[PATCH] sparc64: Add support for Application Data Integrity (ADI)

@@ -0,0 +1,62 @@
+========
+Overview
+========
+
+SPARC M7 processor includes the feature Application Data Integrity (ADI).
+ADI allows a tag to be associated with a virtual memory address range
+and a process must access that memory range with the correct tag. ADI
+tag is embedded in bits 63-60 of virtual address. Once ADI is enabled
+on a range of memory addresses, the process can set a tag for blocks
+in this memory range n the cache using ASI_MCD_PRIMARY or
+ASI_MCD_ST_BLKINIT_PRIMARY. This tag is set for ADI block sized blocks
+which is provided to the kernel by machine description table.
+
+Linux kernel supports an application enabling and setting the ADI tag
+for a subset of its data pages. Those data pages have to be locked in
+memory since saving ADI tags to swap is not supported.
+
+
+New prctl options for ADI
+-------------------------
+
+Following new options to prctl() have been added to support ADI.
+
+	PR_GET_SPARC_ADICAPS - Get ADI capabilities for the processor.
+		These capabilities are used to set up ADI correctly
+		from userspace. Machine description table provides all
+		of the ADI capabilities information. arg2 to prctl() is
+		a pointer to struct adi_caps which is defined in
+		linux/prctl.h.
+
+
+	PR_SET_SPARC_ADI - Set the state of ADI in a user thread by
+		setting PSTATE.mcde bit in the user mode PSTATE register
+		of the calling thread based on the value passed in arg2:
+			1 == enable, 0 == disable, other == no change
+		Return the previous state of the PSTATE.mcde bit:
+			0 == was disabled, 1 == was enabled.
+		Set errno to EINVAL and return -1 if ADI is not available.
+
+
+	PR_ENABLE_SPARC_ADI - Enable ADI checking in all pages in the address
+		range specified. The pages in the range must be already
+		locked. This operation enables the TTE.mcd bit for the
+		pages specified. arg2 is the starting address for address
+		range and must be page aligned. arg3 is the length of
+		memory address range and must be a multiple of page size.
+
+
+	PR_DISABLE_SPARC_ADI - Disable ADI checking on all the pages in the
+		address range specified. This operation disables the
+		TTE.mcd bit for the pages specified. arg2 is the
+		starting address for address range and must be page
+		aligned. arg3 is the length of memory address range and
+		must be a multiple of page size.
+
+
+	PR_GET_SPARC_ADI_STATUS - Check if ADI is enabled or not for a
+		given virtual address. Returns 1 for enabled, else 0.
+
+
+All addresses passed to kernel must be non-ADI tagged addresses.
+Kernel does not enable ADI for kernel code.

