git: b1ad6a9000c3 - main - syscallarg_t: Add a type for system call arguments

From: Brooks Davis <brooks_at_FreeBSD.org>
Date: Mon, 28 Mar 2022 18:43:48 UTC
The branch main has been updated by brooks:

URL: https://cgit.FreeBSD.org/src/commit/?id=b1ad6a9000c3fc58d4373fa5a4733d46a9a365ca

commit b1ad6a9000c3fc58d4373fa5a4733d46a9a365ca
Author:     Brooks Davis <brooks@FreeBSD.org>
AuthorDate: 2022-03-28 18:43:03 +0000
Commit:     Brooks Davis <brooks@FreeBSD.org>
CommitDate: 2022-03-28 18:43:03 +0000

    syscallarg_t: Add a type for system call arguments
    
    This more clearly differentiates system call arguments from integer
    registers and return values. On current architectures it has no effect,
    but on architectures where pointers are not integers (CHERI) and may
    not even share registers (CHERI-MIPS) it is necessiary to differentiate
    between system call arguments (syscallarg_t) and integer register values
    (register_t).
    
    Obtained from:  CheriBSD
    
    Reviewed by:    imp, kib
    Differential Revision:  https://reviews.freebsd.org/D33780
---
 sys/amd64/amd64/trap.c     |  2 +-
 sys/arm/arm/syscall.c      |  6 +++---
 sys/arm64/arm64/trap.c     |  4 ++--
 sys/kern/kern_ktrace.c     |  2 +-
 sys/kern/sys_process.c     |  4 ++--
 sys/riscv/riscv/trap.c     |  4 ++--
 sys/sys/ktrace.h           |  2 +-
 sys/sys/proc.h             |  2 +-
 sys/sys/ptrace.h           |  2 +-
 sys/sys/types.h            |  2 ++
 sys/tools/makesyscalls.lua | 10 +++++-----
 sys/vm/vm_mmap.c           |  2 +-
 usr.bin/truss/setup.c      |  2 +-
 usr.bin/truss/syscall.h    |  8 ++++----
 usr.bin/truss/syscalls.c   |  8 ++++----
 usr.bin/truss/truss.h      |  2 +-
 16 files changed, 32 insertions(+), 30 deletions(-)

diff --git a/sys/amd64/amd64/trap.c b/sys/amd64/amd64/trap.c
index 8d8bdd6fbb6e..19b0c5065e68 100644
--- a/sys/amd64/amd64/trap.c
+++ b/sys/amd64/amd64/trap.c
@@ -1011,7 +1011,7 @@ cpu_fetch_syscall_args_fallback(struct thread *td, struct syscall_args *sa)
 {
 	struct proc *p;
 	struct trapframe *frame;
-	register_t *argp;
+	syscallarg_t *argp;
 	caddr_t params;
 	int reg, regcnt, error;
 
diff --git a/sys/arm/arm/syscall.c b/sys/arm/arm/syscall.c
index a635de0ec716..c083bf552eb5 100644
--- a/sys/arm/arm/syscall.c
+++ b/sys/arm/arm/syscall.c
@@ -100,7 +100,7 @@ int
 cpu_fetch_syscall_args(struct thread *td)
 {
 	struct proc *p;
-	register_t *ap;
+	syscallarg_t *ap;
 	struct syscall_args *sa;
 	u_int nap;
 	int error;
@@ -124,10 +124,10 @@ cpu_fetch_syscall_args(struct thread *td)
 	else
 		sa->callp = &p->p_sysent->sv_table[sa->code];
 	error = 0;
-	memcpy(sa->args, ap, nap * sizeof(register_t));
+	memcpy(sa->args, ap, nap * sizeof(*sa->args));
 	if (sa->callp->sy_narg > nap) {
 		error = copyin((void *)td->td_frame->tf_usr_sp, sa->args +
-		    nap, (sa->callp->sy_narg - nap) * sizeof(register_t));
+		    nap, (sa->callp->sy_narg - nap) * sizeof(*sa->args));
 	}
 	if (error == 0) {
 		td->td_retval[0] = 0;
diff --git a/sys/arm64/arm64/trap.c b/sys/arm64/arm64/trap.c
index 226f69592952..b664501b62fa 100644
--- a/sys/arm64/arm64/trap.c
+++ b/sys/arm64/arm64/trap.c
@@ -134,7 +134,7 @@ int
 cpu_fetch_syscall_args(struct thread *td)
 {
 	struct proc *p;
-	register_t *ap, *dst_ap;
+	syscallarg_t *ap, *dst_ap;
 	struct syscall_args *sa;
 
 	p = td->td_proc;
@@ -159,7 +159,7 @@ cpu_fetch_syscall_args(struct thread *td)
 	KASSERT(sa->callp->sy_narg <= nitems(sa->args),
 	    ("Syscall %d takes too many arguments", sa->code));
 
