Do not allow placing xmon breakpoints on the suffix of a prefix
instruction.
Signed-off-by: Jordan Niethe <jniet...@gmail.com>
---
v8: Add this back from v3
---
arch/powerpc/xmon/xmon.c | 29 +++++++++++++++++++++++++++--
1 file changed, 27 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c
index 647b3829c4eb..d082c35c6638 100644
--- a/arch/powerpc/xmon/xmon.c
+++ b/arch/powerpc/xmon/xmon.c
@@ -889,8 +889,8 @@ static struct bpt *new_breakpoint(unsigned long a)
static void insert_bpts(void)
{
int i;
- struct ppc_inst instr;
- struct bpt *bp;
+ struct ppc_inst instr, instr2;
+ struct bpt *bp, *bp2;
bp = bpts;
for (i = 0; i < NBPTS; ++i, ++bp) {
@@ -908,6 +908,31 @@ static void insert_bpts(void)
bp->enabled = 0;
continue;
}
+ /*
+ * Check the address is not a suffix by looking for a prefix in
+ * front of it.
+ */
+ if (mread_instr(bp->address - 4, &instr2) == 8) {
+ printf("Breakpoint at %lx is on the second word of a "
+ "prefixed instruction, disabling it\n",
+ bp->address);
+ bp->enabled = 0;
+ continue;
+ }
+ /*
+ * We might still be a suffix - if the prefix has already been
+ * replaced by a breakpoint we won't catch it with the above
+ * test.
+ */
+ bp2 = at_breakpoint(bp->address - 4);
+ if (bp2 && ppc_inst_prefixed(ppc_inst_read(bp2->instr))) {
+ printf("Breakpoint at %lx is on the second word of a "
+ "prefixed instruction, disabling it\n",
+ bp->address);
+ bp->enabled = 0;
+ continue;
+ }
+
patch_instruction(bp->instr, instr);
patch_instruction((void *)bp->instr + ppc_inst_len(instr),
ppc_inst(bpinstr));
--
2.17.1
