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

[Christopher M. Riedl]

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 <c...@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