From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
To: Thomas Huth <thuth@redhat.com>
Cc: qemu-trivial@nongnu.org, Markus Armbruster <armbru@redhat.com>,
qemu-devel@nongnu.org, Paolo Bonzini <pbonzini@redhat.com>,
David Gibson <david@gibson.dropbear.id.au>,
Aurelien Jarno <aurelien@aurel32.net>,
Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>,
Artyom Tarasenko <atar4qemu@gmail.com>,
Max Filippov <jcmvbkbc@gmail.com>
Subject: Re: [Qemu-trivial] [Qemu-devel] [PATCH v4] monitor: Fix crashes when using HMP commands without CPU
Date: Tue, 21 Feb 2017 15:34:52 +0000 [thread overview]
Message-ID: <20170221153452.GC9376@work-vm> (raw)
In-Reply-To: <1484309555-1935-1-git-send-email-thuth@redhat.com>
* Thomas Huth (thuth@redhat.com) wrote:
> When running certain HMP commands ("info registers", "info cpustats",
> "info tlb", "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.
>
> Signed-off-by: Thomas Huth <thuth@redhat.com>
Queued for HMP.
> ---
> v4:
> - Added some more target-specifc checks (for "info tlb" for example)
> 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 | 42 ++++++++++++++++++++++++++++++++++--------
> target/i386/monitor.c | 16 +++++++++++++++-
> target/ppc/monitor.c | 4 ++++
> target/sh4/monitor.c | 5 +++++
> target/sparc/monitor.c | 4 ++++
> target/xtensa/monitor.c | 4 ++++
> 7 files changed, 73 insertions(+), 10 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..bf488e9 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;
> }
> @@ -2186,11 +2211,12 @@ expr_error(Monitor *mon, const char *fmt, ...)
> static int get_monitor_def(target_long *pval, const char *name)
> {
> const MonitorDef *md = target_monitor_defs();
> + CPUState *cs = mon_get_cpu();
> void *ptr;
> uint64_t tmp = 0;
> int ret;
>
> - if (md == NULL) {
> + if (cs == NULL || md == NULL) {
> return -1;
> }
>
> @@ -2217,7 +2243,7 @@ static int get_monitor_def(target_long *pval, const char *name)
> }
> }
>
> - ret = target_get_monitor_def(mon_get_cpu(), name, &tmp);
> + ret = target_get_monitor_def(cs, name, &tmp);
> if (!ret) {
> *pval = (target_long) tmp;
> }
> diff --git a/target/i386/monitor.c b/target/i386/monitor.c
> index 468aa07..77ead60 100644
> --- a/target/i386/monitor.c
> +++ b/target/i386/monitor.c
> @@ -210,6 +210,10 @@ void hmp_info_tlb(Monitor *mon, const QDict *qdict)
> CPUArchState *env;
>
> env = mon_get_cpu_env();
> + if (!env) {
> + monitor_printf(mon, "No CPU available\n");
> + return;
> + }
>
> if (!(env->cr[0] & CR0_PG_MASK)) {
> monitor_printf(mon, "PG disabled\n");
> @@ -529,6 +533,10 @@ void hmp_info_mem(Monitor *mon, const QDict *qdict)
> CPUArchState *env;
>
> env = mon_get_cpu_env();
> + if (!env) {
> + monitor_printf(mon, "No CPU available\n");
> + return;
> + }
>
> if (!(env->cr[0] & CR0_PG_MASK)) {
> monitor_printf(mon, "PG disabled\n");
> @@ -624,7 +632,13 @@ const MonitorDef *target_monitor_defs(void)
>
> void hmp_info_local_apic(Monitor *mon, const QDict *qdict)
> {
> - x86_cpu_dump_local_apic_state(mon_get_cpu(), (FILE *)mon, monitor_fprintf,
> + CPUState *cs = mon_get_cpu();
> +
> + if (!cs) {
> + monitor_printf(mon, "No CPU available\n");
> + return;
> + }
> + x86_cpu_dump_local_apic_state(cs, (FILE *)mon, monitor_fprintf,
> CPU_DUMP_FPU);
> }
>
> diff --git a/target/ppc/monitor.c b/target/ppc/monitor.c
> index c2d0806..b8f30e9 100644
> --- a/target/ppc/monitor.c
> +++ b/target/ppc/monitor.c
> @@ -62,6 +62,10 @@ void hmp_info_tlb(Monitor *mon, const QDict *qdict)
> {
> CPUArchState *env1 = mon_get_cpu_env();
>
> + if (!env1) {
> + monitor_printf(mon, "No CPU available\n");
> + return;
> + }
> dump_mmu((FILE*)mon, (fprintf_function)monitor_printf, env1);
> }
>
> diff --git a/target/sh4/monitor.c b/target/sh4/monitor.c
> index 426e5d4..4c7f36c 100644
> --- a/target/sh4/monitor.c
> +++ b/target/sh4/monitor.c
> @@ -44,6 +44,11 @@ void hmp_info_tlb(Monitor *mon, const QDict *qdict)
> CPUArchState *env = mon_get_cpu_env();
> int i;
>
> + if (!env) {
> + monitor_printf(mon, "No CPU available\n");
> + return;
> + }
> +
> monitor_printf (mon, "ITLB:\n");
> for (i = 0 ; i < ITLB_SIZE ; i++)
> print_tlb (mon, i, &env->itlb[i]);
> diff --git a/target/sparc/monitor.c b/target/sparc/monitor.c
> index 7cc1b0f..f3ca524 100644
> --- a/target/sparc/monitor.c
> +++ b/target/sparc/monitor.c
> @@ -32,6 +32,10 @@ void hmp_info_tlb(Monitor *mon, const QDict *qdict)
> {
> CPUArchState *env1 = mon_get_cpu_env();
>
> + if (!env1) {
> + monitor_printf(mon, "No CPU available\n");
> + return;
> + }
> dump_mmu((FILE*)mon, (fprintf_function)monitor_printf, env1);
> }
>
> diff --git a/target/xtensa/monitor.c b/target/xtensa/monitor.c
> index f3fa4cd..2ee2b5b 100644
> --- a/target/xtensa/monitor.c
> +++ b/target/xtensa/monitor.c
> @@ -31,5 +31,9 @@ void hmp_info_tlb(Monitor *mon, const QDict *qdict)
> {
> CPUArchState *env1 = mon_get_cpu_env();
>
> + if (!env1) {
> + monitor_printf(mon, "No CPU available\n");
> + return;
> + }
> dump_mmu((FILE*)mon, (fprintf_function)monitor_printf, env1);
> }
> --
> 1.8.3.1
>
>
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
prev parent reply other threads:[~2017-02-21 15:35 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-01-13 12:12 [Qemu-trivial] [PATCH v4] monitor: Fix crashes when using HMP commands without CPU Thomas Huth
2017-01-13 12:45 ` [Qemu-trivial] [Qemu-devel] " Markus Armbruster
2017-01-15 9:15 ` [Qemu-trivial] " David Gibson
2017-02-15 10:37 ` Michael Tokarev
2017-02-21 15:34 ` Dr. David Alan Gilbert [this message]
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