On 02/17/2012 07:25 PM, Dave Anderson wrote:
----- Original Message -----
On 02/17/2012 12:43 AM, Dave Anderson wrote:
----- Original Message -----
On 02/16/2012 09:52 PM, Dave Anderson wrote:
----- Original Message -----
...
So just do the same thing -- no verbose expanation is required.
There are two ways to fix this :
1) Fix dump_mem_map*() to print the header only when there is
information to dump.
--- a/memory.c
+++ b/memory.c
@@ -4637,13 +4637,6 @@ dump_mem_map_SPARSEMEM(struct meminfo
*mi)
continue;
}
- if (print_hdr) {
- if (!(pc->curcmd_flags&
HEADER_PRINTED))
- fprintf(fp, "%s", hdr);
- print_hdr = FALSE;
- pc->curcmd_flags |= HEADER_PRINTED;
- }
-
pp = section_mem_map_addr(section);
pp = sparse_decode_mem_map(pp, section_nr);
phys = (physaddr_t) section_nr *
PAGES_PER_SECTION()
* PAGESIZE();
@@ -4854,6 +4847,13 @@ dump_mem_map_SPARSEMEM(struct meminfo
*mi)
}
if (bufferindex> buffersize) {
+ if (print_hdr) {
+ if (!(pc->curcmd_flags&
HEADER_PRINTED))
+ fprintf(fp,
"%s",
hdr);
+ print_hdr = FALSE;
+ pc->curcmd_flags |=
HEADER_PRINTED;
+ }
+
fprintf(fp, "%s",
outputbuffer);
bufferindex = 0;
}
@@ -4867,6 +4867,13 @@ dump_mem_map_SPARSEMEM(struct meminfo
*mi)
}
if (bufferindex> 0) {
+ if (print_hdr) {
+ if (!(pc->curcmd_flags&
HEADER_PRINTED))
+ fprintf(fp, "%s", hdr);
+ print_hdr = FALSE;
+ pc->curcmd_flags |= HEADER_PRINTED;
+ }
+
fprintf(fp, "%s", outputbuffer);
}
Similarly for the dump_mem_map().
2) Fix ppc_pgd_vtop() to return FALSE if the paddr>
machdep->memsize
--- a/ppc.c
+++ b/ppc.c
@@ -438,6 +438,10 @@ ppc_pgd_vtop(ulong *pgd, ulong vaddr,
physaddr_t
*paddr, int verbose)
*paddr = PAGEBASE(pte) + PAGEOFFSET(vaddr);
+ if (*paddr> machdep->memsize)
+ /* We don't have pages above System RAM */
+ return FALSE;
+
return TRUE;
no_page:
I prefer the (1). What do you think ?
Hi Suzuki,
Hmmm -- with respect to (1), I suppose that would work, although
given that both x86 and x86_64 pass through
dump_mem_map_SPARSEMEM()
without printing the header in a non-existent-page case, I don't
understand why ppc is different?
Yep, I digged into that a little, but not deep enough to debug it
with
a dump. Nothing was evident from the code :(.
Right -- I tried debugging it from the x86 and x86_64 perspective,
and couldn't see why ppc would be different! ;-)
Ah, well, I was talking about the x86_64 dump.
I could explain the PPC side of affairs :-). We have page the
following
flags set for the page(with the actual PPC44x page flags support) :
VIRTUAL PHYSICAL
d1002000 20ec00000
PAGE DIRECTORY: c0578000
PGD: c0579a20 => c784b000
PMD: c784b000 => c784b010
PTE: c784b010 => 20ec0051b
PAGE: 20ec00000
PTE PHYSICAL FLAGS
20ec0051b 20ec00000 (PRESENT|RW|GUARDED|NO_CACHE|DIRTY|ACCESSED)
So the page is 'present', but there is no page descriptor associated
with it.
Hence dump_mem_map() would still be called and hence the problem.
Why doesn't it get called in x86_64 case even when the flags indicate
page 'PRESENT' ?
I don't know -- that's what I was asking!
The only suspect is :
if (page_exists) {
if ((pc->flags & DEVMEM) && (paddr >= VTOP(vt->high_memory))) <<
return;
But I'd like to prevent it
in all cases with the patch to do_vtop().
Yep, thats the best way to fix it as of now.
Thanks
Suzuki
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