[RFC PATCH v3] sparc64: Add support for Application Data Integrity (ADI)

From: Khalid Aziz
Date: Wed Jan 04 2017 - 17:51:01 EST

ADI is a new feature supported on sparc M7 and newer processors to allow
hardware to catch rogue accesses to memory. ADI is supported for data
fetches only and not instruction fetches. An app can enable ADI on its
data pages, set version tags on them and use versioned addresses to
access the data pages. Upper bits of the address contain the version
tag. On M7 processors, upper four bits (bits 63-60) contain the version
tag. If a rogue app attempts to access ADI enabled data pages, its
access is blocked and processor generates an exception.

This patch extends mprotect to enable ADI (TSTATE.mcde), enable/disable
MCD (Memory Corruption Detection) on selected memory ranges, enable
TTE.mcd in PTEs, return ADI parameters to userspace and save/restore ADI
version tags on page swap out/in. It also adds handlers for all traps
related to MCD. ADI is not enabled by default for any task. A task must
explicitly enable ADI on a memory range and set version tag for ADI to
be effective for the task.

Signed-off-by: Khalid Aziz <khalid.aziz@xxxxxxxxxx>
Cc: Khalid Aziz <khalid@xxxxxxxxxxxxxx>
---
v2:
- Fixed a build error

v3:
- Removed CONFIG_SPARC_ADI
- Replaced prctl commands with mprotect
- Added auxiliary vectors for ADI parameters
- Enabled ADI for swappable pages

Documentation/sparc/adi.txt | 239 ++++++++++++++++++++++++++++++++
arch/sparc/include/asm/adi.h | 6 +
arch/sparc/include/asm/adi_64.h | 46 ++++++
arch/sparc/include/asm/elf_64.h | 8 ++
arch/sparc/include/asm/hugetlb.h | 13 ++
arch/sparc/include/asm/hypervisor.h | 2 +
arch/sparc/include/asm/mman.h | 40 +++++-
arch/sparc/include/asm/mmu_64.h | 2 +
arch/sparc/include/asm/mmu_context_64.h | 32 +++++
arch/sparc/include/asm/pgtable_64.h | 97 ++++++++++++-
arch/sparc/include/asm/ttable.h | 10 ++
arch/sparc/include/asm/uaccess_64.h | 120 +++++++++++++++-
arch/sparc/include/uapi/asm/asi.h | 5 +
arch/sparc/include/uapi/asm/auxvec.h | 8 ++
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 | 93 +++++++++++++
arch/sparc/kernel/entry.h | 3 +
arch/sparc/kernel/head_64.S | 1 +
arch/sparc/kernel/mdesc.c | 4 +
arch/sparc/kernel/process_64.c | 21 +++
arch/sparc/kernel/sun4v_mcd.S | 16 +++
arch/sparc/kernel/traps_64.c | 142 ++++++++++++++++++-
arch/sparc/kernel/ttable_64.S | 6 +-
arch/sparc/mm/gup.c | 37 +++++
arch/sparc/mm/tlb.c | 28 ++++
arch/x86/kernel/signal_compat.c | 2 +-
include/asm-generic/pgtable.h | 5 +
include/linux/mm.h | 2 +
include/uapi/asm-generic/siginfo.h | 5 +-
mm/memory.c | 2 +-
mm/rmap.c | 4 +-
33 files changed, 993 insertions(+), 19 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