@@ -0,0 +1,206 @@
+Application Data Integrity (ADI)
+================================
+
+Sparc M7 processor adds the Application Data Integrity (ADI) feature.
+ADI allows a task to set version tags on any subset of its address
+space. Once ADI is enabled and version tags are set for ranges of
+address space of a task, the processor will compare the tag in pointers
+to memory in these ranges to the version set by the application
+previously. Access to memory is granted only if the tag in given
+pointer matches the tag set by the application. In case of mismatch,
+processor raises an exception.  ADI can be enabled on pages that are
+locked in memory, i.e.  are not swappable.
+
+Following steps must be taken by a task to enable ADI fully:
+
+1. Set the user mode PSTATE.mcde bit
+
+2. Set TTE.mcd bit on any TLB entries that correspond to the range of
+addresses ADI is being enabled on.
+
+3. Set the version tag for memory addresses.
+
+Kernel provides prctl() calls to perform steps 1 (PR_SET_SPARC_ADI) and
+2 (PR_ENABLE_SPARC_ADI). Please see Documentation/prctl/sparc_adi.txt
+for more details on these prctl calls. Step 3 is performed with an
+stxa instruction on the address using ASI_MCD_PRIMARY or
+ASI_MCD_ST_BLKINIT_PRIMARY. Version tags are stoed in bits 63-60 of
+address and are set on a cache line. Version tag values of 0x0 and 0xf
+are reserved.
+
+NOTE:	ADI is supported on hugepage only. Hugepages are already locked
+	in memory.
+
+
+ADI related traps
+-----------------
+
+With ADI enabled, following new traps may occur:
+
+Disrupting memory corruption
+
+	When a store accesses a memory localtion that has TTE.mcd=1,
+	the task is running with ADI enabled (PSTATE.mcde=1), and the ADI
+	tag in the address used (bits 63:60) does not match the tag set on
+	the corresponding cacheline, a memory corruption trap occurs. By
+	default, it is a disrupting trap and is sent to the hypervisor
+	first. Hypervisor creates a sun4v error report and sends a
+	resumable error (TT=0x7e) trap to the kernel. The kernel sends
+	a SIGSEGV to the task that resulted in this trap with the following
+	info:
+
+		siginfo.si_signo = SIGSEGV;
+		siginfo.errno = 0;
+		siginfo.si_code = SEGV_ADIDERR;
+		siginfo.si_addr = addr; /* address that caused trap */
+		siginfo.si_trapno = 0;
+
+
+Precise memory corruption
+
+	When a store accesses a memory location that has TTE.mcd=1,
+	the task is running with ADI enabled (PSTATE.mcde=1), and the ADI
+	tag in the address used (bits 63:60) does not match the tag set on
+	the corresponding cacheline, a memory corruption trap occurs. If
+	MCD precise exception is enabled (MCDPERR=1), a precise
+	exception is sent to the kernel with TT=0x1a. The kernel sends
+	a SIGSEGV to the task that resulted in this trap with the following
+	info:
+
+		siginfo.si_signo = SIGSEGV;
+		siginfo.errno = 0;
+		siginfo.si_code = SEGV_ADIPERR;
+		siginfo.si_addr = addr;	/* address that caused trap */
+		siginfo.si_trapno = 0;
+
+	NOTE: ADI tag mismatch on a load always results in precise trap.
+
+
+MCD disabled
+
+	When a task has not enabled ADI and attempts to set ADI version
+	on a memory address, processor sends an MCD disabled trap. This
+	trap is handled by hypervisor first and the hypervisor vectors this
+	trap through to the kernel as Data Access Exception trap with
+	fault type set to 0xa (invalid ASI). When this occurs, the kernel
+	sends the task SIGBUS signal with following info:
+
+		siginfo.si_signo = SIGBUS;
+		siginfo.errno = 0;
+		siginfo.si_code = SEGV_ACCADI;
+		siginfo.si_addr = addr;	/* address that caused trap */
+		siginfo.si_trapno = 0;
+
+
+Sample program to use ADI
+-------------------------
+
+Following sample program is meant to illustrate how to use the ADI
+functionality with the default 8M hugepages.
+
+#include <unistd.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/ipc.h>
+#include <sys/shm.h>
+#include <asm/asi.h>
+#include <linux/prctl.h>
+
+#define BUFFER_SIZE	32*1024*1024
+
+struct adi_caps adicap;
+
+main()
+{
+	unsigned long i, mcde;
+	char *shmaddr, *tmp_addr, *end, *veraddr, *clraddr;
+	int shmid, version;
+
+	if ((shmid = shmget(2, BUFFER_SIZE,
+				SHM_HUGETLB | IPC_CREAT | SHM_R | SHM_W)) < 0) {
+		perror("shmget failed");
+		exit(1);
+	}
+
+	shmaddr = shmat(shmid, NULL, 0);
+	if (shmaddr == (char *)-1) {
+		perror("shm attach failed");
+		shmctl(shmid, IPC_RMID, NULL);
+		exit(1);
+	}
+
+	/* Get the values for various ADI capabilities bits. These will
+	 * be used later for setting the ADI tag
+	 */
+	if (prctl(PR_GET_SPARC_ADICAPS, &adicap) < 0) {
+		perror("PR_GET_SPARC_ADICAPS failed");
+		goto err_out;
+	}
+
+	/* Set PSTATE.mcde
+	 */
+	if ((mcde = prctl(PR_SET_SPARC_ADI, PR_SET_SPARC_ADI_SET)) < 0) {
+		perror("PR_SET_SPARC_ADI failed");
+		goto err_out;
+	}
+
+	/* Set TTE.mcd on the address range for shm segment
+	 */
+	if (prctl(PR_ENABLE_SPARC_ADI, shmaddr, BUFFER_SIZE) < 0) {
+		perror("prctl failed");
+		goto err_out;
+	}
+
+	/* Set the ADI version tag on the shm segment
+	 */
+	version = 10;
+	tmp_addr = shmaddr;
+	end = shmaddr + BUFFER_SIZE;
+	while (tmp_addr < end) {
+		asm volatile(
+			"stxa %1, [%0]ASI_MCD_PRIMARY\n\t"
+			:
+			: "r" (tmp_addr), "r" (version));
+		tmp_addr += adicap.blksz;
+	}
+
+	/* Create a versioned address from the normal address
+	 */
+	tmp_addr = (void *) ((unsigned long)shmaddr << adicap.nbits);
+	tmp_addr = (void *) ((unsigned long)tmp_addr >> adicap.nbits);
+	veraddr = (void *) (((unsigned long)version << (64-adicap.nbits))
+			| (unsigned long)tmp_addr);
+
+	printf("Starting the writes:\n");
+	for (i = 0; i < BUFFER_SIZE; i++) {
+		veraddr[i] = (char)(i);
+		if (!(i % (1024 * 1024)))
+			printf(".");
+	}
+	printf("\n");
+
+	printf("Verifying data...");
+	for (i = 0; i < BUFFER_SIZE; i++)
+		if (veraddr[i] != (char)i)
+			printf("\nIndex %lu mismatched\n", i);
+	printf("Done.\n");
+
+	/* Disable ADI and clean up
+	 */
+	if (prctl(PR_DISABLE_SPARC_ADI, shmaddr, BUFFER_SIZE) < 0) {
+		perror("prctl failed");
+		goto err_out;
+	}
+
+	if (shmdt((const void *)shmaddr) != 0)
+		perror("Detach failure");
+	shmctl(shmid, IPC_RMID, NULL);
+
+	exit(0);
+
+err_out:
+	if (shmdt((const void *)shmaddr) != 0)
+		perror("Detach failure");
+	shmctl(shmid, IPC_RMID, NULL);
+	exit(1);
+}

