From: claudio <claudio@openbsd.org>
Date: Wed, 26 Apr 2023 16:53:58 +0000 (+0000)
Subject: Implement dt(4) utrace support on amd64 and i386.
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=a28bb56f1e3b6564881b3d3de68367d380458694;p=openbsd

Implement dt(4) utrace support on amd64 and i386.

This adds stacktrace_save_utrace() to extract and save the userland stack
which is stubbed out on most archs. alpha and riscv64 do not even implement
dt(4) and stacktrace_save_at() so the stubs are excluded there.

Additionally add a new ioctl DTIOCGETAUXBASE which allows btrace to
fetch the AUX_BASE vallue from the AUX vector of a process.

OK mpi@ (some time ago) discussed with kettenis@
---

diff --git a/sys/arch/amd64/amd64/db_trace.c b/sys/arch/amd64/amd64/db_trace.c
index e9209c348eb..eed87fee1a2 100644
--- a/sys/arch/amd64/amd64/db_trace.c
+++ b/sys/arch/amd64/amd64/db_trace.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: db_trace.c,v 1.54 2021/09/04 07:13:14 jasper Exp $	*/
+/*	$OpenBSD: db_trace.c,v 1.55 2023/04/26 16:53:58 claudio Exp $	*/
 /*	$NetBSD: db_trace.c,v 1.1 2003/04/26 18:39:27 fvdl Exp $	*/
 
 /*
@@ -287,6 +287,43 @@ stacktrace_save_at(struct stacktrace *st, unsigned int skip)
 	}
 }
 
+void
+stacktrace_save_utrace(struct stacktrace *st)
+{
+	struct callframe f, *frame, *lastframe;
+	struct pcb *pcb = curpcb;
+
+	st->st_count = 0;
+
+	if (pcb == NULL)
+		return;
+
+	frame = __builtin_frame_address(0);
+	KASSERT(INKERNEL(frame));
+	f = *frame;
+
+	while (st->st_count < STACKTRACE_MAX) {
+		if (f.f_retaddr != 0 && !INKERNEL(f.f_retaddr))
+			st->st_pc[st->st_count++] = f.f_retaddr;
+
+		lastframe = frame;
+		frame = f.f_frame;
+
+		if (frame == NULL)
+			break;
+		if (INKERNEL(f.f_retaddr)) {
+			if (frame <= lastframe)
+				break;
+			f = *frame;
+			continue;
+		}
+		if (!INKERNEL(lastframe) && frame <= lastframe)
+			break;
+		if (copyin(frame, &f, sizeof(f)) != 0)
+			break;
+	}
+}
+
 vaddr_t
 db_get_pc(struct trapframe *tf)
 {
diff --git a/sys/arch/arm64/arm64/db_trace.c b/sys/arch/arm64/arm64/db_trace.c
index d36db66c6ad..f0c0bd5b0a0 100644
--- a/sys/arch/arm64/arm64/db_trace.c
+++ b/sys/arch/arm64/arm64/db_trace.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: db_trace.c,v 1.13 2021/07/09 20:59:51 jasper Exp $	*/
+/*	$OpenBSD: db_trace.c,v 1.14 2023/04/26 16:53:58 claudio Exp $	*/
 /*	$NetBSD: db_trace.c,v 1.8 2003/01/17 22:28:48 thorpej Exp $	*/
 
 /*
@@ -183,3 +183,9 @@ stacktrace_save_at(struct stacktrace *st, unsigned int skip)
 			break;
 	}
 }
+
+void
+stacktrace_save_utrace(struct stacktrace *st)
+{
+	st->st_count = 0;
+}
diff --git a/sys/arch/hppa/hppa/db_interface.c b/sys/arch/hppa/hppa/db_interface.c
index 4fdc05da415..2d278b03568 100644
--- a/sys/arch/hppa/hppa/db_interface.c
+++ b/sys/arch/hppa/hppa/db_interface.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: db_interface.c,v 1.48 2020/04/18 04:45:20 visa Exp $	*/
+/*	$OpenBSD: db_interface.c,v 1.49 2023/04/26 16:53:58 claudio Exp $	*/
 