diff --git a/Documentation/sparc/adi.txt b/Documentation/sparc/adi.txt
new file mode 100644
index 0000000..18aa6d0
--- /dev/null
+++ b/Documentation/sparc/adi.txt
@@ -0,0 +1,239 @@
+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.
+
+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.
+
+ADI is enabled on a set of pages using mprotect() with PROT_ADI flag.
+When ADI is enabled on a set of pages by a task for the first time,
+kernel sets the PSTATE.mcde bit fot the task. Version tags for memory
+addresses are set with an stxa instruction on the addresses using
+ASI_MCD_PRIMARY or ASI_MCD_ST_BLKINIT_PRIMARY. Version tags are
+specified in bits 63-60 of address and are set on memory the size of ADI
+block size. ADI block size is provided by the hypervisor to the kernel.
+Kernel returns the value of ADI block size to userspace using auxiliary
+vector along with other ADI info. Following auxiliary vectors are
+provided by the kernel:
+
+ AT_ADI_BLKSZ ADI block size. This is the granularity and
+ alignment, in bytes, of ADI versioning.
+ AT_ADI_NBITS Number of ADI version bits in the VA
+ AT_ADI_UEONADI ADI version of memory containing uncorrectable
+ errors will be set to this value
+
+Version tag values of 0x0 and 0xf are reserved.
+
+
+
+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.
+
+#include <unistd.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <elf.h>
+#include <sys/ipc.h>
+#include <sys/shm.h>
+#include <sys/mman.h>
+#include <asm/asi.h>
+
+#ifndef AT_ADI_BLKSZ
+#define AT_ADI_BLKSZ 34
+#endif
+#ifndef AT_ADI_NBITS
+#define AT_ADI_NBITS 35
+#endif
+#ifndef AT_ADI_UEONADI
+#define AT_ADI_UEONADI 36
+#endif
+
+#ifndef PROT_ADI
+#define PROT_ADI 0x10
+#endif
+
+#define BUFFER_SIZE 32*1024*1024UL
+
+main(int argc, char* argv[], char* envp[])
+{
+ unsigned long i, mcde, adi_blksz, adi_nbits, adi_ueonadi;
+ char *shmaddr, *tmp_addr, *end, *veraddr, *clraddr;
+ int shmid, version;
+ Elf64_auxv_t *auxv;
+
+ adi_blksz = 0;
+
+ while(*envp++ != NULL);
+ for (auxv = (Elf64_auxv_t *)envp; auxv->a_type != AT_NULL; auxv++) {
+ switch (auxv->a_type) {
+ case AT_ADI_BLKSZ:
+ adi_blksz = auxv->a_un.a_val;
+ break;
+ case AT_ADI_NBITS:
+ adi_nbits = auxv->a_un.a_val;
+ break;
+ case AT_ADI_UEONADI:
+ adi_ueonadi = auxv->a_un.a_val;
+ break;
+ }
+ }
+ if (adi_blksz == 0) {
+ fprintf(stderr, "Oops! ADI is not supported\n");
+ exit(1);
+ }
+
+ printf("ADI capabilities:\n");
+ printf("\tBlock size = %ld\n", adi_blksz);
+ printf("\tNumber of bits = %ld\n", adi_nbits);
+ printf("\tUE on ADI error = %ld\n", adi_ueonadi);
+
+ if ((shmid = shmget(2, BUFFER_SIZE,
+ 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);
+ }
+
+ if (mprotect(shmaddr, BUFFER_SIZE, PROT_READ|PROT_WRITE|PROT_ADI)) {
+ perror("mprotect 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]0x90\n\t"
+ :
+ : "r" (tmp_addr), "r" (version));
+ tmp_addr += adi_blksz;
+ }
+ asm volatile("membar #Sync\n\t");
+
+ /* Create a versioned address from the normal address
+ */
+ tmp_addr = (void *) ((unsigned long)shmaddr << adi_nbits);
+ tmp_addr = (void *) ((unsigned long)tmp_addr >> adi_nbits);
+ veraddr = (void *) (((unsigned long)version << (64-adi_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...");
+ fflush(stdout);
+ 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 (mprotect(shmaddr, BUFFER_SIZE, PROT_READ|PROT_WRITE)) {
+ perror("mprotect 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);
+}
diff --git a/arch/sparc/include/asm/adi.h b/arch/sparc/include/asm/adi.h
new file mode 100644
index 0000000..acad0d0
--- /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 0000000..24fe52f
--- /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@xxxxxxxxxx)
+ *
+ * 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 3f2d403..cf00fbc 100644
--- a/arch/sparc/include/asm/elf_64.h
+++ b/arch/sparc/include/asm/elf_64.h
@@ -210,4 +210,12 @@ 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/asm/hugetlb.h b/arch/sparc/include/asm/hugetlb.h
index dcbf985..ac2fe18 100644
--- a/arch/sparc/include/asm/hugetlb.h
+++ b/arch/sparc/include/asm/hugetlb.h
@@ -77,5 +77,18 @@ static inline void arch_clear_hugepage_flags(struct page *page)
void hugetlb_free_pgd_range(struct mmu_gather *tlb, unsigned long addr,
unsigned long end, unsigned long floor,
unsigned long ceiling);
+#ifdef CONFIG_SPARC64
+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 */
diff --git a/arch/sparc/include/asm/hypervisor.h b/arch/sparc/include/asm/hypervisor.h
index 73cb897..31782f7 100644
--- a/arch/sparc/include/asm/hypervisor.h
+++ b/arch/sparc/include/asm/hypervisor.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

diff --git a/arch/sparc/include/asm/mman.h b/arch/sparc/include/asm/mman.h
index 59bb593..95d3abc 100644
--- a/arch/sparc/include/asm/mman.h
+++ b/arch/sparc/include/asm/mman.h
@@ -6,5 +6,43 @@
#ifndef __ASSEMBLY__
#define arch_mmap_check(addr,len,flags) sparc_mmap_check(addr,len)
int sparc_mmap_check(unsigned long addr, unsigned long len);
-#endif
+
+#ifdef CONFIG_SPARC64
+#include <asm/adi_64.h>
+
+#define arch_calc_vm_prot_bits(prot, pkey) sparc_calc_vm_prot_bits(prot)
+static inline unsigned long sparc_calc_vm_prot_bits(unsigned long prot)
+{
+ if (prot & PROT_ADI) {
+ struct pt_regs *regs;
+
+ if (!current->mm->context.adi) {
+ regs = task_pt_regs(current);
+ regs->tstate |= TSTATE_MCDE;
+ current->mm->context.adi = true;
+ }
+ return VM_SPARC_ADI;
+ } else {
+ return 0;
+ }
+}
+
+#define arch_vm_get_page_prot(vm_flags) sparc_vm_get_page_prot(vm_flags)
+static inline pgprot_t sparc_vm_get_page_prot(unsigned long vm_flags)
+{
+ return (vm_flags & VM_SPARC_ADI) ? __pgprot(_PAGE_MCD_4V) : __pgprot(0);
+}
+
+#define arch_validate_prot(prot) sparc_validate_prot(prot)
+static inline int sparc_validate_prot(unsigned long prot)
+{
+ if (prot & ~(PROT_READ | PROT_WRITE | PROT_EXEC | PROT_SEM | PROT_ADI))
+ return 0;
+ if ((prot & PROT_ADI) && !adi_capable())
+ return 0;
+ return 1;
+}
+#endif /* CONFIG_SPARC64 */
+
+#endif /* __ASSEMBLY__ */
#endif /* __SPARC_MMAN_H__ */
diff --git a/arch/sparc/include/asm/mmu_64.h b/arch/sparc/include/asm/mmu_64.h
index f7de0db..85adfd8 100644
--- a/arch/sparc/include/asm/mmu_64.h
+++ b/arch/sparc/include/asm/mmu_64.h
@@ -96,6 +96,8 @@ typedef struct {
unsigned long thp_pte_count;
struct tsb_config tsb_block[MM_NUM_TSBS];
struct hv_tsb_descr tsb_descr[MM_NUM_TSBS];
+ bool adi;
+ unsigned long mcdper;
} mm_context_t;

