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Message-Id: <b96108404af22ac25a0b62b81d338bf511002f63.1550088114.git.khalid.aziz@oracle.com>
Date: Wed, 13 Feb 2019 17:01:32 -0700
From: Khalid Aziz <khalid.aziz@...cle.com>
To: juergh@...il.com, tycho@...ho.ws, jsteckli@...zon.de, ak@...ux.intel.com,
torvalds@...ux-foundation.org, liran.alon@...cle.com,
keescook@...gle.com, akpm@...ux-foundation.org, mhocko@...e.com,
catalin.marinas@....com, will.deacon@....com, jmorris@...ei.org,
konrad.wilk@...cle.com
Cc: Tycho Andersen <tycho@...ker.com>, deepa.srinivasan@...cle.com,
chris.hyser@...cle.com, tyhicks@...onical.com, dwmw@...zon.co.uk,
andrew.cooper3@...rix.com, jcm@...hat.com, boris.ostrovsky@...cle.com,
kanth.ghatraju@...cle.com, oao.m.martins@...cle.com,
jmattson@...gle.com, pradeep.vincent@...cle.com, john.haxby@...cle.com,
tglx@...utronix.de, kirill.shutemov@...ux.intel.com, hch@....de,
steven.sistare@...cle.com, labbott@...hat.com, luto@...nel.org,
dave.hansen@...el.com, peterz@...radead.org,
kernel-hardening@...ts.openwall.com, linux-mm@...ck.org,
x86@...nel.org, linux-arm-kernel@...ts.infradead.org,
linux-kernel@...r.kernel.org, Khalid Aziz <khalid.aziz@...cle.com>
Subject: [RFC PATCH v8 09/14] mm: add a user_virt_to_phys symbol
From: Tycho Andersen <tycho@...ker.com>
We need someting like this for testing XPFO. Since it's architecture
specific, putting it in the test code is slightly awkward, so let's make it
an arch-specific symbol and export it for use in LKDTM.
CC: linux-arm-kernel@...ts.infradead.org
CC: x86@...nel.org
Signed-off-by: Tycho Andersen <tycho@...ker.com>
Tested-by: Marco Benatto <marco.antonio.780@...il.com>
Signed-off-by: Khalid Aziz <khalid.aziz@...cle.com>
---
v6: * add a definition of user_virt_to_phys in the !CONFIG_XPFO case
v7: * make user_virt_to_phys a GPL symbol
arch/x86/mm/xpfo.c | 57 ++++++++++++++++++++++++++++++++++++++++++++
include/linux/xpfo.h | 8 +++++++
2 files changed, 65 insertions(+)
diff --git a/arch/x86/mm/xpfo.c b/arch/x86/mm/xpfo.c
index 6c7502993351..e13b99019c47 100644
--- a/arch/x86/mm/xpfo.c
+++ b/arch/x86/mm/xpfo.c
@@ -117,3 +117,60 @@ inline void xpfo_flush_kernel_tlb(struct page *page, int order)
flush_tlb_kernel_range(kaddr, kaddr + (1 << order) * size);
}
+
+/* Convert a user space virtual address to a physical address.
+ * Shamelessly copied from slow_virt_to_phys() and lookup_address() in
+ * arch/x86/mm/pageattr.c
+ */
+phys_addr_t user_virt_to_phys(unsigned long addr)
+{
+ phys_addr_t phys_addr;
+ unsigned long offset;
+ pgd_t *pgd;
+ p4d_t *p4d;
+ pud_t *pud;
+ pmd_t *pmd;
+ pte_t *pte;
+
+ pgd = pgd_offset(current->mm, addr);
+ if (pgd_none(*pgd))
+ return 0;
+
+ p4d = p4d_offset(pgd, addr);
+ if (p4d_none(*p4d))
+ return 0;
+
+ if (p4d_large(*p4d) || !p4d_present(*p4d)) {
+ phys_addr = (unsigned long)p4d_pfn(*p4d) << PAGE_SHIFT;
+ offset = addr & ~P4D_MASK;
+ goto out;
+ }
+
+ pud = pud_offset(p4d, addr);
+ if (pud_none(*pud))
+ return 0;
+
+ if (pud_large(*pud) || !pud_present(*pud)) {
+ phys_addr = (unsigned long)pud_pfn(*pud) << PAGE_SHIFT;
+ offset = addr & ~PUD_MASK;
+ goto out;
+ }
+
+ pmd = pmd_offset(pud, addr);
+ if (pmd_none(*pmd))
+ return 0;
+
+ if (pmd_large(*pmd) || !pmd_present(*pmd)) {
+ phys_addr = (unsigned long)pmd_pfn(*pmd) << PAGE_SHIFT;
+ offset = addr & ~PMD_MASK;
+ goto out;
+ }
+
+ pte = pte_offset_kernel(pmd, addr);
+ phys_addr = (phys_addr_t)pte_pfn(*pte) << PAGE_SHIFT;
+ offset = addr & ~PAGE_MASK;
+
+out:
+ return (phys_addr_t)(phys_addr | offset);
+}
+EXPORT_SYMBOL_GPL(user_virt_to_phys);
diff --git a/include/linux/xpfo.h b/include/linux/xpfo.h
index 8b029918a958..117869991d5b 100644
--- a/include/linux/xpfo.h
+++ b/include/linux/xpfo.h
@@ -24,6 +24,10 @@ struct page;
#ifdef CONFIG_XPFO
+#include <linux/dma-mapping.h>
+
+#include <linux/types.h>
+
extern struct page_ext_operations page_xpfo_ops;
void set_kpte(void *kaddr, struct page *page, pgprot_t prot);
@@ -49,6 +53,8 @@ void xpfo_temp_unmap(const void *addr, size_t size, void **mapping,
bool xpfo_enabled(void);
+phys_addr_t user_virt_to_phys(unsigned long addr);
+
#else /* !CONFIG_XPFO */
static inline void xpfo_kmap(void *kaddr, struct page *page) { }
@@ -73,6 +79,8 @@ static inline void xpfo_temp_unmap(const void *addr, size_t size,
static inline bool xpfo_enabled(void) { return false; }
+static inline phys_addr_t user_virt_to_phys(unsigned long addr) { return 0; }
+
#endif /* CONFIG_XPFO */
#endif /* _LINUX_XPFO_H */
--
2.17.1
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