-	memcpy(dst_ap, ap, (nitems(sa->args) - 1) * sizeof(register_t));
+	memcpy(dst_ap, ap, (nitems(sa->args) - 1) * sizeof(*dst_ap));
 
 	td->td_retval[0] = 0;
 	td->td_retval[1] = 0;
diff --git a/sys/kern/kern_ktrace.c b/sys/kern/kern_ktrace.c
index f102f7e7b0a4..be3081ac9983 100644
--- a/sys/kern/kern_ktrace.c
+++ b/sys/kern/kern_ktrace.c
@@ -524,7 +524,7 @@ ktr_get_tracevp(struct proc *p, bool ref)
 }
 
 void
-ktrsyscall(int code, int narg, register_t args[])
+ktrsyscall(int code, int narg, syscallarg_t args[])
 {
 	struct ktr_request *req;
 	struct ktr_syscall *ktp;
diff --git a/sys/kern/sys_process.c b/sys/kern/sys_process.c
index 965e22a38598..ce8529bee256 100644
--- a/sys/kern/sys_process.c
+++ b/sys/kern/sys_process.c
@@ -596,7 +596,7 @@ sys_ptrace(struct thread *td, struct ptrace_args *uap)
 		struct fpreg fpreg;
 		struct reg reg;
 		struct iovec vec;
-		char args[sizeof(td->td_sa.args)];
+		syscallarg_t args[nitems(td->td_sa.args)];
 		struct ptrace_sc_ret psr;
 		int ptevents;
 	} r;
@@ -1143,7 +1143,7 @@ kern_ptrace(struct thread *td, int req, pid_t pid, void *addr, int data)
 		/* See the explanation in linux_ptrace_get_syscall_info(). */
 		bcopy(td2->td_sa.args, addr, SV_PROC_ABI(td->td_proc) ==
 		    SV_ABI_LINUX ? sizeof(td2->td_sa.args) :
-		    td2->td_sa.callp->sy_narg * sizeof(register_t));
+		    td2->td_sa.callp->sy_narg * sizeof(syscallarg_t));
 		break;
 
 	case PT_GET_SC_RET:
diff --git a/sys/riscv/riscv/trap.c b/sys/riscv/riscv/trap.c
index b89eae325e0c..0744f5a25fb3 100644
--- a/sys/riscv/riscv/trap.c
+++ b/sys/riscv/riscv/trap.c
@@ -94,7 +94,7 @@ int
 cpu_fetch_syscall_args(struct thread *td)
 {
 	struct proc *p;
-	register_t *ap, *dst_ap;
+	syscallarg_t *ap, *dst_ap;
 	struct syscall_args *sa;
 
 	p = td->td_proc;
@@ -119,7 +119,7 @@ cpu_fetch_syscall_args(struct thread *td)
 	KASSERT(sa->callp->sy_narg <= nitems(sa->args),
 	    ("Syscall %d takes too many arguments", sa->code));
 
-	memcpy(dst_ap, ap, (NARGREG - 1) * sizeof(register_t));
+	memcpy(dst_ap, ap, (NARGREG - 1) * sizeof(*dst_ap));
 
 	td->td_retval[0] = 0;
 	td->td_retval[1] = 0;
diff --git a/sys/sys/ktrace.h b/sys/sys/ktrace.h
index 283a95c36d6c..d00981a93d24 100644
--- a/sys/sys/ktrace.h
+++ b/sys/sys/ktrace.h
@@ -284,7 +284,7 @@ void	ktrpsig(int, sig_t, sigset_t *, int);
 void	ktrfault(vm_offset_t, int);
 void	ktrfaultend(int);
 void	ktrgenio(int, enum uio_rw, struct uio *, int);
-void	ktrsyscall(int, int narg, register_t args[]);
+void	ktrsyscall(int, int narg, syscallarg_t args[]);
 void	ktrsysctl(int *name, u_int namelen);
 void	ktrsysret(int, int, register_t);
 void	ktrprocctor(struct proc *);
diff --git a/sys/sys/proc.h b/sys/sys/proc.h
index 71105239e40e..2556fd574d84 100644
--- a/sys/sys/proc.h
+++ b/sys/sys/proc.h
@@ -357,7 +357,7 @@ struct thread {
 	} td_state;			/* (t) thread state */
 	/* Note: td_state must be accessed using TD_{GET,SET}_STATE(). */
 	union {
-		register_t	tdu_retval[2];
+		syscallarg_t	tdu_retval[2];
 		off_t		tdu_off;
 	} td_uretoff;			/* (k) Syscall aux returns. */
 #define td_retval	td_uretoff.tdu_retval
diff --git a/sys/sys/ptrace.h b/sys/sys/ptrace.h
index 197ac1692dfb..80797f290a41 100644
--- a/sys/sys/ptrace.h
+++ b/sys/sys/ptrace.h
@@ -162,7 +162,7 @@ struct ptrace_lwpinfo32 {
 
