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[PATCH v8 0/9] Application Data Integrity feature introduced by SPARC M7

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  [PATCH v8 0/9] Application Data Integrity feature introduced by SPARC M7 Khalid Aziz <khalid.aziz@oracle.com> - 2017-09-25 19:00 +0200
    [PATCH v8 7/9] mm: Add address parameter to arch_validate_prot() Khalid Aziz <khalid.aziz@oracle.com> - 2017-09-25 19:00 +0200
    [PATCH v8 5/9] sparc64: Add handler for "Memory Corruption Detected" trap Khalid Aziz <khalid.aziz@oracle.com> - 2017-09-25 19:00 +0200
    [PATCH v8 4/9] sparc64: Add HV fault type handlers for ADI related faults Khalid Aziz <khalid.aziz@oracle.com> - 2017-09-25 19:00 +0200
    [PATCH v8 1/9] signals, sparc: Add signal codes for ADI violations Khalid Aziz <khalid.aziz@oracle.com> - 2017-09-25 19:00 +0200
    [PATCH v8 6/9] sparc64: Add auxiliary vectors to report platform ADI properties Khalid Aziz <khalid.aziz@oracle.com> - 2017-09-25 19:00 +0200
    [PATCH v8 2/9] mm, swap: Add infrastructure for saving page metadata as well on swap Khalid Aziz <khalid.aziz@oracle.com> - 2017-09-25 19:00 +0200
    [PATCH v8 8/9] mm: Clear arch specific VM flags on protection change Khalid Aziz <khalid.aziz@oracle.com> - 2017-09-25 19:00 +0200

#1739173 — [PATCH v8 0/9] Application Data Integrity feature introduced by SPARC M7

SPARC M7 processor adds additional metadata for memory address space
that can be used to secure access to regions of memory. This additional
metadata is implemented as a 4-bit tag attached to each cacheline size
block of memory. A task can set a tag on any number of such blocks.
Access to such block is granted only if the virtual address used to
access that block of memory has the tag encoded in the uppermost 4 bits
of VA. Since sparc processor does not implement all 64 bits of VA, top 4
bits are available for ADI tags. Any mismatch between tag encoded in VA
and tag set on the memory block results in a trap. Tags are verified in
the VA presented to the MMU and tags are associated with the physical
page VA maps on to. If a memory page is swapped out and page frame gets
reused for another task, the tags are lost and hence must be saved when
swapping or migrating the page.

A userspace task enables ADI through mprotect(). This patch series adds
a page protection bit PROT_ADI and a corresponding VMA flag
VM_SPARC_ADI. VM_SPARC_ADI is used to trigger setting TTE.mcd bit in the
sparc pte that enables ADI checking on the corresponding page. MMU
validates the tag embedded in VA for every page that has TTE.mcd bit set
in its pte. After enabling ADI on a memory range, the userspace task can
set ADI version tags using stxa instruction with ASI_MCD_PRIMARY or
ASI_MCD_ST_BLKINIT_PRIMARY ASI.

Once userspace task calls mprotect() with PROT_ADI, kernel takes
following overall steps:

1. Find the VMAs covering the address range passed in to mprotect and
set VM_SPARC_ADI flag. If address range covers a subset of a VMA, the
VMA will be split.

2. When a page is allocated for a VA and the VMA covering this VA has
VM_SPARC_ADI flag set, set the TTE.mcd bit so MMU will check the
vwersion tag.

3. Userspace can now set version tags on the memory it has enabled ADI
on. Userspace accesses ADI enabled memory using a virtual address that
has the version tag embedded in the high bits. MMU validates this
version tag against the actual tag set on the memory. If tag matches,
MMU performs the VA->PA translation and access is granted. If there is a
mismatch, hypervisor sends a data access exception or precise memory
corruption detected exception depending upon whether precise exceptions
are enabled or not (controlled by MCDPERR register). Kernel sends
SIGSEGV to the task with appropriate si_code.

4. If a page is being swapped out or migrated, kernel must save any ADI
tags set on the page. Kernel maintains a page worth of tag storage
descriptors. Each descriptors pointsto a tag storage space and the
address range it covers. If the page being swapped out or migrated has
ADI enabled on it, kernel finds a tag storage descriptor that covers the
address range for the page or allocates a new descriptor if none of the
existing descriptors cover the address range. Kernel saves tags from the
page into the tag storage space descriptor points to.

5. When the page is swapped back in or reinstantiated after migration,
kernel restores the version tags on the new physical page by retrieving
the original tag from tag storage pointed to by a tag storage descriptor
for the virtual address range for new page.

User task can disable ADI by calling mprotect() again on the memory
range with PROT_ADI bit unset. Kernel clears the VM_SPARC_ADI flag in
VMAs, merges adjacent VMAs if necessary, and clears TTE.mcd bit in the
corresponding ptes.

IOMMU does not support ADI checking. Any version tags embedded in the
top bits of VA meant for IOMMU, are cleared and replaced with sign
extension of the first non-version tag bit (bit 59 for SPARC M7) for
IOMMU addresses.

This patch series adds support for this feature in 9 patches:

Patch 1/9
  Tag mismatch on access by a task results in a trap from hypervisor as
  data access exception or a precide memory corruption detected
  exception. As part of handling these exceptions, kernel sends a
  SIGSEGV to user process with special si_code to indicate which fault
  occurred. This patch adds three new si_codes to differentiate between
  various mismatch errors.

Patch 2/9
  When a page is swapped or migrated, metadata associated with the page
  must be saved so it can be restored later. This patch adds a new
  function that saves/restores this metadata when updating pte upon a
  swap/migration.

Patch 3/9
  SPARC M7 processor adds new fields to control registers to support ADI
  feature. It also adds a new exception for precise traps on tag
  mismatch. This patch adds definitions for the new control register
  fields, new ASIs for ADI and an exception handler for the precise trap
  on tag mismatch.

