--- /dev/null
+From 047e6575aec71d75b765c22111820c4776cd1c43 Mon Sep 17 00:00:00 2001
+From: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>
+Date: Tue, 24 Sep 2019 09:22:53 +0530
+Subject: powerpc/mm: Fixup tlbie vs mtpidr/mtlpidr ordering issue on POWER9
+
+From: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
+
+commit 047e6575aec71d75b765c22111820c4776cd1c43 upstream.
+
+On POWER9, under some circumstances, a broadcast TLB invalidation will
+fail to invalidate the ERAT cache on some threads when there are
+parallel mtpidr/mtlpidr happening on other threads of the same core.
+This can cause stores to continue to go to a page after it's unmapped.
+
+The workaround is to force an ERAT flush using PID=0 or LPID=0 tlbie
+flush. This additional TLB flush will cause the ERAT cache
+invalidation. Since we are using PID=0 or LPID=0, we don't get
+filtered out by the TLB snoop filtering logic.
+
+We need to still follow this up with another tlbie to take care of
+store vs tlbie ordering issue explained in commit:
+a5d4b5891c2f ("powerpc/mm: Fixup tlbie vs store ordering issue on
+POWER9"). The presence of ERAT cache implies we can still get new
+stores and they may miss store queue marking flush.
+
+Cc: stable@vger.kernel.org
+Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
+Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
+Link: https://lore.kernel.org/r/20190924035254.24612-3-aneesh.kumar@linux.ibm.com
+[sandipan: Backported to v4.19]
+Signed-off-by: Sandipan Das <sandipan@linux.ibm.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ arch/powerpc/include/asm/cputable.h | 3 -
+ arch/powerpc/kernel/dt_cpu_ftrs.c | 2
+ arch/powerpc/kvm/book3s_hv_rm_mmu.c | 42 ++++++++++++++----
+ arch/powerpc/mm/hash_native_64.c | 29 +++++++++++--
+ arch/powerpc/mm/tlb-radix.c | 80 ++++++++++++++++++++++++++++++++----
+ 5 files changed, 134 insertions(+), 22 deletions(-)
+
+--- a/arch/powerpc/include/asm/cputable.h
++++ b/arch/powerpc/include/asm/cputable.h
+@@ -214,6 +214,7 @@ static inline void cpu_feature_keys_init
+ #define CPU_FTR_P9_TM_XER_SO_BUG LONG_ASM_CONST(0x0000200000000000)
+ #define CPU_FTR_P9_TLBIE_STQ_BUG LONG_ASM_CONST(0x0000400000000000)
+ #define CPU_FTR_P9_TIDR LONG_ASM_CONST(0x0000800000000000)
++#define CPU_FTR_P9_TLBIE_ERAT_BUG LONG_ASM_CONST(0x0001000000000000)
+
+ #ifndef __ASSEMBLY__
+
+@@ -460,7 +461,7 @@ static inline void cpu_feature_keys_init
+ CPU_FTR_CFAR | CPU_FTR_HVMODE | CPU_FTR_VMX_COPY | \
+ CPU_FTR_DBELL | CPU_FTR_HAS_PPR | CPU_FTR_ARCH_207S | \
+ CPU_FTR_TM_COMP | CPU_FTR_ARCH_300 | CPU_FTR_PKEY | \
+- CPU_FTR_P9_TLBIE_STQ_BUG | CPU_FTR_P9_TIDR)
++ CPU_FTR_P9_TLBIE_STQ_BUG | CPU_FTR_P9_TLBIE_ERAT_BUG | CPU_FTR_P9_TIDR)
+ #define CPU_FTRS_POWER9_DD2_0 CPU_FTRS_POWER9
+ #define CPU_FTRS_POWER9_DD2_1 (CPU_FTRS_POWER9 | CPU_FTR_POWER9_DD2_1)
+ #define CPU_FTRS_POWER9_DD2_2 (CPU_FTRS_POWER9 | CPU_FTR_POWER9_DD2_1 | \
+--- a/arch/powerpc/kernel/dt_cpu_ftrs.c
++++ b/arch/powerpc/kernel/dt_cpu_ftrs.c
+@@ -717,6 +717,8 @@ static __init void update_tlbie_feature_
+ WARN_ONCE(1, "Unknown PVR");
+ cur_cpu_spec->cpu_features |= CPU_FTR_P9_TLBIE_STQ_BUG;
+ }
++
++ cur_cpu_spec->cpu_features |= CPU_FTR_P9_TLBIE_ERAT_BUG;
+ }
+ }
+
+--- a/arch/powerpc/kvm/book3s_hv_rm_mmu.c
++++ b/arch/powerpc/kvm/book3s_hv_rm_mmu.c
+@@ -434,6 +434,37 @@ static inline int is_mmio_hpte(unsigned
+ (HPTE_R_KEY_HI | HPTE_R_KEY_LO));
+ }
+
++static inline void fixup_tlbie_lpid(unsigned long rb_value, unsigned long lpid)
++{
++
++ if (cpu_has_feature(CPU_FTR_P9_TLBIE_ERAT_BUG)) {
++ /* Radix flush for a hash guest */
++
++ unsigned long rb,rs,prs,r,ric;
++
++ rb = PPC_BIT(52); /* IS = 2 */
++ rs = 0; /* lpid = 0 */
++ prs = 0; /* partition scoped */
++ r = 1; /* radix format */
++ ric = 0; /* RIC_FLSUH_TLB */
++
++ /*
++ * Need the extra ptesync to make sure we don't
++ * re-order the tlbie
