git: 140ceb5d956b - main - ptrace(2): add PT_SC_REMOTE remote syscall request
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Date: Thu, 22 Dec 2022 22:10:55 UTC
The branch main has been updated by kib:
URL: https://cgit.FreeBSD.org/src/commit/?id=140ceb5d956bb8795a77c23d3fd5ef047b0f3c68
commit 140ceb5d956bb8795a77c23d3fd5ef047b0f3c68
Author: Konstantin Belousov <kib@FreeBSD.org>
AuthorDate: 2022-11-30 08:45:52 +0000
Commit: Konstantin Belousov <kib@FreeBSD.org>
CommitDate: 2022-12-22 21:11:35 +0000
ptrace(2): add PT_SC_REMOTE remote syscall request
Reviewed by: markj
Discussed with: jhb
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D37590
---
sys/compat/freebsd32/freebsd32.h | 7 ++
sys/compat/freebsd32/freebsd32_misc.c | 32 ++++++++
sys/kern/kern_sig.c | 142 +++++++++++++++++++++++++++++-----
sys/kern/sys_process.c | 74 +++++++++++++++++-
sys/sys/proc.h | 1 +
sys/sys/ptrace.h | 16 ++++
6 files changed, 250 insertions(+), 22 deletions(-)
diff --git a/sys/compat/freebsd32/freebsd32.h b/sys/compat/freebsd32/freebsd32.h
index 91d95d7852b3..3f37b3d85435 100644
--- a/sys/compat/freebsd32/freebsd32.h
+++ b/sys/compat/freebsd32/freebsd32.h
@@ -503,4 +503,11 @@ struct ptrace_coredump32 {
uint32_t pc_limit1, pc_limit2;
};
+struct ptrace_sc_remote32 {
+ struct ptrace_sc_ret32 pscr_ret;
+ u_int pscr_syscall;
+ u_int pscr_nargs;
+ uint32_t pscr_args;
+};
+
#endif /* !_COMPAT_FREEBSD32_FREEBSD32_H_ */
diff --git a/sys/compat/freebsd32/freebsd32_misc.c b/sys/compat/freebsd32/freebsd32_misc.c
index 7537ff3e9dee..7e96dd9296ee 100644
--- a/sys/compat/freebsd32/freebsd32_misc.c
+++ b/sys/compat/freebsd32/freebsd32_misc.c
@@ -966,6 +966,7 @@ freebsd32_ptrace(struct thread *td, struct freebsd32_ptrace_args *uap)
struct ptrace_lwpinfo pl;
struct ptrace_vm_entry pve;
struct ptrace_coredump pc;
+ struct ptrace_sc_remote sr;
struct dbreg32 dbreg;
struct fpreg32 fpreg;
struct reg32 reg;
@@ -979,10 +980,13 @@ freebsd32_ptrace(struct thread *td, struct freebsd32_ptrace_args *uap)
struct ptrace_lwpinfo32 pl;
struct ptrace_vm_entry32 pve;
struct ptrace_coredump32 pc;
+ struct ptrace_sc_remote32 sr;
uint32_t args[nitems(td->td_sa.args)];
struct ptrace_sc_ret32 psr;
struct iovec32 vec;
} r32;
+ syscallarg_t pscr_args[nitems(td->td_sa.args)];
+ u_int pscr_args32[nitems(td->td_sa.args)];
void *addr;
int data, error, i;
@@ -1081,6 +1085,28 @@ freebsd32_ptrace(struct thread *td, struct freebsd32_ptrace_args *uap)
r.pc.pc_limit = PAIR32TO64(off_t, r32.pc.pc_limit);
data = sizeof(r.pc);
break;
+ case PT_SC_REMOTE:
+ if (uap->data != sizeof(r32.sr)) {
+ error = EINVAL;
+ break;
+ }
+ error = copyin(uap->addr, &r32.sr, uap->data);
+ if (error != 0)
+ break;