#endif /* !__ASSEMBLY__ */
diff --git a/arch/sparc/include/asm/mmu_context_64.h b/arch/sparc/include/asm/mmu_context_64.h
index b84be67..79f3c7a 100644
--- a/arch/sparc/include/asm/mmu_context_64.h
+++ b/arch/sparc/include/asm/mmu_context_64.h
@@ -7,6 +7,7 @@

#include <linux/spinlock.h>
#include <asm/spitfire.h>
+#include <asm/adi_64.h>
#include <asm-generic/mm_hooks.h>

static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)
@@ -79,6 +80,21 @@ static inline void switch_mm(struct mm_struct *old_mm, struct mm_struct *mm, str
if (unlikely(mm == &init_mm))
return;

+ /* Save the current state of MCDPER register for the process we are
+ * switching from
+ */
+ if (adi_capable()) {
+ register unsigned long tmp_mcdper;
+
+ __asm__ __volatile__(
+ ".word 0xa1438000\n\t" /* rd %mcdper, %l0 */
+ "mov %%l0, %0\n\t"
+ : "=r" (tmp_mcdper)
+ :
+ : "l0");
+ old_mm->context.mcdper = tmp_mcdper;
+ }
+
spin_lock_irqsave(&mm->context.lock, flags);
ctx_valid = CTX_VALID(mm->context);
if (!ctx_valid)
@@ -127,6 +143,22 @@ static inline void switch_mm(struct mm_struct *old_mm, struct mm_struct *mm, str
__flush_tlb_mm(CTX_HWBITS(mm->context),
SECONDARY_CONTEXT);
}
+
+ /* Restore the state of MCDPER register for the process we are
+ * switching to
+ */
+ if (adi_capable()) {
+ register unsigned long tmp_mcdper;
+
+ tmp_mcdper = mm->context.mcdper;
+ __asm__ __volatile__(
+ "mov %0, %%l1\n\t"
+ ".word 0x9d800011\n\t" /* wr %g0, %l1, %mcdper */
+ :
+ : "ir" (tmp_mcdper)
+ : "l1");
+ }
+
spin_unlock_irqrestore(&mm->context.lock, flags);
}

diff --git a/arch/sparc/include/asm/pgtable_64.h b/arch/sparc/include/asm/pgtable_64.h
index 1fb317f..c543a33 100644
--- a/arch/sparc/include/asm/pgtable_64.h
+++ b/arch/sparc/include/asm/pgtable_64.h
@@ -17,6 +17,7 @@
#include <asm/types.h>
#include <asm/spitfire.h>
#include <asm/asi.h>
+#include <asm/adi.h>
#include <asm/page.h>
#include <asm/processor.h>

@@ -162,6 +163,9 @@ 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 */
@@ -562,6 +566,18 @@ 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;
@@ -919,6 +935,10 @@ static inline void __set_pte_at(struct mm_struct *mm, unsigned long addr,
#define pte_clear_not_present_full(mm,addr,ptep,fullmm) \
__set_pte_at((mm), (addr), (ptep), __pte(0UL), (fullmm))

+#define __HAVE_ARCH_PTEP_CLEAR_FLUSH
+pte_t ptep_clear_flush(struct vm_area_struct *vma, unsigned long addr,
+ pte_t *ptep);
+
#ifdef DCACHE_ALIASING_POSSIBLE
#define __HAVE_ARCH_MOVE_PTE
#define move_pte(pte, prot, old_addr, new_addr) \
@@ -962,9 +982,14 @@ void pgtable_trans_huge_deposit(struct mm_struct *mm, pmd_t *pmdp,
pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp);
#endif

-/* Encode and de-code a swap entry */
+/* Encode and de-code a swap entry. Upper bits of offset are used to
+ * store the ADI version tag for pages that have ADI enabled and tags set
+ */
#define __swp_type(entry) (((entry).val >> PAGE_SHIFT) & 0xffUL)
-#define __swp_offset(entry) ((entry).val >> (PAGE_SHIFT + 8UL))
+#define __swp_offset(entry) \
+ ((((entry).val << adi_nbits()) >> adi_nbits()) >> (PAGE_SHIFT + 8UL))
+#define __swp_aditag(entry) \
+ ((entry).val >> (sizeof(unsigned long)-adi_nbits()))
#define __swp_entry(type, offset) \
( (swp_entry_t) \
{ \
@@ -987,6 +1012,74 @@ int page_in_phys_avail(unsigned long paddr);
int remap_pfn_range(struct vm_area_struct *, unsigned long, unsigned long,
unsigned long, pgprot_t);