Patch 4/9
  New hypervisor fault types were added by sparc M7 processor to support
  ADI feature. This patch adds code to handle these fault types for data
  access exception handler.

Patch 5/9
  When ADI is in use for a page and a tag mismatch occurs, processor
  raises "Memory corruption Detected" trap. This patch adds a handler
  for this trap.

Patch 6/9
  ADI usage is governed by ADI properties on a platform. These
  properties are provided to kernel by firmware. Thsi patch adds new
  auxiliary vectors that provide these values to userpsace.

Patch 7/9
  arch_validate_prot() is used to validate the new protection bits asked
  for by the userspace app. Validating protection bits may need the
  context of address space the bits are being applied to. One such
  example is PROT_ADI bit on sparc processor that enables ADI protection
  on an address range. ADI protection applies only to addresses covered
  by physical RAM and not other PFN mapped addresses or device
  addresses. This patch adds "address" to the parameters being passed to
  arch_validate_prot() to provide that context.

Patch 8/9
  When protection bits are changed on a page, kernel carries forward all
  protection bits except for read/write/exec. Additional code was added
  to allow kernel to clear PKEY bits on x86 but this requirement to
  clear other bits is not unique to x86. This patch extends the existing
  code to allow other architectures to clear any other protection bits
  as well on protection bit change.

Patch 9/9
  This patch adds support for a user space task to enable ADI and enable
  tag checking for subsets of its address space. As part of enabling
  this feature, this patch adds to support manipulation of precise
  exception for memory corruption detection, adds code to save and
  restore tags on page swap and migration, and adds code to handle ADI
  tagged addresses for DMA.

Changelog v8:

	- Patch 1/9: No changes
	- Patch 2/9: Fixed and erroneous "}"
	- Patch 3/9: Minor print formatting change
	- Patch 4/9: No changes
	- Patch 5/9: No changes
	- Patch 6/9: Added AT_ADI_UEONADI back
	- Patch 7/9: Added addr parameter to powerpc arch_validate_prot()
	- Patch 8/9: No changes
	- Patch 9/9:
		- Documentation updates
		- Added an IPI on mprotect(...PROT_ADI...) call and
		  restore of TSTATE.MCDE on context switch
		- Removed restriction on enabling ADI on read-only
		  memory
		- Changed kzalloc() for tag storage to use GFP_NOWAIT
		- Added code to handle overflow and underflow when
		  allocating tag storage
		- Replaced sun_m7_patch_1insn_range() with
		  sun4v_patch_1insn_range()
		- Added membar after restoring ADI tags in
		  copy_user_highpage()

Changelog v7:

	- Patch 1/9: No changes
	- Patch 2/9: Updated parameters to arch specific swap in/out
	  handlers
	- Patch 3/9: No changes
	- Patch 4/9: new patch split off from patch 4/4 in v6
	- Patch 5/9: new patch split off from patch 4/4 in v6
	- Patch 6/9: new patch split off from patch 4/4 in v6
	- Patch 7/9: new patch
	- Patch 8/9: new patch
	- Patch 9/9:
		- Enhanced arch_validate_prot() to enable ADI only on
		  writable addresses backed by physical RAM
		- Added support for saving/restoring ADI tags for each
		  ADI block size address range on a page on swap in/out
		- copy ADI tags on COW
		- Updated values for auxiliary vectors to not conflict
		  with values on other architectures to avoid conflict
		  in glibc
		- Disable same page merging on ADI enabled pages
		- Enable ADI only on writable addresses backed by
		  physical RAM
		- Split parts of patch off into separate patches

Changelog v6:
	- Patch 1/4: No changes
	- Patch 2/4: No changes
	- Patch 3/4: Added missing nop in the delay slot in
	  sun4v_mcd_detect_precise
	- Patch 4/4: Eliminated instructions to read and write PSTATE
	  as well as MCDPER and PMCDPER on every access to userspace
	  addresses by setting PSTATE and PMCDPER correctly upon entry
	  into kernel

Changelog v5:
	- Patch 1/4: No changes
	- Patch 2/4: Replaced set_swp_pte_at() with new architecture
	  functions arch_do_swap_page() and arch_unmap_one() that
	  suppoprt architecture specific actions to be taken on page
	  swap and migration
	- Patch 3/4: Fixed indentation issues in assembly code
	- Patch 4/4:
		- Fixed indentation issues and instrcuctions in assembly
		  code
		- Removed CONFIG_SPARC64 from mdesc.c
		- Changed to maintain state of MCDPER register in thread
		  info flags as opposed to in mm context. MCDPER is a
		  per-thread state and belongs in thread info flag as
		  opposed to mm context which is shared across threads.
		  Added comments to clarify this is a lazily maintained
		  state and must be updated on context switch and
		  copy_process() 
		- Updated code to use the new arch_do_swap_page() and
		  arch_unmap_one() functions

Testing:

- All functionality was tested with 8K normal pages as well as hugepages
  using malloc, mmap and shm.
- Multiple long duration stress tests were run using hugepages over 2+
  months. Normal pages were tested with shorter duration stress tests.
- Tested swapping with malloc and shm by reducing max memory and
  allocating three times the available system memory by active processes
  using ADI on allocated memory. Ran through multiple hours long runs of
  this test.
- Tested page migration with malloc and shm by migrating data pages of
  active ADI test process using migratepages, back and forth between two
  nodes every few seconds over an hour long run. Verified page migration
  through /proc/<pid>/numa_maps.
- Tested COW support using test that forks children that read from
  ADI enabled pages shared with parent and other children and write to
  them as well forcing COW.


