Re: panic in drm or vt or deadlock on mutex or ...

On 2/8/21 1:53 PM, Alastair Hogge wrote:
> Boot to multi-user; login (getty):
> $ doas kldload /boot/modules/amdgpu.ko
> $ sysctl
> [panic]
> 
> ..is a guaranteed way to panic my system.

Hi,

Maybe you could do a hack and edit the sysctl source code:

1) print the sysctl before it is queried.
2) sleep 1 second between print and query.

Should be easy to nail this down!

--HPS

_______________________________________________
[email protected] mailing list
https://lists.freebsd.org/mailman/listinfo/freebsd-current
To unsubscribe, send any mail to "[email protected]"

diff --git a/sbin/sysctl/sysctl.c b/sbin/sysctl/sysctl.c
index 30d6d94723f..4b45bb2f967 100644
--- a/sbin/sysctl/sysctl.c
+++ b/sbin/sysctl/sysctl.c
@@ -336,6 +336,10 @@ parse_numeric(const char *newvalstr, const char *fmt, u_int kind,
 	return (true);
 }
 
+#define	sysctl(...) ({ \
+  usleep(1000000); \
+  sysctl(__VA_ARGS__); })
+
 /*
  * Parse a name into a MIB entry.
  * Lookup and print out the MIB entry if it exists.