From: Michael Ellerman <mpe@ellerman•id.au>
To: Breno Leitao <leitao@debian•org>, linuxppc-dev@lists•ozlabs.org
Cc: gromero@br•ibm.com
Subject: Re: kernel BUG at mm/usercopy.c:72!
Date: Thu, 18 May 2017 20:17:20 +1000 [thread overview]
Message-ID: <87zieajwpb.fsf@concordia.ellerman.id.au> (raw)
In-Reply-To: <20170515191949.GA13641@gmail.com>
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 --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
prev parent reply other threads:[~2017-05-18 10:17 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-05-15 19:19 kernel BUG at mm/usercopy.c:72! Breno Leitao
2017-05-16 4:00 ` Anshuman Khandual
2017-05-16 4:44 ` Balbir Singh
2017-05-16 5:04 ` Anshuman Khandual
2017-05-16 11:02 ` Michael Ellerman
2017-05-16 16:15 ` Breno Leitao
2017-05-16 11:09 ` Michael Ellerman
2017-05-16 14:32 ` Kees Cook
2017-05-16 14:35 ` Laura Abbott
2017-05-18 5:09 ` Michael Ellerman
2017-05-17 10:05 ` Balbir Singh
2017-05-18 10:16 ` Michael Ellerman
2017-05-18 10:58 ` Balbir Singh
2017-05-18 10:17 ` Michael Ellerman [this message]
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