From: Clemens Gößnitzer <clemens@goessnitzer.info>
Subject: Re: ddb(4): db_read_bytes, db_write_bytes: change data parameter to void pointer
To: tech@openbsd.org, Scott Cheloha <scottcheloha@gmail.com>
Date: Thu, 08 Feb 2024 22:47:41 +0000

On 8 February 2024 16:01:43 UTC, Scott Cheloha <scottcheloha@gmail.com> wrote:
>Almost all db_read_bytes/db_write_bytes callers cast the data
>parameter to a "char *", which suggests that the function prototypes
>don't match how the functions are actually used.
>
>Change the data parameter to db_read_bytes/db_write/bytes from
>"char *" to "void *", update all implementations to use a "char *"
>internally, and update all callers to remove the casts.
>
>While we're updating the callers, we can also change any magic sizes
>to sizeof.
>
>ok?
>
>Index: ./ddb/db_access.h
>===================================================================
>RCS file: /cvs/src/sys/ddb/db_access.h,v
>diff -u -p -r1.11 db_access.h
>--- ./ddb/db_access.h	20 Jan 2020 15:58:23 -0000	1.11
>+++ ./ddb/db_access.h	8 Feb 2024 15:43:26 -0000
>@@ -36,5 +36,5 @@
> db_expr_t db_get_value(vaddr_t, size_t, int);
> void db_put_value(vaddr_t, size_t, db_expr_t);
> 
>-void db_read_bytes(vaddr_t, size_t, char *);
>-void db_write_bytes(vaddr_t, size_t, char *);
>+void db_read_bytes(vaddr_t, size_t, void *);
>+void db_write_bytes(vaddr_t, size_t, void *);
>Index: ./arch/alpha/alpha/db_interface.c
>===================================================================
>RCS file: /cvs/src/sys/arch/alpha/alpha/db_interface.c,v
>diff -u -p -r1.28 db_interface.c
>--- ./arch/alpha/alpha/db_interface.c	14 Apr 2022 19:47:10 -0000	1.28
>+++ ./arch/alpha/alpha/db_interface.c	8 Feb 2024 15:43:26 -0000
>@@ -191,9 +191,9 @@ void
> db_read_bytes(addr, size, data)

Shouldn't data be changed to datap here as well?

> 	vaddr_t		addr;
> 	register size_t	size;
>-	register char	*data;
>+	register void	*datap;
> {
>-	register char	*src;
>+	register char	*data = datap, *src;
> 
> 	src = (char *)addr;
> 	while (size-- > 0)
>@@ -207,9 +207,9 @@ void
> db_write_bytes(addr, size, data)
> 	vaddr_t		addr;
> 	register size_t	size;
>-	register char	*data;
>+	register void	*datap;
> {
>-	register char	*dst;
>+	register char	*data = datap, *dst;
> 
> 	dst = (char *)addr;
> 	while (size-- > 0)
>Index: ./arch/amd64/amd64/db_memrw.c
>===================================================================
>RCS file: /cvs/src/sys/arch/amd64/amd64/db_memrw.c,v
>diff -u -p -r1.8 db_memrw.c
>--- ./arch/amd64/amd64/db_memrw.c	30 Apr 2017 13:04:49 -0000	1.8
>+++ ./arch/amd64/amd64/db_memrw.c	8 Feb 2024 15:43:26 -0000
>@@ -60,9 +60,9 @@
>  * Read bytes from kernel address space for debugger.
>  */
> void
>-db_read_bytes(vaddr_t addr, size_t size, char *data)
>+db_read_bytes(vaddr_t addr, size_t size, void *datap)
> {
>-	char *src;
>+	char *data = datap, *src;
> 
> 	src = (char *)addr;
> 
>@@ -90,12 +90,12 @@ db_read_bytes(vaddr_t addr, size_t size,
>  * pages writable temporarily.