++ */
++ asm volatile("ptesync": : :"memory");
++ asm volatile(PPC_TLBIE_5(%0, %4, %3, %2, %1)
++ : : "r"(rb), "i"(r), "i"(prs),
++ "i"(ric), "r"(rs) : "memory");
++ }
++
++ if (cpu_has_feature(CPU_FTR_P9_TLBIE_STQ_BUG)) {
++ asm volatile("ptesync": : :"memory");
++ asm volatile(PPC_TLBIE_5(%0,%1,0,0,0) : :
++ "r" (rb_value), "r" (lpid));
++ }
++}
++
+ static void do_tlbies(struct kvm *kvm, unsigned long *rbvalues,
+ long npages, int global, bool need_sync)
+ {
+@@ -452,16 +483,7 @@ static void do_tlbies(struct kvm *kvm, u
+ "r" (rbvalues[i]), "r" (kvm->arch.lpid));
+ }
+
+- if (cpu_has_feature(CPU_FTR_P9_TLBIE_STQ_BUG)) {
+- /*
+- * Need the extra ptesync to make sure we don't
+- * re-order the tlbie
+- */
+- asm volatile("ptesync": : :"memory");
+- asm volatile(PPC_TLBIE_5(%0,%1,0,0,0) : :
+- "r" (rbvalues[0]), "r" (kvm->arch.lpid));
+- }
+-
++ fixup_tlbie_lpid(rbvalues[i - 1], kvm->arch.lpid);
+ asm volatile("eieio; tlbsync; ptesync" : : : "memory");
+ } else {
+ if (need_sync)
+--- a/arch/powerpc/mm/hash_native_64.c
++++ b/arch/powerpc/mm/hash_native_64.c
+@@ -201,8 +201,31 @@ static inline unsigned long ___tlbie(un
+ return va;
+ }
+
+-static inline void fixup_tlbie(unsigned long vpn, int psize, int apsize, int ssize)
++static inline void fixup_tlbie_vpn(unsigned long vpn, int psize,
++ int apsize, int ssize)
+ {
++ if (cpu_has_feature(CPU_FTR_P9_TLBIE_ERAT_BUG)) {
++ /* Radix flush for a hash guest */
++
++ unsigned long rb,rs,prs,r,ric;
++
++ rb = PPC_BIT(52); /* IS = 2 */
++ rs = 0; /* lpid = 0 */
++ prs = 0; /* partition scoped */
++ r = 1; /* radix format */
++ ric = 0; /* RIC_FLSUH_TLB */
++
++ /*
++ * Need the extra ptesync to make sure we don't
++ * re-order the tlbie
++ */
++ asm volatile("ptesync": : :"memory");
++ asm volatile(PPC_TLBIE_5(%0, %4, %3, %2, %1)
++ : : "r"(rb), "i"(r), "i"(prs),
++ "i"(ric), "r"(rs) : "memory");
++ }
++
++
+ if (cpu_has_feature(CPU_FTR_P9_TLBIE_STQ_BUG)) {
+ /* Need the extra ptesync to ensure we don't reorder tlbie*/
+ asm volatile("ptesync": : :"memory");
+@@ -287,7 +310,7 @@ static inline void tlbie(unsigned long v
+ asm volatile("ptesync": : :"memory");
+ } else {
+ __tlbie(vpn, psize, apsize, ssize);
+- fixup_tlbie(vpn, psize, apsize, ssize);
++ fixup_tlbie_vpn(vpn, psize, apsize, ssize);
+ asm volatile("eieio; tlbsync; ptesync": : :"memory");
+ }
+ if (lock_tlbie && !use_local)
+@@ -860,7 +883,7 @@ static void native_flush_hash_range(unsi
+ /*
+ * Just do one more with the last used values.
+ */
+- fixup_tlbie(vpn, psize, psize, ssize);
++ fixup_tlbie_vpn(vpn, psize, psize, ssize);
+ asm volatile("eieio; tlbsync; ptesync":::"memory");
+
+ if (lock_tlbie)
+--- a/arch/powerpc/mm/tlb-radix.c
++++ b/arch/powerpc/mm/tlb-radix.c
+@@ -215,21 +215,82 @@ static inline void __tlbie_lpid_va(unsig
+ trace_tlbie(lpid, 0, rb, rs, ric, prs, r);
+ }
+
+-static inline void fixup_tlbie(void)
++
++static inline void fixup_tlbie_va(unsigned long va, unsigned long pid,
++ unsigned long ap)
+ {
+- unsigned long pid = 0;
++ if (cpu_has_feature(CPU_FTR_P9_TLBIE_ERAT_BUG)) {
++ asm volatile("ptesync": : :"memory");
++ __tlbie_va(va, 0, ap, RIC_FLUSH_TLB);
++ }
++
++ if (cpu_has_feature(CPU_FTR_P9_TLBIE_STQ_BUG)) {
++ asm volatile("ptesync": : :"memory");
++ __tlbie_va(va, pid, ap, RIC_FLUSH_TLB);
++ }
++}
++
++static inline void fixup_tlbie_va_range(unsigned long va, unsigned long pid,
++ unsigned long ap)
++{
++ if (cpu_has_feature(CPU_FTR_P9_TLBIE_ERAT_BUG)) {
++ asm volatile("ptesync": : :"memory");
++ __tlbie_pid(0, RIC_FLUSH_TLB);
++ }
++
++ if (cpu_has_feature(CPU_FTR_P9_TLBIE_STQ_BUG)) {
++ asm volatile("ptesync": : :"memory");
++ __tlbie_va(va, pid, ap, RIC_FLUSH_TLB);
++ }
++}
++
++static inline void fixup_tlbie_pid(unsigned long pid)
++{
++ /*
++ * We can use any address for the invalidation, pick one which is
++ * probably unused as an optimisation.
