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-rw-r--r--src/arch/riscv/registers.hh2
-rw-r--r--src/sim/futex_map.hh135
-rw-r--r--src/sim/process.cc10
-rw-r--r--src/sim/syscall_emul.cc144
-rw-r--r--src/sim/syscall_emul.hh97
-rw-r--r--src/sim/system.hh8
6 files changed, 282 insertions, 114 deletions
diff --git a/src/arch/riscv/registers.hh b/src/arch/riscv/registers.hh
index d8977030d..0793398fb 100644
--- a/src/arch/riscv/registers.hh
+++ b/src/arch/riscv/registers.hh
@@ -50,9 +50,9 @@
#include <map>
#include <string>
+#include "arch/isa_traits.hh"
#include "arch/riscv/generated/max_inst_regs.hh"
#include "base/types.hh"
-#include "sim/system.hh"
namespace RiscvISA {
diff --git a/src/sim/futex_map.hh b/src/sim/futex_map.hh
new file mode 100644
index 000000000..998f8d481
--- /dev/null
+++ b/src/sim/futex_map.hh
@@ -0,0 +1,135 @@
+/*
+ * Copyright (c) 2017 Advanced Micro Devices, Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met: redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer;
+ * redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution;
+ * neither the name of the copyright holders nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * Authors: Brandon Potter
+ * Steve Reinhardt
+ * Alexandru Dutu
+ */
+
+#ifndef __FUTEX_MAP_HH__
+#define __FUTEX_MAP_HH__
+
+#include <unordered_map>
+
+#include <cpu/thread_context.hh>
+
+/**
+ * FutexKey class defines an unique identifier for a particular futex in the
+ * system. The tgid and an address are the unique values needed as the key.
+ */
+class FutexKey {
+ public:
+ uint64_t addr;
+ uint64_t tgid;
+
+ FutexKey(uint64_t addr_in, uint64_t tgid_in)
+ : addr(addr_in), tgid(tgid_in)
+ {
+ }
+
+ bool
+ operator==(const FutexKey &in) const
+ {
+ return addr == in.addr && tgid == in.tgid;
+ }
+};
+
+namespace std {
+ /**
+ * The unordered_map structure needs the parenthesis operator defined for
+ * std::hash if a user defined key is used. Our key is is user defined
+ * so we need to provide the hash functor.
+ */
+ template <>
+ struct hash<FutexKey>
+ {
+ size_t operator()(const FutexKey& in) const
+ {
+ size_t hash = 65521;
+ for (int i = 0; i < sizeof(uint64_t) / sizeof(size_t); i++) {
+ hash ^= (size_t)(in.addr >> sizeof(size_t) * i) ^
+ (size_t)(in.tgid >> sizeof(size_t) * i);
+ }
+ return hash;
+ }
+ };
+}
+
+typedef std::list<ThreadContext *> ThreadContextList;
+
+/**
+ * FutexMap class holds a map of all futexes used in the system
+ */
+class FutexMap : public std::unordered_map<FutexKey, ThreadContextList>
+{
+ public:
+ /** Inserts a futex into the map with one waiting TC */
+ void
+ suspend(Addr addr, uint64_t tgid, ThreadContext *tc)
+ {
+ FutexKey key(addr, tgid);
+ auto it = find(key);
+
+ if (it == end()) {
+ ThreadContextList tcList {tc};
+ insert({key, tcList});
+ } else {
+ it->second.push_back(tc);
+ }
+
+ /** Suspend the thread context */
+ tc->suspend();
+ }
+
+ /** Wakes up at most count waiting threads on a futex */
+ int
+ wakeup(Addr addr, uint64_t tgid, int count)
+ {
+ FutexKey key(addr, tgid);
+ auto it = find(key);
+
+ if (it == end())
+ return 0;
+
+ int woken_up = 0;
+ auto &tcList = it->second;
+
+ while (!tcList.empty() && woken_up < count) {
+ tcList.front()->activate();
+ tcList.pop_front();
+ woken_up++;
+ }
+
+ if (tcList.empty())
+ erase(it);
+
+ return woken_up;
+ }
+
+};
+
+#endif // __FUTEX_MAP_HH__
diff --git a/src/sim/process.cc b/src/sim/process.cc
index 71f398893..406b38679 100644
--- a/src/sim/process.cc
+++ b/src/sim/process.cc
@@ -50,6 +50,7 @@
#include <unistd.h>
#include <array>
+#include <csignal>
#include <map>
#include <string>
#include <vector>
@@ -71,20 +72,27 @@
#if THE_ISA == ALPHA_ISA