>  */
> static void
>-db_write_text(vaddr_t addr, size_t size, char *data)
>+db_write_text(vaddr_t addr, size_t size, void *datap)
> {
> 	pt_entry_t *pte, oldpte, tmppte;
> 	vaddr_t pgva;
> 	size_t limit;
>-	char *dst;
>+	char *data = datap, *dst;
> 
> 	if (size == 0)
> 		return;
>Index: ./arch/arm/arm/db_interface.c
>===================================================================
>RCS file: /cvs/src/sys/arch/arm/arm/db_interface.c,v
>diff -u -p -r1.20 db_interface.c
>--- ./arch/arm/arm/db_interface.c	15 Oct 2022 08:04:02 -0000	1.20
>+++ ./arch/arm/arm/db_interface.c	8 Feb 2024 15:43:27 -0000
>@@ -182,9 +182,9 @@ db_validate_address(vaddr_t addr)
>  * Read bytes from kernel address space for debugger.
>  */
> void
>-db_read_bytes(vaddr_t addr, size_t size, char *data)
>+db_read_bytes(vaddr_t addr, size_t size, void *datap)
> {
>-	char	*src = (char *)addr;
>+	char *data = datap, *src = (char *)addr;
> 
> 	if (db_validate_address((u_int)src)) {
> 		db_printf("address %p is invalid\n", src);
>@@ -211,14 +211,14 @@ db_read_bytes(vaddr_t addr, size_t size,
> }
> 
> static void
>-db_write_text(vaddr_t addr, size_t size, char *data)
>+db_write_text(vaddr_t addr, size_t size, void *datap)
> {        
> 	struct pmap *pmap = pmap_kernel();
> 	pd_entry_t *pde, oldpde, tmppde;
> 	pt_entry_t *pte, oldpte, tmppte;
> 	vaddr_t pgva;
> 	size_t limit, savesize;
>-	char *dst;
>+	char *data = datap, *dst;
> 
> 	/* XXX: gcc */
> 	oldpte = 0;
>@@ -434,7 +434,7 @@ db_branch_taken(u_int insn, vaddr_t pc, 
> 	case 0x7:	/* ldr pc, [pc, reg, lsl #2] */
> 		addr = db_fetch_reg(insn & 0xf, db_regs);
> 		addr = pc + 8 + (addr << 2);
>-		db_read_bytes(addr, 4, (char *)&addr);
>+		db_read_bytes(addr, sizeof addr, &addr);
> 		return (addr);
> 	case 0x1:	/* mov pc, reg */
> 		addr = db_fetch_reg(insn & 0xf, db_regs);
>@@ -460,7 +460,7 @@ db_branch_taken(u_int insn, vaddr_t pc, 
> 			addr = addr + 4 + ((nregs - 1) << 2);
> 			break;
> 		}
>-		db_read_bytes(addr, 4, (char *)&addr);
>+		db_read_bytes(addr, sizeof addr, &addr);
> 		return (addr);
> 	default:
> 		panic("branch_taken: botch");
>Index: ./arch/arm64/arm64/db_interface.c
>===================================================================
>RCS file: /cvs/src/sys/arch/arm64/arm64/db_interface.c,v
>diff -u -p -r1.14 db_interface.c
>--- ./arch/arm64/arm64/db_interface.c	7 Nov 2022 09:43:04 -0000	1.14
>+++ ./arch/arm64/arm64/db_interface.c	8 Feb 2024 15:43:26 -0000
>@@ -197,9 +197,9 @@ db_validate_address(vaddr_t addr)
>  * Read bytes from kernel address space for debugger.
>  */
> void
>-db_read_bytes(vaddr_t addr, size_t size, char *data)
>+db_read_bytes(vaddr_t addr, size_t size, void *datap)
> {
>-	char	*src = (char *)addr;
>+	char *data = datap, *src = (char *)addr;
> 
> 	if (db_validate_address((vaddr_t)src)) {
> 		db_printf("address %p is invalid\n", src);
>@@ -235,11 +235,11 @@ db_read_bytes(vaddr_t addr, size_t size,
>  * pages writable temporarily.