 /*
  * Copyright (c) 1999-2003 Michael Shalayeff
@@ -341,3 +341,9 @@ stacktrace_save_at(struct stacktrace *st, unsigned int skip)
 		fp = (register_t *)fp[0];
 	}
 }
+
+void
+stacktrace_save_utrace(struct stacktrace *st)
+{
+	st->st_count = 0;
+}
diff --git a/sys/arch/i386/i386/db_trace.c b/sys/arch/i386/i386/db_trace.c
index 8242374ab97..5f73dabee4d 100644
--- a/sys/arch/i386/i386/db_trace.c
+++ b/sys/arch/i386/i386/db_trace.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: db_trace.c,v 1.43 2023/01/30 10:49:05 jsg Exp $	*/
+/*	$OpenBSD: db_trace.c,v 1.44 2023/04/26 16:53:58 claudio Exp $	*/
 /*	$NetBSD: db_trace.c,v 1.18 1996/05/03 19:42:01 christos Exp $	*/
 
 /*
@@ -292,6 +292,43 @@ stacktrace_save_at(struct stacktrace *st, unsigned int skip)
 	}
 }
 
+void
+stacktrace_save_utrace(struct stacktrace *st)
+{
+	struct callframe f, *frame, *lastframe;
+	struct pcb *pcb = curpcb;
+
+	st->st_count = 0;
+
+	if (pcb == NULL)
+		return;
+
+	frame = __builtin_frame_address(0);
+	KASSERT(INKERNEL(frame));
+	f = *frame;
+
+	while (st->st_count < STACKTRACE_MAX) {
+		if (f.f_retaddr != 0 && !INKERNEL(f.f_retaddr))
+			st->st_pc[st->st_count++] = f.f_retaddr;
+
+		lastframe = frame;
+		frame = f.f_frame;
+
+		if (frame == NULL)
+			break;
+		if (INKERNEL(f.f_retaddr)) {
+			if (frame <= lastframe)
+				break;
+			f = *frame;
+			continue;
+		}
+		if (!INKERNEL(lastframe) && frame <= lastframe)
+			break;
+		if (copyin(frame, &f, sizeof(f)) != 0)
+			break;
+	}
+}
+
 vaddr_t
 db_get_pc(struct trapframe *tf)
 {
diff --git a/sys/arch/mips64/mips64/trap.c b/sys/arch/mips64/mips64/trap.c
index ba018dd9f48..df4d2adebe5 100644
--- a/sys/arch/mips64/mips64/trap.c
+++ b/sys/arch/mips64/mips64/trap.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: trap.c,v 1.166 2023/02/11 23:07:27 deraadt Exp $	*/
+/*	$OpenBSD: trap.c,v 1.167 2023/04/26 16:53:59 claudio Exp $	*/
 
 /*
  * Copyright (c) 1988 University of Utah.
@@ -1479,6 +1479,12 @@ stacktrace_save_at(struct stacktrace *st, unsigned int skip)
 		sp += framesize;
 	}
 }
+
+void
+stacktrace_save_utrace(struct stacktrace *st)
+{
+	st->st_count = 0;
+}
 #endif
 
 #undef	VALID_ADDRESS
diff --git a/sys/arch/powerpc/ddb/db_trace.c b/sys/arch/powerpc/ddb/db_trace.c
index e9351e93f6c..46cba9b61e4 100644
--- a/sys/arch/powerpc/ddb/db_trace.c
+++ b/sys/arch/powerpc/ddb/db_trace.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: db_trace.c,v 1.19 2022/02/07 22:28:15 gkoehler Exp $	*/
+/*	$OpenBSD: db_trace.c,v 1.20 2023/04/26 16:53:59 claudio Exp $	*/
 /*	$NetBSD: db_trace.c,v 1.15 1996/02/22 23:23:41 gwr Exp $	*/
 