@@ -80,6 +80,7 @@ config SPARC64
 	select NO_BOOTMEM
 	select HAVE_ARCH_AUDITSYSCALL
 	select ARCH_SUPPORTS_ATOMIC_RMW
+	select SPARC_ADI
 
 config ARCH_DEFCONFIG
 	string

@@ -314,6 +315,17 @@ if SPARC64
 source "kernel/power/Kconfig"
 endif
 
+config SPARC_ADI
+	bool "Application Data Integrity support"
+	def_bool y if SPARC64
+	help
+	  Support for Application Data Integrity (ADI). ADI feature allows
+	  a process to tag memory blocks with version tags. Once ADI is
+	  enabled and version tag is set on a memory block, any access to
+	  it is allowed only if the correct version tag is presented by
+	  a process. This feature is meant to help catch rogue accesses
+	  to memory.
+
 config SCHED_SMT
 	bool "SMT (Hyperthreading) scheduler support"
 	depends on SPARC64 && SMP

@@ -82,4 +82,18 @@ static inline void arch_clear_hugepage_flags(struct page *page)
 {
 }
 
+#ifdef CONFIG_SPARC_ADI
+static inline pte_t arch_make_huge_pte(pte_t entry, struct vm_area_struct *vma,
+			 struct page *page, int writeable)
+{
+	/* If this vma has ADI enabled on it, turn on TTE.mcd
+	 */
+	if (vma->vm_flags & VM_SPARC_ADI)
+		return pte_mkmcd(entry);
+	else
+		return pte_mknotmcd(entry);
+}
+#define arch_make_huge_pte arch_make_huge_pte
+#endif
+
 #endif /* _ASM_SPARC64_HUGETLB_H */

@@ -547,6 +547,8 @@ struct hv_fault_status {
 #define HV_FAULT_TYPE_RESV1	13
 #define HV_FAULT_TYPE_UNALIGNED	14
 #define HV_FAULT_TYPE_INV_PGSZ	15
+#define HV_FAULT_TYPE_MCD	17
+#define HV_FAULT_TYPE_MCD_DIS	18
 /* Values 16 --> -2 are reserved.  */
 #define HV_FAULT_TYPE_MULTIPLE	-1
 

@@ -95,6 +95,7 @@ typedef struct {
 	unsigned long		huge_pte_count;
 	struct tsb_config	tsb_block[MM_NUM_TSBS];
 	struct hv_tsb_descr	tsb_descr[MM_NUM_TSBS];
+	unsigned char		adi;
 } mm_context_t;
 
 #endif /* !__ASSEMBLY__ */

@@ -162,6 +162,9 @@ bool kern_addr_valid(unsigned long addr);
 #define _PAGE_E_4V	  _AC(0x0000000000000800,UL) /* side-Effect          */
 #define _PAGE_CP_4V	  _AC(0x0000000000000400,UL) /* Cacheable in P-Cache */
 #define _PAGE_CV_4V	  _AC(0x0000000000000200,UL) /* Cacheable in V-Cache */
+/* Bit 9 is used to enable MCD corruption detection instead on M7
+ */
+#define _PAGE_MCD_4V	  _AC(0x0000000000000200,UL) /* Memory Corruption    */
 #define _PAGE_P_4V	  _AC(0x0000000000000100,UL) /* Privileged Page      */
 #define _PAGE_EXEC_4V	  _AC(0x0000000000000080,UL) /* Executable Page      */
 #define _PAGE_W_4V	  _AC(0x0000000000000040,UL) /* Writable             */

@@ -541,6 +544,18 @@ static inline pte_t pte_mkspecial(pte_t pte)
 	return pte;
 }
 
+static inline pte_t pte_mkmcd(pte_t pte)
+{
+	pte_val(pte) |= _PAGE_MCD_4V;
+	return pte;
+}
+
+static inline pte_t pte_mknotmcd(pte_t pte)
+{
+	pte_val(pte) &= ~_PAGE_MCD_4V;
+	return pte;
+}
+
 static inline unsigned long pte_young(pte_t pte)
 {
 	unsigned long mask;