 /* Argument structure for PT_GET_SC_RET. */
 struct ptrace_sc_ret {
-	register_t	sr_retval[2];	/* Only valid if sr_error == 0. */
+	syscallarg_t	sr_retval[2];	/* Only valid if sr_error == 0. */
 	int		sr_error;
 };
 
diff --git a/sys/sys/types.h b/sys/sys/types.h
index 66f11aa3e31d..d37ab8b823dc 100644
--- a/sys/sys/types.h
+++ b/sys/sys/types.h
@@ -270,6 +270,8 @@ typedef	__vm_size_t	vm_size_t;
 
 typedef __rman_res_t    rman_res_t;
 
+typedef __register_t	syscallarg_t;
+
 #ifdef _KERNEL
 typedef	int		boolean_t;
 typedef	struct _device	*device_t;
diff --git a/sys/tools/makesyscalls.lua b/sys/tools/makesyscalls.lua
index 178869d03b0e..ec79ae30d130 100644
--- a/sys/tools/makesyscalls.lua
+++ b/sys/tools/makesyscalls.lua
@@ -860,7 +860,7 @@ local function handle_noncompat(sysnum, thr_flag, flags, sysflags, rettype,
 			write_line("sysarg", "};\n")
 		else
 			write_line("sysarg", string.format(
-			    "struct %s {\n\tregister_t dummy;\n};\n", argalias))
+			    "struct %s {\n\tsyscallarg_t dummy;\n};\n", argalias))
 		end
 	end
 
@@ -986,7 +986,7 @@ local function handle_compat(sysnum, thr_flag, flags, sysflags, rettype,
 		write_line(out, "};\n")
 	elseif flags & nargflags == 0 then
 		write_line("sysarg", string.format(
-		    "struct %s {\n\tregister_t dummy;\n};\n", argalias))
+		    "struct %s {\n\tsyscallarg_t dummy;\n};\n", argalias))
 	end
 	if flags & dprotoflags == 0 then
 		write_line(outdcl, string.format(
@@ -1439,8 +1439,8 @@ struct proc;
 
 struct thread;
 
-#define	PAD_(t)	(sizeof(register_t) <= sizeof(t) ? \
-		0 : sizeof(register_t) - sizeof(t))
+#define	PAD_(t)	(sizeof(syscallarg_t) <= sizeof(t) ? \
+		0 : sizeof(syscallarg_t) - sizeof(t))
 
 #if BYTE_ORDER == LITTLE_ENDIAN
 #define	PADL_(t)	0
@@ -1530,7 +1530,7 @@ systrace_return_setargdesc(int sysnum, int ndx, char *desc, size_t descsz)
 process_sysfile(sysfile)
 
 write_line("sysinc",
-    "\n#define AS(name) (sizeof(struct name) / sizeof(register_t))\n")
+    "\n#define AS(name) (sizeof(struct name) / sizeof(syscallarg_t))\n")
 
 for _, v in pairs(compat_options) do
 	if v["count"] > 0 then
diff --git a/sys/vm/vm_mmap.c b/sys/vm/vm_mmap.c
index 8ad049ed6d5e..db9a32d1c9bc 100644
--- a/sys/vm/vm_mmap.c
+++ b/sys/vm/vm_mmap.c
@@ -420,7 +420,7 @@ kern_mmap(struct thread *td, const struct mmap_req *mrp)
 	}
 