 /*
@@ -268,3 +268,9 @@ stacktrace_save_at(struct stacktrace *st, unsigned int skip)
 			break;
 	}
 }
+
+void
+stacktrace_save_utrace(struct stacktrace *st)
+{
+	st->st_count = 0;
+}
diff --git a/sys/arch/powerpc64/powerpc64/db_trace.c b/sys/arch/powerpc64/powerpc64/db_trace.c
index 9dc63224f93..f70d5200e1f 100644
--- a/sys/arch/powerpc64/powerpc64/db_trace.c
+++ b/sys/arch/powerpc64/powerpc64/db_trace.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: db_trace.c,v 1.8 2022/01/28 18:37:40 gkoehler Exp $	*/
+/*	$OpenBSD: db_trace.c,v 1.9 2023/04/26 16:53:59 claudio Exp $	*/
 /*	$NetBSD: db_trace.c,v 1.15 1996/02/22 23:23:41 gwr Exp $	*/
 
 /*
@@ -232,3 +232,9 @@ stacktrace_save_at(struct stacktrace *st, unsigned int skip)
 			break;
 	}
 }
+
+void
+stacktrace_save_utrace(struct stacktrace *st)
+{
+	st->st_count = 0;
+}
diff --git a/sys/arch/sparc64/sparc64/db_trace.c b/sys/arch/sparc64/sparc64/db_trace.c
index 70d8f90df14..88e40b0c2ae 100644
--- a/sys/arch/sparc64/sparc64/db_trace.c
+++ b/sys/arch/sparc64/sparc64/db_trace.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: db_trace.c,v 1.24 2022/10/25 06:00:34 guenther Exp $	*/
+/*	$OpenBSD: db_trace.c,v 1.25 2023/04/26 16:53:59 claudio Exp $	*/
 /*	$NetBSD: db_trace.c,v 1.23 2001/07/10 06:06:16 eeh Exp $ */
 
 /*
@@ -188,6 +188,12 @@ stacktrace_save_at(struct stacktrace *st, unsigned int skip)
 	}
 }
 
+void
+stacktrace_save_utrace(struct stacktrace *st)
+{
+	st->st_count = 0;
+}
+
 void
 db_dump_window(db_expr_t addr, int have_addr, db_expr_t count, char *modif)
 {
diff --git a/sys/dev/dt/dt_dev.c b/sys/dev/dt/dt_dev.c
index 4f84e5dd4fc..96c4709f2f7 100644
--- a/sys/dev/dt/dt_dev.c
+++ b/sys/dev/dt/dt_dev.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: dt_dev.c,v 1.25 2023/03/10 22:14:32 bluhm Exp $ */
+/*	$OpenBSD: dt_dev.c,v 1.26 2023/04/26 16:53:59 claudio Exp $ */
 
 /*
  * Copyright (c) 2019 Martin Pieuchot <mpi@openbsd.org>
@@ -20,8 +20,10 @@
 #include <sys/systm.h>
 #include <sys/param.h>
 #include <sys/device.h>
+#include <sys/exec_elf.h>
 #include <sys/malloc.h>
 #include <sys/proc.h>
+#include <sys/ptrace.h>
 
 #include <dev/dt/dtvar.h>
 
@@ -135,6 +137,7 @@ int	dt_ioctl_record_start(struct dt_softc *);
 void	dt_ioctl_record_stop(struct dt_softc *);
 int	dt_ioctl_probe_enable(struct dt_softc *, struct dtioc_req *);
 int	dt_ioctl_probe_disable(struct dt_softc *, struct dtioc_req *);
+int	dt_ioctl_get_auxbase(struct dt_softc *, struct dtioc_getaux *);
 
 int	dt_pcb_ring_copy(struct dt_pcb *, struct dt_evt *, size_t, uint64_t *);
 