---------
Khalid Aziz (9):
  signals, sparc: Add signal codes for ADI violations
  mm, swap: Add infrastructure for saving page metadata as well on swap
  sparc64: Add support for ADI register fields, ASIs and traps
  sparc64: Add HV fault type handlers for ADI related faults
  sparc64: Add handler for "Memory Corruption Detected" trap
  sparc64: Add auxiliary vectors to report platform ADI properties
  mm: Add address parameter to arch_validate_prot()
  mm: Clear arch specific VM flags on protection change
  sparc64: Add support for ADI (Application Data Integrity)

 Documentation/sparc/adi.txt             | 278 +++++++++++++++++++++++
 arch/powerpc/include/asm/mman.h         |   4 +-
 arch/powerpc/kernel/syscalls.c          |   2 +-
 arch/sparc/include/asm/adi.h            |   6 +
 arch/sparc/include/asm/adi_64.h         |  46 ++++
 arch/sparc/include/asm/elf_64.h         |   9 +
 arch/sparc/include/asm/hypervisor.h     |   2 +
 arch/sparc/include/asm/mman.h           |  84 ++++++-
 arch/sparc/include/asm/mmu_64.h         |  17 ++
 arch/sparc/include/asm/mmu_context_64.h |  50 +++++
 arch/sparc/include/asm/page_64.h        |   4 +
 arch/sparc/include/asm/pgtable_64.h     |  48 ++++
 arch/sparc/include/asm/thread_info_64.h |   2 +-
 arch/sparc/include/asm/trap_block.h     |   2 +
 arch/sparc/include/asm/ttable.h         |  10 +
 arch/sparc/include/uapi/asm/asi.h       |   5 +
 arch/sparc/include/uapi/asm/auxvec.h    |  11 +
 arch/sparc/include/uapi/asm/mman.h      |   2 +
 arch/sparc/include/uapi/asm/pstate.h    |  10 +
 arch/sparc/kernel/Makefile              |   1 +
 arch/sparc/kernel/adi_64.c              | 384 ++++++++++++++++++++++++++++++++
 arch/sparc/kernel/entry.h               |   3 +
 arch/sparc/kernel/etrap_64.S            |  28 ++-
 arch/sparc/kernel/head_64.S             |   1 +
 arch/sparc/kernel/mdesc.c               |   2 +
 arch/sparc/kernel/process_64.c          |  25 +++
 arch/sparc/kernel/setup_64.c            |   2 +
 arch/sparc/kernel/sun4v_mcd.S           |  17 ++
 arch/sparc/kernel/traps_64.c            | 142 +++++++++++-
 arch/sparc/kernel/ttable_64.S           |   6 +-
 arch/sparc/kernel/vmlinux.lds.S         |   5 +
 arch/sparc/mm/gup.c                     |  37 +++
 arch/sparc/mm/hugetlbpage.c             |  14 +-
 arch/sparc/mm/init_64.c                 |  34 +++
 arch/sparc/mm/tsb.c                     |  21 ++
 arch/x86/kernel/signal_compat.c         |   2 +-
 include/asm-generic/pgtable.h           |  36 +++
 include/linux/mm.h                      |   9 +
 include/linux/mman.h                    |   2 +-
 include/uapi/asm-generic/siginfo.h      |   5 +-
 mm/ksm.c                                |   4 +
 mm/memory.c                             |   1 +
 mm/mprotect.c                           |   4 +-
 mm/rmap.c                               |  14 ++
 44 files changed, 1374 insertions(+), 17 deletions(-)
 create mode 100644 Documentation/sparc/adi.txt
 create mode 100644 arch/sparc/include/asm/adi.h
 create mode 100644 arch/sparc/include/asm/adi_64.h
 create mode 100644 arch/sparc/kernel/adi_64.c
 create mode 100644 arch/sparc/kernel/sun4v_mcd.S

-- 
2.11.0

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#1739174 — [PATCH v8 7/9] mm: Add address parameter to arch_validate_prot()

A protection flag may not be valid across entire address space and
hence arch_validate_prot() might need the address a protection bit is
being set on to ensure it is a valid protection flag. For example, sparc
processors support memory corruption detection (as part of ADI feature)
flag on memory addresses mapped on to physical RAM but not on PFN mapped
pages or addresses mapped on to devices. This patch adds address to the
parameters being passed to arch_validate_prot() so protection bits can
be validated in the relevant context.

Signed-off-by: Khalid Aziz <khalid.aziz@oracle.com>
Cc: Khalid Aziz <khalid@gonehiking.org>
---
v8:
	- Added addr parameter to powerpc arch_validate_prot() (suggested
	  by Michael Ellerman)
v7:
	- new patch

 arch/powerpc/include/asm/mman.h | 4 ++--
 arch/powerpc/kernel/syscalls.c  | 2 +-
 include/linux/mman.h            | 2 +-
 mm/mprotect.c                   | 2 +-
 4 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/arch/powerpc/include/asm/mman.h b/arch/powerpc/include/asm/mman.h
index 30922f699341..1d129f4521ac 100644
--- a/arch/powerpc/include/asm/mman.h
+++ b/arch/powerpc/include/asm/mman.h
@@ -32,7 +32,7 @@ static inline pgprot_t arch_vm_get_page_prot(unsigned long vm_flags)
 }
 #define arch_vm_get_page_prot(vm_flags) arch_vm_get_page_prot(vm_flags)
 
-static inline bool arch_validate_prot(unsigned long prot)
+static inline bool arch_validate_prot(unsigned long prot, unsigned long addr)
 {
 	if (prot & ~(PROT_READ | PROT_WRITE | PROT_EXEC | PROT_SEM | PROT_SAO))
 		return false;
@@ -40,7 +40,7 @@ static inline bool arch_validate_prot(unsigned long prot)
 		return false;
 	return true;
 }
-#define arch_validate_prot(prot) arch_validate_prot(prot)
+#define arch_validate_prot arch_validate_prot
 
 #endif /* CONFIG_PPC64 */
 #endif	/* _ASM_POWERPC_MMAN_H */
diff --git a/arch/powerpc/kernel/syscalls.c b/arch/powerpc/kernel/syscalls.c
index a877bf8269fe..6d90ddbd2d11 100644
--- a/arch/powerpc/kernel/syscalls.c
+++ b/arch/powerpc/kernel/syscalls.c
@@ -48,7 +48,7 @@ static inline long do_mmap2(unsigned long addr, size_t len,
 {
 	long ret = -EINVAL;
 