@@ -97,6 +97,25 @@ struct thread_struct {
 struct task_struct;
 unsigned long thread_saved_pc(struct task_struct *);
 
+#ifdef CONFIG_SPARC_ADI
+extern struct adi_caps *get_adi_caps(void);
+extern long get_sparc_adicaps(unsigned long);
+extern long set_sparc_pstate_mcde(unsigned long);
+extern long enable_sparc_adi(unsigned long, unsigned long);
+extern long disable_sparc_adi(unsigned long, unsigned long);
+extern long get_sparc_adi_status(unsigned long);
+extern bool adi_capable(void);
+
+#define GET_SPARC_ADICAPS(a)	get_sparc_adicaps(a)
+#define SET_SPARC_MCDE(a)	set_sparc_pstate_mcde(a)
+#define ENABLE_SPARC_ADI(a, b)	enable_sparc_adi(a, b)
+#define DISABLE_SPARC_ADI(a, b)	disable_sparc_adi(a, b)
+#define GET_SPARC_ADI_STATUS(a)	get_sparc_adi_status(a)
+#define ADI_CAPABLE()		adi_capable()
+#else
+#define ADI_CAPABLE()		0
+#endif
+
 /* On Uniprocessor, even in RMO processes see TSO semantics */
 #ifdef CONFIG_SMP
 #define TSTATE_INITIAL_MM	TSTATE_TSO

@@ -212,6 +212,16 @@
 	nop;						\
 	nop;
 
+#define SUN4V_MCD_PRECISE				\
+	ldxa	[%g0] ASI_SCRATCHPAD, %g2;		\
+	ldx	[%g2 + HV_FAULT_D_ADDR_OFFSET], %g4;	\
+	ldx	[%g2 + HV_FAULT_D_CTX_OFFSET], %g5;	\
+	ba,pt	%xcc, sun4v_mcd_detect_precise;		\
+	 nop;						\
+	nop;						\
+	nop;						\
+	nop;
+
 /* Before touching these macros, you owe it to yourself to go and
  * see how arch/sparc64/kernel/winfixup.S works... -DaveM
  *

@@ -244,6 +244,9 @@
 #define ASI_UDBL_CONTROL_R	0x7f /* External UDB control regs rd low*/
 #define ASI_INTR_R		0x7f /* IRQ vector dispatch read	*/
 #define ASI_INTR_DATAN_R	0x7f /* (III) In irq vector data reg N	*/
+#define ASI_MCD_PRIMARY		0x90 /* (NG7) MCD version load/store	*/
+#define ASI_MCD_ST_BLKINIT_PRIMARY	\
+				0x92 /* (NG7) MCD store BLKINIT primary	*/
 #define ASI_PIC			0xb0 /* (NG4) PIC registers		*/
 #define ASI_PST8_P		0xc0 /* Primary, 8 8-bit, partial	*/
 #define ASI_PST8_S		0xc1 /* Secondary, 8 8-bit, partial	*/

@@ -10,7 +10,12 @@
  * -----------------------------------------------------------------------
  *  63  12  11   10    9     8    7   6   5     4     3     2     1    0
  */
+/* IG on V9 conflicts with MCDE on M7. PSTATE_MCDE will only be used on
+ * processors that support ADI which do not use IG, hence there is no
+ * functional conflict
+ */
 #define PSTATE_IG   _AC(0x0000000000000800,UL) /* Interrupt Globals.	*/
+#define PSTATE_MCDE _AC(0x0000000000000800,UL) /* MCD Enable		*/
 #define PSTATE_MG   _AC(0x0000000000000400,UL) /* MMU Globals.		*/
 #define PSTATE_CLE  _AC(0x0000000000000200,UL) /* Current Little Endian.*/
 #define PSTATE_TLE  _AC(0x0000000000000100,UL) /* Trap Little Endian.	*/

@@ -47,7 +52,12 @@
 #define TSTATE_ASI	_AC(0x00000000ff000000,UL) /* AddrSpace ID.	*/
 #define TSTATE_PIL	_AC(0x0000000000f00000,UL) /* %pil (Linux traps)*/
 #define TSTATE_PSTATE	_AC(0x00000000000fff00,UL) /* PSTATE.		*/
+/* IG on V9 conflicts with MCDE on M7. TSTATE_MCDE will only be used on
+ * processors that support ADI which do not support IG, hence there is
+ * no functional conflict
+ */
 #define TSTATE_IG	_AC(0x0000000000080000,UL) /* Interrupt Globals.*/
+#define TSTATE_MCDE	_AC(0x0000000000080000,UL) /* MCD enable.       */
 #define TSTATE_MG	_AC(0x0000000000040000,UL) /* MMU Globals.	*/
 #define TSTATE_CLE	_AC(0x0000000000020000,UL) /* CurrLittleEndian.	*/
 #define TSTATE_TLE	_AC(0x0000000000010000,UL) /* TrapLittleEndian.	*/

