On Thu, Nov 25, 2010 at 02:13:35PM +0100, Mark Kettenis wrote:
> > Date: Wed, 24 Nov 2010 23:07:45 +1000
> > From: David Gwynne <l...@animata.net>
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> >
> > without this diff this box panics on boot while attaching the 36th
> > cpu. its a buffer overrun...
> >
> > analysis done by kettenis.
> >
> > ok?
>
> I think the check should involve MAXCPUS. Your diff makes clear
> though that simply bumping MAXCPUS to 64 isn't going to fly. At the
> very least cpus_attached needs to be changed into a 64-bit integer.
>
> > Index: cpu.c
> > ===================================================================
> > RCS file: /cvs/src/sys/arch/amd64/amd64/cpu.c,v
> > retrieving revision 1.38
> > diff -u -p -r1.38 cpu.c
> > --- cpu.c 13 Nov 2010 04:16:42 -0000 1.38
> > +++ cpu.c 24 Nov 2010 13:04:30 -0000
> > @@ -168,6 +168,9 @@ cpu_match(struct device *parent, void *m
> > struct cfdata *cf = match;
> > struct cpu_attach_args *caa = aux;
> >
> > + if (~cpus_attached == 0)
> > + return 0;
> > +
> > if (strcmp(caa->caa_name, cf->cf_driver->cd_name) == 0)
> > return 1;
> > return 0;
>
Hmmm. I can't actually find any *use* of cpus_attached. Is it a relic?
The diff below compiles and runs fine on my 6-proc amd64 box.
.... Ken
Index: amd64/cpu.c
===================================================================
RCS file: /cvs/src/sys/arch/amd64/amd64/cpu.c,v
retrieving revision 1.38
diff -u -p -r1.38 cpu.c
--- amd64/cpu.c 13 Nov 2010 04:16:42 -0000 1.38
+++ amd64/cpu.c 25 Nov 2010 23:00:44 -0000
@@ -135,8 +135,6 @@ struct cpu_info cpu_info_primary = { 0,
struct cpu_info *cpu_info_list = &cpu_info_primary;
-u_int32_t cpus_attached = 0;
-
#ifdef MULTIPROCESSOR
/*
* Array of CPU info structures. Must be statically-allocated because
@@ -345,8 +343,6 @@ cpu_attach(struct device *parent, struct
panic("unknown processor type??");
}
cpu_vm_init(ci);
-
- cpus_attached |= (1 << ci->ci_cpuid);
#if defined(MULTIPROCESSOR)
if (mp_verbose) {
Index: include/cpu.h
===================================================================
RCS file: /cvs/src/sys/arch/amd64/include/cpu.h,v
retrieving revision 1.60
diff -u -p -r1.60 cpu.h
--- include/cpu.h 22 Nov 2010 21:07:18 -0000 1.60
+++ include/cpu.h 25 Nov 2010 23:00:44 -0000
@@ -211,8 +211,6 @@ extern struct cpu_info cpu_info_primary;
#define aston(p) ((p)->p_md.md_astpending = 1)
-extern u_int32_t cpus_attached;
-
#define curpcb curcpu()->ci_curpcb
/*