++ */
+ unsigned long va = ((1UL << 52) - 1);
+
++ if (cpu_has_feature(CPU_FTR_P9_TLBIE_ERAT_BUG)) {
++ asm volatile("ptesync": : :"memory");
++ __tlbie_pid(0, RIC_FLUSH_TLB);
++ }
++
+ if (cpu_has_feature(CPU_FTR_P9_TLBIE_STQ_BUG)) {
+ asm volatile("ptesync": : :"memory");
+ __tlbie_va(va, pid, mmu_get_ap(MMU_PAGE_64K), RIC_FLUSH_TLB);
+ }
+ }
+
++
++static inline void fixup_tlbie_lpid_va(unsigned long va, unsigned long lpid,
++ unsigned long ap)
++{
++ if (cpu_has_feature(CPU_FTR_P9_TLBIE_ERAT_BUG)) {
++ asm volatile("ptesync": : :"memory");
++ __tlbie_lpid_va(va, 0, ap, RIC_FLUSH_TLB);
++ }
++
++ if (cpu_has_feature(CPU_FTR_P9_TLBIE_STQ_BUG)) {
++ asm volatile("ptesync": : :"memory");
++ __tlbie_lpid_va(va, lpid, ap, RIC_FLUSH_TLB);
++ }
++}
++
+ static inline void fixup_tlbie_lpid(unsigned long lpid)
+ {
++ /*
++ * We can use any address for the invalidation, pick one which is
++ * probably unused as an optimisation.
++ */
+ unsigned long va = ((1UL << 52) - 1);
+
++ if (cpu_has_feature(CPU_FTR_P9_TLBIE_ERAT_BUG)) {
++ asm volatile("ptesync": : :"memory");
++ __tlbie_lpid(0, RIC_FLUSH_TLB);
++ }
++
+ if (cpu_has_feature(CPU_FTR_P9_TLBIE_STQ_BUG)) {
+ asm volatile("ptesync": : :"memory");
+ __tlbie_lpid_va(va, lpid, mmu_get_ap(MMU_PAGE_64K), RIC_FLUSH_TLB);
+@@ -277,6 +338,7 @@ static inline void _tlbie_pid(unsigned l
+ switch (ric) {
+ case RIC_FLUSH_TLB:
+ __tlbie_pid(pid, RIC_FLUSH_TLB);
++ fixup_tlbie_pid(pid);
+ break;
+ case RIC_FLUSH_PWC:
+ __tlbie_pid(pid, RIC_FLUSH_PWC);
+@@ -284,8 +346,8 @@ static inline void _tlbie_pid(unsigned l
+ case RIC_FLUSH_ALL:
+ default:
+ __tlbie_pid(pid, RIC_FLUSH_ALL);
++ fixup_tlbie_pid(pid);
+ }
+- fixup_tlbie();
+ asm volatile("eieio; tlbsync; ptesync": : :"memory");
+ }
+
+@@ -329,6 +391,7 @@ static inline void _tlbie_lpid(unsigned
+ switch (ric) {
+ case RIC_FLUSH_TLB:
+ __tlbie_lpid(lpid, RIC_FLUSH_TLB);
++ fixup_tlbie_lpid(lpid);
+ break;
+ case RIC_FLUSH_PWC:
+ __tlbie_lpid(lpid, RIC_FLUSH_PWC);
+@@ -336,8 +399,8 @@ static inline void _tlbie_lpid(unsigned
+ case RIC_FLUSH_ALL:
+ default:
+ __tlbie_lpid(lpid, RIC_FLUSH_ALL);
++ fixup_tlbie_lpid(lpid);
+ }
+- fixup_tlbie_lpid(lpid);
+ asm volatile("eieio; tlbsync; ptesync": : :"memory");
+ }
+
+@@ -410,6 +473,8 @@ static inline void __tlbie_va_range(unsi
+
+ for (addr = start; addr < end; addr += page_size)
+ __tlbie_va(addr, pid, ap, RIC_FLUSH_TLB);
++
++ fixup_tlbie_va_range(addr - page_size, pid, ap);
+ }
+
+ static inline void _tlbie_va(unsigned long va, unsigned long pid,
+@@ -419,7 +484,7 @@ static inline void _tlbie_va(unsigned lo
+
+ asm volatile("ptesync": : :"memory");
+ __tlbie_va(va, pid, ap, ric);
+- fixup_tlbie();
++ fixup_tlbie_va(va, pid, ap);
+ asm volatile("eieio; tlbsync; ptesync": : :"memory");
+ }
+
+@@ -430,7 +495,7 @@ static inline void _tlbie_lpid_va(unsign
+
+ asm volatile("ptesync": : :"memory");
+ __tlbie_lpid_va(va, lpid, ap, ric);
+- fixup_tlbie_lpid(lpid);
++ fixup_tlbie_lpid_va(va, lpid, ap);
+ asm volatile("eieio; tlbsync; ptesync": : :"memory");
+ }
+
+@@ -442,7 +507,6 @@ static inline void _tlbie_va_range(unsig
+ if (also_pwc)
+ __tlbie_pid(pid, RIC_FLUSH_PWC);
+ __tlbie_va_range(start, end, pid, page_size, psize);
+- fixup_tlbie();
+ asm volatile("eieio; tlbsync; ptesync": : :"memory");
+ }
+
+@@ -773,7 +837,7 @@ is_local:
+ if (gflush)
+ __tlbie_va_range(gstart, gend, pid,
+ PUD_SIZE, MMU_PAGE_1G);
+- fixup_tlbie();
++
+ asm volatile("eieio; tlbsync; ptesync": : :"memory");
+ }
+ }
--- /dev/null
+From 93cad5f789951eaa27c3392b15294b4e51253944 Mon Sep 17 00:00:00 2001
+From: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>
+Date: Tue, 24 Sep 2019 09:22:54 +0530
+Subject: selftests/powerpc: Add test case for tlbie vs mtpidr ordering issue
+
+From: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
+
+commit 93cad5f789951eaa27c3392b15294b4e51253944 upstream.