 	if (error == 0)
-		td->td_retval[0] = (register_t) (addr + pageoff);
+		td->td_retval[0] = addr + pageoff;
 done:
 	if (fp)
 		fdrop(fp, td);
diff --git a/usr.bin/truss/setup.c b/usr.bin/truss/setup.c
index b5a1d4e32d2b..db5361a88e86 100644
--- a/usr.bin/truss/setup.c
+++ b/usr.bin/truss/setup.c
@@ -561,7 +561,7 @@ exit_syscall(struct trussinfo *info, struct ptrace_lwpinfo *pl)
 			 */
 			if (psr.sr_error != 0) {
 				asprintf(&temp, "0x%lx",
-				    t->cs.args[sc->decode.args[i].offset]);
+				    (long)t->cs.args[sc->decode.args[i].offset]);
 			} else {
 				temp = print_arg(&sc->decode.args[i],
 				    t->cs.args, psr.sr_retval, info);
diff --git a/usr.bin/truss/syscall.h b/usr.bin/truss/syscall.h
index 53a1fd6ee8d7..c16aed732230 100644
--- a/usr.bin/truss/syscall.h
+++ b/usr.bin/truss/syscall.h
@@ -228,7 +228,7 @@ struct syscall {
 };
 
 struct syscall *get_syscall(struct threadinfo *, u_int, u_int);
-char *print_arg(struct syscall_arg *, unsigned long *, register_t *,
+char *print_arg(struct syscall_arg *, syscallarg_t *, syscallarg_t *,
     struct trussinfo *);
 
 /*
@@ -252,8 +252,8 @@ char *print_arg(struct syscall_arg *, unsigned long *, register_t *,
 #define LINUX_SENDMSG		16
 #define LINUX_RECVMSG		17
 
-#define PAD_(t) (sizeof(register_t) <= sizeof(t) ? \
-    0 : sizeof(register_t) - sizeof(t))
+#define PAD_(t) (sizeof(syscallarg_t) <= sizeof(t) ? \
+    0 : sizeof(syscallarg_t) - sizeof(t))
 
 #if BYTE_ORDER == LITTLE_ENDIAN
 #define PADL_(t)	0
@@ -272,5 +272,5 @@ struct linux_socketcall_args {
 };
 
 void print_syscall(struct trussinfo *);
-void print_syscall_ret(struct trussinfo *, int, register_t *);
+void print_syscall_ret(struct trussinfo *, int, syscallarg_t *);
 void print_summary(struct trussinfo *trussinfo);
diff --git a/usr.bin/truss/syscalls.c b/usr.bin/truss/syscalls.c
index d611f3f73471..bd055fb687ed 100644
--- a/usr.bin/truss/syscalls.c
+++ b/usr.bin/truss/syscalls.c
@@ -1558,7 +1558,7 @@ user_ptr32_to_psaddr(int32_t user_pointer)
  * an array of all of the system call arguments.
  */
 char *
-print_arg(struct syscall_arg *sc, unsigned long *args, register_t *retval,
+print_arg(struct syscall_arg *sc, syscallarg_t *args, syscallarg_t *retval,
     struct trussinfo *trussinfo)
 {
 	FILE *fp;
@@ -1592,10 +1592,10 @@ print_arg(struct syscall_arg *sc, unsigned long *args, register_t *retval,
 		break;
 	}
 	case LongHex:
-		fprintf(fp, "0x%lx", args[sc->offset]);
+		fprintf(fp, "0x%lx", (long)args[sc->offset]);
 		break;
 	case Long:
-		fprintf(fp, "%ld", args[sc->offset]);
+		fprintf(fp, "%ld", (long)args[sc->offset]);
 		break;
 	case Sizet:
 		fprintf(fp, "%zu", (size_t)args[sc->offset]);
@@ -2734,7 +2734,7 @@ print_syscall(struct trussinfo *trussinfo)
 }
 
 void
-print_syscall_ret(struct trussinfo *trussinfo, int error, register_t *retval)
+print_syscall_ret(struct trussinfo *trussinfo, int error, syscallarg_t *retval)
 {
 	struct timespec timediff;
 	struct threadinfo *t;
diff --git a/usr.bin/truss/truss.h b/usr.bin/truss/truss.h
index a3ce8f27d953..4d2680cd4913 100644
--- a/usr.bin/truss/truss.h
+++ b/usr.bin/truss/truss.h
@@ -81,7 +81,7 @@ struct current_syscall {
 	struct syscall *sc;
 	unsigned int number;
 	unsigned int nargs;
-	unsigned long args[10];
+	syscallarg_t args[10];
 	char *s_args[10];	/* the printable arguments */
 };