+ CP(r32.sr, r.sr, pscr_syscall);
+ CP(r32.sr, r.sr, pscr_nargs);
+ if (r.sr.pscr_nargs > nitems(td->td_sa.args)) {
+ error = EINVAL;
+ break;
+ }
+ error = copyin(PTRIN(r32.sr.pscr_args), pscr_args32,
+ sizeof(u_int) * r32.sr.pscr_nargs);
+ if (error != 0)
+ break;
+ for (i = 0; i < r32.sr.pscr_nargs; i++)
+ pscr_args[i] = pscr_args32[i];
+ r.sr.pscr_args = pscr_args;
+ break;
default:
addr = uap->addr;
break;
@@ -1141,6 +1167,12 @@ freebsd32_ptrace(struct thread *td, struct freebsd32_ptrace_args *uap)
error = copyout(&r32.psr, uap->addr, MIN(uap->data,
sizeof(r32.psr)));
break;
+ case PT_SC_REMOTE:
+ ptrace_sc_ret_to32(&r.sr.pscr_ret, &r32.sr.pscr_ret);
+ error = copyout(&r32.sr.pscr_ret, uap->addr +
+ offsetof(struct ptrace_sc_remote32, pscr_ret),
+ sizeof(r32.psr));
+ break;
}
return (error);
diff --git a/sys/kern/kern_sig.c b/sys/kern/kern_sig.c
index eea624019fff..df40cdf404db 100644
--- a/sys/kern/kern_sig.c
+++ b/sys/kern/kern_sig.c
@@ -39,9 +39,11 @@
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
+#include "opt_capsicum.h"
#include "opt_ktrace.h"
#include <sys/param.h>
+#include <sys/capsicum.h>
#include <sys/ctype.h>
#include <sys/systm.h>
#include <sys/signalvar.h>
@@ -75,6 +77,7 @@ __FBSDID("$FreeBSD$");
#include <sys/smp.h>
#include <sys/stat.h>
#include <sys/sx.h>
+#include <sys/syscall.h>
#include <sys/syscallsubr.h>
#include <sys/sysctl.h>
#include <sys/sysent.h>
@@ -82,6 +85,7 @@ __FBSDID("$FreeBSD$");
#include <sys/sysproto.h>
#include <sys/timers.h>
#include <sys/unistd.h>
+#include <sys/vmmeter.h>
#include <sys/wait.h>
#include <vm/vm.h>
#include <vm/vm_extern.h>
@@ -2633,37 +2637,128 @@ out:
}
static void
-ptrace_coredump(struct thread *td)
+ptrace_coredumpreq(struct thread *td, struct proc *p,
+ struct thr_coredump_req *tcq)
{
- struct proc *p;
- struct thr_coredump_req *tcq;
void *rl_cookie;
- MPASS(td == curthread);
- p = td->td_proc;
- PROC_LOCK_ASSERT(p, MA_OWNED);
- if ((td->td_dbgflags & TDB_COREDUMPREQ) == 0)
- return;
- KASSERT((p->p_flag & P_STOPPED_TRACE) != 0, ("not stopped"));
-
- tcq = td->td_remotereq;
- KASSERT(tcq != NULL, ("td_remotereq is NULL"));
-
if (p->p_sysent->sv_coredump == NULL) {
tcq->tc_error = ENOSYS;
- goto wake;
+ return;
}
- PROC_UNLOCK(p);
rl_cookie = vn_rangelock_wlock(tcq->tc_vp, 0, OFF_MAX);
-
tcq->tc_error = p->p_sysent->sv_coredump(td, tcq->tc_vp,
tcq->tc_limit, tcq->tc_flags);
-
vn_rangelock_unlock(tcq->tc_vp, rl_cookie);
+}
+
+static void
+ptrace_syscallreq(struct thread *td, struct proc *p,
+ struct thr_syscall_req *tsr)
+{
+ struct sysentvec *sv;
+ struct sysent *se;
+ register_t rv_saved[2];
+ int error, nerror;
+ int sc;
+ bool audited, sy_thr_static;
+