>  */
> static void
>-db_write_text(vaddr_t addr, size_t size, char *data)
>+db_write_text(vaddr_t addr, size_t size, void *datap)
> {
> 	vaddr_t pgva;
> 	size_t limit;
>-	char *dst;
>+	char *data = datap, *dst;
> 
> 	if (size == 0)
> 		return;
>Index: ./arch/hppa/hppa/db_interface.c
>===================================================================
>RCS file: /cvs/src/sys/arch/hppa/hppa/db_interface.c,v
>diff -u -p -r1.49 db_interface.c
>--- ./arch/hppa/hppa/db_interface.c	26 Apr 2023 16:53:58 -0000	1.49
>+++ ./arch/hppa/hppa/db_interface.c	8 Feb 2024 15:43:26 -0000
>@@ -134,8 +134,9 @@ db_enter(void)
> }
> 
> void
>-db_read_bytes(vaddr_t addr, size_t size, char *data)
>+db_read_bytes(vaddr_t addr, size_t size, void *datap)
> {
>+	char *data = datap;
> 	register char *src = (char *)addr;
> 
> 	while (size--)
>@@ -143,8 +144,9 @@ db_read_bytes(vaddr_t addr, size_t size,
> }
> 
> void
>-db_write_bytes(vaddr_t addr, size_t size, char *data)
>+db_write_bytes(vaddr_t addr, size_t size, void *datap)
> {
>+	char *data = datap;
> 	register char *dst = (char *)addr;
> 
> 	while (size--)
>Index: ./arch/i386/i386/db_memrw.c
>===================================================================
>RCS file: /cvs/src/sys/arch/i386/i386/db_memrw.c,v
>diff -u -p -r1.18 db_memrw.c
>--- ./arch/i386/i386/db_memrw.c	23 Sep 2020 15:13:26 -0000	1.18
>+++ ./arch/i386/i386/db_memrw.c	8 Feb 2024 15:43:26 -0000
>@@ -50,9 +50,9 @@
>  * Read bytes from kernel address space for debugger.
>  */
> void
>-db_read_bytes(vaddr_t addr, size_t size, char *data)
>+db_read_bytes(vaddr_t addr, size_t size, void *datap)
> {
>-	char	*src;
>+	char *data = datap, *src;
> 
> 	src = (char *)addr;
> 	while (size-- > 0)
>@@ -64,12 +64,12 @@ db_read_bytes(vaddr_t addr, size_t size,
>  * pages writable temporarily.
>  */
> static void
>-db_write_text(vaddr_t addr, size_t size, char *data)
>+db_write_text(vaddr_t addr, size_t size, char *datap)
> {
> 	vaddr_t pgva;
> 	size_t limit;
> 	uint32_t bits;
>-	char *dst;
>+	char *data = datap, *dst;
> 
> 	if (size == 0)
> 		return;
>Index: ./arch/m88k/m88k/db_interface.c
>===================================================================
>RCS file: /cvs/src/sys/arch/m88k/m88k/db_interface.c,v
>diff -u -p -r1.28 db_interface.c
>--- ./arch/m88k/m88k/db_interface.c	14 Apr 2022 19:47:11 -0000	1.28
>+++ ./arch/m88k/m88k/db_interface.c	8 Feb 2024 15:43:26 -0000
>@@ -487,9 +487,9 @@ ddb_entry_trap(level, eframe)
>  * Read bytes from kernel address space for debugger.
>  */
> void
>-db_read_bytes(vaddr_t addr, size_t size, char *data)
>+db_read_bytes(vaddr_t addr, size_t size, void *datap)
> {
>-	char *src;
>+	char *data = datap, *src;
> 
> 	src = (char *)addr;
> 
>@@ -502,10 +502,10 @@ db_read_bytes(vaddr_t addr, size_t size,
>  * Write bytes to kernel address space for debugger.