@@ -289,6 +292,7 @@ dtioctl(dev_t dev, u_long cmd, caddr_t addr, int flag, struct proc *p)
 	case DTIOCRECORD:
 	case DTIOCPRBENABLE:
 	case DTIOCPRBDISABLE:
+	case DTIOCGETAUXBASE:
 		/* root only ioctl(2) */
 		break;
 	default:
@@ -312,6 +316,9 @@ dtioctl(dev_t dev, u_long cmd, caddr_t addr, int flag, struct proc *p)
 	case DTIOCPRBDISABLE:
 		error = dt_ioctl_probe_disable(sc, (struct dtioc_req *)addr);
 		break;
+	case DTIOCGETAUXBASE:
+		error = dt_ioctl_get_auxbase(sc, (struct dtioc_getaux *)addr);
+		break;
 	default:
 		KASSERT(0);
 	}
@@ -575,6 +582,42 @@ dt_ioctl_probe_disable(struct dt_softc *sc, struct dtioc_req *dtrq)
 	return 0;
 }
 
+int
+dt_ioctl_get_auxbase(struct dt_softc *sc, struct dtioc_getaux *dtga)
+{
+	struct uio uio;
+	struct iovec iov;
+	struct process *pr;
+	struct proc *p = curproc;
+	AuxInfo auxv[ELF_AUX_ENTRIES];
+	int i, error;
+
+	dtga->dtga_auxbase = 0;
+
+	if ((pr = prfind(dtga->dtga_pid)) == NULL)
+		return ESRCH;
+
+	iov.iov_base = auxv;
+	iov.iov_len = sizeof(auxv);
+	uio.uio_iov = &iov;
+	uio.uio_iovcnt = 1;
+	uio.uio_offset = pr->ps_auxinfo;
+	uio.uio_resid = sizeof(auxv);
+	uio.uio_segflg = UIO_SYSSPACE;
+	uio.uio_procp = p;
+	uio.uio_rw = UIO_READ;
+
+	error = process_domem(p, pr, &uio, PT_READ_D);
+	if (error)
+		return error;
+
+	for (i = 0; i < ELF_AUX_ENTRIES; i++)
+		if (auxv[i].au_id == AUX_base)
+			dtga->dtga_auxbase = auxv[i].au_v;
+
+	return 0;
+}
+
 struct dt_probe *
 dt_dev_alloc_probe(const char *func, const char *name, struct dt_provider *dtpv)
 {
@@ -725,12 +768,14 @@ dt_pcb_ring_get(struct dt_pcb *dp, int profiling)
 	if (ISSET(dp->dp_evtflags, DTEVT_EXECNAME))
 		strlcpy(dtev->dtev_comm, p->p_p->ps_comm, sizeof(dtev->dtev_comm));
 
-	if (ISSET(dp->dp_evtflags, DTEVT_KSTACK|DTEVT_USTACK)) {
+	if (ISSET(dp->dp_evtflags, DTEVT_KSTACK)) {
 		if (profiling)
 			stacktrace_save_at(&dtev->dtev_kstack, DT_FA_PROFILE);
 		else
 			stacktrace_save_at(&dtev->dtev_kstack, DT_FA_STATIC);
 	}
+	if (ISSET(dp->dp_evtflags, DTEVT_USTACK))
+		stacktrace_save_utrace(&dtev->dtev_ustack);
 
 	return dtev;
 }
diff --git a/sys/dev/dt/dt_prov_profile.c b/sys/dev/dt/dt_prov_profile.c
index 502e99828f3..d6db0797bf0 100644
--- a/sys/dev/dt/dt_prov_profile.c
+++ b/sys/dev/dt/dt_prov_profile.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: dt_prov_profile.c,v 1.4 2021/09/03 16:45:45 jasper Exp $ */
+/*	$OpenBSD: dt_prov_profile.c,v 1.5 2023/04/26 16:53:59 claudio Exp $ */
 
