From 7136a1d97aa22e7d0e50bbfb67013b1b96a3e7f1 Mon Sep 17 00:00:00 2001
From: John Baldwin <jhb@FreeBSD.org>
Date: Fri, 2 Jun 2017 13:33:50 +0000
Subject: [PATCH] Decode the arguments passed to __cap_rights_get() and
 cap_rights_limit().

Submitted by:	tobik
---
 usr.bin/truss/syscall.h  |  3 ++-
 usr.bin/truss/syscalls.c | 17 +++++++++++++++++
 2 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/usr.bin/truss/syscall.h b/usr.bin/truss/syscall.h
index 46bef46b2308..f0b39b468bbf 100644
--- a/usr.bin/truss/syscall.h
+++ b/usr.bin/truss/syscall.h
@@ -28,6 +28,7 @@
  * Kevent -- a pointer to an array of struct kevents.  Prints all elements.
  * Pathconf -- the 2nd argument of pathconf().
  * Utrace -- utrace(2) buffer.
+ * CapRights -- a pointer to a cap_rights_t.  Prints all set capabilities.
  *
  * In addition, the pointer types (String, Ptr) may have OUT masked in --
  * this means that the data is set on *return* from the system call -- or
@@ -47,7 +48,7 @@ enum Argtype { None = 1, Hex, Octal, Int, UInt, LongHex, Name, Ptr, Stat, Ioctl,
 	Sysarch, ExecArgs, ExecEnv, PipeFds, QuadHex, Utrace, IntArray, Pipe2,
 	CapFcntlRights, Fadvice, FileFlags, Flockop, Getfsstatmode, Kldsymcmd,
 	Kldunloadflags, Sizet, Madvice, Socklent, Sockprotocol, Sockoptlevel,
-	Sockoptname, Msgflags,
+	Sockoptname, Msgflags, CapRights,
 
 	CloudABIAdvice, CloudABIClockID, ClouduABIFDSFlags,
 	CloudABIFDStat, CloudABIFileStat, CloudABIFileType,
diff --git a/usr.bin/truss/syscalls.c b/usr.bin/truss/syscalls.c
index 1bf1e88ed8ad..f8c1943125ec 100644
--- a/usr.bin/truss/syscalls.c
+++ b/usr.bin/truss/syscalls.c
@@ -37,6 +37,7 @@ __FBSDID("$FreeBSD$");
  * arguments.
  */
 
+#include <sys/capsicum.h>
 #include <sys/types.h>
 #include <sys/event.h>
 #include <sys/ioccom.h>
@@ -76,6 +77,8 @@ __FBSDID("$FreeBSD$");
  */
 static struct syscall decoded_syscalls[] = {
 	/* Native ABI */
+	{ .name = "__cap_rights_get", .ret_type = 1, .nargs = 3,
+	  .args = { { Int, 0 }, { Int, 1 }, { CapRights | OUT, 2 } } },
 	{ .name = "__getcwd", .ret_type = 1, .nargs = 2,
 	  .args = { { Name | OUT, 0 }, { Int, 1 } } },
 	{ .name = "_umtx_op", .ret_type = 1, .nargs = 5,
@@ -96,6 +99,8 @@ static struct syscall decoded_syscalls[] = {
 	  .args = { { Int, 0 }, { CapFcntlRights | OUT, 1 } } },
 	{ .name = "cap_fcntls_limit", .ret_type = 1, .nargs = 2,
 	  .args = { { Int, 0 }, { CapFcntlRights, 1 } } },
+	{ .name = "cap_rights_limit", .ret_type = 1, .nargs = 2,
+	  .args = { { Int, 0 }, { CapRights, 1 } } },
 	{ .name = "chdir", .ret_type = 1, .nargs = 1,
 	  .args = { { Name, 0 } } },
 	{ .name = "chflags", .ret_type = 1, .nargs = 2,
@@ -1976,6 +1981,18 @@ print_arg(struct syscall_args *sc, unsigned long *args, long *retval,
 	case Msgflags:
 		print_mask_arg(sysdecode_msg_flags, fp, args[sc->offset]);
 		break;
+	case CapRights: {
+		cap_rights_t rights;
+
+		if (get_struct(pid, (void *)args[sc->offset], &rights,
+		    sizeof(rights)) != -1) {
+			fputs("{ ", fp);
+			sysdecode_cap_rights(fp, &rights);
+			fputs(" }", fp);
+		} else
+			fprintf(fp, "0x%lx", args[sc->offset]);
+		break;
+	}
 
 	case CloudABIAdvice:
 		fputs(xlookup(cloudabi_advice, args[sc->offset]), fp);