Commit 6c7a4f0a authored by Jordan Niethe's avatar Jordan Niethe Committed by Michael Ellerman
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powerpc/xmon: Use a function for reading instructions 



Currently in xmon, mread() is used for reading instructions. In
preparation for prefixed instructions, create and use a new function,
mread_instr(), especially for reading instructions.

Signed-off-by: default avatarJordan Niethe <jniethe5@gmail.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Reviewed-by: default avatarAlistair Popple <alistair@popple.id.au>
Link: https://lore.kernel.org/r/20200506034050.24806-19-jniethe5@gmail.com
parent 622cf6f4

arch/powerpc/xmon/xmon.c

+24 −4
Original line number Diff line number Diff line
@@ -122,6 +122,7 @@ static unsigned bpinstr = 0x7fe00008; /* trap */ 
static int cmds(struct pt_regs *);

static int mread(unsigned long, void *, int);

static int mwrite(unsigned long, void *, int);

static int mread_instr(unsigned long, struct ppc_inst *);

static int handle_fault(struct pt_regs *);

static void byterev(unsigned char *, int);

static void memex(void);
@@ -896,7 +897,7 @@ static void insert_bpts(void) 
	for (i = 0; i < NBPTS; ++i, ++bp) {

		if ((bp->enabled & (BP_TRAP|BP_CIABR)) == 0)

			continue;

		if (mread(bp->address, &instr, 4) != 4) {

		if (!mread_instr(bp->address, &instr)) {

			printf("Couldn't read instruction at %lx, "

			       "disabling breakpoint there\n", bp->address);

			bp->enabled = 0;
@@ -946,7 +947,7 @@ static void remove_bpts(void) 
	for (i = 0; i < NBPTS; ++i, ++bp) {

		if ((bp->enabled & (BP_TRAP|BP_CIABR)) != BP_TRAP)

			continue;

		if (mread(bp->address, &instr, 4) == 4

		if (mread_instr(bp->address, &instr)

		    && ppc_inst_equal(instr, ppc_inst(bpinstr))

		    && patch_instruction(

			(struct ppc_inst *)bp->address, ppc_inst_read(bp->instr)) != 0)
@@ -1162,7 +1163,7 @@ static int do_step(struct pt_regs *regs) 
	force_enable_xmon();

	/* check we are in 64-bit kernel mode, translation enabled */

	if ((regs->msr & (MSR_64BIT|MSR_PR|MSR_IR)) == (MSR_64BIT|MSR_IR)) {

		if (mread(regs->nip, &instr, 4) == 4) {

		if (mread_instr(regs->nip, &instr)) {

			stepped = emulate_step(regs, instr);

			if (stepped < 0) {

				printf("Couldn't single-step %s instruction\n",
@@ -1329,7 +1330,7 @@ static long check_bp_loc(unsigned long addr) 
		printf("Breakpoints may only be placed at kernel addresses\n");

		return 0;

	}

	if (!mread(addr, &instr, sizeof(instr))) {

	if (!mread_instr(addr, &instr)) {

		printf("Can't read instruction at address %lx\n", addr);

		return 0;

	}
@@ -2122,6 +2123,25 @@ mwrite(unsigned long adrs, void *buf, int size) 
	return n;

}



static int

mread_instr(unsigned long adrs, struct ppc_inst *instr)

{

	volatile int n;



	n = 0;

	if (setjmp(bus_error_jmp) == 0) {

		catch_memory_errors = 1;

		sync();

		*instr = ppc_inst_read((struct ppc_inst *)adrs);

		sync();

		/* wait a little while to see if we get a machine check */

		__delay(200);

		n = ppc_inst_len(*instr);

	}

	catch_memory_errors = 0;

	return n;

}



static int fault_type;

static int fault_except;

static char *fault_chars[] = { "--", "**", "##" };