+static inline void set_swp_pte_at(struct mm_struct *mm, unsigned long addr,
+ pte_t *ptep, pte_t pte, pte_t oldpte)
+{
+ pte_t orig = *ptep;
+
+ if (!pte_none(pte) && !pte_present(pte)) {
+ if (pte_val(oldpte) & _PAGE_MCD_4V) {
+ unsigned long version, paddr;
+
+ paddr = pte_val(oldpte) & _PAGE_PADDR_4V;
+ asm volatile("ldxa [%1] %2, %0\n\t"
+ : "=r" (version)
+ : "r" (paddr), "i" (ASI_MCD_REAL));
+ if (version) {
+ swp_entry_t tmp;
+ pgoff_t swap_off;
+ unsigned long swap_type, shift_size;
+
+ /* Save ADI version tag in the top bits
+ * of swap offset
+ */
+ tmp = __pte_to_swp_entry(pte);
+ swap_off = __swp_offset(tmp);
+ swap_type = __swp_type(tmp);
+ shift_size = PAGE_SHIFT + 8UL + adi_nbits();
+ swap_off = (swap_off << shift_size)>>shift_size;
+ swap_off = (version << (sizeof(unsigned long) -
+ shift_size)) | swap_off;
+ tmp = __swp_entry(swap_type, swap_off);
+ pte = __swp_entry_to_pte(tmp);
+ }
+ }
+ *ptep = pte;
+ maybe_tlb_batch_add(mm, addr, ptep, orig, 0);
+ } else
+ if (pte_val(pte) & _PAGE_MCD_4V) {
+ swp_entry_t tmp;
+ pgoff_t swap_off;
+ unsigned long swap_type, version;
+
+ *ptep = pte;
+ maybe_tlb_batch_add(mm, addr, ptep, orig, 0);
+
+ /* Check if the swapped out page has an ADI version
+ * saved in the swap offset. If yes, restore
+ * version tag to the newly allocated page
+ */
+ tmp = __pte_to_swp_entry(oldpte);
+ swap_off = __swp_offset(tmp);
+ swap_type = __swp_type(tmp);
+ version = __swp_aditag(tmp);
+ if (version) {
+ unsigned long i, paddr;
+
+ paddr = pte_val(pte) & _PAGE_PADDR_4V;
+ for (i = paddr; i < (paddr+PAGE_SIZE);
+ i += adi_blksize())
+ asm volatile("stxa %0, [%1] %2\n\t"
+ :
+ : "r" (version), "r" (i),
+ "i" (ASI_MCD_REAL));
+ }
+ } else {
+ *ptep = pte;
+ maybe_tlb_batch_add(mm, addr, ptep, orig, 0);
+ }
+}
+
static inline int io_remap_pfn_range(struct vm_area_struct *vma,
unsigned long from, unsigned long pfn,
unsigned long size, pgprot_t prot)
diff --git a/arch/sparc/include/asm/ttable.h b/arch/sparc/include/asm/ttable.h
index 781b9f1..77cc073 100644
--- a/arch/sparc/include/asm/ttable.h
+++ b/arch/sparc/include/asm/ttable.h
@@ -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, etrap; \
+ rd %pc, %g7; \
+ ba,pt %xcc, sun4v_mcd_detect_precise; \
+ nop; \
+ nop;
+
/* Before touching these macros, you owe it to yourself to go and
* see how arch/sparc64/kernel/winfixup.S works... -DaveM
*
diff --git a/arch/sparc/include/asm/uaccess_64.h b/arch/sparc/include/asm/uaccess_64.h
index 5373136..6bfe818 100644
--- a/arch/sparc/include/asm/uaccess_64.h
+++ b/arch/sparc/include/asm/uaccess_64.h
@@ -10,8 +10,10 @@
#include <linux/compiler.h>
#include <linux/string.h>
#include <linux/thread_info.h>
+#include <linux/sched.h>
#include <asm/asi.h>
#include <asm/spitfire.h>
+#include <asm/adi_64.h>
#include <asm-generic/uaccess-unaligned.h>
#include <asm/extable_64.h>
#endif
@@ -72,6 +74,31 @@ static inline bool __chk_range_not_ok(unsigned long addr, unsigned long size, un
__chk_range_not_ok((unsigned long __force)(addr), size, limit); \
})

+static inline void enable_adi(void)
+{
+ /*
+ * If userspace is using ADI, it could potentially pass a pointer
+ * with version tag embedded in it. To maintain the ADI security,
+ * we must enable PSTATE.mcde. Userspace would have already set
+ * TTE.mcd in an earlier call to kernel and set the version tag
+ * for the address being dereferenced. Setting PSTATE.mcde would
+ * ensure any access to userspace data through a system call
+ * honors ADI and does not allow a rogue app to bypass ADI by
+ * using system calls. Also to ensure the right exception,
+ * precise or disrupting, is delivered to the userspace, update
+ * PMCDPER to match MCDPER
+ */
+ __asm__ __volatile__(
+ "rdpr %%pstate, %%g1\n\t"
+ "or %%g1, %0, %%g1\n\t"
+ "wrpr %%g1, %%g0, %%pstate\n\t"
+ ".word 0x83438000\n\t" /* rd %mcdper, %g1 */
+ ".word 0xaf900001\n\t" /* wrpr %g0, %g1, %pmcdper */
+ :
+ : "i" (PSTATE_MCDE)
+ : "g1");
+}
+
static inline int __access_ok(const void __user * addr, unsigned long size)
{
return 1;
@@ -112,7 +139,9 @@ struct __large_struct { unsigned long buf[100]; };
#define __m(x) ((struct __large_struct *)(x))

