[RFC PATCH v4 1/2] powerpc/xmon: Allow listing active breakpoints in read-only mode

["Christopher M. Riedl" <cmr@informatik.wtf>]

Xmon can enter read-only mode dynamically due to changes in kernel
lockdown state. This transition does not clear active breakpoints and
any these breakpoints should remain visible to the xmon'er.

Signed-off-by: Christopher M. Riedl <cmr@informatik.wtf>
---
 arch/powerpc/xmon/xmon.c | 19 ++++++++++++++-----
 1 file changed, 14 insertions(+), 5 deletions(-)

diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c
index d0620d762a5a..bb63ecc599fd 100644
--- a/arch/powerpc/xmon/xmon.c
+++ b/arch/powerpc/xmon/xmon.c
@@ -1045,10 +1045,6 @@ cmds(struct pt_regs *excp)
 			set_lpp_cmd();
 			break;
 		case 'b':
-			if (xmon_is_ro) {
-				printf(xmon_ro_msg);
-				break;
-			}
 			bpt_cmds();
 			break;
 		case 'C':
@@ -1317,11 +1313,16 @@ bpt_cmds(void)
 	struct bpt *bp;
 
 	cmd = inchar();
+
 	switch (cmd) {
 #ifndef CONFIG_PPC_8xx
 	static const char badaddr[] = "Only kernel addresses are permitted for breakpoints\n";
 	int mode;
 	case 'd':	/* bd - hardware data breakpoint */
+		if (xmon_is_ro) {
+			printf(xmon_ro_msg);
+			break;
+		}
 		if (!ppc_breakpoint_available()) {
 			printf("Hardware data breakpoint not supported on this cpu\n");
 			break;
@@ -1349,6 +1350,10 @@ bpt_cmds(void)
 		break;
 
 	case 'i':	/* bi - hardware instr breakpoint */
+		if (xmon_is_ro) {
+			printf(xmon_ro_msg);
+			break;
+		}
 		if (!cpu_has_feature(CPU_FTR_ARCH_207S)) {
 			printf("Hardware instruction breakpoint "
 			       "not supported on this cpu\n");
@@ -1372,6 +1377,10 @@ bpt_cmds(void)
 #endif
 
 	case 'c':
+		if (xmon_is_ro) {
+			printf(xmon_ro_msg);
+			break;
+		}
 		if (!scanhex(&a)) {
 			/* clear all breakpoints */
 			for (i = 0; i < NBPTS; ++i)
@@ -1407,7 +1416,7 @@ bpt_cmds(void)
 			break;
 		}
 		termch = cmd;
-		if (!scanhex(&a)) {
+		if (xmon_is_ro || !scanhex(&a)) {
 			/* print all breakpoints */
 			printf("   type            address\n");
 			if (dabr.enabled) {
-- 
2.22.0