-	if (!arch_validate_prot(prot))
+	if (!arch_validate_prot(prot, addr))
 		goto out;
 
 	if (shift) {
diff --git a/include/linux/mman.h b/include/linux/mman.h
index c8367041fafd..b42ad5c9d6a2 100644
--- a/include/linux/mman.h
+++ b/include/linux/mman.h
@@ -49,7 +49,7 @@ static inline void vm_unacct_memory(long pages)
  *
  * Returns true if the prot flags are valid
  */
-static inline bool arch_validate_prot(unsigned long prot)
+static inline bool arch_validate_prot(unsigned long prot, unsigned long addr)
 {
 	return (prot & ~(PROT_READ | PROT_WRITE | PROT_EXEC | PROT_SEM)) == 0;
 }
diff --git a/mm/mprotect.c b/mm/mprotect.c
index bd0f409922cb..4f0e46bb1797 100644
--- a/mm/mprotect.c
+++ b/mm/mprotect.c
@@ -395,7 +395,7 @@ static int do_mprotect_pkey(unsigned long start, size_t len,
 	end = start + len;
 	if (end <= start)
 		return -ENOMEM;
-	if (!arch_validate_prot(prot))
+	if (!arch_validate_prot(prot, start))
 		return -EINVAL;
 
 	reqprot = prot;
-- 
2.11.0

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#1739175 — [PATCH v8 5/9] sparc64: Add handler for "Memory Corruption Detected" trap

M7 and newer processors add a "Memory corruption Detected" trap with
the addition of ADI feature. This trap is vectored into kernel by HV
through resumable error trap with error attribute for the resumable
error set to 0x00000800.

Signed-off-by: Khalid Aziz <khalid.aziz@oracle.com>
Cc: Khalid Aziz <khalid@gonehiking.org>
---
v7:
	- new patch split off from patch 4/4 in v6

 arch/sparc/kernel/traps_64.c | 59 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 59 insertions(+)

diff --git a/arch/sparc/kernel/traps_64.c b/arch/sparc/kernel/traps_64.c
index 7775d011691c..565e3c2836aa 100644
--- a/arch/sparc/kernel/traps_64.c
+++ b/arch/sparc/kernel/traps_64.c
@@ -1825,6 +1825,7 @@ struct sun4v_error_entry {
 #define SUN4V_ERR_ATTRS_ASI		0x00000080
 #define SUN4V_ERR_ATTRS_PRIV_REG	0x00000100
 #define SUN4V_ERR_ATTRS_SPSTATE_MSK	0x00000600
+#define SUN4V_ERR_ATTRS_MCD		0x00000800
 #define SUN4V_ERR_ATTRS_SPSTATE_SHFT	9
 #define SUN4V_ERR_ATTRS_MODE_MSK	0x03000000
 #define SUN4V_ERR_ATTRS_MODE_SHFT	24
@@ -2022,6 +2023,56 @@ static void sun4v_log_error(struct pt_regs *regs, struct sun4v_error_entry *ent,
 	}
 }
 
+/* Handle memory corruption detected error which is vectored in
+ * through resumable error trap.
+ */
+void do_mcd_err(struct pt_regs *regs, struct sun4v_error_entry ent)
+{
+	siginfo_t info;
+
+	if (notify_die(DIE_TRAP, "MCD error", regs, 0, 0x34,
+		       SIGSEGV) == NOTIFY_STOP)
+		return;
+
+	if (regs->tstate & TSTATE_PRIV) {
+		/* MCD exception could happen because the task was
+		 * running a system call with MCD enabled and passed a
+		 * non-versioned pointer or pointer with bad version
+		 * tag to the system call. In such cases, hypervisor
+		 * places the address of offending instruction in the
+		 * resumable error report. This is a deferred error,
+		 * so the read/write that caused the trap was potentially
+		 * retired long time back and we may have no choice
+		 * but to send SIGSEGV to the process.
+		 */
+		const struct exception_table_entry *entry;
+
+		entry = search_exception_tables(regs->tpc);
+		if (entry) {
+			/* Looks like a bad syscall parameter */
+#ifdef DEBUG_EXCEPTIONS
+			pr_emerg("Exception: PC<%016lx> faddr<UNKNOWN>\n",
+				 regs->tpc);
+			pr_emerg("EX_TABLE: insn<%016lx> fixup<%016lx>\n",
+				 ent.err_raddr, entry->fixup);
+#endif
+			regs->tpc = entry->fixup;
+			regs->tnpc = regs->tpc + 4;
+			return;
+		}
+	}
+
+	/* Send SIGSEGV to the userspace process with the right signal
+	 * code
+	 */
+	info.si_signo = SIGSEGV;
+	info.si_errno = 0;
+	info.si_code = SEGV_ADIDERR;
+	info.si_addr = (void __user *)ent.err_raddr;
+	info.si_trapno = 0;
+	force_sig_info(SIGSEGV, &info, current);
+}
+
 /* We run with %pil set to PIL_NORMAL_MAX and PSTATE_IE enabled in %pstate.
  * Log the event and clear the first word of the entry.
  */
@@ -2059,6 +2110,14 @@ void sun4v_resum_error(struct pt_regs *regs, unsigned long offset)
 		goto out;
 	}
 
+	/* If this is a memory corruption detected error vectored in
+	 * by HV through resumable error trap, call the handler
+	 */
+	if (local_copy.err_attrs & SUN4V_ERR_ATTRS_MCD) {
+		do_mcd_err(regs, local_copy);
+		return;
+	}
+
 	sun4v_log_error(regs, &local_copy, cpu,
 			KERN_ERR "RESUMABLE ERROR",
 			&sun4v_resum_oflow_cnt);
-- 
2.11.0

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#1739177 — [PATCH v8 4/9] sparc64: Add HV fault type handlers for ADI related faults

ADI (Application Data Integrity) feature on M7 and newer processors
adds new fault types for hypervisor - Invalid ASI and MCD disabled.
This patch expands data access exception handler to handle these
faults.