#define __put_user_nocheck(data, addr, size) ({ \
- register int __pu_ret; \
+ register int __pu_ret, __adi_status; \
+ if ((__adi_status = (current->mm && current->mm->context.adi))) \
+ enable_adi(); \
switch (size) { \
case 1: __put_user_asm(data, b, addr, __pu_ret); break; \
case 2: __put_user_asm(data, h, addr, __pu_ret); break; \
@@ -120,6 +149,9 @@ struct __large_struct { unsigned long buf[100]; };
case 8: __put_user_asm(data, x, addr, __pu_ret); break; \
default: __pu_ret = __put_user_bad(); break; \
} \
+ if (__adi_status) \
+ /* wrpr %g0, %pmcdper */ \
+ __asm__ __volatile__(".word 0xaf900000"::); \
__pu_ret; \
})

@@ -146,8 +178,10 @@ __asm__ __volatile__( \
int __put_user_bad(void);

#define __get_user_nocheck(data, addr, size, type) ({ \
- register int __gu_ret; \
+ register int __gu_ret, __adi_status; \
register unsigned long __gu_val; \
+ if ((__adi_status = (current->mm && current->mm->context.adi))) \
+ enable_adi(); \
switch (size) { \
case 1: __get_user_asm(__gu_val, ub, addr, __gu_ret); break; \
case 2: __get_user_asm(__gu_val, uh, addr, __gu_ret); break; \
@@ -159,6 +193,9 @@ int __put_user_bad(void);
break; \
} \
data = (__force type) __gu_val; \
+ if (__adi_status) \
+ /* wrpr %g0, %pmcdper */ \
+ __asm__ __volatile__(".word 0xaf900000"::); \
__gu_ret; \
})

@@ -185,15 +222,53 @@ __asm__ __volatile__( \

int __get_user_bad(void);

+/* When kernel access userspace memory, it must honor ADI setting
+ * to ensure ADI protection continues across system calls. Kernel
+ * must set PSTATE.mcde bit. It must also update PMCDPER register
+ * to reflect MCDPER register so the kind of exception generated
+ * in case of ADI version tag mismatch, is what the userspace is
+ * expecting. PMCDPER exists only on the processors that support
+ * ADI and must be accessed conditionally to avoid illegal
+ * instruction trap.
+ */
+#define user_access_begin() \
+ do { \
+ if (current->mm && current->mm->context.adi) \
+ enable_adi(); \
+ } while (0)
+
+#define user_access_end() \
+ do { \
+ if (adi_capable()) \
+ /* wrpr %g0, %pmcdper */ \
+ __asm__ __volatile__(".word 0xaf900000"::); \
+ } while (0)
+
+#define unsafe_get_user(x, ptr, err) \
+ do { if (unlikely(__get_user(x, ptr))) goto err; } while (0)
+#define unsafe_put_user(x, ptr, err) \
+ do { if (unlikely(__put_user(x, ptr))) goto err; } while (0)
+
+
unsigned long __must_check ___copy_from_user(void *to,
const void __user *from,
unsigned long size);
static inline unsigned long __must_check
copy_from_user(void *to, const void __user *from, unsigned long size)
{
+ unsigned long ret, adi_status;
+
check_object_size(to, size, false);

- return ___copy_from_user(to, from, size);
+ if ((adi_status = (current->mm && current->mm->context.adi)))
+ enable_adi();
+
+ ret = ___copy_from_user(to, from, size);
+ if (adi_status)
+ /* wrpr %g0, %pmcdper */
+ __asm__ __volatile__(".word 0xaf900000"::);
+
+ return ret;
}
#define __copy_from_user copy_from_user

@@ -203,9 +278,18 @@ unsigned long __must_check ___copy_to_user(void __user *to,
static inline unsigned long __must_check
copy_to_user(void __user *to, const void *from, unsigned long size)
{
+ unsigned long ret, adi_status;
+
check_object_size(from, size, true);

- return ___copy_to_user(to, from, size);
+ if ((adi_status = (current->mm && current->mm->context.adi)))
+ enable_adi();
+
+ ret = ___copy_to_user(to, from, size);
+ if (adi_status)
+ /* wrpr %g0, %pmcdper */
+ __asm__ __volatile__(".word 0xaf900000"::);
+ return ret;
}
#define __copy_to_user copy_to_user

@@ -215,13 +299,37 @@ unsigned long __must_check ___copy_in_user(void __user *to,
static inline unsigned long __must_check
copy_in_user(void __user *to, void __user *from, unsigned long size)
{
- return ___copy_in_user(to, from, size);
+ unsigned long ret, adi_status;
+
+ if ((adi_status = (current->mm && current->mm->context.adi)))
+ enable_adi();
+
+ ret = ___copy_in_user(to, from, size);
+ if (adi_status)
+ /* wrpr %g0, %pmcdper */
+ __asm__ __volatile__(".word 0xaf900000"::);
+
+ return ret;
}
#define __copy_in_user copy_in_user

unsigned long __must_check __clear_user(void __user *, unsigned long);

