTACH:
+ case PT_ATTACH_PD:
/* security check done above */
/*
* It would be nice if the tracing relationship was separate
@@ -1859,6 +1877,8 @@
PROC_UNLOCK(p);
if (proctree_locked)
sx_xunlock(&proctree_lock);
+ if (pfp != NULL)
+ fdrop(pfp, td);
return (error);
}
#undef PROC_READ
diff --git a/sys/sys/caprights.h b/sys/sys/caprights.h
--- a/sys/sys/caprights.h
+++ b/sys/sys/caprights.h
@@ -95,6 +95,7 @@
extern const cap_rights_t cap_pdkill_rights;
extern const cap_rights_t cap_pdwait_rights;
extern const cap_rights_t cap_pread_rights;
+extern const cap_rights_t cap_ptrace_attach_rights;
extern const cap_rights_t cap_pwrite_rights;
extern const cap_rights_t cap_read_rights;
extern const cap_rights_t cap_recv_rights;
diff --git a/sys/sys/capsicum.h b/sys/sys/capsicum.h
--- a/sys/sys/capsicum.h
+++ b/sys/sys/capsicum.h
@@ -299,7 +299,9 @@
/* Allows pddupfd(2). */
#define CAP_PDDUPFD CAPRIGHT(1, 0x0000000000800000ULL)
-#define CAP_UNUSED1_25 CAPRIGHT(1, 0x0000000001000000ULL)
+/* Allows ptrace(PT_ATTACH_PD) */
+#define CAP_PTRACE_ATTACH CAPRIGHT(1, 0x0000000001000000ULL)
+
#define CAP_UNUSED1_26 CAPRIGHT(1, 0x0000000002000000ULL)
#define CAP_UNUSED1_27 CAPRIGHT(1, 0x0000000004000000ULL)
#define CAP_UNUSED1_28 CAPRIGHT(1, 0x0000000008000000ULL)
@@ -334,7 +336,7 @@
#define CAP_UNUSED1_57 CAPRIGHT(1, 0x0100000000000000ULL)
/* All used bits for index 1. */
-#define CAP_ALL1 CAPRIGHT(1, 0x0000000000FFFFFFULL)
+#define CAP_ALL1 CAPRIGHT(1, 0x0000000001FFFFFFULL)
/* Backward compatibility. */
#define CAP_POLL_EVENT CAP_EVENT
diff --git a/sys/sys/procdesc.h b/sys/sys/procdesc.h
--- a/sys/sys/procdesc.h
+++ b/sys/sys/procdesc.h
@@ -113,7 +113,9 @@
int procdesc_falloc(struct thread *, struct file **, int *, int,
struct filecaps *);
-
+int fget_procdesc(struct thread *td, int pfd,
+ const cap_rights_t *cap_rights, struct file **pfp,
+ struct procdesc **pdp, struct proc **pp);
#else /* !_KERNEL */
#include <sys/cdefs.h>
diff --git a/sys/sys/ptrace.h b/sys/sys/ptrace.h
--- a/sys/sys/ptrace.h
+++ b/sys/sys/ptrace.h
@@ -85,6 +85,7 @@
#define PT_GETREGSET 42 /* Get a target register set */
#define PT_SETREGSET 43 /* Set a target register set */
#define PT_SC_REMOTE 44 /* Execute a syscall */
+#define PT_ATTACH_PD 45 /* Attach by process descriptor */
#define PT_FIRSTMACH 64 /* for machine-specific requests */
#define PT_LASTMACH 127

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