>  */
> void
>-db_write_bytes(vaddr_t addr, size_t size, char *data)
>+db_write_bytes(vaddr_t addr, size_t size, void *datap)
> {
> 	extern pt_entry_t *pmap_pte(pmap_t, vaddr_t);
>-	char *dst = (char *)addr;
>+	char *data = datap, *dst = (char *)addr;
> 	vaddr_t va;
> 	paddr_t pa;
> 	pt_entry_t *pte, opte, npte;
>Index: ./arch/mips64/mips64/db_machdep.c
>===================================================================
>RCS file: /cvs/src/sys/arch/mips64/mips64/db_machdep.c,v
>diff -u -p -r1.60 db_machdep.c
>--- ./arch/mips64/mips64/db_machdep.c	11 Jan 2023 03:17:56 -0000	1.60
>+++ ./arch/mips64/mips64/db_machdep.c	8 Feb 2024 15:43:26 -0000
>@@ -281,8 +281,10 @@ db_cpuinfo_cmd(db_expr_t addr, int have_
> #endif
> 
> void
>-db_read_bytes(vaddr_t addr, size_t size, char *data)
>+db_read_bytes(vaddr_t addr, size_t size, void *datap)
> {
>+	char *data = datap;
>+
> 	while (size >= sizeof(uint32_t)) {
> 		*(uint32_t *)data = kdbpeek(addr);
> 		data += sizeof(uint32_t);
>@@ -302,8 +304,9 @@ db_read_bytes(vaddr_t addr, size_t size,
> }
> 
> void
>-db_write_bytes(vaddr_t addr, size_t size, char *data)
>+db_write_bytes(vaddr_t addr, size_t size, void *datap)
> {
>+	char *data = datap;
> 	vaddr_t ptr = addr;
> 	size_t len = size;
> 
>Index: ./arch/powerpc/ddb/db_memrw.c
>===================================================================
>RCS file: /cvs/src/sys/arch/powerpc/ddb/db_memrw.c,v
>diff -u -p -r1.6 db_memrw.c
>--- ./arch/powerpc/ddb/db_memrw.c	15 Oct 2022 08:04:02 -0000	1.6
>+++ ./arch/powerpc/ddb/db_memrw.c	8 Feb 2024 15:43:26 -0000
>@@ -53,9 +53,9 @@
>  * Read bytes from kernel address space for debugger.
>  */
> void
>-db_read_bytes(vaddr_t addr, size_t size, char *data)
>+db_read_bytes(vaddr_t addr, size_t size, void *datap)
> {
>-	char	*src = (char *)addr;
>+	char *data = datap, *src = (char *)addr;
> 	faultbuf env;
> 	faultbuf *old_onfault = curpcb->pcb_onfault;
> 	if (setfault(&env)) {
>@@ -80,9 +80,9 @@ db_read_bytes(vaddr_t addr, size_t size,
>  * Write bytes to kernel address space for debugger.
>  */
> void
>-db_write_bytes(vaddr_t addr, size_t size, char *data)
>+db_write_bytes(vaddr_t addr, size_t size, void *datap)
> {
>-	char	*dst = (char *)addr;
>+	char *data = datap, *dst = (char *)addr;
> 	faultbuf env;
> 	faultbuf *old_onfault = curpcb->pcb_onfault;
> 
>Index: ./arch/powerpc64/powerpc64/db_memrw.c
>===================================================================
>RCS file: /cvs/src/sys/arch/powerpc64/powerpc64/db_memrw.c,v
>diff -u -p -r1.2 db_memrw.c
>--- ./arch/powerpc64/powerpc64/db_memrw.c	12 Jun 2020 22:01:01 -0000	1.2
>+++ ./arch/powerpc64/powerpc64/db_memrw.c	8 Feb 2024 15:43:26 -0000
>@@ -46,9 +46,9 @@
>  * Read bytes from kernel address space for debugger.
>  */
> void
>-db_read_bytes(vaddr_t addr, size_t size, char *data)
>+db_read_bytes(vaddr_t addr, size_t size, void *datap)
> {
>-	char *src;
>+	char *data = datap, *src;
> 
> 	src = (char *)addr;
> 
>@@ -76,13 +76,13 @@ db_read_bytes(vaddr_t addr, size_t size,
>  * pages writable temporarily.
>  */
> void
>-db_write_text(vaddr_t addr, size_t size, char *data)
>+db_write_text(vaddr_t addr, size_t size, void *datap)
> {
> 	struct pte *pte;
> 	uint64_t old_pte_lo;
> 	vaddr_t pgva;
> 	size_t limit;
>-	char *dst;
>+	char *data = datap, *dst;
> 
> 	if (size == 0)
> 		return;
>Index: ./arch/riscv64/riscv64/db_interface.c
>===================================================================
>RCS file: /cvs/src/sys/arch/riscv64/riscv64/db_interface.c,v
>diff -u -p -r1.8 db_interface.c
>--- ./arch/riscv64/riscv64/db_interface.c	14 Apr 2022 19:47:11 -0000	1.8
>+++ ./arch/riscv64/riscv64/db_interface.c	8 Feb 2024 15:43:27 -0000
>@@ -179,9 +179,9 @@ db_validate_address(vaddr_t addr)
>  * Read bytes from kernel address space for debugger.
