sim-se: add new getpgrp system call

This changeset adds new (relatively simple) system call
support. The getpgrp call returns a thread context's
pgid.

Change-Id: I361bdbfb9c01b761ddd5a4923d23f86971f8d614
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/17111
Maintainer: Brandon Potter <Brandon.Potter@amd.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Ayaz Akram <yazakram@ucdavis.edu>

sim-se: adding pipe2 syscall

pipe2 builds on top of the pipe syscall implementation by
adding some extra flags for the files (to avoid have to
make separate calls to fcntl).

Change-Id: I88cf6f1387b9d14e60b33a32db412da9ed93a3e6
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/12310
Reviewed-by: Brandon Potter <Brandon.Potter@amd.com>
Maintainer: Brandon Potter <Brandon.Potter@amd.com>
Tested-by: kokoro <noreply+kokoro@google.com>

sim-se: fstat64 bugfix

The fstat64 system call does an upcast on entries in the file
descriptor array to check if the file descriptor has a backing
host-filesystem file opened. It does so because it needs to pass
the host fd into the fstat call (since we rely on the host
filesystem to service filesystem system calls).

The upcast was overly specific. This changeset alters the system
call to use the most general base class of the file descriptor
entries that can satisfy the code.

Change-Id: I10daf820257cea4d678ee6917e01e9cc9cd1cf5e
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/17110
Tested-by: kokoro <noreply+kokoro@google.com>
Maintainer: Brandon Potter <Brandon.Potter@amd.com>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>

sim-se: add new option to getrlimit syscall

The NPROC option was not serviced by the getrlimit syscall.
This changeset adds in the necessary code to service the option.

Change-Id: I679d3949c3bbb0628188f4e33034028d7726fdcb
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/17109
Maintainer: Brandon Potter <Brandon.Potter@amd.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Matt Sinclair <mattdsinclair@gmail.com>

arch, base, cpu, gpu, sim: Merge getMemProxy and getVirtProxy.

These two functions were performing the same function but had two
different names for historical reasons. This change merges them
together, keeping the getVirtProxy name to be consistent with the
getPhysProxy method used to get a non-translating proxy port.

Change-Id: Idd83c6b899f9343795075b030ccbc723a79e52a4
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/18581
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>

arch, base, sim: Demote (SE|FS)TranslatingPortProxy &s to PortProxy &s.

Al(most) all of the interesting differences between the two classes
have been removed. There are some control methods which are still
specific to each type which may require treating them as their true
type, but most code that consumes them doesn't need to worry about
which is which.

Change-Id: Ie592676f1e496c7940605b66e55cd7fae18e59d6
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/18577
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Reviewed-by: Brandon Potter <Brandon.Potter@amd.com>
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>

arch, base, dev, sim: Remove now unnecessary casts from PortProxy methods.

Change-Id: Ia73b2d86a10d02fa09c924a4571477bb5f200eb7
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/18572
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>

sim-se: change syscall function signature

The system calls had four parameters. One of the parameters
is ThreadContext and another is Process. The ThreadContext
holds the value of the current process so the Process parameter
is redundant since the system call functions already have
indirect access.

With the old API, it is possible to call into the functions with
the wrong supplied Process which could end up being a confusing
error.

This patch removes the redundancy by forcing access through the
ThreadContext field within each system call.

Change-Id: Ib43d3f65824f6d425260dfd9f67de1892b6e8b7c
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/12299
Reviewed-by: Brandon Potter <Brandon.Potter@amd.com>
Maintainer: Brandon Potter <Brandon.Potter@amd.com>
Tested-by: kokoro <noreply+kokoro@google.com>

sim-se: remove /sys from special paths

Currently, the open system call implementation in SE mode
treats /sys/ as a special path that is opened using a
special open handler. The ROC runtime, however, reads
several files in /sys/ that are supported via path
redirection. Here we remove /sys/ from the special files
so that the necessary files may be read via path
redirection.

Change-Id: Ifdab38ea1e6cc486ad43aec96b6e032fe63f137d
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/12127
Reviewed-by: Anthony Gutierrez <anthony.gutierrez@amd.com>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Anthony Gutierrez <anthony.gutierrez@amd.com>
Tested-by: kokoro <noreply+kokoro@google.com>

sim-se: correct statfs inclusion on !linux host

- Added missing header
- Fixed typo on __linux__ macro conditional
- s/ifdef/if defined/g for consistency

Change-Id: I83b69856e5ec8b23b707642c0e14216cf62db31e
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/18668
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Reviewed-by: Brandon Potter <Brandon.Potter@amd.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>
Tested-by: kokoro <noreply+kokoro@google.com>

sim-se: add eventfd system call

Change-Id: I7aeb4fe808d0c8f2fb8041e3662d330d8458f09c
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/12125
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Ciro Santilli <ciro.santilli@arm.com>
Maintainer: Brandon Potter <Brandon.Potter@amd.com>

sim-se: use DPRINTF_SYSCALL for ioctl/wait4

Change-Id: I4fbaf1a0653f13ae964a2574cc26bbaac2dc0686
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/12124
Maintainer: Brandon Potter <Brandon.Potter@amd.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>

sim-se: add socket ioctls

The OpenMPI 1.8.2 runtime needs the ioctl code
included in this patch to issue socket operations
on the host machine.