 /*
  * Copyright (c) 2019 Martin Pieuchot <mpi@openbsd.org>
@@ -27,7 +27,7 @@ struct dt_probe	*dtpp_profile;		/* per-CPU profile probe */
 struct dt_probe	*dtpp_interval;		/* global periodic probe */
 
 /* Flags that make sense for this provider */
-#define DTEVT_PROV_PROFILE	DTEVT_KSTACK
+#define DTEVT_PROV_PROFILE	DTEVT_COMMON
 
 int	dt_prov_profile_alloc(struct dt_probe *, struct dt_softc *,
 	    struct dt_pcb_list *, struct dtioc_req *);
diff --git a/sys/dev/dt/dtvar.h b/sys/dev/dt/dtvar.h
index 5d4aeac21a9..9b5d3de08ee 100644
--- a/sys/dev/dt/dtvar.h
+++ b/sys/dev/dt/dtvar.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: dtvar.h,v 1.16 2023/04/10 04:21:20 jsg Exp $ */
+/*	$OpenBSD: dtvar.h,v 1.17 2023/04/26 16:53:59 claudio Exp $ */
 
 /*
  * Copyright (c) 2019 Martin Pieuchot <mpi@openbsd.org>
@@ -53,6 +53,7 @@ struct dt_evt {
 	 * Recorded if the corresponding flag is set.
 	 */
 	struct stacktrace	dtev_kstack;	/* kernel stack frame */
+	struct stacktrace	dtev_ustack;	/* userland stack frame */
 	char			dtev_comm[DTMAXCOMLEN]; /* current pr. name */
 	union {
 		register_t		E_entry[DTMAXFUNCARGS];
@@ -80,7 +81,6 @@ struct dt_evt {
 	"\002USTACK"		\
 	"\003KSTACK"		\
 	"\004FUNCARGS"		\
-	"\005RETVAL"		\
 
 /*
  * Each PCB can have a filter attached to itself.  A filter do not
@@ -139,12 +139,18 @@ struct dtioc_stat {
 	uint64_t		 dtst_dropevt;	/* events dropped */
 };
 
+struct dtioc_getaux {
+	pid_t			 dtga_pid;	/* process to inspect */
+	unsigned long		 dtga_auxbase;	/* AUX_base value */
+};
+
 #define DTIOCGPLIST	_IOWR('D', 1, struct dtioc_probe)
 #define DTIOCGSTATS	_IOR('D', 2, struct dtioc_stat)
 #define DTIOCRECORD	_IOW('D', 3, int)
 #define DTIOCPRBENABLE	_IOW('D', 4, struct dtioc_req)
 #define DTIOCPRBDISABLE	 _IOW('D', 5, struct dtioc_req)
 #define DTIOCGARGS	_IOWR('D', 6, struct dtioc_arg)
+#define DTIOCGETAUXBASE	 _IOWR('D', 7, struct dtioc_getaux)
 
 #ifdef _KERNEL
 
diff --git a/sys/sys/stacktrace.h b/sys/sys/stacktrace.h
index 5d78b757a16..1348b715db2 100644
--- a/sys/sys/stacktrace.h
+++ b/sys/sys/stacktrace.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: stacktrace.h,v 1.3 2020/04/18 04:45:20 visa Exp $	*/
+/*	$OpenBSD: stacktrace.h,v 1.4 2023/04/26 16:53:59 claudio Exp $	*/
 
 /*
  * Copyright (c) 2017 Visa Hankala
@@ -29,6 +29,7 @@ struct stacktrace {
 #ifdef _KERNEL
 void	stacktrace_print(struct stacktrace *, int (*)(const char *, ...));
 void	stacktrace_save_at(struct stacktrace *, unsigned int);
+void	stacktrace_save_utrace(struct stacktrace *);
 
 static inline void
 stacktrace_save(struct stacktrace *st)