-#define clear_user __clear_user
+static inline unsigned long __must_check
+___clear_user(void __user *uaddr, unsigned long size)
+{
+ unsigned long ret, adi_status;
+
+ if ((adi_status = (current->mm && current->mm->context.adi)))
+ enable_adi();
+ ret = __clear_user(uaddr, size);
+ if (adi_status)
+ /* wrpr %g0, %pmcdper */
+ __asm__ __volatile__(".word 0xaf900000"::);
+ return ret;
+}
+
+#define clear_user ___clear_user

__must_check long strlen_user(const char __user *str);
__must_check long strnlen_user(const char __user *str, long n);
diff --git a/arch/sparc/include/uapi/asm/asi.h b/arch/sparc/include/uapi/asm/asi.h
index 7ad7203d..2bcdaa5 100644
--- a/arch/sparc/include/uapi/asm/asi.h
+++ b/arch/sparc/include/uapi/asm/asi.h
@@ -144,6 +144,8 @@
* ASIs, "(4V)" designates SUN4V specific ASIs. "(NG4)" designates SPARC-T4
* and later ASIs.
*/
+#define ASI_MCD_PRIV_PRIMARY 0x02 /* (NG7) Privileged MCD version VA */
+#define ASI_MCD_REAL 0x05 /* (NG7) Privileged MCD version PA */
#define ASI_PHYS_USE_EC 0x14 /* PADDR, E-cachable */
#define ASI_PHYS_BYPASS_EC_E 0x15 /* PADDR, E-bit */
#define ASI_BLK_AIUP_4V 0x16 /* (4V) Prim, user, block ld/st */
@@ -244,6 +246,9 @@
#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 */
diff --git a/arch/sparc/include/uapi/asm/auxvec.h b/arch/sparc/include/uapi/asm/auxvec.h
index ad6f360..6fe1249 100644
--- a/arch/sparc/include/uapi/asm/auxvec.h
+++ b/arch/sparc/include/uapi/asm/auxvec.h
@@ -1,4 +1,12 @@
#ifndef __ASMSPARC_AUXVEC_H
#define __ASMSPARC_AUXVEC_H

+#ifdef CONFIG_SPARC64
+#define AT_ADI_BLKSZ 34
+#define AT_ADI_NBITS 35
+#define AT_ADI_UEONADI 36
+
+#define AT_VECTOR_SIZE_ARCH 3
+#endif
+
#endif /* !(__ASMSPARC_AUXVEC_H) */
diff --git a/arch/sparc/include/uapi/asm/mman.h b/arch/sparc/include/uapi/asm/mman.h
index 9765896..a72c033 100644
--- a/arch/sparc/include/uapi/asm/mman.h
+++ b/arch/sparc/include/uapi/asm/mman.h
@@ -5,6 +5,8 @@

/* SunOS'ified... */

+#define PROT_ADI 0x10 /* ADI enabled */
+
#define MAP_RENAME MAP_ANONYMOUS /* In SunOS terminology */
#define MAP_NORESERVE 0x40 /* don't reserve swap pages */
#define MAP_INHERIT 0x80 /* SunOS doesn't do this, but... */
diff --git a/arch/sparc/include/uapi/asm/pstate.h b/arch/sparc/include/uapi/asm/pstate.h
index cf832e1..d0521db 100644
--- a/arch/sparc/include/uapi/asm/pstate.h
+++ b/arch/sparc/include/uapi/asm/pstate.h
@@ -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. */
diff --git a/arch/sparc/kernel/Makefile b/arch/sparc/kernel/Makefile
index fa3c02d..c9c4e76 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 0000000..aba1960
--- /dev/null
+++ b/arch/sparc/kernel/adi_64.c
@@ -0,0 +1,93 @@
+/* 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@xxxxxxxxxx)
+ *
+ * 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;
+ if (hp)
+ mdesc_release(hp);
+}
diff --git a/arch/sparc/kernel/entry.h b/arch/sparc/kernel/entry.h
index 0f67942..2078468 100644
--- a/arch/sparc/kernel/entry.h
+++ b/arch/sparc/kernel/entry.h
@@ -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;
diff --git a/arch/sparc/kernel/head_64.S b/arch/sparc/kernel/head_64.S
index 6aa3da1..818f869 100644
--- a/arch/sparc/kernel/head_64.S
+++ b/arch/sparc/kernel/head_64.S
@@ -873,6 +873,7 @@ 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"
diff --git a/arch/sparc/kernel/mdesc.c b/arch/sparc/kernel/mdesc.c
index 8a6982d..68b03bf 100644
--- a/arch/sparc/kernel/mdesc.c
+++ b/arch/sparc/kernel/mdesc.c
@@ -20,6 +20,7 @@
#include <asm/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
@@ -1104,5 +1105,8 @@ void __init sun4v_mdesc_init(void)

cur_mdesc = hp;

+#ifdef CONFIG_SPARC64
+ mdesc_adi_init();
+#endif
report_platform_properties();
}
diff --git a/arch/sparc/kernel/process_64.c b/arch/sparc/kernel/process_64.c
index 47ff558..740cecb 100644
--- a/arch/sparc/kernel/process_64.c
+++ b/arch/sparc/kernel/process_64.c
@@ -680,6 +680,27 @@ int copy_thread(unsigned long clone_flags, unsigned long sp,
return 0;
}

