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authorJordan Niethe <jniethe5@gmail.com>2020-05-06 13:40:38 +1000
committerMichael Ellerman <mpe@ellerman.id.au>2020-05-19 00:10:38 +1000
commit6c7a4f0a9f66fc7fdc6e208559e5d562f53e0991 (patch)
tree29e5517780650246640780ca4c15ab6d2f035bfa /arch/powerpc/xmon
parent622cf6f436a12338bbcfbb3474629755547fd112 (diff)
downloadlinux-6c7a4f0a9f66fc7fdc6e208559e5d562f53e0991.tar.bz2
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: Jordan Niethe <jniethe5@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Reviewed-by: Alistair Popple <alistair@popple.id.au> Link: https://lore.kernel.org/r/20200506034050.24806-19-jniethe5@gmail.com
Diffstat (limited to 'arch/powerpc/xmon')
-rw-r--r--arch/powerpc/xmon/xmon.c28
1 files changed, 24 insertions, 4 deletions
diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c
index a4f8f570dbbe..d8b29f6925be 100644
--- a/arch/powerpc/xmon/xmon.c
+++ b/arch/powerpc/xmon/xmon.c
@@ -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[] = { "--", "**", "##" };