#include "arch/alpha/linux/process.hh"
+
#elif THE_ISA == SPARC_ISA
#include "arch/sparc/linux/process.hh"
#include "arch/sparc/solaris/process.hh"
+
#elif THE_ISA == MIPS_ISA
#include "arch/mips/linux/process.hh"
+
#elif THE_ISA == ARM_ISA
-#include "arch/arm/linux/process.hh"
#include "arch/arm/freebsd/process.hh"
+#include "arch/arm/linux/process.hh"
+
#elif THE_ISA == X86_ISA
#include "arch/x86/linux/process.hh"
+
#elif THE_ISA == POWER_ISA
#include "arch/power/linux/process.hh"
+
#elif THE_ISA == RISCV_ISA
#include "arch/riscv/linux/process.hh"
+
#else
#error "THE_ISA not set"
#endif
diff --git a/src/sim/syscall_emul.cc b/src/sim/syscall_emul.cc
index 1441592a8..4cf17a266 100644
--- a/src/sim/syscall_emul.cc
+++ b/src/sim/syscall_emul.cc
@@ -34,6 +34,7 @@
#include <fcntl.h>
#include <unistd.h>
+#include <csignal>
#include <iostream>
#include <string>
@@ -75,67 +76,116 @@ ignoreFunc(SyscallDesc *desc, int callnum, Process *process,
}
static void
-exitFutexWake(ThreadContext *tc, uint64_t uaddr)
-{
- std::map<uint64_t, std::list<ThreadContext *> * >
- &futex_map = tc->getSystemPtr()->futexMap;
-
- int wokenUp = 0;
- std::list<ThreadContext *> * tcWaitList;
- if (futex_map.count(uaddr)) {
- tcWaitList = futex_map.find(uaddr)->second;
- if (tcWaitList->size() > 0) {
- tcWaitList->front()->activate();
- tcWaitList->pop_front();
- wokenUp++;
+exitFutexWake(ThreadContext *tc, Addr addr, uint64_t tgid)
+{
+ // Clear value at address pointed to by thread's childClearTID field.
+ BufferArg ctidBuf(addr, sizeof(long));
+ long *ctid = (long *)ctidBuf.bufferPtr();
+ *ctid = 0;
+ ctidBuf.copyOut(tc->getMemProxy());
+
+ FutexMap &futex_map = tc->getSystemPtr()->futexMap;
+ // Wake one of the waiting threads.
+ futex_map.wakeup(addr, tgid, 1);
+}
+
+static SyscallReturn
+exitImpl(SyscallDesc *desc, int callnum, Process *p, ThreadContext *tc,
+ bool group)
+{
+ int index = 0;
+ int status = p->getSyscallArg(tc, index);
+
+ System *sys = tc->getSystemPtr();
+
+ int activeContexts = 0;
+ for (auto &system: sys->systemList)
+ activeContexts += system->numRunningContexts();
+ if (activeContexts == 1) {
+ exitSimLoop("exiting with last active thread context", status & 0xff);
+ return status;
+ }
+
+ if (group)
+ *p->exitGroup = true;
+
+ if (p->childClearTID)
+ exitFutexWake(tc, p->childClearTID, p->tgid());
+
+ bool last_thread = true;
+ Process *parent = nullptr, *tg_lead = nullptr;
+ for (int i = 0; last_thread && i < sys->numContexts(); i++) {
+ Process *walk;
+ if (!(walk = sys->threadContexts[i]->getProcessPtr()))
+ continue;
+
+ /**
+ * Threads in a thread group require special handing. For instance,
+ * we send the SIGCHLD signal so that it appears that it came from
+ * the head of the group. We also only delete file descriptors if
+ * we are the last thread in the thread group.
+ */
+ if (walk->pid() == p->tgid())
+ tg_lead = walk;
+
+ if ((sys->threadContexts[i]->status() != ThreadContext::Halted)
+ && (walk != p)) {
+ /**
+ * Check if we share thread group with the pointer; this denotes
+ * that we are not the last thread active in the thread group.
+ * Note that setting this to false also prevents further
+ * iterations of the loop.
+ */
+ if (walk->tgid() == p->tgid())
+ last_thread = false;
+
+ /**
+ * A corner case exists which involves execve(). After execve(),
+ * the execve will enable SIGCHLD in the process. The problem
+ * occurs when the exiting process is the root process in the
+ * system; there is no parent to receive the signal. We obviate
+ * this problem by setting the root process' ppid to zero in the
+ * Python configuration files. We really should handle the
+ * root/execve specific case more gracefully.
