In Cortex-A9 machine, with LPAE feature enabled and physical address space
larger than 4G, Capture kernel will Oops on reading the /proc/vmcore file.
In copy_oldmem_page function, it simply use "pfn << PAGE_SHIFT" to get
the physical address, but this will cause overflow when LPAE enabled and
physical address space is larger than 4G, thus get the result as 0 and
cause Oops.
Fix it to use __pfn_to_phys instead. __pfn_to_phys will first cast the pfn
to type phys_addr_t which is the type u64 when LPAE enabled, and left shifted
by PAGE_SHIFT to get the proper physical address.
Signed-off-by: ivan lam <ivan.lam2...@gmail.com>
---
arch/arm/kernel/crash_dump.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/arm/kernel/crash_dump.c b/arch/arm/kernel/crash_dump.c
index 90c50d4..5d1286d 100644
--- a/arch/arm/kernel/crash_dump.c
+++ b/arch/arm/kernel/crash_dump.c
@@ -39,7 +39,7 @@ ssize_t copy_oldmem_page(unsigned long pfn, char *buf,
if (!csize)
return 0;
- vaddr = ioremap(pfn << PAGE_SHIFT, PAGE_SIZE);
+ vaddr = ioremap(__pfn_to_phys(pfn), PAGE_SIZE);
if (!vaddr)
return -ENOMEM;
--
1.7.9.5
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