>  */
> void
>-db_read_bytes(vaddr_t addr, size_t size, char *data)
>+db_read_bytes(vaddr_t addr, size_t size, void *datap)
> {
>-	char	*src = (char *)addr;
>+	char	*data = datap, *src = (char *)addr;
> 
> 	if (db_validate_address((vaddr_t)src)) {
> 		db_printf("address %p is invalid\n", src);
>@@ -217,7 +217,7 @@ db_read_bytes(vaddr_t addr, size_t size,
>  * Write bytes to kernel address space for debugger.
>  */
> void
>-db_write_bytes(vaddr_t addr, size_t size, char *data)
>+db_write_bytes(vaddr_t addr, size_t size, void *datap)
> {
> 	// XXX
> }
>Index: ./arch/sh/sh/db_memrw.c
>===================================================================
>RCS file: /cvs/src/sys/arch/sh/sh/db_memrw.c,v
>diff -u -p -r1.1.1.1 db_memrw.c
>--- ./arch/sh/sh/db_memrw.c	6 Oct 2006 21:02:55 -0000	1.1.1.1
>+++ ./arch/sh/sh/db_memrw.c	8 Feb 2024 15:43:27 -0000
>@@ -49,9 +49,9 @@
>  * Read bytes from kernel address space for debugger.
>  */
> void
>-db_read_bytes(vaddr_t addr, size_t size, char *data)
>+db_read_bytes(vaddr_t addr, size_t size, void *datap)
> {
>-	char *src = (char *)addr;
>+	char *data = datap, *src = (char *)addr;
> 
> 	/* properly aligned 4-byte */
> 	if (size == 4 && ((addr & 3) == 0) && (((uintptr_t)data & 3) == 0)) {
>@@ -73,9 +73,9 @@ db_read_bytes(vaddr_t addr, size_t size,
>  * Write bytes to kernel address space for debugger.
>  */
> void
>-db_write_bytes(vaddr_t addr, size_t size, char *data)
>+db_write_bytes(vaddr_t addr, size_t size, void *datap)
> {
>-	char *dst = (char *)addr;
>+	char *data = datap, *dst = (char *)addr;
> 
> 	/* properly aligned 4-byte */
> 	if (size == 4 && ((addr & 3) == 0) && (((uintptr_t)data & 3) == 0)) {
>Index: ./arch/sparc64/sparc64/db_interface.c
>===================================================================
>RCS file: /cvs/src/sys/arch/sparc64/sparc64/db_interface.c,v
>diff -u -p -r1.61 db_interface.c
>--- ./arch/sparc64/sparc64/db_interface.c	31 Jan 2023 15:18:55 -0000	1.61
>+++ ./arch/sparc64/sparc64/db_interface.c	8 Feb 2024 15:43:27 -0000
>@@ -523,8 +523,9 @@ db_stopcpu(struct cpu_info *ci)
>  * Read bytes from kernel address space for debugger.
>  */
> void
>-db_read_bytes(vaddr_t addr, size_t size, char *data)
>+db_read_bytes(vaddr_t addr, size_t size, void *datap)
> {
>+	char *data = datap;
> 	register char	*src;
> 
> 	src = (char *)addr;
>@@ -541,8 +542,9 @@ db_read_bytes(vaddr_t addr, size_t size,
>  * Write bytes to kernel address space for debugger.
>  */
> void
>-db_write_bytes(vaddr_t addr, size_t size, char *data)
>+db_write_bytes(vaddr_t addr, size_t size, void *datap)
> {
>+	char *data = datap;
> 	register char	*dst;
> 	extern vaddr_t ktext;
> 	extern paddr_t ktextp;
>Index: arch/arm/arm/db_interface.c
>===================================================================
>RCS file: /cvs/src/sys/arch/arm/arm/db_interface.c,v
>diff -u -p -r1.20 db_interface.c
>--- arch/arm/arm/db_interface.c	15 Oct 2022 08:04:02 -0000	1.20
>+++ arch/arm/arm/db_interface.c	8 Feb 2024 15:43:27 -0000
>@@ -182,9 +182,9 @@ db_validate_address(vaddr_t addr)
>  * Read bytes from kernel address space for debugger.