+ sv = p->p_sysent;
+ if (sv->sv_table == NULL || sv->sv_size < tsr->ts_sa.code) {
+ tsr->ts_ret.sr_error = ENOSYS;
+ return;
+ }
+
+ sc = tsr->ts_sa.code;
+ if (sc == SYS_syscall || sc == SYS___syscall) {
+ memmove(&tsr->ts_sa.args[0], &tsr->ts_sa.args[1],
+ sizeof(register_t) * (tsr->ts_nargs - 1));
+ }
+
+ tsr->ts_sa.callp = se = &sv->sv_table[sc];
+
+ VM_CNT_INC(v_syscall);
+ td->td_pticks = 0;
+ if (__predict_false(td->td_cowgen != atomic_load_int(
+ &td->td_proc->p_cowgen)))
+ thread_cow_update(td);
+
+#ifdef CAPABILITY_MODE
+ if (IN_CAPABILITY_MODE(td) && (se->sy_flags & SYF_CAPENABLED) == 0) {
+ tsr->ts_ret.sr_error = ECAPMODE;
+ return;
+ }
+#endif
+
+ sy_thr_static = (se->sy_thrcnt & SY_THR_STATIC) != 0;
+ audited = AUDIT_SYSCALL_ENTER(tsr->ts_syscall, td) != 0;
+
+ if (!sy_thr_static) {
+ error = syscall_thread_enter(td, se);
+ if (error != 0) {
+ tsr->ts_ret.sr_error = error;
+ return;
+ }
+ }
+
+ rv_saved[0] = td->td_retval[0];
+ rv_saved[1] = td->td_retval[1];
+ nerror = td->td_errno;
+ td->td_retval[0] = 0;
+ td->td_retval[1] = 0;
+
+#ifdef KDTRACE_HOOKS
+ if (se->sy_entry != 0)
+ (*systrace_probe_func)(&tsr->ts_sa, SYSTRACE_ENTRY, 0);
+#endif
+ tsr->ts_ret.sr_error = se->sy_call(td, tsr->ts_sa.args);
+#ifdef KDTRACE_HOOKS
+ if (se->sy_return != 0)
+ (*systrace_probe_func)(&tsr->ts_sa, SYSTRACE_RETURN,
+ tsr->ts_ret->sr_error != 0 ? -1 : td->td_retval[0]);
+#endif
+
+ tsr->ts_ret.sr_retval[0] = td->td_retval[0];
+ tsr->ts_ret.sr_retval[1] = td->td_retval[1];
+ td->td_retval[0] = rv_saved[0];
+ td->td_retval[1] = rv_saved[1];
+ td->td_errno = nerror;
+
+ if (audited)
+ AUDIT_SYSCALL_EXIT(error, td);
+ if (!sy_thr_static)
+ syscall_thread_exit(td, se);
+}
+
+static void
+ptrace_remotereq(struct thread *td, int flag)
+{
+ struct proc *p;
+
+ MPASS(td == curthread);
+ p = td->td_proc;
+ PROC_LOCK_ASSERT(p, MA_OWNED);
+ if ((td->td_dbgflags & flag) == 0)
+ return;
+ KASSERT((p->p_flag & P_STOPPED_TRACE) != 0, ("not stopped"));
+ KASSERT(td->td_remotereq != NULL, ("td_remotereq is NULL"));
+
+ PROC_UNLOCK(p);
+ switch (flag) {
+ case TDB_COREDUMPREQ:
+ ptrace_coredumpreq(td, p, td->td_remotereq);
+ break;
+ case TDB_SCREMOTEREQ:
+ ptrace_syscallreq(td, p, td->td_remotereq);
+ break;
+ default:
+ __unreachable();
+ }
PROC_LOCK(p);
-wake:
- td->td_dbgflags &= ~TDB_COREDUMPREQ;
+
+ MPASS((td->td_dbgflags & flag) != 0);
+ td->td_dbgflags &= ~flag;
td->td_remotereq = NULL;
wakeup(p);
}
@@ -2795,9 +2890,14 @@ stopme:
td->td_dbgflags |= TDB_SSWITCH;
thread_suspend_switch(td, p);
td->td_dbgflags &= ~TDB_SSWITCH;
- if ((td->td_dbgflags & TDB_COREDUMPREQ) != 0) {
+ if ((td->td_dbgflags & (TDB_COREDUMPREQ |
+ TDB_SCREMOTEREQ)) != 0) {