Signed-off-by: Khalid Aziz <khalid.aziz@oracle.com>
Cc: Khalid Aziz <khalid@gonehiking.org>
---
v7:
	- new patch split off from patch 4/4 in v6

 arch/sparc/kernel/traps_64.c | 29 ++++++++++++++++++++++++++---
 1 file changed, 26 insertions(+), 3 deletions(-)

diff --git a/arch/sparc/kernel/traps_64.c b/arch/sparc/kernel/traps_64.c
index 0fe0eed3cecb..7775d011691c 100644
--- a/arch/sparc/kernel/traps_64.c
+++ b/arch/sparc/kernel/traps_64.c
@@ -352,12 +352,35 @@ void sun4v_data_access_exception(struct pt_regs *regs, unsigned long addr, unsig
 		regs->tpc &= 0xffffffff;
 		regs->tnpc &= 0xffffffff;
 	}
-	info.si_signo = SIGSEGV;
+	/* MCD (Memory Corruption Detection) disabled trap (TT=0x19) in HV
+	 * is vectored thorugh data access exception trap with fault type
+	 * set to HV_FAULT_TYPE_MCD_DIS. Check for MCD disabled trap.
+	 * Accessing an address with invalid ASI for the address, for
+	 * example setting an ADI tag on an address with ASI_MCD_PRIMARY
+	 * when TTE.mcd is not set for the VA, is also vectored into
+	 * kerbel by HV as data access exception with fault type set to
+	 * HV_FAULT_TYPE_INV_ASI.
+	 */
 	info.si_errno = 0;
-	info.si_code = SEGV_MAPERR;
 	info.si_addr = (void __user *) addr;
 	info.si_trapno = 0;
-	force_sig_info(SIGSEGV, &info, current);
+	switch (type) {
+	case HV_FAULT_TYPE_INV_ASI:
+		info.si_signo = SIGILL;
+		info.si_code = ILL_ILLADR;
+		force_sig_info(SIGILL, &info, current);
+		break;
+	case HV_FAULT_TYPE_MCD_DIS:
+		info.si_signo = SIGSEGV;
+		info.si_code = SEGV_ACCADI;
+		force_sig_info(SIGSEGV, &info, current);
+		break;
+	default:
+		info.si_signo = SIGSEGV;
+		info.si_code = SEGV_MAPERR;
+		force_sig_info(SIGSEGV, &info, current);
+		break;
+	}
 }
 
 void sun4v_data_access_exception_tl1(struct pt_regs *regs, unsigned long addr, unsigned long type_ctx)
-- 
2.11.0

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#1739178 — [PATCH v8 1/9] signals, sparc: Add signal codes for ADI violations

SPARC M7 processor introduces a new feature - Application Data
Integrity (ADI). ADI allows MMU to  catch rogue accesses to memory.
When a rogue access occurs, MMU blocks the access and raises an
exception. In response to the exception, kernel sends the offending
task a SIGSEGV with si_code that indicates the nature of exception.
This patch adds three new signal codes specific to ADI feature:

1. ADI is not enabled for the address and task attempted to access
   memory using ADI
2. Task attempted to access memory using wrong ADI tag and caused
   a deferred exception.
3. Task attempted to access memory using wrong ADI tag and caused
   a precise exception.

Signed-off-by: Khalid Aziz <khalid.aziz@oracle.com>
Cc: Khalid Aziz <khalid@gonehiking.org>
---
 arch/x86/kernel/signal_compat.c    | 2 +-
 include/uapi/asm-generic/siginfo.h | 5 ++++-
 2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kernel/signal_compat.c b/arch/x86/kernel/signal_compat.c
index 71beb28600d4..e6e0b50230c3 100644
--- a/arch/x86/kernel/signal_compat.c
+++ b/arch/x86/kernel/signal_compat.c
@@ -26,7 +26,7 @@ static inline void signal_compat_build_tests(void)
 	 */
 	BUILD_BUG_ON(NSIGILL  != 8);
 	BUILD_BUG_ON(NSIGFPE  != 8);
-	BUILD_BUG_ON(NSIGSEGV != 4);
+	BUILD_BUG_ON(NSIGSEGV != 7);
 	BUILD_BUG_ON(NSIGBUS  != 5);
 	BUILD_BUG_ON(NSIGTRAP != 4);
 	BUILD_BUG_ON(NSIGCHLD != 6);
diff --git a/include/uapi/asm-generic/siginfo.h b/include/uapi/asm-generic/siginfo.h
index 9c4eca6b374a..72b435beb930 100644
--- a/include/uapi/asm-generic/siginfo.h
+++ b/include/uapi/asm-generic/siginfo.h
@@ -224,7 +224,10 @@ typedef struct siginfo {
 #define SEGV_ACCERR	(__SI_FAULT|2)	/* invalid permissions for mapped object */
 #define SEGV_BNDERR	(__SI_FAULT|3)  /* failed address bound checks */
 #define SEGV_PKUERR	(__SI_FAULT|4)  /* failed protection key checks */
-#define NSIGSEGV	4
+#define SEGV_ACCADI	(__SI_FAULT|5)	/* ADI not enabled for mapped object */
+#define SEGV_ADIDERR	(__SI_FAULT|6)	/* Disrupting MCD error */
+#define SEGV_ADIPERR	(__SI_FAULT|7)	/* Precise MCD exception */
+#define NSIGSEGV	7
 
 /*
  * SIGBUS si_codes
-- 
2.11.0

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#1739179 — [PATCH v8 6/9] sparc64: Add auxiliary vectors to report platform ADI properties

ADI feature on M7 and newer processors has three important properties
relevant to userspace apps using ADI capabilities - (1) Size of block of
memory an ADI version tag applies to, (2) Number of uppermost bits in
virtual address used to encode ADI tag, and (3) The value M7 processor
will force the ADI tags to if it detects uncorrectable error in an ADI
tagged cacheline. Kernel can retrieve these properties for a platform
through machine description provided by the firmware. This patch adds
code to retrieve these properties and report them to userspace through
auxiliary vectors.

