/* * Copyright (c) 2016, 2022, Oracle and/or its affiliates. All rights reserved. * Copyright (c) 2016, 2019 SAP SE. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. *
*/
// put OS-includes here # include <sys/types.h> # include <sys/mman.h> # include <pthread.h> # include <signal.h> # include <errno.h> # include <dlfcn.h> # include <stdlib.h> # include <stdio.h> # include <unistd.h> # include <sys/resource.h> # include <pthread.h> # include <sys/stat.h> # include <sys/time.h> # include <sys/utsname.h> # include <sys/socket.h> # include <sys/wait.h> # include <pwd.h> # include <poll.h> # include <ucontext.h>
assert(((uint64_t)csp & (frame::alignment_in_bytes-1)) == 0, "SP must be aligned"); return (address) csp;
}
char* os::non_memory_address_word() { // Must never look like an address returned by reserve_memory, // even in its subfields (as defined by the CPU immediate fields, // if the CPU splits constants across multiple instructions). return (char*) -1;
}
// Frame information (pc, sp, fp) retrieved via ucontext // always looks like a C-frame according to the frame // conventions in frame_s390.hpp.
address os::Posix::ucontext_get_pc(const ucontext_t * uc) { return (address)uc->uc_mcontext.psw.addr;
}
frame os::get_sender_for_C_frame(frame* fr) { if (*fr->sp() == 0) { // fr is the last C frame. return frame();
}
// If its not one of our frames, the return pc is saved at gpr14 // stack slot. The call_stub stores the return_pc to the stack slot // of gpr10. if ((Interpreter::code() != NULL && Interpreter::contains(fr->pc())) ||
(CodeCache::contains(fr->pc()) && !StubRoutines::contains(fr->pc()))) { return frame(fr->sender_sp(), fr->sender_pc());
} else { if (StubRoutines::contains(fr->pc())) {
StubCodeDesc* desc = StubCodeDesc::desc_for(fr->pc()); if (desc && !strcmp(desc->name(),"call_stub")) { return frame(fr->sender_sp(), fr->callstub_sender_pc());
} else { return frame(fr->sender_sp(), fr->sender_pc());
}
} else { return frame(fr->sender_sp(), fr->native_sender_pc());
}
}
}
frame os::current_frame() { // Expected to return the stack pointer of this method. // But if inlined, returns the stack pointer of our caller!
intptr_t* csp = (intptr_t*) *((intptr_t*) os::current_stack_pointer());
assert (csp != NULL, "sp should not be NULL"); // Pass a dummy pc. This way we don't have to load it from the // stack, since we don't know in which slot we can find it.
frame topframe(csp, (address)0x8); if (os::is_first_C_frame(&topframe)) { // Stack is not walkable. return frame();
} else {
frame senderFrame = os::get_sender_for_C_frame(&topframe);
assert(senderFrame.pc() != NULL, "Sender pc should not be NULL"); // Return sender of sender of current topframe which hopefully // both have pc != NULL. #ifdef _NMT_NOINLINE_ // Is set in slowdebug builds. // Current_stack_pointer is not inlined, we must pop one more frame.
frame tmp = os::get_sender_for_C_frame(&topframe); return os::get_sender_for_C_frame(&tmp); #else return os::get_sender_for_C_frame(&topframe); #endif
}
}
// Decide if this trap can be handled by a stub.
address stub = NULL;
address pc = NULL; // Pc as retrieved from PSW. Usually points past failing instruction.
address trap_pc = NULL; // Pc of the instruction causing the trap.
//%note os_trap_1 if (info != NULL && uc != NULL && thread != NULL) {
pc = os::Posix::ucontext_get_pc(uc); if (TraceTraps) {
tty->print_cr(" pc at " INTPTR_FORMAT, p2i(pc));
} if ((unsignedlong)(pc - (address)info->si_addr) <= (unsignedlong)Assembler::instr_maxlen() ) {
trap_pc = (address)info->si_addr; if (TraceTraps) {
tty->print_cr("trap_pc at " INTPTR_FORMAT, p2i(trap_pc));
}
}
// Handle ALL stack overflow variations here if (sig == SIGSEGV) {
address addr = (address)info->si_addr; // Address causing SIGSEGV, usually mem ref target.