>  */
> void
>-db_read_bytes(vaddr_t addr, size_t size, char *data)
>+db_read_bytes(vaddr_t addr, size_t size, void *datap)
> {
>-	char	*src = (char *)addr;
>+	char *data = datap, *src = (char *)addr;
> 
> 	if (db_validate_address((u_int)src)) {
> 		db_printf("address %p is invalid\n", src);
>@@ -211,14 +211,14 @@ db_read_bytes(vaddr_t addr, size_t size,
> }
> 
> static void
>-db_write_text(vaddr_t addr, size_t size, char *data)
>+db_write_text(vaddr_t addr, size_t size, void *datap)
> {        
> 	struct pmap *pmap = pmap_kernel();
> 	pd_entry_t *pde, oldpde, tmppde;
> 	pt_entry_t *pte, oldpte, tmppte;
> 	vaddr_t pgva;
> 	size_t limit, savesize;
>-	char *dst;
>+	char *data = datap, *dst;
> 
> 	/* XXX: gcc */
> 	oldpte = 0;
>@@ -434,7 +434,7 @@ db_branch_taken(u_int insn, vaddr_t pc, 
> 	case 0x7:	/* ldr pc, [pc, reg, lsl #2] */
> 		addr = db_fetch_reg(insn & 0xf, db_regs);
> 		addr = pc + 8 + (addr << 2);
>-		db_read_bytes(addr, 4, (char *)&addr);
>+		db_read_bytes(addr, sizeof addr, &addr);
> 		return (addr);
> 	case 0x1:	/* mov pc, reg */
> 		addr = db_fetch_reg(insn & 0xf, db_regs);
>@@ -460,7 +460,7 @@ db_branch_taken(u_int insn, vaddr_t pc, 
> 			addr = addr + 4 + ((nregs - 1) << 2);
> 			break;
> 		}
>-		db_read_bytes(addr, 4, (char *)&addr);
>+		db_read_bytes(addr, sizeof addr, &addr);
> 		return (addr);
> 	default:
> 		panic("branch_taken: botch");
>Index: arch/arm64/arm64/db_trace.c
>===================================================================
>RCS file: /cvs/src/sys/arch/arm64/arm64/db_trace.c,v
>diff -u -p -r1.15 db_trace.c
>--- arch/arm64/arm64/db_trace.c	17 Jun 2023 08:13:56 -0000	1.15
>+++ arch/arm64/arm64/db_trace.c	8 Feb 2024 15:43:27 -0000
>@@ -86,10 +86,8 @@ db_stack_trace_print(db_expr_t addr, int
> 			lastlr =  p->p_addr->u_pcb.pcb_tf->tf_elr;
> 		} else {
> 			sp = addr;
>-			db_read_bytes(sp, sizeof(vaddr_t),
>-			    (char *)&frame);
>-			db_read_bytes(sp + 8, sizeof(vaddr_t),
>-			    (char *)&lr);
>+			db_read_bytes(sp, sizeof frame, &frame);
>+			db_read_bytes(sp + 8, sizeof lr, &lr);
> 			lastlr = 0;
> 		}
> 	}
>@@ -109,11 +107,11 @@ db_stack_trace_print(db_expr_t addr, int
> 		(*pr)("\n");
> 
> 		// can we detect traps ?
>-		db_read_bytes(frame, sizeof(vaddr_t), (char *)&frame);
>+		db_read_bytes(frame, sizeof frame, &frame);
> 		if (frame == 0)
> 			break;
> 		lastlr = lr;
>-		db_read_bytes(frame + 8, sizeof(vaddr_t), (char *)&lr);
>+		db_read_bytes(frame + 8, sizeof lr, &lr);
> 
> 		if (name != NULL) {
> 			if ((strcmp (name, "handle_el0_irq") == 0) ||
>Index: arch/m88k/m88k/db_sstep.c
>===================================================================
>RCS file: /cvs/src/sys/arch/m88k/m88k/db_sstep.c,v
>diff -u -p -r1.8 db_sstep.c
>--- arch/m88k/m88k/db_sstep.c	8 Nov 2019 15:01:15 -0000	1.8
>+++ arch/m88k/m88k/db_sstep.c	8 Feb 2024 15:43:27 -0000
>@@ -149,7 +149,7 @@ db_set_single_step(db_regs_t *regs)
> 		 * User was stopped at pc, e.g. the instruction
> 		 * at pc was not executed.
