Andrew Hecox wrote:
On Thu, 2008-02-07 at 15:38 -0500, Dave Anderson wrote:
Andrew Hecox wrote:
I get the same:
(/boot/System.map-2.6.9-67.0.1.ELhugemem)
02323bd8 d log_buf_len
(/usr/lib/debug/lib/modules/2.6.9-67.0.1.ELhugemem/vmlinux)
$1 = (int *) 0x2323bd8
-Andrew
So, as Takao suggested, can you dump the incoming vaddr and
resultant pfn values in diskdumpmsg.c:read_buffer()?
The vaddr value is: 36846552.
-Andrew
Dave
OK, so the incoming vaddr is 36846552 is which is 0x2323bd8.
To get a pfn, that hugemem kernel virtual address is passed
through vtop() and then divided by 4096:
static int read_buffer(DumpFile *dump, addr_t vaddr, size_t len, void *buf)
{
addr_t paddr;
int block_size = get_page_size();
unsigned long pfn;
int ret;
size_t copy_len, offs;
void *page_data;
paddr = vtop(dump, vaddr);
pfn = paddr / block_size;
offs = paddr % block_size;
When 0x2323bd8 is run through vtop(), it simply strips off the
hugemem unity-map identifier:
addr_t vtop(DumpFile *dump, addr_t vaddr)
{
if (strstr("hugemem", dump->utsname->release))
return vaddr - 0x02000000L;
else
return vaddr - 0xc0000000L;
}
leaving 0x323bd8 -- which gets divided by the page size of 4096, leaving
a pfn of 0x323.
But you see that the pfn was 271139 (0x42323). If that is expanded
to a physical address it would be 0x42323000. It looks like it's
using the non-hugemem value in vtop(), i,e, subtracting c0000000 from
the incoming vaddr. In other words, 0x2323bd8 - 0xc000000 is
equal to 0x42323bd8. If that is divided by 4096, you get
the funky pfn of 271139 (0x42323).
Print out the dump->utsname->release string in vtop(). It must
not contain "hugemem".
Dave
:
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