+ */
+ if (*p->sigchld && (p->ppid() != 0) && (walk->pid() == p->ppid()))
+ parent = walk;
}
- if (tcWaitList->empty()) {
- futex_map.erase(uaddr);
- delete tcWaitList;
+ }
+
+ if (last_thread) {
+ if (parent) {
+ assert(tg_lead);
+ sys->signalList.push_back(BasicSignal(tg_lead, parent, SIGCHLD));
+ }
+
+ /**
+ * Run though FD array of the exiting process and close all file
+ * descriptors except for the standard file descriptors.
+ * (The standard file descriptors are shared with gem5.)
+ */
+ for (int i = 0; i < p->fds->getSize(); i++) {
+ if ((*p->fds)[i])
+ p->fds->closeFDEntry(i);
}
}
- DPRINTF(SyscallVerbose, "exit: FUTEX_WAKE, activated %d waiting "
- "thread contexts\n", wokenUp);
+
+ tc->halt();
+ return status;
}
SyscallReturn
exitFunc(SyscallDesc *desc, int callnum, Process *p, ThreadContext *tc)
{
- if (p->system->numRunningContexts() == 1 && !p->childClearTID) {
- // Last running free-parent context; exit simulator.
- int index = 0;
- exitSimLoop("target called exit()",
- p->getSyscallArg(tc, index) & 0xff);
- } else {
- if (p->childClearTID)
- exitFutexWake(tc, p->childClearTID);
- tc->halt();
- }
-
- return 1;
+ return exitImpl(desc, callnum, p, tc, false);
}
-
SyscallReturn
-exitGroupFunc(SyscallDesc *desc, int callnum, Process *process,
- ThreadContext *tc)
+exitGroupFunc(SyscallDesc *desc, int callnum, Process *p, ThreadContext *tc)
{
- // halt all threads belonging to this process
- for (auto i: process->contextIds) {
- process->system->getThreadContext(i)->halt();
- }
-
- if (!process->system->numRunningContexts()) {
- // all threads belonged to this process... exit simulator
- int index = 0;
- exitSimLoop("target called exit()",
- process->getSyscallArg(tc, index) & 0xff);
- }
-
- return 1;
+ return exitImpl(desc, callnum, p, tc, true);
}
-
SyscallReturn
getpagesizeFunc(SyscallDesc *desc, int num, Process *p, ThreadContext *tc)
{
diff --git a/src/sim/syscall_emul.hh b/src/sim/syscall_emul.hh
index 2380e4779..a0fb7e4ed 100644
--- a/src/sim/syscall_emul.hh
+++ b/src/sim/syscall_emul.hh
@@ -93,6 +93,7 @@
#include "mem/page_table.hh"
#include "params/Process.hh"
#include "sim/emul_driver.hh"
+#include "sim/futex_map.hh"
#include "sim/process.hh"
#include "sim/syscall_debug_macros.hh"
#include "sim/syscall_desc.hh"
@@ -304,79 +305,44 @@ SyscallReturn
futexFunc(SyscallDesc *desc, int callnum, Process *process,
ThreadContext *tc)
{
- int index_uaddr = 0;
- int index_op = 1;
- int index_val = 2;
- int index_timeout = 3;
+ using namespace std;
- uint64_t uaddr = process->getSyscallArg(tc, index_uaddr);
- int op = process->getSyscallArg(tc, index_op);
- int val = process->getSyscallArg(tc, index_val);
- uint64_t timeout = process->getSyscallArg(tc, index_timeout);
-
- std::map<uint64_t, std::list<ThreadContext *> * >
- &futex_map = tc->getSystemPtr()->futexMap;
-
- DPRINTF(SyscallVerbose, "futex: Address=%llx, op=%d, val=%d\n",
- uaddr, op, val);
+ int index = 0;
+ Addr uaddr = process->getSyscallArg(tc, index);
+ int op = process->getSyscallArg(tc, index);
+ int val = process->getSyscallArg(tc, index);
+ /*
+ * Unsupported option that does not affect the correctness of the
+ * application. This is a performance optimization utilized by Linux.
+ */
op &= ~OS::TGT_FUTEX_PRIVATE_FLAG;
- if (op == OS::TGT_FUTEX_WAIT) {
- if (timeout != 0) {
- warn("futex: FUTEX_WAIT with non-null timeout unimplemented;"
- "we'll wait indefinitely");
- }
+ FutexMap &futex_map = tc->getSystemPtr()->futexMap;
- uint8_t *buf = new uint8_t[sizeof(int)];
- tc->getMemProxy().readBlob((Addr)uaddr, buf, (int)sizeof(int));
- int mem_val = *((int *)buf);
- delete[] buf;
+ if (OS::TGT_FUTEX_WAIT == op) {
+ // Ensure futex system call accessed atomically.