> 		 */
>-		db_read_bytes(pc, sizeof(inst), (caddr_t)&inst);
>+		db_read_bytes(pc, sizeof inst, &inst);
> 
> 		/*
> 		 * Find if this instruction may cause a branch, and set up a
>Index: arch/m88k/m88k/db_trace.c
>===================================================================
>RCS file: /cvs/src/sys/arch/m88k/m88k/db_trace.c,v
>diff -u -p -r1.19 db_trace.c
>--- arch/m88k/m88k/db_trace.c	11 Apr 2023 00:45:07 -0000	1.19
>+++ arch/m88k/m88k/db_trace.c	8 Feb 2024 15:43:27 -0000
>@@ -286,7 +286,7 @@ db_trace_get_val(vaddr_t addr, u_int *pt
> 		db_recover = prev;
> 		return 0;
> 	} else {
>-		db_read_bytes(addr, 4, (char *)ptr);
>+		db_read_bytes(addr, sizeof *ptr, ptr);
> 		db_recover = prev;
> 		return 1;
> 	}
>@@ -772,7 +772,7 @@ db_stack_trace_cmd2(db_regs_t *regs, int
> 		    badaddr((vaddr_t)(stack + 4), 4))
> 			break;
> 
>-		db_read_bytes((vaddr_t)stack, 2 * sizeof(int), (char *)pair);
>+		db_read_bytes((vaddr_t)stack, sizeof pair, pair);
> 
> 		/* the pairs should match and equal stack+8 */
> 		if (pair[0] == pair[1]) {
>Index: arch/powerpc/ddb/db_trace.c
>===================================================================
>RCS file: /cvs/src/sys/arch/powerpc/ddb/db_trace.c,v
>diff -u -p -r1.20 db_trace.c
>--- arch/powerpc/ddb/db_trace.c	26 Apr 2023 16:53:59 -0000	1.20
>+++ arch/powerpc/ddb/db_trace.c	8 Feb 2024 15:43:27 -0000
>@@ -158,7 +158,7 @@ db_stack_trace_print(db_expr_t addr, int
> 			addr = p->p_addr->u_pcb.pcb_sp;
> 		}
> 		sp = addr;
>-		db_read_bytes(sp + 4, sizeof(vaddr_t), (char *)&lr);
>+		db_read_bytes(sp + 4, sizeof lr, &lr);
> 	}
> 
> 	while (count && sp != 0) {
>@@ -213,11 +213,11 @@ db_stack_trace_print(db_expr_t addr, int
> 				(*pr)("--- trap (type 0x%x) ---\n", type);
> 		}
> 
>-		db_read_bytes(sp, sizeof(vaddr_t), (char *)&sp);
>+		db_read_bytes(sp, sizeof sp, &sp);
> 		if (sp == 0)
> 			break;
> 
>-		db_read_bytes(sp + 4, sizeof(vaddr_t), (char *)&lr);
>+		db_read_bytes(sp + 4, sizeof lr, &lr);
> 
> 		if (INKERNEL(sp)) {
> 			if (sp <= lastsp) {
>Index: arch/powerpc64/powerpc64/db_trace.c
>===================================================================
>RCS file: /cvs/src/sys/arch/powerpc64/powerpc64/db_trace.c,v
>diff -u -p -r1.9 db_trace.c
>--- arch/powerpc64/powerpc64/db_trace.c	26 Apr 2023 16:53:59 -0000	1.9
>+++ arch/powerpc64/powerpc64/db_trace.c	8 Feb 2024 15:43:27 -0000
>@@ -120,8 +120,8 @@ db_stack_trace_print(db_expr_t addr, int
> 		} else
> 			sp = addr;
> 		/* The 1st return address is in the 2nd frame. */
>-		db_read_bytes(sp, sizeof(vaddr_t), (char *)&sp);
>-		db_read_bytes(sp + 16, sizeof(vaddr_t), (char *)&lr);