Signed-off-by: Khalid Aziz <khalid.aziz@oracle.com>
Cc: Khalid Aziz <khalid@gonehiking.org>
---
v8:
	- Added AT_ADI_UEONADI back
v7:
	- new patch split off from patch 4/4 in v6

 arch/sparc/include/asm/adi.h         |  6 +++
 arch/sparc/include/asm/adi_64.h      | 46 +++++++++++++++++
 arch/sparc/include/asm/elf_64.h      |  9 ++++
 arch/sparc/include/uapi/asm/auxvec.h | 11 +++++
 arch/sparc/kernel/Makefile           |  1 +
 arch/sparc/kernel/adi_64.c           | 95 ++++++++++++++++++++++++++++++++++++
 arch/sparc/kernel/mdesc.c            |  2 +
 7 files changed, 170 insertions(+)
 create mode 100644 arch/sparc/include/asm/adi.h
 create mode 100644 arch/sparc/include/asm/adi_64.h
 create mode 100644 arch/sparc/kernel/adi_64.c

diff --git a/arch/sparc/include/asm/adi.h b/arch/sparc/include/asm/adi.h
new file mode 100644
index 000000000000..acad0d04e4c6
--- /dev/null
+++ b/arch/sparc/include/asm/adi.h
@@ -0,0 +1,6 @@
+#ifndef ___ASM_SPARC_ADI_H
+#define ___ASM_SPARC_ADI_H
+#if defined(__sparc__) && defined(__arch64__)
+#include <asm/adi_64.h>
+#endif
+#endif
diff --git a/arch/sparc/include/asm/adi_64.h b/arch/sparc/include/asm/adi_64.h
new file mode 100644
index 000000000000..24fe52fe9e8f
--- /dev/null
+++ b/arch/sparc/include/asm/adi_64.h
@@ -0,0 +1,46 @@
+/* adi_64.h: ADI related data structures
+ *
+ * Copyright (C) 2016 Khalid Aziz (khalid.aziz@oracle.com)
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2.
+ */
+#ifndef __ASM_SPARC64_ADI_H
+#define __ASM_SPARC64_ADI_H
+
+#include <linux/types.h>
+
+#ifndef __ASSEMBLY__
+
+struct adi_caps {
+	__u64 blksz;
+	__u64 nbits;
+	__u64 ue_on_adi;
+};
+
+struct adi_config {
+	bool enabled;
+	struct adi_caps caps;
+};
+
+extern struct adi_config adi_state;
+
+extern void mdesc_adi_init(void);
+
+static inline bool adi_capable(void)
+{
+	return adi_state.enabled;
+}
+
+static inline unsigned long adi_blksize(void)
+{
+	return adi_state.caps.blksz;
+}
+
+static inline unsigned long adi_nbits(void)
+{
+	return adi_state.caps.nbits;
+}
+
+#endif	/* __ASSEMBLY__ */
+
+#endif	/* !(__ASM_SPARC64_ADI_H) */
diff --git a/arch/sparc/include/asm/elf_64.h b/arch/sparc/include/asm/elf_64.h
index 3f2d403873bd..6371d7e0330e 100644
--- a/arch/sparc/include/asm/elf_64.h
+++ b/arch/sparc/include/asm/elf_64.h
@@ -9,6 +9,7 @@
 #include <asm/processor.h>
 #include <asm/extable_64.h>
 #include <asm/spitfire.h>
+#include <asm/adi.h>
 
 /*
  * Sparc section types
@@ -210,4 +211,12 @@ do {	if ((ex).e_ident[EI_CLASS] == ELFCLASS32)	\
 			(current->personality & (~PER_MASK)));	\
 } while (0)
 
+#define ARCH_DLINFO						\
+do {								\
+	extern struct adi_config adi_state;			\
+	NEW_AUX_ENT(AT_ADI_BLKSZ, adi_state.caps.blksz);	\
+	NEW_AUX_ENT(AT_ADI_NBITS, adi_state.caps.nbits);	\
+	NEW_AUX_ENT(AT_ADI_UEONADI, adi_state.caps.ue_on_adi);	\
+} while (0)
+
 #endif /* !(__ASM_SPARC64_ELF_H) */
diff --git a/arch/sparc/include/uapi/asm/auxvec.h b/arch/sparc/include/uapi/asm/auxvec.h
index ad6f360261f6..9ab8b10e85d7 100644
--- a/arch/sparc/include/uapi/asm/auxvec.h
+++ b/arch/sparc/include/uapi/asm/auxvec.h
@@ -1,4 +1,15 @@
 #ifndef __ASMSPARC_AUXVEC_H
 #define __ASMSPARC_AUXVEC_H
 