+
+Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
+[mpe: Some minor fixes to make it build]
+Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
+Link: https://lore.kernel.org/r/20190924035254.24612-4-aneesh.kumar@linux.ibm.com
+[sandipan: Backported to v4.19]
+Signed-off-by: Sandipan Das <sandipan@linux.ibm.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ tools/testing/selftests/powerpc/mm/Makefile | 2
+ tools/testing/selftests/powerpc/mm/tlbie_test.c | 734 ++++++++++++++++++++++++
+ 2 files changed, 736 insertions(+)
+
+--- a/tools/testing/selftests/powerpc/mm/Makefile
++++ b/tools/testing/selftests/powerpc/mm/Makefile
+@@ -3,6 +3,7 @@ noarg:
+ $(MAKE) -C ../
+
+ TEST_GEN_PROGS := hugetlb_vs_thp_test subpage_prot prot_sao segv_errors
++TEST_GEN_PROGS_EXTENDED := tlbie_test
+ TEST_GEN_FILES := tempfile
+
+ top_srcdir = ../../../../..
+@@ -15,3 +16,4 @@ $(OUTPUT)/prot_sao: ../utils.c
+ $(OUTPUT)/tempfile:
+ dd if=/dev/zero of=$@ bs=64k count=1
+
++$(OUTPUT)/tlbie_test: LDLIBS += -lpthread
+--- /dev/null
++++ b/tools/testing/selftests/powerpc/mm/tlbie_test.c
+@@ -0,0 +1,734 @@
++// SPDX-License-Identifier: GPL-2.0
++
++/*
++ * Copyright 2019, Nick Piggin, Gautham R. Shenoy, Aneesh Kumar K.V, IBM Corp.
++ */
++
++/*
++ *
++ * Test tlbie/mtpidr race. We have 4 threads doing flush/load/compare/store
++ * sequence in a loop. The same threads also rung a context switch task
++ * that does sched_yield() in loop.
++ *
++ * The snapshot thread mark the mmap area PROT_READ in between, make a copy
++ * and copy it back to the original area. This helps us to detect if any
++ * store continued to happen after we marked the memory PROT_READ.
++ */
++
++#define _GNU_SOURCE
++#include <stdio.h>
++#include <sys/mman.h>
++#include <sys/types.h>
++#include <sys/wait.h>
++#include <sys/ipc.h>
++#include <sys/shm.h>
++#include <sys/stat.h>
++#include <sys/time.h>
++#include <linux/futex.h>
++#include <unistd.h>
++#include <asm/unistd.h>
++#include <string.h>
++#include <stdlib.h>
++#include <fcntl.h>
++#include <sched.h>
++#include <time.h>
++#include <stdarg.h>
++#include <sched.h>
++#include <pthread.h>
++#include <signal.h>
++#include <sys/prctl.h>
++
++static inline void dcbf(volatile unsigned int *addr)
++{
++ __asm__ __volatile__ ("dcbf %y0; sync" : : "Z"(*(unsigned char *)addr) : "memory");
++}
++
++static void err_msg(char *msg)
++{
++
++ time_t now;
++ time(&now);
++ printf("=================================\n");
++ printf(" Error: %s\n", msg);
++ printf(" %s", ctime(&now));
++ printf("=================================\n");
++ exit(1);
++}
++
++static char *map1;
++static char *map2;
++static pid_t rim_process_pid;
++
++/*
++ * A "rim-sequence" is defined to be the sequence of the following
++ * operations performed on a memory word:
++ * 1) FLUSH the contents of that word.
++ * 2) LOAD the contents of that word.
++ * 3) COMPARE the contents of that word with the content that was
++ * previously stored at that word
++ * 4) STORE new content into that word.
++ *
++ * The threads in this test that perform the rim-sequence are termed
++ * as rim_threads.
++ */
++
++/*
++ * A "corruption" is defined to be the failed COMPARE operation in a
++ * rim-sequence.
++ *
++ * A rim_thread that detects a corruption informs about it to all the
++ * other rim_threads, and the mem_snapshot thread.
++ */
++static volatile unsigned int corruption_found;
++
++/*
++ * This defines the maximum number of rim_threads in this test.
++ *
++ * The THREAD_ID_BITS denote the number of bits required
++ * to represent the thread_ids [0..MAX_THREADS - 1].
++ * We are being a bit paranoid here and set it to 8 bits,
++ * though 6 bits suffice.
++ *
++ */
++#define MAX_THREADS 64
++#define THREAD_ID_BITS 8
++#define THREAD_ID_MASK ((1 << THREAD_ID_BITS) - 1)
++static unsigned int rim_thread_ids[MAX_THREADS];
++static pthread_t rim_threads[MAX_THREADS];
++
++
++/*
++ * Each rim_thread works on an exclusive "chunk" of size
++ * RIM_CHUNK_SIZE.
++ *
++ * The ith rim_thread works on the ith chunk.