>+		db_read_bytes(sp, sizeof sp, &sp);
>+		db_read_bytes(sp + 16, sizeof lr, &lr);
> 		callpc = lr - 4;
> 		has_frame = 1;
> 	}
>@@ -138,8 +138,7 @@ db_stack_trace_print(db_expr_t addr, int
> 			iaddr = sym->st_value;
> 			limit = MIN(iaddr + 0x100, callpc);
> 			for (; iaddr < limit; iaddr += 4) {
>-				db_read_bytes(iaddr, sizeof(ins),
>-				    (char *)&ins);
>+				db_read_bytes(iaddr, sizeof ins, &ins);
> 				if (inst_establish_frame(ins)) {
> 					has_frame = 1;
> 					break;
>@@ -178,14 +177,14 @@ db_stack_trace_print(db_expr_t addr, int
> 			lr = ddb_regs.lr;
> 			has_frame = 1;
> 		} else {
>-			db_read_bytes(sp, sizeof(vaddr_t), (char *)&sp);
>+			db_read_bytes(sp, sizeof sp, &sp);
> 			if (sp == 0)
> 				break;
> 			if (sp <= lastsp) {
> 				(*pr)("Bad frame pointer: 0x%lx\n", sp);
> 				break;
> 			}
>-			db_read_bytes(sp + 16, sizeof(vaddr_t), (char *)&lr);
>+			db_read_bytes(sp + 16, sizeof lr, &lr);
> 		}
> 		callpc = lr - 4;
> 
>Index: arch/riscv64/riscv64/db_trace.c
>===================================================================
>RCS file: /cvs/src/sys/arch/riscv64/riscv64/db_trace.c,v
>diff -u -p -r1.5 db_trace.c
>--- arch/riscv64/riscv64/db_trace.c	22 Feb 2022 07:46:04 -0000	1.5
>+++ arch/riscv64/riscv64/db_trace.c	8 Feb 2024 15:43:27 -0000
>@@ -74,8 +74,8 @@ db_stack_trace_print(db_expr_t addr, int
> 		ra = ddb_regs.tf_ra;
> 		frame = ddb_regs.tf_s[0];
> 	} else {
>-		db_read_bytes(addr - 16, sizeof(vaddr_t), (char *)&frame);
>-		db_read_bytes(addr - 8, sizeof(vaddr_t), (char *)&ra);
>+		db_read_bytes(addr - 16, sizeof frame, &frame);
>+		db_read_bytes(addr - 8, sizeof ra, &ra);
> 	}
> 
> 	while (count != 0 && frame != 0) {
>@@ -109,20 +109,18 @@ db_stack_trace_print(db_expr_t addr, int
> 		    subr == (vaddr_t)cpu_exception_handler_user) {
> 			struct trapframe *tf = (struct trapframe *)frame;
> 
>-			db_read_bytes((vaddr_t)&tf->tf_ra, sizeof(ra),
>-			    (char *)&ra);
>-			db_read_bytes((vaddr_t)&tf->tf_s[0], sizeof(frame),
>-			    (char *)&frame);
>+			db_read_bytes((vaddr_t)&tf->tf_ra, sizeof ra, &ra);
>+			db_read_bytes((vaddr_t)&tf->tf_s[0], sizeof frame,
>+			    &frame);
> 		} else {
>-			db_read_bytes(frame - 16, sizeof(frame),
>-			    (char *)&frame);
>+			db_read_bytes(frame - 16, sizeof frame, &frame);
> 			if (frame == 0)
> 				break;
> 			if ((frame & 0x7) != 0) {
> 				(*pr)("bad frame pointer: 0x%lx\n", frame);
> 				break;
> 			}
>-			db_read_bytes(frame - 8, sizeof(ra), (char *)&ra);
>+			db_read_bytes(frame - 8, sizeof ra, &ra);
> 		}
> 
> 		if (INKERNEL(frame)) {
>


-- 
Sent from a mobile device. Please excuse my brevity.