@@ -159,6 +159,9 @@ void sun4v_resum_overflow(struct pt_regs *regs);
 void sun4v_nonresum_error(struct pt_regs *regs,
 			  unsigned long offset);
 void sun4v_nonresum_overflow(struct pt_regs *regs);
+void sun4v_mem_corrupt_detect_precise(struct pt_regs *regs,
+				      unsigned long addr,
+				      unsigned long context);
 
 extern unsigned long sun4v_err_itlb_vaddr;
 extern unsigned long sun4v_err_itlb_ctx;

@@ -878,6 +878,7 @@ sparc64_boot_end:
 #include "helpers.S"
 #include "hvcalls.S"
 #include "sun4v_tlb_miss.S"
+#include "sun4v_mcd.S"
 #include "sun4v_ivec.S"
 #include "ktlb.S"
 #include "tsb.S"

@@ -12,6 +12,7 @@
 #include <linux/miscdevice.h>
 #include <linux/bootmem.h>
 #include <linux/export.h>
+#include <linux/prctl.h>
 
 #include <asm/cpudata.h>
 #include <asm/hypervisor.h>

@@ -512,6 +513,11 @@ EXPORT_SYMBOL(mdesc_node_name);
 
 static u64 max_cpus = 64;
 
+static struct {
+	bool enabled;
+	struct adi_caps caps;
+} adi_state;
+
 static void __init report_platform_properties(void)
 {
 	struct mdesc_handle *hp = mdesc_grab();

@@ -1007,6 +1013,80 @@ static int mdesc_open(struct inode *inode, struct file *file)
 	return 0;
 }
 
+bool adi_capable(void)
+{
+	return adi_state.enabled;
+}
+
+struct adi_caps *get_adi_caps(void)
+{
+	return &adi_state.caps;
+}
+
+void __init
+init_adi(void)
+{
+	struct mdesc_handle *hp = mdesc_grab();
+	const char *prop;
+	u64 pn, *val;
+	int len;
+
+	adi_state.enabled = false;
+
+	if (!hp)
+		return;
+
+	pn = mdesc_node_by_name(hp, MDESC_NODE_NULL, "cpu");
+	if (pn == MDESC_NODE_NULL)
+		goto out;
+
+	prop = mdesc_get_property(hp, pn, "hwcap-list", &len);
+	if (!prop)
+		goto out;
+
+	/*
+	 * Look for "adp" keyword in hwcap-list which would indicate
+	 * ADI support
+	 */
+	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 out;
+
+	pn = mdesc_node_by_name(hp, MDESC_NODE_NULL, "platform");
+	if (pn == MDESC_NODE_NULL)
+		goto out;
+
+	val = (u64 *) mdesc_get_property(hp, pn, "adp-blksz", &len);
+	if (!val)
+		goto out;
+	adi_state.caps.blksz = *val;
+
+	val = (u64 *) mdesc_get_property(hp, pn, "adp-nbits", &len);
+	if (!val)
+		goto out;
+	adi_state.caps.nbits = *val;
+
+	val = (u64 *) mdesc_get_property(hp, pn, "ue-on-adp", &len);
+	if (!val)
+		goto out;
+	adi_state.caps.ue_on_adi = *val;
+
+out:
+	mdesc_release(hp);
+}
+
 static ssize_t mdesc_read(struct file *file, char __user *buf,
 			  size_t len, loff_t *offp)
 {

@@ -1110,5 +1190,6 @@ void __init sun4v_mdesc_init(void)
 
 	cur_mdesc = hp;
 
+	init_adi();
 	report_platform_properties();
 }

@@ -32,6 +32,8 @@
 #include <linux/sysrq.h>
 #include <linux/nmi.h>
 #include <linux/context_tracking.h>
+#include <linux/prctl.h>
+#include <linux/hugetlb.h>
 