++ *
++ * The ith chunk begins at
++ * map1 + (i * RIM_CHUNK_SIZE)
++ */
++#define RIM_CHUNK_SIZE 1024
++#define BITS_PER_BYTE 8
++#define WORD_SIZE (sizeof(unsigned int))
++#define WORD_BITS (WORD_SIZE * BITS_PER_BYTE)
++#define WORDS_PER_CHUNK (RIM_CHUNK_SIZE/WORD_SIZE)
++
++static inline char *compute_chunk_start_addr(unsigned int thread_id)
++{
++ char *chunk_start;
++
++ chunk_start = (char *)((unsigned long)map1 +
++ (thread_id * RIM_CHUNK_SIZE));
++
++ return chunk_start;
++}
++
++/*
++ * The "word-offset" of a word-aligned address inside a chunk, is
++ * defined to be the number of words that precede the address in that
++ * chunk.
++ *
++ * WORD_OFFSET_BITS denote the number of bits required to represent
++ * the word-offsets of all the word-aligned addresses of a chunk.
++ */
++#define WORD_OFFSET_BITS (__builtin_ctz(WORDS_PER_CHUNK))
++#define WORD_OFFSET_MASK ((1 << WORD_OFFSET_BITS) - 1)
++
++static inline unsigned int compute_word_offset(char *start, unsigned int *addr)
++{
++ unsigned int delta_bytes, ret;
++ delta_bytes = (unsigned long)addr - (unsigned long)start;
++
++ ret = delta_bytes/WORD_SIZE;
++
++ return ret;
++}
++
++/*
++ * A "sweep" is defined to be the sequential execution of the
++ * rim-sequence by a rim_thread on its chunk one word at a time,
++ * starting from the first word of its chunk and ending with the last
++ * word of its chunk.
++ *
++ * Each sweep of a rim_thread is uniquely identified by a sweep_id.
++ * SWEEP_ID_BITS denote the number of bits required to represent
++ * the sweep_ids of rim_threads.
++ *
++ * As to why SWEEP_ID_BITS are computed as a function of THREAD_ID_BITS,
++ * WORD_OFFSET_BITS, and WORD_BITS, see the "store-pattern" below.
++ */
++#define SWEEP_ID_BITS (WORD_BITS - (THREAD_ID_BITS + WORD_OFFSET_BITS))
++#define SWEEP_ID_MASK ((1 << SWEEP_ID_BITS) - 1)
++
++/*
++ * A "store-pattern" is the word-pattern that is stored into a word
++ * location in the 4)STORE step of the rim-sequence.
++ *
++ * In the store-pattern, we shall encode:
++ *
++ * - The thread-id of the rim_thread performing the store
++ * (The most significant THREAD_ID_BITS)
++ *
++ * - The word-offset of the address into which the store is being
++ * performed (The next WORD_OFFSET_BITS)
++ *
++ * - The sweep_id of the current sweep in which the store is
++ * being performed. (The lower SWEEP_ID_BITS)
++ *
++ * Store Pattern: 32 bits
++ * |------------------|--------------------|---------------------------------|
++ * | Thread id | Word offset | sweep_id |
++ * |------------------|--------------------|---------------------------------|
++ * THREAD_ID_BITS WORD_OFFSET_BITS SWEEP_ID_BITS
++ *
++ * In the store pattern, the (Thread-id + Word-offset) uniquely identify the
++ * address to which the store is being performed i.e,
++ * address == map1 +
++ * (Thread-id * RIM_CHUNK_SIZE) + (Word-offset * WORD_SIZE)
++ *
++ * And the sweep_id in the store pattern identifies the time when the
++ * store was performed by the rim_thread.
++ *
++ * We shall use this property in the 3)COMPARE step of the
++ * rim-sequence.
++ */
++#define SWEEP_ID_SHIFT 0
++#define WORD_OFFSET_SHIFT (SWEEP_ID_BITS)
++#define THREAD_ID_SHIFT (WORD_OFFSET_BITS + SWEEP_ID_BITS)
++
++/*
++ * Compute the store pattern for a given thread with id @tid, at
++ * location @addr in the sweep identified by @sweep_id
++ */
++static inline unsigned int compute_store_pattern(unsigned int tid,
++ unsigned int *addr,
++ unsigned int sweep_id)
++{
++ unsigned int ret = 0;
++ char *start = compute_chunk_start_addr(tid);
++ unsigned int word_offset = compute_word_offset(start, addr);
++
++ ret += (tid & THREAD_ID_MASK) << THREAD_ID_SHIFT;
++ ret += (word_offset & WORD_OFFSET_MASK) << WORD_OFFSET_SHIFT;
++ ret += (sweep_id & SWEEP_ID_MASK) << SWEEP_ID_SHIFT;
++ return ret;
++}
++
++/* Extract the thread-id from the given store-pattern */
++static inline unsigned int extract_tid(unsigned int pattern)
++{
++ unsigned int ret;
++
++ ret = (pattern >> THREAD_ID_SHIFT) & THREAD_ID_MASK;
++ return ret;
++}
++
++/* Extract the word-offset from the given store-pattern */
++static inline unsigned int extract_word_offset(unsigned int pattern)
++{
++ unsigned int ret;
++
++ ret = (pattern >> WORD_OFFSET_SHIFT) & WORD_OFFSET_MASK;
++
++ return ret;
++}
++
++/* Extract the sweep-id from the given store-pattern */