+/* Update the state of MCDPER register in current task's mm context before
+ * dup so the dup'd task will inherit flags in this register correctly.
+ * Current task may have updated flags since it started running.
+ */
+int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
+{
+ if (adi_capable() && src->mm) {
+ register unsigned long tmp_mcdper;
+
+ __asm__ __volatile__(
+ ".word 0x83438000\n\t" /* rd %mcdper, %g1 */
+ "mov %%g1, %0\n\t"
+ : "=r" (tmp_mcdper)
+ :
+ : "g1");
+ src->mm->context.mcdper = tmp_mcdper;
+ }
+ *dst = *src;
+ return 0;
+}
+
typedef struct {
union {
unsigned int pr_regs[32];
diff --git a/arch/sparc/kernel/sun4v_mcd.S b/arch/sparc/kernel/sun4v_mcd.S
new file mode 100644
index 0000000..a36e337
--- /dev/null
+++ b/arch/sparc/kernel/sun4v_mcd.S
@@ -0,0 +1,16 @@
+/* sun4v_mcd.S: Sun4v memory corruption detected precise exception handler
+ *
+ * Copyright (C) 2015 Bob Picco <bob.picco@xxxxxxxxxx>
+ * Copyright (C) 2015 Khalid Aziz <khalid.aziz@xxxxxxxxxx>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2.
+ */
+ .text
+ .align 32
+
+sun4v_mcd_detect_precise:
+ or %l4, %g0, %o1
+ or %l5, %g0, %o2
+ call sun4v_mem_corrupt_detect_precise
+ add %sp, PTREGS_OFF, %o0
+ ba,a,pt %xcc, rtrap
diff --git a/arch/sparc/kernel/traps_64.c b/arch/sparc/kernel/traps_64.c
index 4094a51..576937c 100644
--- a/arch/sparc/kernel/traps_64.c
+++ b/arch/sparc/kernel/traps_64.c
@@ -44,6 +44,7 @@
#include <asm/memctrl.h>
#include <asm/cacheflush.h>
#include <asm/setup.h>
+#include <asm/adi_64.h>

#include "entry.h"
#include "kernel.h"
@@ -351,12 +352,31 @@ 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 +1821,7 @@ 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 +2019,54 @@ 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 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 +2104,14 @@ 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 +2608,65 @@ void sun4v_do_mna(struct pt_regs *regs, unsigned long addr, unsigned long type_c
force_sig_info(SIGBUS, &info, current);
}

+/* sun4v_mem_corrupt_detect_precise() - Handle precise exception on an ADI
+ * tag mismatch.
+ *
+ * ADI version tag mismatch on a load from memory always results in a
+ * precise exception. Tag mismatch on a store to memory will result in
+ * precise exception if MCDPER or PMCDPER is set to 1.
+ */
+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) {
+ /* 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.
+ */
+ 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",
+ regs->tpc, entry->fixup);
+#endif
+ regs->tpc = entry->fixup;
+ regs->tnpc = regs->tpc + 4;
+ return;
+ }
+ 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();
diff --git a/arch/sparc/kernel/ttable_64.S b/arch/sparc/kernel/ttable_64.S
index c6dfdaa..2343bf0 100644
--- a/arch/sparc/kernel/ttable_64.S
+++ b/arch/sparc/kernel/ttable_64.S
@@ -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)
diff --git a/arch/sparc/mm/gup.c b/arch/sparc/mm/gup.c
index cd0e32b..579f7ae 100644
--- a/arch/sparc/mm/gup.c
+++ b/arch/sparc/mm/gup.c
@@ -11,6 +11,7 @@
#include <linux/pagemap.h>
#include <linux/rwsem.h>
#include <asm/pgtable.h>
+#include <asm/adi.h>

/*
* The performance critical leaf functions are made noinline otherwise gcc
@@ -157,6 +158,24 @@ int __get_user_pages_fast(unsigned long start, int nr_pages, int write,
pgd_t *pgdp;
int nr = 0;

+#ifdef CONFIG_SPARC64
+ if (adi_capable()) {
+ long addr = start;
+
+ /* If userspace has passed a versioned address, kernel
+ * will not find it in the VMAs since it does not store
+ * the version tags in the list of VMAs. Storing version
+ * tags in list of VMAs is impractical since they can be
+ * changed any time from userspace without dropping into
+ * kernel. Any address search in VMAs will be done with
+ * non-versioned addresses. Ensure the ADI version bits
+ * are dropped here by sign extending the last bit before
+ * ADI bits. IOMMU does not implement version tags.
+ */
+ addr = (addr << (long)adi_nbits()) >> (long)adi_nbits();
+ start = addr;
+ }
+#endif
start &= PAGE_MASK;
addr = start;
len = (unsigned long) nr_pages << PAGE_SHIFT;
@@ -187,6 +206,24 @@ int get_user_pages_fast(unsigned long start, int nr_pages, int write,
pgd_t *pgdp;
int nr = 0;