 #include <asm/uaccess.h>
 #include <asm/page.h>

@@ -777,3 +779,222 @@ unsigned long get_wchan(struct task_struct *task)
 out:
 	return ret;
 }
+
+#ifdef CONFIG_SPARC_ADI
+long get_sparc_adicaps(unsigned long val)
+{
+	struct adi_caps *caps;
+
+	if (!ADI_CAPABLE())
+		return -EINVAL;
+
+	caps = get_adi_caps();
+	if (val)
+		if (copy_to_user((void *)val, caps, sizeof(struct adi_caps)))
+			return -EFAULT;
+	return 0;
+}
+
+long set_sparc_pstate_mcde(unsigned long val)
+{
+	unsigned long error;
+	struct pt_regs *regs;
+
+	if (!ADI_CAPABLE())
+		return -EINVAL;
+
+	/* We do not allow anonymous tasks to enable ADI because they
+	 * run in borrowed aadress space.
+	 */
+	if (current->mm == NULL)
+		return -EINVAL;
+
+	regs = task_pt_regs(current);
+	if (regs->tstate & TSTATE_MCDE)
+		error = 1;
+	else
+		error = 0;
+	switch (val) {
+	case 1:
+		regs->tstate |= TSTATE_MCDE;
+		current->mm->context.adi = 1;
+		break;
+	case 0:
+		regs->tstate &= ~TSTATE_MCDE;
+		current->mm->context.adi = 0;
+		break;
+	default:
+		break;
+	}
+
+	return error;
+}
+
+long enable_sparc_adi(unsigned long addr, unsigned long len)
+{
+	unsigned long end, pagemask;
+	int error;
+	struct vm_area_struct *vma, *vma2;
+	struct mm_struct *mm;
+
+	if (!ADI_CAPABLE())
+		return -EINVAL;
+
+	vma = find_vma(current->mm, addr);
+	if (unlikely(!vma) || (vma->vm_start > addr))
+		return -EFAULT;
+
+	/* ADI is supported for hugepages only
+	 */
+	if (!is_vm_hugetlb_page(vma))
+		return -EFAULT;
+
+	/* Is the start address page aligned and is the length multiple
+	 * of page size?
+	 */
+	pagemask = ~(vma_kernel_pagesize(vma) - 1);
+	if (addr & ~pagemask)
+		return -EINVAL;
+	if (len & ~pagemask)
+		return -EINVAL;
+
+	end = addr + len;
+	if (end == addr)
+		return 0;
+
+	/* Verify end of the region is not out of bounds
+	 */
+	vma2 = find_vma(current->mm, end-1);
+	if (unlikely(!vma2) || (vma2->vm_start > end))
+		return -EFAULT;
+
+	error = 0;
+	while (1) {
+		/* If the address space ADI is to be enabled in, does not cover
+		 * this vma in its entirety, we will need to split it.
+		 */
+		mm = vma->vm_mm;
+		if (addr != vma->vm_start) {
+			error = split_vma(mm, vma, addr, 1);
+			if (error)
+				goto out;
+		}
+
+		if (end < vma->vm_end) {
+			error = split_vma(mm, vma, end, 0);
+			if (error)
+				goto out;
+		}
+
+		/* Update the ADI info in vma and PTE
+		 */
+		vma->vm_flags |= VM_SPARC_ADI;
+
+		if (end > vma->vm_end) {
+			change_protection(vma, addr, vma->vm_end,
+					  vma->vm_page_prot,
+					  vma_wants_writenotify(vma), 0);
+			addr = vma->vm_end;
+		} else {
+			change_protection(vma, addr, end, vma->vm_page_prot,
+					vma_wants_writenotify(vma), 0);
+			break;
+		}
+
+		vma = find_vma(current->mm, addr);
+		if (unlikely(!vma) || (vma->vm_start > addr))
+			return -EFAULT;
+	}
+out:
+	if (error == -ENOMEM)
+		error = -EAGAIN;
+	return error;
+}
+
+long disable_sparc_adi(unsigned long addr, unsigned long len)
+{
+	unsigned long end, pagemask;
+	struct vm_area_struct *vma, *vma2, *prev;
+	struct mm_struct *mm;
+	pgoff_t pgoff;
+
+	if (!ADI_CAPABLE())
+		return -EINVAL;
+
+	vma = find_vma(current->mm, addr);
+	if (unlikely(!vma) || (vma->vm_start > addr))
+		return -EFAULT;
+
+	/* ADI is supported for hugepages only
+	 */
+	if (!is_vm_hugetlb_page(vma))
+		return -EINVAL;
+
+	/* Is the start address page aligned and is the length multiple
+	 * of page size?
+	 */
+	pagemask = ~(vma_kernel_pagesize(vma) - 1);
+	if (addr & ~pagemask)
+		return -EINVAL;
+	if (len & ~pagemask)
+		return -EINVAL;
+
+	end = addr + len;
+	if (end == addr)
+		return 0;
+
+	/* Verify end of the region is not out of bounds
+	 */
+	vma2 = find_vma(current->mm, end-1);
+	if (unlikely(!vma2) || (vma2->vm_start > end))
+		return -EFAULT;
+
+	while (1) {
+		mm = vma->vm_mm;
+
+		/* Update the ADI info in vma and check if this vma can
+		 * be merged with adjacent ones
+		 */
+		pgoff = vma->vm_pgoff + ((addr - vma->vm_start) >> PAGE_SHIFT);
+		prev = vma_merge(mm, prev, addr, end, vma->vm_flags,
+				 vma->anon_vma, vma->vm_file, pgoff,
+				 vma_policy(vma), vma->vm_userfaultfd_ctx);
+		if (prev)
+			vma = prev;
+
+		vma->vm_flags &= ~VM_SPARC_ADI;
+		if (end > vma->vm_end) {
+			change_protection(vma, addr, vma->vm_end,
+					  vma->vm_page_prot,
+					  vma_wants_writenotify(vma), 0);
+			addr = vma->vm_end;
+		} else {
+			change_protection(vma, addr, end, vma->vm_page_prot,
+					  vma_wants_writenotify(vma), 0);
+			break;
+		}
+
+		vma = find_vma_prev(current->mm, addr, &prev);
+		if (unlikely(!vma) || (vma->vm_start > addr))
+			return -EFAULT;
+	}
+	return 0;
+}
+
+long get_sparc_adi_status(unsigned long addr)
+{
+	struct vm_area_struct *vma;
+
+	if (!ADI_CAPABLE())
+		return -EINVAL;
+
+	vma = find_vma(current->mm, addr);
+	if (unlikely(!vma) || (vma->vm_start > addr))
+		return -EFAULT;
+
+	if (vma->vm_flags & VM_SPARC_ADI)
+		return 1;
+
+	return 0;
+}
+#endif

