On 15/02/22 3:00 pm, Markus Armbruster wrote:
Rohit Kumar <rohit.kum...@nutanix.com> writes:
Qemu might crash when provided incomplete '-global' option.
For example:
qemu-system-x86_64 -global driver=isa-fdc
qemu-system-x86_64: ../../devel/qemu/qapi/string-input-visitor.c:394:
string_input_visitor_new: Assertion `str' failed.
Aborted (core dumped)
Resolves:
https://urldefense.proofpoint.com/v2/url?u=https-3A__gitlab.com_qemu-2Dproject_qemu_-2D_issues_604&d=DwIBAg&c=s883GpUCOChKOHiocYtGcg&r=ABSkr7gy7ZTfApFfI-Xxt1gZNtsDDiXoXOXc0OrkyFs&m=YfuOt9ozXVjjleGOXTdWK4Hu8PoU3kTzGTXAJ223138_AM934NRnuqUQHpaLSWTs&s=WEGcm58m7pR4XrWGsUvHOVPj18ym0OrlAObwY_CfKlc&e=
The original qemu_global_option() only ever created QemuOpts with all
three options present. Code consuming these QemuOpts relies on this
invariant. Commit 3751d7c43f "vl: allow full-blown QemuOpts syntax for
-global" (v2.4.0) wrecked it.
Let's point to the root cause:
Fixes: 3751d7c43f795b45ffdb9429cfb09c6beea55c68
Thanks, Markus for pointing out this. I will add it in the next patch.
Signed-off-by: Rohit Kumar <rohit.kum...@nutanix.com>
---
diff to v1:
- Removed '\n' from error log message.
softmmu/qdev-monitor.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/softmmu/qdev-monitor.c b/softmmu/qdev-monitor.c
index 01f3834db5..51b33caeca 100644
--- a/softmmu/qdev-monitor.c
+++ b/softmmu/qdev-monitor.c
@@ -1020,6 +1020,7 @@ int qemu_global_option(const char *str)
char driver[64], property[64];
QemuOpts *opts;
int rc, offset;
+ Error *err = NULL;
rc = sscanf(str, "%63[^.=].%63[^=]%n", driver, property, &offset);
if (rc == 2 && str[offset] == '=') {
@@ -1031,7 +1032,12 @@ int qemu_global_option(const char *str)
}
opts = qemu_opts_parse_noisily(&qemu_global_opts, str, false);
- if (!opts) {
+ if (!opts || !qemu_opt_get(opts, "driver") ||
!qemu_opt_get(opts,"property") ||
+ !qemu_opt_get(opts, "value")) {
+ error_setg(&err, "Invalid 'global' option format! "
+ "Use -global <driver>.<property>=<value> or "
+ "-global driver=driver,property=property,value=value");
+ error_report_err(err);
return -1;
}
This fix isn't quite right.
When qemu_opts_parse_noisily() fails, it reports an error and returns
null. Your patch reports a second error then. Reproducer:
$ qemu-system-x86_64 -global =
qemu-system-x86_64: -global =: Invalid parameter ''
qemu-system-x86_64: -global =: Invalid 'global' option format! Use -global
<driver>.<property>=<value> or -global
driver=driver,property=property,value=value
You should do something like
opts = qemu_opts_parse_noisily(&qemu_global_opts, str, false);
if (!opts) {
return -1;
}
if (!qemu_opt_get(opts, "driver")
|| !qemu_opt_get(opts, "property")
|| !qemu_opt_get(opts, "value")) {
error_report("options 'driver', 'property', and 'value'"
" are required');
return -1;
}
Ack., I will update it in the next patch. Thanks.