Change-Id: I687b31f375a846f0bab2debd9b9472605a4d2c7d
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/12123
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>

sim-se: add a faux-filesystem

This change introduces the concept of a faux-filesystem.
The faux-filesystem creates a directory structure in m5out
(or whatever output dir the user specifies) where system calls
may be redirected.

This is useful to avoid non-determinism when reading files
with varying path names (e.g., variations from run-to-run if
the simulation is scheduled on a cluster where paths may change).

Also, this changeset allows circumventing host pseudofiles which
have information specific to the host processor (such as cache
hierarchy or processor information). Bypassing host pseudofiles
can be useful when executing runtimes in the absence of an
operating system kernel since runtimes may try to query standard
files (i.e. /proc or /sys) which are not relevant to an
application executing in syscall emulation mode.

Change-Id: I90821b3b403168b904a662fa98b85def1628621c
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/12119
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>
Tested-by: kokoro <noreply+kokoro@google.com>

sim-se: Enhance clone for X86KvmCPU

This changeset enables clone to work with X86KvmCPU model, which
will allow running multi-threaded applications at near hardware
speeds. Even though the application is multi-threaded, the KvmCPU
model uses one event queue, therefore, only one hardware thread
will be used, through KVM, to simulate multiple application threads.

Change-Id: I2b2a7b1edb1c56eeb9c4fa0553cd236029cd53f8
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/18268
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>
Tested-by: kokoro <noreply+kokoro@google.com>

kern,sim: implement FUTEX_WAKE_OP

This patch implements FUTEX_WAKE_OP operation in the futex syscall.
Below is its description:

int futex(int *uaddr, int futex_op, int val,
const struct timespec *timeout,
int *uaddr2, int val3);

This operation was added to support some user-space use cases where more
than one futex must be handled at the same time. The most notable
example is the implementation of pthread_cond_signal(3), which requires
operations on two futexes, the one used to implement the mutex and the
one used in the implementation of the wait queue associated with the
condition variable. FUTEX_WAKE_OP allows such cases to be implemented
without leading to high rates of contention and context switching.

Reference: http://man7.org/linux/man-pages/man2/futex.2.html

Change-Id: I215f3c2a7bdc6374e5dfe06ee721c76933a10f2d
Reviewed-on: https://gem5-review.googlesource.com/c/9630
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Reviewed-by: Brandon Potter <Brandon.Potter@amd.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>

sim, kern: support FUTEX_CMP_REQUEUE

This patch supports FUTEX_CMP_REQUEUE operation. Below is its
description from Linux man page:

futex syscall: int futex(int *uaddr, int futex_op, int val,
const struct timespec *timeout,
int *uaddr2, int val3);

This operation first checks whether the location uaddr still contains
the value val3. If not, the operation fails with the error EAGAIN.
Otherwise, the operation wakes up a maximum of val waiters that are
waiting on the futex at uaddr. If there are more than val waiters, then
the remaining waiters are removed from the wait queue of the source
futex at uaddr and added to the wait queue of the target futex at
uaddr2. The val2 argument specifies an upper limit on the number of
waiters that are requeued to the futex at uaddr2.

Reference: http://man7.org/linux/man-pages/man2/futex.2.html

Change-Id: I6d2ebd19a935b656d19d8342f7ab450c0d2031f4
Reviewed-on: https://gem5-review.googlesource.com/c/9629
Reviewed-by: Brandon Potter <Brandon.Potter@amd.com>
Maintainer: Brandon Potter <Brandon.Potter@amd.com>

sim: handle the case when there're not enough HW thread contexts

In SE mode, since there's no OS scheduler, the number of active SW
threads is limited by the number of HW thread contexts. Previously, if
there is no spare HW thread context, the simulator just fails and stops.
Instead, this patch returns EAGAIN error code from a clone syscall if
there's no available HW thread context. Then it's up to the simulated
program to handle the error.

Linux man page reference:
http://man7.org/linux/man-pages/man2/clone.2.html
http://man7.org/linux/man-pages/man2/fork.2.html

Change-Id: Ib4e092433e49de4dde376c8cb81f7d3f7851cbc0
Reviewed-on: https://gem5-review.googlesource.com/c/9628
Reviewed-by: Brandon Potter <Brandon.Potter@amd.com>
Maintainer: Brandon Potter <Brandon.Potter@amd.com>

sim,kern: support FUTEX_WAIT_BITSET and FUTEX_WAKE_BITSET ops

This patch adds support for two operations in futex system call:
FUTEX_WAIT_BITSET and FUTEX_WAKE_BITSET. The two operations are used to
selectively wake up a certain thread waiting on a futex variable.

Basically each thread waiting on a futex variable is associated with a
bitset that is checked when another thread tries to wake up all threads
waiting on the futex variable.