@@ -0,0 +1,16 @@
+/* sun4v_mcd.S: Sun4v memory corruption detected precise exception handler
+ *
+ * Copyright (C) 2015 Bob Picco <bob.picco@oracle.com>
+ * Copyright (C) 2015 Khalid Aziz <khalid.aziz@oracle.com>
+ */
+	.text
+	.align 32
+
+sun4v_mcd_detect_precise:
+	ba,pt	%xcc, etrap
+	rd	%pc, %g7
+	or	%l4, %g0, %o1
+	or 	%l5, %g0, %o2
+	call	sun4v_mem_corrupt_detect_precise
+	add	%sp, PTREGS_OFF, %o0
+	ba,a,pt	%xcc, rtrap

@@ -351,12 +351,31 @@ 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
+	 */
 	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)

@@ -1801,6 +1820,7 @@ 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

@@ -1998,6 +2018,36 @@ 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) {
+		/* ADI tag mismatch in kernel mode means illegal access to
+		 * kernel memory through rogue means potentially.
+		 */
+		pr_emerg("mcd_err: ADI tag mismatch in kernel at "
+			"ADDR[%016llx], going.\n", ent.err_raddr);
+		die_if_kernel("MCD error", regs);
+	}
+
+	/* Send SIGSEGV to the userspace process with the right 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.
  */

@@ -2035,6 +2085,14 @@ void sun4v_resum_error(struct pt_regs *regs, unsigned long offset)
 		goto out;
 	}
 
+	/* If this is a memory corruption detected error, 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);

@@ -2531,6 +2589,38 @@ void sun4v_do_mna(struct pt_regs *regs, unsigned long addr, unsigned long type_c
 	force_sig_info(SIGBUS, &info, current);
 }
 
+void sun4v_mem_corrupt_detect_precise(struct pt_regs *regs, unsigned long addr,
+				      unsigned long context)
+{
+	siginfo_t info;
+
+	if (!ADI_CAPABLE()) {
+		bad_trap(regs, 0x1a);
+		return;
+	}
+
+	if (notify_die(DIE_TRAP, "memory corruption precise exception", regs,
+		       0, 0x8, SIGSEGV) == NOTIFY_STOP)
+		return;
+
+	if (regs->tstate & TSTATE_PRIV) {
+		pr_emerg("sun4v_mem_corrupt_detect_precise: ADDR[%016lx] "
+			"CTX[%lx], going.\n", addr, context);
+		die_if_kernel("MCD precise", regs);
+	}
+
+	if (test_thread_flag(TIF_32BIT)) {
+		regs->tpc &= 0xffffffff;
+		regs->tnpc &= 0xffffffff;
+	}
+	info.si_signo = SIGSEGV;
+	info.si_code = SEGV_ADIPERR;
+	info.si_errno = 0;
+	info.si_addr = (void __user *) addr;
+	info.si_trapno = 0;
+	force_sig_info(SIGSEGV, &info, current);
+}
+
 void do_privop(struct pt_regs *regs)
 {
 	enum ctx_state prev_state = exception_enter();