++static inline unsigned int extract_sweep_id(unsigned int pattern)
++
++{
++ unsigned int ret;
++
++ ret = (pattern >> SWEEP_ID_SHIFT) & SWEEP_ID_MASK;
++
++ return ret;
++}
++
++/************************************************************
++ * *
++ * Logging the output of the verification *
++ * *
++ ************************************************************/
++#define LOGDIR_NAME_SIZE 100
++static char logdir[LOGDIR_NAME_SIZE];
++
++static FILE *fp[MAX_THREADS];
++static const char logfilename[] ="Thread-%02d-Chunk";
++
++static inline void start_verification_log(unsigned int tid,
++ unsigned int *addr,
++ unsigned int cur_sweep_id,
++ unsigned int prev_sweep_id)
++{
++ FILE *f;
++ char logfile[30];
++ char path[LOGDIR_NAME_SIZE + 30];
++ char separator[2] = "/";
++ char *chunk_start = compute_chunk_start_addr(tid);
++ unsigned int size = RIM_CHUNK_SIZE;
++
++ sprintf(logfile, logfilename, tid);
++ strcpy(path, logdir);
++ strcat(path, separator);
++ strcat(path, logfile);
++ f = fopen(path, "w");
++
++ if (!f) {
++ err_msg("Unable to create logfile\n");
++ }
++
++ fp[tid] = f;
++
++ fprintf(f, "----------------------------------------------------------\n");
++ fprintf(f, "PID = %d\n", rim_process_pid);
++ fprintf(f, "Thread id = %02d\n", tid);
++ fprintf(f, "Chunk Start Addr = 0x%016lx\n", (unsigned long)chunk_start);
++ fprintf(f, "Chunk Size = %d\n", size);
++ fprintf(f, "Next Store Addr = 0x%016lx\n", (unsigned long)addr);
++ fprintf(f, "Current sweep-id = 0x%08x\n", cur_sweep_id);
++ fprintf(f, "Previous sweep-id = 0x%08x\n", prev_sweep_id);
++ fprintf(f, "----------------------------------------------------------\n");
++}
++
++static inline void log_anamoly(unsigned int tid, unsigned int *addr,
++ unsigned int expected, unsigned int observed)
++{
++ FILE *f = fp[tid];
++
++ fprintf(f, "Thread %02d: Addr 0x%lx: Expected 0x%x, Observed 0x%x\n",
++ tid, (unsigned long)addr, expected, observed);
++ fprintf(f, "Thread %02d: Expected Thread id = %02d\n", tid, extract_tid(expected));
++ fprintf(f, "Thread %02d: Observed Thread id = %02d\n", tid, extract_tid(observed));
++ fprintf(f, "Thread %02d: Expected Word offset = %03d\n", tid, extract_word_offset(expected));
++ fprintf(f, "Thread %02d: Observed Word offset = %03d\n", tid, extract_word_offset(observed));
++ fprintf(f, "Thread %02d: Expected sweep-id = 0x%x\n", tid, extract_sweep_id(expected));
++ fprintf(f, "Thread %02d: Observed sweep-id = 0x%x\n", tid, extract_sweep_id(observed));
++ fprintf(f, "----------------------------------------------------------\n");
++}
++
++static inline void end_verification_log(unsigned int tid, unsigned nr_anamolies)
++{
++ FILE *f = fp[tid];
++ char logfile[30];
++ char path[LOGDIR_NAME_SIZE + 30];
++ char separator[] = "/";
++
++ fclose(f);
++
++ if (nr_anamolies == 0) {
++ remove(path);
++ return;
++ }
++
++ sprintf(logfile, logfilename, tid);
++ strcpy(path, logdir);
++ strcat(path, separator);
++ strcat(path, logfile);
++
++ printf("Thread %02d chunk has %d corrupted words. For details check %s\n",
++ tid, nr_anamolies, path);
++}
++
++/*
++ * When a COMPARE step of a rim-sequence fails, the rim_thread informs
++ * everyone else via the shared_memory pointed to by
++ * corruption_found variable. On seeing this, every thread verifies the
++ * content of its chunk as follows.
++ *
++ * Suppose a thread identified with @tid was about to store (but not
++ * yet stored) to @next_store_addr in its current sweep identified
++ * @cur_sweep_id. Let @prev_sweep_id indicate the previous sweep_id.
++ *
++ * This implies that for all the addresses @addr < @next_store_addr,
++ * Thread @tid has already performed a store as part of its current
++ * sweep. Hence we expect the content of such @addr to be:
++ * |-------------------------------------------------|
++ * | tid | word_offset(addr) | cur_sweep_id |
++ * |-------------------------------------------------|
++ *
++ * Since Thread @tid is yet to perform stores on address
++ * @next_store_addr and above, we expect the content of such an
++ * address @addr to be:
++ * |-------------------------------------------------|
++ * | tid | word_offset(addr) | prev_sweep_id |
++ * |-------------------------------------------------|
++ *
++ * The verifier function @verify_chunk does this verification and logs
++ * any anamolies that it finds.