+#ifdef CONFIG_SPARC64
+ if (adi_capable()) {
+ long addr = start;
+
+ /* If userspace has passed a versioned address, kernel
+ * will not find it in the VMAs since it does not store
+ * the version tags in the list of VMAs. Storing version
+ * tags in list of VMAs is impractical since they can be
+ * changed any time from userspace without dropping into
+ * kernel. Any address search in VMAs will be done with
+ * non-versioned addresses. Ensure the ADI version bits
+ * are dropped here by sign extending the last bit before
+ * ADI bits. IOMMU does not implements version tags,
+ */
+ addr = (addr << (long)adi_nbits()) >> (long)adi_nbits();
+ start = addr;
+ }
+#endif
start &= PAGE_MASK;
addr = start;
len = (unsigned long) nr_pages << PAGE_SHIFT;
diff --git a/arch/sparc/mm/tlb.c b/arch/sparc/mm/tlb.c
index c56a195..557f2c38 100644
--- a/arch/sparc/mm/tlb.c
+++ b/arch/sparc/mm/tlb.c
@@ -15,6 +15,7 @@
#include <asm/cacheflush.h>
#include <asm/mmu_context.h>
#include <asm/tlb.h>
+#include <asm/asi.h>

/* Heavily inspired by the ppc64 code. */

@@ -142,6 +143,33 @@ void tlb_batch_add(struct mm_struct *mm, unsigned long vaddr,
tlb_batch_add_one(mm, vaddr, pte_exec(orig), huge);
}

+pte_t ptep_clear_flush(struct vm_area_struct *vma, unsigned long address,
+ pte_t *ptep)
+{
+ struct mm_struct *mm = (vma)->vm_mm;
+ pte_t pte;
+
+ pte = *ptep;
+ /* If we are getting ready to swap out a page with ADI enabled
+ * and version tags set, save the version tags so we can restore
+ * them when page is swapped back in.
+ */
+ if (pte_val(pte) & _PAGE_MCD_4V) {
+ unsigned long version, paddr;
+
+ paddr = pte_val(pte) & _PAGE_PADDR_4V;
+ asm volatile(
+ "ldxa [%1] %2, %0\n\t"
+ : "=r" (version)
+ : "r" (paddr), "i" (ASI_MCD_REAL));
+ }
+
+ pte = ptep_get_and_clear(mm, address, ptep);
+ if (pte_accessible(mm, pte))
+ flush_tlb_page(vma, address);
+ return pte;
+}
+
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
static void tlb_batch_pmd_scan(struct mm_struct *mm, unsigned long vaddr,
pmd_t pmd)
diff --git a/arch/x86/kernel/signal_compat.c b/arch/x86/kernel/signal_compat.c
index ec1f756..d1e860c 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/asm-generic/pgtable.h b/include/asm-generic/pgtable.h
index c4f8fd2..5043e5a 100644
--- a/include/asm-generic/pgtable.h
+++ b/include/asm-generic/pgtable.h
@@ -294,6 +294,11 @@ static inline int pmd_same(pmd_t pmd_a, pmd_t pmd_b)
# define pte_accessible(mm, pte) ((void)(pte), 1)
#endif

+#ifndef set_swp_pte_at
+#define set_swp_pte_at(mm, addr, ptep, pte, oldpte) \
+ set_pte_at(mm, addr, ptep, pte)
+#endif
+
#ifndef flush_tlb_fix_spurious_fault
#define flush_tlb_fix_spurious_fault(vma, address) flush_tlb_page(vma, address)
#endif
diff --git a/include/linux/mm.h b/include/linux/mm.h
index a92c8d7..5c894a5 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -225,6 +225,8 @@ 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
diff --git a/include/uapi/asm-generic/siginfo.h b/include/uapi/asm-generic/siginfo.h
index 1abaf62..2446864 100644
--- a/include/uapi/asm-generic/siginfo.h
+++ b/include/uapi/asm-generic/siginfo.h
@@ -213,7 +213,10 @@ 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
diff --git a/mm/memory.c b/mm/memory.c
index e18c57b..1cc3b55 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -2642,7 +2642,7 @@ int do_swap_page(struct fault_env *fe, pte_t orig_pte)
flush_icache_page(vma, page);
if (pte_swp_soft_dirty(orig_pte))
pte = pte_mksoft_dirty(pte);
- set_pte_at(vma->vm_mm, fe->address, fe->pte, pte);
+ set_swp_pte_at(vma->vm_mm, fe->address, fe->pte, pte, orig_pte);
if (page == swapcache) {
do_page_add_anon_rmap(page, vma, fe->address, exclusive);
mem_cgroup_commit_charge(page, memcg, true, false);
diff --git a/mm/rmap.c b/mm/rmap.c
index 1ef3640..d58cb94 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -1539,7 +1539,7 @@ static int try_to_unmap_one(struct page *page, struct vm_area_struct *vma,
swp_pte = swp_entry_to_pte(entry);
if (pte_soft_dirty(pteval))
swp_pte = pte_swp_mksoft_dirty(swp_pte);
- set_pte_at(mm, address, pte, swp_pte);
+ set_swp_pte_at(mm, address, pte, swp_pte, pteval);
} else if (PageAnon(page)) {
swp_entry_t entry = { .val = page_private(page) };
pte_t swp_pte;
@@ -1572,7 +1572,7 @@ static int try_to_unmap_one(struct page *page, struct vm_area_struct *vma,
swp_pte = swp_entry_to_pte(entry);
if (pte_soft_dirty(pteval))
swp_pte = pte_swp_mksoft_dirty(swp_pte);
- set_pte_at(mm, address, pte, swp_pte);
+ set_swp_pte_at(mm, address, pte, swp_pte, pteval);
} else
dec_mm_counter(mm, mm_counter_file(page));

--
2.7.4