// Check if fault address is within thread stack. if (thread->is_in_full_stack(addr)) { // stack overflow if (os::Posix::handle_stack_overflow(thread, addr, pc, uc, &stub)) { returntrue; // continue
}
}
}
if (thread->thread_state() == _thread_in_Java) { // Java thread running in Java code => find exception handler if any // a fault inside compiled code, the interpreter, or a stub
// Handle signal from NativeJump::patch_verified_entry(). if (sig == SIGILL && nativeInstruction_at(pc)->is_sigill_not_entrant()) { if (TraceTraps) {
tty->print_cr("trap: not_entrant (SIGILL)");
}
stub = SharedRuntime::get_handle_wrong_method_stub();
}
// Info->si_addr only points to the page base address, so we // must extract the real si_addr from the instruction and the // ucontext.
assert(((NativeInstruction*)pc)->is_safepoint_poll(), "must be safepoint poll"); const address real_si_addr = ((NativeInstruction*)pc)->get_poll_address(uc);
}
elseif (sig == SIGBUS) { // BugId 4454115: A read from a MappedByteBuffer can fault here if the // underlying file has been truncated. Do not crash the VM in such a case.
CodeBlob* cb = CodeCache::find_blob(pc);
CompiledMethod* nm = (cb != NULL) ? cb->as_compiled_method_or_null() : NULL; if (nm != NULL && nm->has_unsafe_access()) { // We don't really need a stub here! Just set the pending exception and // continue at the next instruction after the faulting read. Returning // garbage from this read is ok.
thread->set_pending_unsafe_access_error();
uc->uc_mcontext.psw.addr = ((unsignedlong)pc) + Assembler::instr_len(pc); returntrue;
}
}
}
else { // thread->thread_state() != _thread_in_Java if ((sig == SIGILL) && VM_Version::is_determine_features_test_running()) { // SIGILL must be caused by VM_Version::determine_features() // when attempting to execute a non-existing instruction. //*(int *) (pc-6)=0; // Patch instruction to 0 to indicate that it causes a SIGILL. // Flushing of icache is not necessary.
stub = pc; // Continue with next instruction.
} elseif ((sig == SIGFPE) && VM_Version::is_determine_features_test_running()) { // SIGFPE is known to be caused by trying to execute a vector instruction // when the vector facility is installed, but operating system support is missing.
VM_Version::reset_has_VectorFacility();
stub = pc; // Continue with next instruction.
} elseif ((thread->thread_state() == _thread_in_vm ||
thread->thread_state() == _thread_in_native) &&
sig == SIGBUS && thread->doing_unsafe_access()) { // We don't really need a stub here! Just set the pending exception and // continue at the next instruction after the faulting read. Returning // garbage from this read is ok.
thread->set_pending_unsafe_access_error();
os::Posix::ucontext_set_pc(uc, pc + Assembler::instr_len(pc)); returntrue;
}
}
// jni_fast_Get<Primitive>Field can trap at certain pc's if a GC kicks in // and the heap gets shrunk before the field access. if ((sig == SIGSEGV) || (sig == SIGBUS)) {
address addr = JNI_FastGetField::find_slowcase_pc(pc); if (addr != (address)-1) {
stub = addr;
}
}
}
if (stub != NULL) { // Save all thread context in case we need to restore it. if (thread != NULL) thread->set_saved_exception_pc(pc);
os::Posix::ucontext_set_pc(uc, stub); returntrue;
}
returnfalse;
}
void os::Linux::init_thread_fpu_state(void) { // Nothing to do on z/Architecture.
}
int os::Linux::get_fpu_control_word(void) { // Nothing to do on z/Architecture. return 0;
}
void os::Linux::set_fpu_control_word(int fpu_control) { // Nothing to do on z/Architecture.
}
// Note: it may be unsafe to inspect memory near pc. For example, pc may // point to garbage if entry point in an nmethod is corrupted. Leave // this at the end, and hope for the best.
address pc = os::Posix::ucontext_get_pc(uc);
print_instructions(st, pc, /*intrsize=*/4);
st->cr();
}
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