diff mbox

kernel BUG at mm/usercopy.c:72!

Message ID 87zieajwpb.fsf@concordia.ellerman.id.au (mailing list archive)
State Not Applicable
Headers show

Commit Message

Michael Ellerman May 18, 2017, 10:17 a.m. UTC 
Breno Leitao <leitao@debian.org> writes:

> Hello,
>
> Kernel 4.12-rc1 is showing a bug when I try it on a POWER8 virtual
> machine. Justing SSHing into the machine causes this issue.

Can you try this?

cheers
diff mbox

Patch

diff --git a/arch/powerpc/include/asm/page.h b/arch/powerpc/include/asm/page.h
index 2a32483c7b6c..8da5d4c1cab2 100644
--- a/arch/powerpc/include/asm/page.h
+++ b/arch/powerpc/include/asm/page.h
@@ -132,7 +132,19 @@  extern long long virt_phys_offset;
 #define virt_to_pfn(kaddr)	(__pa(kaddr) >> PAGE_SHIFT)
 #define virt_to_page(kaddr)	pfn_to_page(virt_to_pfn(kaddr))
 #define pfn_to_kaddr(pfn)	__va((pfn) << PAGE_SHIFT)
+
+#ifdef CONFIG_PPC_BOOK3S_64
+/*
+ * On hash the vmalloc and other regions alias to the kernel region when passed
+ * through __pa(), which virt_to_pfn() uses. That means virt_addr_valid() can
+ * return true for some vmalloc addresses, which is incorrect. So explicitly
+ * check that the address is in the kernel region.
+ */
+#define virt_addr_valid(kaddr) (REGION_ID(kaddr) == KERNEL_REGION_ID && \
+				pfn_valid(virt_to_pfn(kaddr)))
+#else
 #define virt_addr_valid(kaddr)	pfn_valid(virt_to_pfn(kaddr))
+#endif
 
 /*
  * On Book-E parts we need __va to parse the device tree and we can't