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[Qemu-trivial] [PATCH v3] monitor: Fix crashes when using HMP commands w
From: |
Thomas Huth |
Subject: |
[Qemu-trivial] [PATCH v3] monitor: Fix crashes when using HMP commands without CPU |
Date: |
Thu, 12 Jan 2017 13:38:52 +0100 |
When running certain HMP commands ("info registers", "info cpustats",
"nmi", "memsave" or dumping virtual memory) with the "none" machine,
QEMU crashes with a segmentation fault. This happens because the "none"
machine does not have any CPUs by default, but these HMP commands did
not check for a valid CPU pointer yet. Add such checks now, so we get
an error message about the missing CPU instead.
Reviewed-by: Dr. David Alan Gilbert <address@hidden>
Signed-off-by: Thomas Huth <address@hidden>
---
v3:
- Use UNASSIGNED_CPU_INDEX instead of hard-coded -1
v2:
- Added more checks to cover "nmi" and "memsave", too
hmp.c | 8 +++++++-
monitor.c | 37 +++++++++++++++++++++++++++++++------
2 files changed, 38 insertions(+), 7 deletions(-)
diff --git a/hmp.c b/hmp.c
index b869617..b1c503a 100644
--- a/hmp.c
+++ b/hmp.c
@@ -1013,8 +1013,14 @@ void hmp_memsave(Monitor *mon, const QDict *qdict)
const char *filename = qdict_get_str(qdict, "filename");
uint64_t addr = qdict_get_int(qdict, "val");
Error *err = NULL;
+ int cpu_index = monitor_get_cpu_index();
- qmp_memsave(addr, size, filename, true, monitor_get_cpu_index(), &err);
+ if (cpu_index < 0) {
+ monitor_printf(mon, "No CPU available\n");
+ return;
+ }
+
+ qmp_memsave(addr, size, filename, true, cpu_index, &err);
hmp_handle_error(mon, &err);
}
diff --git a/monitor.c b/monitor.c
index 0841d43..17121ff 100644
--- a/monitor.c
+++ b/monitor.c
@@ -1025,6 +1025,9 @@ int monitor_set_cpu(int cpu_index)
CPUState *mon_get_cpu(void)
{
if (!cur_mon->mon_cpu) {
+ if (!first_cpu) {
+ return NULL;
+ }
monitor_set_cpu(first_cpu->cpu_index);
}
cpu_synchronize_state(cur_mon->mon_cpu);
@@ -1033,17 +1036,27 @@ CPUState *mon_get_cpu(void)
CPUArchState *mon_get_cpu_env(void)
{
- return mon_get_cpu()->env_ptr;
+ CPUState *cs = mon_get_cpu();
+
+ return cs ? cs->env_ptr : NULL;
}
int monitor_get_cpu_index(void)
{
- return mon_get_cpu()->cpu_index;
+ CPUState *cs = mon_get_cpu();
+
+ return cs ? cs->cpu_index : UNASSIGNED_CPU_INDEX;
}
static void hmp_info_registers(Monitor *mon, const QDict *qdict)
{
- cpu_dump_state(mon_get_cpu(), (FILE *)mon, monitor_fprintf, CPU_DUMP_FPU);
+ CPUState *cs = mon_get_cpu();
+
+ if (!cs) {
+ monitor_printf(mon, "No CPU available\n");
+ return;
+ }
+ cpu_dump_state(cs, (FILE *)mon, monitor_fprintf, CPU_DUMP_FPU);
}
static void hmp_info_jit(Monitor *mon, const QDict *qdict)
@@ -1076,7 +1089,13 @@ static void hmp_info_history(Monitor *mon, const QDict
*qdict)
static void hmp_info_cpustats(Monitor *mon, const QDict *qdict)
{
- cpu_dump_statistics(mon_get_cpu(), (FILE *)mon, &monitor_fprintf, 0);
+ CPUState *cs = mon_get_cpu();
+
+ if (!cs) {
+ monitor_printf(mon, "No CPU available\n");
+ return;
+ }
+ cpu_dump_statistics(cs, (FILE *)mon, &monitor_fprintf, 0);
}
static void hmp_info_trace_events(Monitor *mon, const QDict *qdict)
@@ -1235,6 +1254,12 @@ static void memory_dump(Monitor *mon, int count, int
format, int wsize,
int l, line_size, i, max_digits, len;
uint8_t buf[16];
uint64_t v;
+ CPUState *cs = mon_get_cpu();
+
+ if (!cs && (format == 'i' || !is_physical)) {
+ monitor_printf(mon, "Can not dump without CPU\n");
+ return;
+ }
if (format == 'i') {
int flags = 0;
@@ -1264,7 +1289,7 @@ static void memory_dump(Monitor *mon, int count, int
format, int wsize,
flags = msr_le << 16;
flags |= env->bfd_mach;
#endif
- monitor_disas(mon, mon_get_cpu(), addr, count, is_physical, flags);
+ monitor_disas(mon, cs, addr, count, is_physical, flags);
return;
}
@@ -1303,7 +1328,7 @@ static void memory_dump(Monitor *mon, int count, int
format, int wsize,
if (is_physical) {
cpu_physical_memory_read(addr, buf, l);
} else {
- if (cpu_memory_rw_debug(mon_get_cpu(), addr, buf, l, 0) < 0) {
+ if (cpu_memory_rw_debug(cs, addr, buf, l, 0) < 0) {
monitor_printf(mon, " Cannot access memory\n");
break;
}
--
1.8.3.1
- [Qemu-trivial] [PATCH v3] monitor: Fix crashes when using HMP commands without CPU,
Thomas Huth <=