+ MPASS((td->td_dbgflags & (TDB_COREDUMPREQ |
+ TDB_SCREMOTEREQ)) !=
+ (TDB_COREDUMPREQ | TDB_SCREMOTEREQ));
PROC_SUNLOCK(p);
- ptrace_coredump(td);
+ ptrace_remotereq(td, td->td_dbgflags &
+ (TDB_COREDUMPREQ | TDB_SCREMOTEREQ));
PROC_SLOCK(p);
goto stopme;
}
diff --git a/sys/kern/sys_process.c b/sys/kern/sys_process.c
index 15b93cee0f5a..47fdf91b87d5 100644
--- a/sys/kern/sys_process.c
+++ b/sys/kern/sys_process.c
@@ -592,6 +592,7 @@ sys_ptrace(struct thread *td, struct ptrace_args *uap)
struct ptrace_lwpinfo pl;
struct ptrace_vm_entry pve;
struct ptrace_coredump pc;
+ struct ptrace_sc_remote sr;
struct dbreg dbreg;
struct fpreg fpreg;
struct reg reg;
@@ -600,6 +601,7 @@ sys_ptrace(struct thread *td, struct ptrace_args *uap)
struct ptrace_sc_ret psr;
int ptevents;
} r;
+ syscallarg_t pscr_args[nitems(td->td_sa.args)];
void *addr;
int error;
@@ -657,6 +659,24 @@ sys_ptrace(struct thread *td, struct ptrace_args *uap)
else
error = copyin(uap->addr, &r.pc, uap->data);
break;
+ case PT_SC_REMOTE:
+ if (uap->data != sizeof(r.sr)) {
+ error = EINVAL;
+ break;
+ }
+ error = copyin(uap->addr, &r.sr, uap->data);
+ if (error != 0)
+ break;
+ if (r.sr.pscr_nargs > nitems(td->td_sa.args)) {
+ error = EINVAL;
+ break;
+ }
+ error = copyin(r.sr.pscr_args, pscr_args,
+ sizeof(u_long) * r.sr.pscr_nargs);
+ if (error != 0)
+ break;
+ r.sr.pscr_args = pscr_args;
+ break;
default:
addr = uap->addr;
break;
@@ -703,6 +723,11 @@ sys_ptrace(struct thread *td, struct ptrace_args *uap)
error = copyout(&r.psr, uap->addr, MIN(uap->data,
sizeof(r.psr)));
break;
+ case PT_SC_REMOTE:
+ error = copyout(&r.sr.pscr_ret, uap->addr +
+ offsetof(struct ptrace_sc_remote, pscr_ret),
+ sizeof(r.sr.pscr_ret));
+ break;
}
return (error);
@@ -812,9 +837,11 @@ kern_ptrace(struct thread *td, int req, pid_t pid, void *addr, int data)
struct ptrace_io_desc *piod = NULL;
struct ptrace_lwpinfo *pl;
struct ptrace_sc_ret *psr;
+ struct ptrace_sc_remote *pscr;
struct file *fp;
struct ptrace_coredump *pc;
struct thr_coredump_req *tcq;
+ struct thr_syscall_req *tsr;
int error, num, tmp;
lwpid_t tid = 0, *buf;
#ifdef COMPAT_FREEBSD32
@@ -1559,7 +1586,8 @@ kern_ptrace(struct thread *td, int req, pid_t pid, void *addr, int data)
error = EBUSY;
goto coredump_cleanup_locked;
}
- KASSERT((td2->td_dbgflags & TDB_COREDUMPREQ) == 0,
+ KASSERT((td2->td_dbgflags & (TDB_COREDUMPREQ |
+ TDB_SCREMOTEREQ)) == 0,
("proc %d tid %d req coredump", p->p_pid, td2->td_tid));
tcq->tc_vp = fp->f_vnode;
@@ -1584,6 +1612,50 @@ coredump_cleanup_nofp:
PROC_LOCK(p);
break;
+ case PT_SC_REMOTE:
+ pscr = addr;
+ CTR2(KTR_PTRACE, "PT_SC_REMOTE: pid %d, syscall %d",
+ p->p_pid, pscr->pscr_syscall);