@@ -25,8 +25,10 @@ tl0_ill:	membar #Sync
 		TRAP_7INSNS(do_illegal_instruction)
 tl0_privop:	TRAP(do_privop)
 tl0_resv012:	BTRAP(0x12) BTRAP(0x13) BTRAP(0x14) BTRAP(0x15) BTRAP(0x16) BTRAP(0x17)
-tl0_resv018:	BTRAP(0x18) BTRAP(0x19) BTRAP(0x1a) BTRAP(0x1b) BTRAP(0x1c) BTRAP(0x1d)
-tl0_resv01e:	BTRAP(0x1e) BTRAP(0x1f)
+tl0_resv018:	BTRAP(0x18) BTRAP(0x19)
+tl0_mcd:	SUN4V_MCD_PRECISE
+tl0_resv01b:	BTRAP(0x1b)
+tl0_resv01c:	BTRAP(0x1c) BTRAP(0x1d)	BTRAP(0x1e) BTRAP(0x1f)
 tl0_fpdis:	TRAP_NOSAVE(do_fpdis)
 tl0_fpieee:	TRAP_SAVEFPU(do_fpieee)
 tl0_fpother:	TRAP_NOSAVE(do_fpother_check_fitos)

@@ -168,6 +168,8 @@ extern unsigned int kobjsize(const void *objp);
 # define VM_GROWSUP	VM_ARCH_1
 #elif defined(CONFIG_IA64)
 # define VM_GROWSUP	VM_ARCH_1
+#elif defined(CONFIG_SPARC64)
+# define VM_SPARC_ADI	VM_ARCH_1	/* Uses ADI tag for access control */
 #elif !defined(CONFIG_MMU)
 # define VM_MAPPED_COPY	VM_ARCH_1	/* T if mapped copy of data (nommu mmap) */
 #endif

@@ -206,7 +206,10 @@ typedef struct siginfo {
 #define SEGV_MAPERR	(__SI_FAULT|1)	/* address not mapped to object */
 #define SEGV_ACCERR	(__SI_FAULT|2)	/* invalid permissions for mapped object */
 #define SEGV_BNDERR	(__SI_FAULT|3)  /* failed address bound checks */
-#define NSIGSEGV	3
+#define SEGV_ACCADI	(__SI_FAULT|4)	/* ADI not enabled for mapped object */
+#define SEGV_ADIDERR	(__SI_FAULT|5)	/* Disrupting MCD error */
+#define SEGV_ADIPERR	(__SI_FAULT|6)	/* Precise MCD exception */
+#define NSIGSEGV	6
 
 /*
  * SIGBUS si_codes

@@ -197,4 +197,20 @@ struct prctl_mm_map {
 # define PR_CAP_AMBIENT_LOWER		3
 # define PR_CAP_AMBIENT_CLEAR_ALL	4
 
+/* SPARC ADI operations, see Documentation/prctl/sparc_adi.txt for details */
+#define PR_GET_SPARC_ADICAPS	48
+#define PR_SET_SPARC_ADI	49
+# define PR_SET_SPARC_ADI_CLEAR	0
+# define PR_SET_SPARC_ADI_SET	1
+#define PR_ENABLE_SPARC_ADI	50
+#define PR_DISABLE_SPARC_ADI	51
+#define PR_GET_SPARC_ADI_STATUS	52
+
+/* Data structure returned by PR_GET_SPARC_ADICAPS */
+struct adi_caps {
+	__u64 blksz;
+	__u64 nbits;
+	__u64 ue_on_adi;
+};
+
 #endif /* _LINUX_PRCTL_H */

@@ -103,6 +103,21 @@
 #ifndef SET_FP_MODE
 # define SET_FP_MODE(a,b)	(-EINVAL)
 #endif
+#ifndef GET_SPARC_ADICAPS
+# define GET_SPARC_ADICAPS(a)		(-EINVAL)
+#endif
+#ifndef SET_SPARC_MCDE
+# define SET_SPARC_MCDE(a)		(-EINVAL)
+#endif
+#ifndef ENABLE_SPARC_ADI
+# define ENABLE_SPARC_ADI(a, b)		(-EINVAL)
+#endif
+#ifndef DISABLE_SPARC_ADI
+# define DISABLE_SPARC_ADI(a, b)	(-EINVAL)
+#endif
+#ifndef GET_SPARC_ADI_STATUS
+# define GET_SPARC_ADI_STATUS(a)	(-EINVAL)
+#endif
 
 /*
  * this is where the system-wide overflow UID and GID are defined, for

@@ -2266,6 +2281,21 @@ SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3,
 	case PR_GET_FP_MODE:
 		error = GET_FP_MODE(me);
 		break;
+	case PR_GET_SPARC_ADICAPS:
+		error = GET_SPARC_ADICAPS(arg2);
+		break;
+	case PR_SET_SPARC_ADI:
+		error = SET_SPARC_MCDE(arg2);
+		break;
+	case PR_ENABLE_SPARC_ADI:
+		error = ENABLE_SPARC_ADI(arg2, arg3);
+		break;
+	case PR_DISABLE_SPARC_ADI:
+		error = DISABLE_SPARC_ADI(arg2, arg3);
+		break;
+	case PR_GET_SPARC_ADI_STATUS:
+		error = GET_SPARC_ADI_STATUS(arg2);
+		break;
 	default:
 		error = -EINVAL;
 		break;