Commit-ID:  c1192f8428414679c8126180e690f8daa1d4d98a
Gitweb:     http://git.kernel.org/tip/c1192f8428414679c8126180e690f8daa1d4d98a
Author:     Dave Hansen <[email protected]>
AuthorDate: Fri, 12 Feb 2016 13:02:27 -0800
Committer:  Ingo Molnar <[email protected]>
CommitDate: Thu, 18 Feb 2016 19:46:29 +0100

x86/mm/pkeys: Dump pkey from VMA in /proc/pid/smaps

The protection key can now be just as important as read/write
permissions on a VMA.  We need some debug mechanism to help
figure out if it is in play.  smaps seems like a logical
place to expose it.

arch/x86/kernel/setup.c is a bit of a weirdo place to put
this code, but it already had seq_file.h and there was not
a much better existing place to put it.

We also use no #ifdef.  If protection keys is .config'd out we
will effectively get the same function as if we used the weak
generic function.

Signed-off-by: Dave Hansen <[email protected]>
Reviewed-by: Thomas Gleixner <[email protected]>
Cc: Al Viro <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Andy Lutomirski <[email protected]>
Cc: Baoquan He <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Brian Gerst <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: Dave Young <[email protected]>
Cc: Denys Vlasenko <[email protected]>
Cc: H. Peter Anvin <[email protected]>
Cc: Jerome Marchand <[email protected]>
Cc: Jiri Kosina <[email protected]>
Cc: Joerg Roedel <[email protected]>
Cc: Johannes Weiner <[email protected]>
Cc: Kirill A. Shutemov <[email protected]>
Cc: Konstantin Khlebnikov <[email protected]>
Cc: Laurent Dufour <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Mark Salter <[email protected]>
Cc: Mark Williamson <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Naoya Horiguchi <[email protected]>
Cc: Paolo Bonzini <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Rik van Riel <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Cc: [email protected]
Cc: [email protected]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
---
 arch/x86/kernel/setup.c |  9 +++++++++
 fs/proc/task_mmu.c      | 14 ++++++++++++++
 2 files changed, 23 insertions(+)

diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index d3d80e6..7260f99 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -112,6 +112,7 @@
 #include <asm/alternative.h>
 #include <asm/prom.h>
 #include <asm/microcode.h>
+#include <asm/mmu_context.h>
 
 /*
  * max_low_pfn_mapped: highest direct mapped pfn under 4GB
@@ -1282,3 +1283,11 @@ static int __init register_kernel_offset_dumper(void)
        return 0;
 }
 __initcall(register_kernel_offset_dumper);
+
+void arch_show_smap(struct seq_file *m, struct vm_area_struct *vma)
+{
+       if (!boot_cpu_has(X86_FEATURE_OSPKE))
+               return;
+
+       seq_printf(m, "ProtectionKey:  %8u\n", vma_pkey(vma));
+}
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index fa95ab2..9df4316 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -660,11 +660,20 @@ static void show_smap_vma_flags(struct seq_file *m, 
struct vm_area_struct *vma)
                [ilog2(VM_MERGEABLE)]   = "mg",
                [ilog2(VM_UFFD_MISSING)]= "um",
                [ilog2(VM_UFFD_WP)]     = "uw",
+#ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS
+               /* These come out via ProtectionKey: */
+               [ilog2(VM_PKEY_BIT0)]   = "",
+               [ilog2(VM_PKEY_BIT1)]   = "",
+               [ilog2(VM_PKEY_BIT2)]   = "",
+               [ilog2(VM_PKEY_BIT3)]   = "",
+#endif
        };
        size_t i;
 
        seq_puts(m, "VmFlags: ");
        for (i = 0; i < BITS_PER_LONG; i++) {
+               if (!mnemonics[i][0])
+                       continue;
                if (vma->vm_flags & (1UL << i)) {
                        seq_printf(m, "%c%c ",
                                   mnemonics[i][0], mnemonics[i][1]);
@@ -702,6 +711,10 @@ static int smaps_hugetlb_range(pte_t *pte, unsigned long 
hmask,
 }
 #endif /* HUGETLB_PAGE */
 
+void __weak arch_show_smap(struct seq_file *m, struct vm_area_struct *vma)
+{
+}
+
 static int show_smap(struct seq_file *m, void *v, int is_pid)
 {
        struct vm_area_struct *vma = v;
@@ -783,6 +796,7 @@ static int show_smap(struct seq_file *m, void *v, int 
is_pid)
                   (vma->vm_flags & VM_LOCKED) ?
                        (unsigned long)(mss.pss >> (10 + PSS_SHIFT)) : 0);
 
+       arch_show_smap(m, vma);
        show_smap_vma_flags(m, vma);
        m_cache_vma(m, vma);
        return 0;

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