+#ifdef CONFIG_SPARC64
+/* Avoid overlap with other AT_* values since they are consolidated in
+ * glibc and any overlaps can cause problems
+ */
+#define AT_ADI_BLKSZ	48
+#define AT_ADI_NBITS	49
+#define AT_ADI_UEONADI	50
+
+#define AT_VECTOR_SIZE_ARCH	3
+#endif
+
 #endif /* !(__ASMSPARC_AUXVEC_H) */
diff --git a/arch/sparc/kernel/Makefile b/arch/sparc/kernel/Makefile
index aac609889ee4..8149e175e899 100644
--- a/arch/sparc/kernel/Makefile
+++ b/arch/sparc/kernel/Makefile
@@ -67,6 +67,7 @@ obj-$(CONFIG_SPARC64)   += visemul.o
 obj-$(CONFIG_SPARC64)   += hvapi.o
 obj-$(CONFIG_SPARC64)   += sstate.o
 obj-$(CONFIG_SPARC64)   += mdesc.o
+obj-$(CONFIG_SPARC64)   += adi_64.o
 obj-$(CONFIG_SPARC64)	+= pcr.o
 obj-$(CONFIG_SPARC64)	+= nmi.o
 obj-$(CONFIG_SPARC64_SMP) += cpumap.o
diff --git a/arch/sparc/kernel/adi_64.c b/arch/sparc/kernel/adi_64.c
new file mode 100644
index 000000000000..9abf7ea815fd
--- /dev/null
+++ b/arch/sparc/kernel/adi_64.c
@@ -0,0 +1,95 @@
+/* adi_64.c: support for ADI (Application Data Integrity) feature on
+ * sparc m7 and newer processors. This feature is also known as
+ * SSM (Silicon Secured Memory).
+ *
+ * Copyright (C) 2016 Khalid Aziz (khalid.aziz@oracle.com)
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2.
+ */
+#include <linux/init.h>
+#include <asm/mdesc.h>
+#include <asm/adi_64.h>
+
+struct adi_config adi_state;
+
+/* mdesc_adi_init() : Parse machine description provided by the
+ *	hypervisor to detect ADI capabilities
+ *
+ * Hypervisor reports ADI capabilities of platform in "hwcap-list" property
+ * for "cpu" node. If the platform supports ADI, "hwcap-list" property
+ * contains the keyword "adp". If the platform supports ADI, "platform"
+ * node will contain "adp-blksz", "adp-nbits" and "ue-on-adp" properties
+ * to describe the ADI capabilities.
+ */
+void __init mdesc_adi_init(void)
+{
+	struct mdesc_handle *hp = mdesc_grab();
+	const char *prop;
+	u64 pn, *val;
+	int len;
+
+	if (!hp)
+		goto adi_not_found;
+
+	pn = mdesc_node_by_name(hp, MDESC_NODE_NULL, "cpu");
+	if (pn == MDESC_NODE_NULL)
+		goto adi_not_found;
+
+	prop = mdesc_get_property(hp, pn, "hwcap-list", &len);
+	if (!prop)
+		goto adi_not_found;
+
+	/*
+	 * Look for "adp" keyword in hwcap-list which would indicate
+	 * ADI support
+	 */
+	adi_state.enabled = false;
+	while (len) {
+		int plen;
+
+		if (!strcmp(prop, "adp")) {
+			adi_state.enabled = true;
+			break;
+		}
+
+		plen = strlen(prop) + 1;
+		prop += plen;
+		len -= plen;
+	}
+
+	if (!adi_state.enabled)
+		goto adi_not_found;
+
+	/* Find the ADI properties in "platform" node. If all ADI
+	 * properties are not found, ADI support is incomplete and
+	 * do not enable ADI in the kernel.
+	 */
+	pn = mdesc_node_by_name(hp, MDESC_NODE_NULL, "platform");
+	if (pn == MDESC_NODE_NULL)
+		goto adi_not_found;
+
+	val = (u64 *) mdesc_get_property(hp, pn, "adp-blksz", &len);
+	if (!val)
+		goto adi_not_found;
+	adi_state.caps.blksz = *val;
+
+	val = (u64 *) mdesc_get_property(hp, pn, "adp-nbits", &len);
+	if (!val)
+		goto adi_not_found;
+	adi_state.caps.nbits = *val;
+
+	val = (u64 *) mdesc_get_property(hp, pn, "ue-on-adp", &len);
+	if (!val)
+		goto adi_not_found;
+	adi_state.caps.ue_on_adi = *val;
+
+	mdesc_release(hp);
+	return;
+
+adi_not_found:
+	adi_state.enabled = false;
+	adi_state.caps.blksz = 0;
+	adi_state.caps.nbits = 0;
+	if (hp)
+		mdesc_release(hp);
+}
diff --git a/arch/sparc/kernel/mdesc.c b/arch/sparc/kernel/mdesc.c
index fa466ce45bc9..d008e74da638 100644
--- a/arch/sparc/kernel/mdesc.c
+++ b/arch/sparc/kernel/mdesc.c
@@ -20,6 +20,7 @@
 #include <linux/uaccess.h>
 #include <asm/oplib.h>
 #include <asm/smp.h>
+#include <asm/adi.h>
 
 /* Unlike the OBP device tree, the machine description is a full-on
  * DAG.  An arbitrary number of ARCs are possible from one
@@ -1343,5 +1344,6 @@ void __init sun4v_mdesc_init(void)
 
 	cur_mdesc = hp;
 
+	mdesc_adi_init();
 	report_platform_properties();
 }
-- 
2.11.0

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#1739180 — [PATCH v8 2/9] mm, swap: Add infrastructure for saving page metadata as well on swap

If a processor supports special metadata for a page, for example ADI
version tags on SPARC M7, this metadata must be saved when the page is
swapped out. The same metadata must be restored when the page is swapped
back in. This patch adds two new architecture specific functions -
arch_do_swap_page() to be called when a page is swapped in, and
arch_unmap_one() to be called when a page is being unmapped for swap
out. These architecture hooks allow page metadata to be saved if the
architecture supports it.