++ */
++static void verify_chunk(unsigned int tid, unsigned int *next_store_addr,
++ unsigned int cur_sweep_id,
++ unsigned int prev_sweep_id)
++{
++ unsigned int *iter_ptr;
++ unsigned int size = RIM_CHUNK_SIZE;
++ unsigned int expected;
++ unsigned int observed;
++ char *chunk_start = compute_chunk_start_addr(tid);
++
++ int nr_anamolies = 0;
++
++ start_verification_log(tid, next_store_addr,
++ cur_sweep_id, prev_sweep_id);
++
++ for (iter_ptr = (unsigned int *)chunk_start;
++ (unsigned long)iter_ptr < (unsigned long)chunk_start + size;
++ iter_ptr++) {
++ unsigned int expected_sweep_id;
++
++ if (iter_ptr < next_store_addr) {
++ expected_sweep_id = cur_sweep_id;
++ } else {
++ expected_sweep_id = prev_sweep_id;
++ }
++
++ expected = compute_store_pattern(tid, iter_ptr, expected_sweep_id);
++
++ dcbf((volatile unsigned int*)iter_ptr); //Flush before reading
++ observed = *iter_ptr;
++
++ if (observed != expected) {
++ nr_anamolies++;
++ log_anamoly(tid, iter_ptr, expected, observed);
++ }
++ }
++
++ end_verification_log(tid, nr_anamolies);
++}
++
++static void set_pthread_cpu(pthread_t th, int cpu)
++{
++ cpu_set_t run_cpu_mask;
++ struct sched_param param;
++
++ CPU_ZERO(&run_cpu_mask);
++ CPU_SET(cpu, &run_cpu_mask);
++ pthread_setaffinity_np(th, sizeof(cpu_set_t), &run_cpu_mask);
++
++ param.sched_priority = 1;
++ if (0 && sched_setscheduler(0, SCHED_FIFO, ¶m) == -1) {
++ /* haven't reproduced with this setting, it kills random preemption which may be a factor */
++ fprintf(stderr, "could not set SCHED_FIFO, run as root?\n");
++ }
++}
++
++static void set_mycpu(int cpu)
++{
++ cpu_set_t run_cpu_mask;
++ struct sched_param param;
++
++ CPU_ZERO(&run_cpu_mask);
++ CPU_SET(cpu, &run_cpu_mask);
++ sched_setaffinity(0, sizeof(cpu_set_t), &run_cpu_mask);
++
++ param.sched_priority = 1;
++ if (0 && sched_setscheduler(0, SCHED_FIFO, ¶m) == -1) {
++ fprintf(stderr, "could not set SCHED_FIFO, run as root?\n");
++ }
++}
++
++static volatile int segv_wait;
++
++static void segv_handler(int signo, siginfo_t *info, void *extra)
++{
++ while (segv_wait) {
++ sched_yield();
++ }
++
++}
++
++static void set_segv_handler(void)
++{
++ struct sigaction sa;
++
++ sa.sa_flags = SA_SIGINFO;
++ sa.sa_sigaction = segv_handler;
++
++ if (sigaction(SIGSEGV, &sa, NULL) == -1) {
++ perror("sigaction");
++ exit(EXIT_FAILURE);
++ }
++}
++
++int timeout = 0;
++/*
++ * This function is executed by every rim_thread.
++ *
++ * This function performs sweeps over the exclusive chunks of the
++ * rim_threads executing the rim-sequence one word at a time.
++ */
++static void *rim_fn(void *arg)
++{
++ unsigned int tid = *((unsigned int *)arg);
++
++ int size = RIM_CHUNK_SIZE;
++ char *chunk_start = compute_chunk_start_addr(tid);
++
++ unsigned int prev_sweep_id;
++ unsigned int cur_sweep_id = 0;
++
++ /* word access */
++ unsigned int pattern = cur_sweep_id;
++ unsigned int *pattern_ptr = &pattern;
++ unsigned int *w_ptr, read_data;
++
++ set_segv_handler();
++
++ /*
++ * Let us initialize the chunk:
++ *
++ * Each word-aligned address addr in the chunk,
++ * is initialized to :
++ * |-------------------------------------------------|
++ * | tid | word_offset(addr) | 0 |
++ * |-------------------------------------------------|
++ */
++ for (w_ptr = (unsigned int *)chunk_start;
++ (unsigned long)w_ptr < (unsigned long)(chunk_start) + size;
++ w_ptr++) {
++
++ *pattern_ptr = compute_store_pattern(tid, w_ptr, cur_sweep_id);
++ *w_ptr = *pattern_ptr;
++ }
++
++ while (!corruption_found && !timeout) {
++ prev_sweep_id = cur_sweep_id;
++ cur_sweep_id = cur_sweep_id + 1;
++
++ for (w_ptr = (unsigned int *)chunk_start;
++ (unsigned long)w_ptr < (unsigned long)(chunk_start) + size;
++ w_ptr++) {
++ unsigned int old_pattern;
++
++ /*
++ * Compute the pattern that we would have
++ * stored at this location in the previous
++ * sweep.
++ */
++ old_pattern = compute_store_pattern(tid, w_ptr, prev_sweep_id);
++
++ /*
++ * FLUSH:Ensure that we flush the contents of
++ * the cache before loading
++ */
++ dcbf((volatile unsigned int*)w_ptr); //Flush
++
++ /* LOAD: Read the value */
++ read_data = *w_ptr; //Load
++
++ /*
++ * COMPARE: Is it the same as what we had stored
++ * in the previous sweep ? It better be!
++ */
++ if (read_data != old_pattern) {
++ /* No it isn't! Tell everyone */
++ corruption_found = 1;
++ }
++
++ /*
++ * Before performing a store, let us check if
++ * any rim_thread has found a corruption.
++ */
++ if (corruption_found || timeout) {
++ /*
++ * Yes. Someone (including us!) has found
++ * a corruption :(
++ *
++ * Let us verify that our chunk is
++ * correct.
++ */
++ /* But first, let us allow the dust to settle down! */
++ verify_chunk(tid, w_ptr, cur_sweep_id, prev_sweep_id);
++
++ return 0;
++ }
++
++ /*
++ * Compute the new pattern that we are going
++ * to write to this location
++ */
++ *pattern_ptr = compute_store_pattern(tid, w_ptr, cur_sweep_id);
++
++ /*
++ * STORE: Now let us write this pattern into
++ * the location
++ */
++ *w_ptr = *pattern_ptr;
++ }
++ }
++
++ return NULL;
++}
++
++
++static unsigned long start_cpu = 0;
++static unsigned long nrthreads = 4;
++
++static pthread_t mem_snapshot_thread;
++
++static void *mem_snapshot_fn(void *arg)
++{
++ int page_size = getpagesize();
++ size_t size = page_size;
++ void *tmp = malloc(size);
++
++ while (!corruption_found && !timeout) {
++ /* Stop memory migration once corruption is found */
++ segv_wait = 1;
++
++ mprotect(map1, size, PROT_READ);
++
++ /*
++ * Load from the working alias (map1). Loading from map2
++ * also fails.
