On 01/29/2016 07:17 PM, Dave Hansen wrote:
From: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
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 <dave.hansen@xxxxxxxxxxxxxxx>
Reviewed-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: vbabka@xxxxxxx
---
b/arch/x86/kernel/setup.c | 9 +++++++++
b/fs/proc/task_mmu.c | 14 ++++++++++++++
2 files changed, 23 insertions(+)
diff -puN arch/x86/kernel/setup.c~pkeys-40-smaps arch/x86/kernel/setup.c
--- a/arch/x86/kernel/setup.c~pkeys-40-smaps 2016-01-28 15:52:26.386680200 -0800
+++ b/arch/x86/kernel/setup.c 2016-01-28 15:52:26.391680429 -0800
@@ -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
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 -puN fs/proc/task_mmu.c~pkeys-40-smaps fs/proc/task_mmu.c
--- a/fs/proc/task_mmu.c~pkeys-40-smaps 2016-01-28 15:52:26.387680246 -0800
+++ b/fs/proc/task_mmu.c 2016-01-28 15:52:26.391680429 -0800
@@ -668,11 +668,20 @@ static void show_smap_vma_flags(struct s
[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]);
@@ -710,6 +719,10 @@ static int smaps_hugetlb_range(pte_t *pt
}
#endif /* HUGETLB_PAGE */
+void __weak arch_show_smap(struct seq_file *m, struct vm_area_struct *vma)
+{
+}
Is it valid that this serves also as a declaration? Or should it be also
in some header?
+
static int show_smap(struct seq_file *m, void *v, int is_pid)
{
struct vm_area_struct *vma = v;
@@ -791,6 +804,7 @@ static int show_smap(struct seq_file *m,
(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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