+ BufferArg buf(uaddr, sizeof(int));
+ buf.copyIn(tc->getMemProxy());
+ int mem_val = *(int*)buf.bufferPtr();
- if (val != mem_val) {
- DPRINTF(SyscallVerbose, "futex: FUTEX_WAKE, read: %d, "
- "expected: %d\n", mem_val, val);
+ /*
+ * The value in memory at uaddr is not equal with the expected val
+ * (a different thread must have changed it before the system call was
+ * invoked). In this case, we need to throw an error.
+ */
+ if (val != mem_val)
return -OS::TGT_EWOULDBLOCK;
- }
- // Queue the thread context
- std::list<ThreadContext *> * tcWaitList;
- if (futex_map.count(uaddr)) {
- tcWaitList = futex_map.find(uaddr)->second;
- } else {
- tcWaitList = new std::list<ThreadContext *>();
- futex_map.insert(std::pair< uint64_t,
- std::list<ThreadContext *> * >(uaddr, tcWaitList));
- }
- tcWaitList->push_back(tc);
- DPRINTF(SyscallVerbose, "futex: FUTEX_WAIT, suspending calling thread "
- "context on address 0x%lx\n", uaddr);
- tc->suspend();
- return 0;
- } else if (op == OS::TGT_FUTEX_WAKE){
- int wokenUp = 0;
- std::list<ThreadContext *> * tcWaitList;
- if (futex_map.count(uaddr)) {
- tcWaitList = futex_map.find(uaddr)->second;
- while (tcWaitList->size() > 0 && wokenUp < val) {
- tcWaitList->front()->activate();
- tcWaitList->pop_front();
- wokenUp++;
- }
- if (tcWaitList->empty()) {
- futex_map.erase(uaddr);
- delete tcWaitList;
- }
- }
- DPRINTF(SyscallVerbose, "futex: FUTEX_WAKE, activated %d waiting "
- "thread context on address 0x%lx\n",
- wokenUp, uaddr);
- return wokenUp;
- } else {
- warn("futex: op %d is not implemented, just returning...", op);
+ futex_map.suspend(uaddr, process->tgid(), tc);
+
return 0;
+ } else if (OS::TGT_FUTEX_WAKE == op) {
+ return futex_map.wakeup(uaddr, process->tgid(), val);
}
+ warn("futex: op %d not implemented; ignoring.", op);
+ return -ENOSYS;
}
@@ -1319,6 +1285,13 @@ cloneFunc(SyscallDesc *desc, int callnum, Process *p, ThreadContext *tc)
cp->initState();
p->clone(tc, ctc, cp, flags);
+ if (flags & OS::TGT_CLONE_THREAD) {
+ delete cp->sigchld;
+ cp->sigchld = p->sigchld;
+ } else if (flags & OS::TGT_SIGCHLD) {
+ *cp->sigchld = true;
+ }
+
if (flags & OS::TGT_CLONE_CHILD_SETTID) {
BufferArg ctidBuf(ctidPtr, sizeof(long));
long *ctid = (long *)ctidBuf.bufferPtr();
diff --git a/src/sim/system.hh b/src/sim/system.hh
index 7584cebc9..c3c178dbd 100644
--- a/src/sim/system.hh
+++ b/src/sim/system.hh
@@ -48,6 +48,7 @@
#define __SYSTEM_HH__
#include <string>
+#include <unordered_map>
#include <utility>
#include <vector>
@@ -57,10 +58,11 @@
#include "config/the_isa.hh"
#include "enums/MemoryMode.hh"
#include "mem/mem_object.hh"
+#include "mem/physical.hh"
#include "mem/port.hh"
#include "mem/port_proxy.hh"
-#include "mem/physical.hh"
#include "params/System.hh"
+#include "sim/futex_map.hh"
#include "sim/se_signal.hh"
/**
@@ -69,6 +71,7 @@
*/
#if THE_ISA != NULL_ISA
#include "cpu/pc_event.hh"
+
#endif
class BaseRemoteGDB;
@@ -549,8 +552,7 @@ class System : public MemObject
static void printSystems();
- // For futex system call
- std::map<uint64_t, std::list<ThreadContext *> * > futexMap;
+ FutexMap futexMap;
static const int maxPID = 32768;
generated by cgit v1.2.3 (git 2.25.1) at 2024-07-05 03:51:21 +0000