+ if ((td2->td_dbgflags & TDB_BOUNDARY) == 0) {
+ error = EBUSY;
+ break;
+ }
+ PROC_UNLOCK(p);
+ MPASS(pscr->pscr_nargs <= nitems(td->td_sa.args));
+
+ tsr = malloc(sizeof(struct thr_syscall_req), M_TEMP,
+ M_WAITOK | M_ZERO);
+
+ tsr->ts_sa.code = pscr->pscr_syscall;
+ tsr->ts_nargs = pscr->pscr_nargs;
+ memcpy(&tsr->ts_sa.args, pscr->pscr_args,
+ sizeof(syscallarg_t) * tsr->ts_nargs);
+
+ PROC_LOCK(p);
+ error = proc_can_ptrace(td, p);
+ if (error != 0) {
+ free(tsr, M_TEMP);
+ break;
+ }
+ if (td2->td_proc != p) {
+ free(tsr, M_TEMP);
+ error = ESRCH;
+ break;
+ }
+ KASSERT((td2->td_dbgflags & (TDB_COREDUMPREQ |
+ TDB_SCREMOTEREQ)) == 0,
+ ("proc %d tid %d req coredump", p->p_pid, td2->td_tid));
+
+ td2->td_remotereq = tsr;
+ td2->td_dbgflags |= TDB_SCREMOTEREQ;
+ thread_run_flash(td2);
+ while ((td2->td_dbgflags & TDB_SCREMOTEREQ) != 0)
+ msleep(p, &p->p_mtx, PPAUSE, "pscrx", 0);
+ error = 0;
+ memcpy(&pscr->pscr_ret, &tsr->ts_ret, sizeof(tsr->ts_ret));
+ free(tsr, M_TEMP);
+ break;
+
default:
#ifdef __HAVE_PTRACE_MACHDEP
if (req >= PT_FIRSTMACH) {
diff --git a/sys/sys/proc.h b/sys/sys/proc.h
index f17207d741c1..2da5d8edee6d 100644
--- a/sys/sys/proc.h
+++ b/sys/sys/proc.h
@@ -524,6 +524,7 @@ enum {
#define TDB_SSWITCH 0x00004000 /* Suspended in ptracestop */
#define TDB_BOUNDARY 0x00008000 /* ptracestop() at boundary */
#define TDB_COREDUMPREQ 0x00010000 /* Coredump request */
+#define TDB_SCREMOTEREQ 0x00020000 /* Remote syscall request */
/*
* "Private" flags kept in td_pflags:
diff --git a/sys/sys/ptrace.h b/sys/sys/ptrace.h
index 80797f290a41..94d09eac95b1 100644
--- a/sys/sys/ptrace.h
+++ b/sys/sys/ptrace.h
@@ -87,6 +87,7 @@
#define PT_VM_ENTRY 41 /* Get VM map (entry) */
#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_FIRSTMACH 64 /* for machine-specific requests */
#include <machine/ptrace.h> /* machine-specific requests, if any */
@@ -192,8 +193,17 @@ struct ptrace_coredump {
#define PC_COMPRESS 0x00000001 /* Allow compression */
#define PC_ALL 0x00000002 /* Include non-dumpable entries */
+struct ptrace_sc_remote {
+ struct ptrace_sc_ret pscr_ret;
+ u_int pscr_syscall;
+ u_int pscr_nargs;
+ syscallarg_t *pscr_args;
+};
+
#ifdef _KERNEL
+#include <sys/proc.h>
+
struct thr_coredump_req {
struct vnode *tc_vp; /* vnode to write coredump to. */
off_t tc_limit; /* max coredump file size. */
@@ -201,6 +211,12 @@ struct thr_coredump_req {
int tc_error; /* request result */
};
+struct thr_syscall_req {
+ struct ptrace_sc_ret ts_ret;
+ u_int ts_nargs;
+ struct syscall_args ts_sa;
+};
+
int ptrace_set_pc(struct thread *_td, unsigned long _addr);
int ptrace_single_step(struct thread *_td);
int ptrace_clear_single_step(struct thread *_td);