++ */
++ memcpy(tmp, map1, size);
++
++ /*
++ * Stores must go via map2 which has write permissions, but
++ * the corrupted data tends to be seen in the snapshot buffer,
++ * so corruption does not appear to be introduced at the
++ * copy-back via map2 alias here.
++ */
++ memcpy(map2, tmp, size);
++ /*
++ * Before releasing other threads, must ensure the copy
++ * back to
++ */
++ asm volatile("sync" ::: "memory");
++ mprotect(map1, size, PROT_READ|PROT_WRITE);
++ asm volatile("sync" ::: "memory");
++ segv_wait = 0;
++
++ usleep(1); /* This value makes a big difference */
++ }
++
++ return 0;
++}
++
++void alrm_sighandler(int sig)
++{
++ timeout = 1;
++}
++
++int main(int argc, char *argv[])
++{
++ int c;
++ int page_size = getpagesize();
++ time_t now;
++ int i, dir_error;
++ pthread_attr_t attr;
++ key_t shm_key = (key_t) getpid();
++ int shmid, run_time = 20 * 60;
++ struct sigaction sa_alrm;
++
++ snprintf(logdir, LOGDIR_NAME_SIZE,
++ "/tmp/logdir-%u", (unsigned int)getpid());
++ while ((c = getopt(argc, argv, "r:hn:l:t:")) != -1) {
++ switch(c) {
++ case 'r':
++ start_cpu = strtoul(optarg, NULL, 10);
++ break;
++ case 'h':
++ printf("%s [-r <start_cpu>] [-n <nrthreads>] [-l <logdir>] [-t <timeout>]\n", argv[0]);
++ exit(0);
++ break;
++ case 'n':
++ nrthreads = strtoul(optarg, NULL, 10);
++ break;
++ case 'l':
++ strncpy(logdir, optarg, LOGDIR_NAME_SIZE);
++ break;
++ case 't':
++ run_time = strtoul(optarg, NULL, 10);
++ break;
++ default:
++ printf("invalid option\n");
++ exit(0);
++ break;
++ }
++ }
++
++ if (nrthreads > MAX_THREADS)
++ nrthreads = MAX_THREADS;
++
++ shmid = shmget(shm_key, page_size, IPC_CREAT|0666);
++ if (shmid < 0) {
++ err_msg("Failed shmget\n");
++ }
++
++ map1 = shmat(shmid, NULL, 0);
++ if (map1 == (void *) -1) {
++ err_msg("Failed shmat");
++ }
++
++ map2 = shmat(shmid, NULL, 0);
++ if (map2 == (void *) -1) {
++ err_msg("Failed shmat");
++ }
++
++ dir_error = mkdir(logdir, 0755);
++
++ if (dir_error) {
++ err_msg("Failed mkdir");
++ }
++
++ printf("start_cpu list:%lu\n", start_cpu);
++ printf("number of worker threads:%lu + 1 snapshot thread\n", nrthreads);
++ printf("Allocated address:0x%016lx + secondary map:0x%016lx\n", (unsigned long)map1, (unsigned long)map2);
++ printf("logdir at : %s\n", logdir);
++ printf("Timeout: %d seconds\n", run_time);
++
++ time(&now);
++ printf("=================================\n");
++ printf(" Starting Test\n");
++ printf(" %s", ctime(&now));
++ printf("=================================\n");
++
++ for (i = 0; i < nrthreads; i++) {
++ if (1 && !fork()) {
++ prctl(PR_SET_PDEATHSIG, SIGKILL);
++ set_mycpu(start_cpu + i);
++ for (;;)
++ sched_yield();
++ exit(0);
++ }
++ }
++
++
++ sa_alrm.sa_handler = &alrm_sighandler;
++ sigemptyset(&sa_alrm.sa_mask);
++ sa_alrm.sa_flags = 0;
++
++ if (sigaction(SIGALRM, &sa_alrm, 0) == -1) {
++ err_msg("Failed signal handler registration\n");
++ }
++
++ alarm(run_time);
++
++ pthread_attr_init(&attr);
++ for (i = 0; i < nrthreads; i++) {
++ rim_thread_ids[i] = i;
++ pthread_create(&rim_threads[i], &attr, rim_fn, &rim_thread_ids[i]);
++ set_pthread_cpu(rim_threads[i], start_cpu + i);
++ }
++
++ pthread_create(&mem_snapshot_thread, &attr, mem_snapshot_fn, map1);
++ set_pthread_cpu(mem_snapshot_thread, start_cpu + i);
++
++
++ pthread_join(mem_snapshot_thread, NULL);
++ for (i = 0; i < nrthreads; i++) {
++ pthread_join(rim_threads[i], NULL);
++ }
++
++ if (!timeout) {
++ time(&now);
++ printf("=================================\n");
++ printf(" Data Corruption Detected\n");
++ printf(" %s", ctime(&now));
++ printf(" See logfiles in %s\n", logdir);
++ printf("=================================\n");
++ return 1;
++ }
++ return 0;
++}
projects / thirdparty / kernel / stable-queue.git / commitdiff