Signed-off-by: Khalid Aziz <khalid.aziz@oracle.com>
Cc: Khalid Aziz <khalid@gonehiking.org>
Acked-by: Jerome Marchand <jmarchan@redhat.com>
---
v8:
	- Fixed an erroneous "}"
v6:
	- Updated parameter list for arch_do_swap_page() and
	  arch_unmap_one()
v5:
	- Replaced set_swp_pte() function with new architecture
	  functions arch_do_swap_page() and arch_unmap_one()

 include/asm-generic/pgtable.h | 36 ++++++++++++++++++++++++++++++++++++
 mm/memory.c                   |  1 +
 mm/rmap.c                     | 14 ++++++++++++++
 3 files changed, 51 insertions(+)

diff --git a/include/asm-generic/pgtable.h b/include/asm-generic/pgtable.h
index 7dfa767dc680..15668c2470b4 100644
--- a/include/asm-generic/pgtable.h
+++ b/include/asm-generic/pgtable.h
@@ -392,6 +392,42 @@ static inline int pud_same(pud_t pud_a, pud_t pud_b)
 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 #endif
 
+#ifndef __HAVE_ARCH_DO_SWAP_PAGE
+/*
+ * Some architectures support metadata associated with a page. When a
+ * page is being swapped out, this metadata must be saved so it can be
+ * restored when the page is swapped back in. SPARC M7 and newer
+ * processors support an ADI (Application Data Integrity) tag for the
+ * page as metadata for the page. arch_do_swap_page() can restore this
+ * metadata when a page is swapped back in.
+ */
+static inline void arch_do_swap_page(struct mm_struct *mm,
+				     struct vm_area_struct *vma,
+				     unsigned long addr,
+				     pte_t pte, pte_t oldpte)
+{
+
+}
+#endif
+
+#ifndef __HAVE_ARCH_UNMAP_ONE
+/*
+ * Some architectures support metadata associated with a page. When a
+ * page is being swapped out, this metadata must be saved so it can be
+ * restored when the page is swapped back in. SPARC M7 and newer
+ * processors support an ADI (Application Data Integrity) tag for the
+ * page as metadata for the page. arch_unmap_one() can save this
+ * metadata on a swap-out of a page.
+ */
+static inline int arch_unmap_one(struct mm_struct *mm,
+				  struct vm_area_struct *vma,
+				  unsigned long addr,
+				  pte_t orig_pte)
+{
+	return 0;
+}
+#endif
+
 #ifndef __HAVE_ARCH_PGD_OFFSET_GATE
 #define pgd_offset_gate(mm, addr)	pgd_offset(mm, addr)
 #endif
diff --git a/mm/memory.c b/mm/memory.c
index 56e48e4593cb..ef0459938e96 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -2828,6 +2828,7 @@ int do_swap_page(struct vm_fault *vmf)
 	if (pte_swp_soft_dirty(vmf->orig_pte))
 		pte = pte_mksoft_dirty(pte);
 	set_pte_at(vma->vm_mm, vmf->address, vmf->pte, pte);
+	arch_do_swap_page(vma->vm_mm, vma, vmf->address, pte, vmf->orig_pte);
 	vmf->orig_pte = pte;
 	if (page == swapcache) {
 		do_page_add_anon_rmap(page, vma, vmf->address, exclusive);
diff --git a/mm/rmap.c b/mm/rmap.c
index c570f82e6827..40a436c927c6 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -1448,6 +1448,14 @@ static bool try_to_unmap_one(struct page *page, struct vm_area_struct *vma,
 				(flags & TTU_MIGRATION)) {
 			swp_entry_t entry;
 			pte_t swp_pte;
+
+			if (arch_unmap_one(mm, vma, address, pteval) < 0) {
+				set_pte_at(mm, address, pvmw.pte, pteval);
+				ret = false;
+				page_vma_mapped_walk_done(&pvmw);
+				break;
+			}
+
 			/*
 			 * Store the pfn of the page in a special migration
 			 * pte. do_swap_page() will wait until the migration
@@ -1498,6 +1506,12 @@ static bool try_to_unmap_one(struct page *page, struct vm_area_struct *vma,
 				page_vma_mapped_walk_done(&pvmw);
 				break;
 			}
+			if (arch_unmap_one(mm, vma, address, pteval) < 0) {
+				set_pte_at(mm, address, pvmw.pte, pteval);
+				ret = false;
+				page_vma_mapped_walk_done(&pvmw);
+				break;
+			}
 			if (list_empty(&mm->mmlist)) {
 				spin_lock(&mmlist_lock);
 				if (list_empty(&mm->mmlist))
-- 
2.11.0

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#1739181 — [PATCH v8 8/9] mm: Clear arch specific VM flags on protection change

When protection bits are changed on a VMA, some of the architecture
specific flags should be cleared as well. An examples of this are the
PKEY flags on x86. This patch expands the current code that clears
PKEY flags for x86, to support similar functionality for other
architectures as well.

Signed-off-by: Khalid Aziz <khalid.aziz@oracle.com>
Cc: Khalid Aziz <khalid@gonehiking.org>
---
v7:
	- new patch

 include/linux/mm.h | 6 ++++++
 mm/mprotect.c      | 2 +-
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/include/linux/mm.h b/include/linux/mm.h
index c1f6c95f3496..cbb21facce6b 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -271,6 +271,12 @@ extern unsigned int kobjsize(const void *objp);
 /* This mask is used to clear all the VMA flags used by mlock */
 #define VM_LOCKED_CLEAR_MASK	(~(VM_LOCKED | VM_LOCKONFAULT))
 
+/* Arch-specific flags to clear when updating VM flags on protection change */
+#ifndef VM_ARCH_CLEAR
+# define VM_ARCH_CLEAR	VM_NONE
+#endif
+#define VM_FLAGS_CLEAR	(ARCH_VM_PKEY_FLAGS | VM_ARCH_CLEAR)
+
 /*
  * mapping from the currently active vm_flags protection bits (the
  * low four bits) to a page protection mask..
diff --git a/mm/mprotect.c b/mm/mprotect.c
index 4f0e46bb1797..85b65b3a823d 100644
--- a/mm/mprotect.c
+++ b/mm/mprotect.c
@@ -453,7 +453,7 @@ static int do_mprotect_pkey(unsigned long start, size_t len,
 		 * cleared from the VMA.
 		 */
 		mask_off_old_flags = VM_READ | VM_WRITE | VM_EXEC |
-					ARCH_VM_PKEY_FLAGS;
+					VM_FLAGS_CLEAR;
 
 		new_vma_pkey = arch_override_mprotect_pkey(vma, prot, pkey);
 		newflags = calc_vm_prot_bits(prot, new_vma_pkey);
-- 
2.11.0

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