[Crash-utility] using crash for ARM

[Rabin Vincent]

2012/10/4 Mika Westerberg <mika.westerberg at iki.fi>:
> The unity-mapped region is mapped using 1MB pages. However, we actually have
> (when using the Linux ARM 2-level translation scheme):
>
> see arch/arm/include/asm/pgtable-2level.h:
>
> #define PMD_SHIFT               21
> #define PGDIR_SHIFT             21
>
> #define PTRS_PER_PGD            2048
>
> So we have 2048 entries in a PGD instead of 4096 making a PGD entry an array
> of "two pointers".
>
> Anyway as you and Paawan suggested it looks like a bug - we always use the
> first entry instead of the second given that bit 20 is set in the virtual
> address.

Isn't the problem actually that we read the section entry wrong?
The following (and attached) is the fix I've been using for this.

Rabin

diff --git a/arm.c b/arm.c
index 5930c02..4e7b6dc 100644
--- a/arm.c
+++ b/arm.c
@@ -957,12 +957,14 @@ arm_vtop(ulong vaddr, ulong *pgd, physaddr_t
*paddr, int verbose)
 			MKSTR((ulong)page_middle)), pmd_pte);

 	if ((pmd_pte & PMD_TYPE_MASK) == PMD_TYPE_SECT) {
+		ulong sectionbase = pmd_pte & _SECTION_PAGE_MASK;
+
 		if (verbose) {
 			fprintf(fp, " PAGE: %s  (1MB)\n\n",
 				mkstring(buf, VADDR_PRLEN, RJUST | LONG_HEX,
-				MKSTR(PAGEBASE(pmd_pte))));
+				MKSTR(sectionbase)));
 		}
-		*paddr = PAGEBASE(pmd_pte) + (vaddr & ~_SECTION_PAGE_MASK);
+		*paddr = sectionbase + (vaddr & ~_SECTION_PAGE_MASK);
 		return TRUE;
 	}
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