Change-Id: I2300e53b144d8fae226423fa2efb0238c1d93ef9
Reviewed-on: https://gem5-review.googlesource.com/c/9621
Reviewed-by: Brandon Potter <Brandon.Potter@amd.com>
Maintainer: Brandon Potter <Brandon.Potter@amd.com>

sim: added missed macro definition on MacOS

A recent patch add the use of the macro:
CMSG_ALIGN
This macro is not very cross-platform, and needs to be
defined according to the platform.

This patch defines the missing macro on MacOS.

Change-Id: I582f69e652dc060b4532358141179ad6d37eafc7
Reviewed-on: https://gem5-review.googlesource.com/c/16102
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Brandon Potter <Brandon.Potter@amd.com>

sim-se add readv and modifies writev

Change-Id: I6cbce4389d5697da34058dc910306394e48c6582
Reviewed-on: https://gem5-review.googlesource.com/c/12117
Reviewed-by: Anthony Gutierrez <anthony.gutierrez@amd.com>
Maintainer: Anthony Gutierrez <anthony.gutierrez@amd.com>

sim-se: add ability to get/set sock metadata

Add getsockopt, getsockname, setsockname, and getpeername
system calls.

Change-Id: Ifa1d9a95f15b4fb12859dbfd3c4bd248de2e3d32
Reviewed-on: https://gem5-review.googlesource.com/c/12116
Reviewed-by: Anthony Gutierrez <anthony.gutierrez@amd.com>
Maintainer: Anthony Gutierrez <anthony.gutierrez@amd.com>

sim-se: add syscalls related to polling

Fix poll so that it will use the syscall retry capability
instead of causing a blocking call.

Add the accept and wait4 system calls.

Add polling to read to remove deadlocks that occur in the
event queue that are caused by blocking system calls.

Modify the write system call to return an error number in
case of error.

Change-Id: I0b4091a2e41e4187ebf69d63e0088f988f37d5da
Reviewed-on: https://gem5-review.googlesource.com/c/12115
Reviewed-by: Anthony Gutierrez <anthony.gutierrez@amd.com>
Maintainer: Anthony Gutierrez <anthony.gutierrez@amd.com>

sim-se: add calls for network transmissions

Add recvfrom, sendto, recvmsg, and sendmsg system calls.

Change-Id: I2eb50ea7823c8af57d99b3b8d443d2099418c06c
Reviewed-on: https://gem5-review.googlesource.com/c/12114
Reviewed-by: Anthony Gutierrez <anthony.gutierrez@amd.com>
Maintainer: Anthony Gutierrez <anthony.gutierrez@amd.com>

sim-se: add socket-based functionality

Add socket, socketpair, bind, list, connect and shutdown
system calls.

Change-Id: I635af3fca410f96fe28f8fe497e3d457a9dbc470
Reviewed-on: https://gem5-review.googlesource.com/c/12113
Reviewed-by: Anthony Gutierrez <anthony.gutierrez@amd.com>
Maintainer: Anthony Gutierrez <anthony.gutierrez@amd.com>

cpu: dev: sim: gpu-compute: Banish some ISA specific register types.

These types are IntReg, FloatReg, FloatRegBits, and MiscReg. There are
some remaining types, specifically the vector registers and the CCReg.
I'm less familiar with these new types of registers, and so will look
at getting rid of them at some later time.

Change-Id: Ide8f76b15c531286f61427330053b44074b8ac9b
Reviewed-on: https://gem5-review.googlesource.com/c/13624
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>

sim-se, arch-arm: Add support for getdents64

Change-Id: Ib27950144d4c9802ffb842db98aec9e433ccbfc5
Signed-off-by: Andreas Sandberg <andreas.sandberg@arm.com>
Cc: Giacomo Travaglini <giacomo.travaglini@arm.com>
Cc: Javier Setoain <javier.setoain@arm.com>
Cc: Brandon Potter <Brandon.Potter@amd.com>
Reviewed-on: https://gem5-review.googlesource.com/c/15438
Maintainer: Brandon Potter <Brandon.Potter@amd.com>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>

sim-se: Refactor clone to avoid most ifdefs

Some parts of clone are architecture dependent. In some cases, we are
able to use architecture-specific helper functions or register
aliases. However, there is still some architecture-specific that is
protected by ifdefs in the common clone implementation.

Move these architecture-specific bits to the architecture-specific OS
class instead to avoid these ifdefs and make the code a bit more
readable.

Change-Id: Ia0903d738d0ba890863bddfa77e3b717db7f45de
Signed-off-by: Andreas Sandberg <andreas.sandberg@arm.com>
Cc: Giacomo Travaglini <giacomo.travaglini@arm.com>
Cc: Javier Setoain <javier.setoain@arm.com>
Cc: Brandon Potter <Brandon.Potter@amd.com>
Reviewed-on: https://gem5-review.googlesource.com/c/15435
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Brandon Potter <Brandon.Potter@amd.com>

sim-se: Correctly calculate next PC in clone

The clone syscall doesn't propagate all state in the PCState object
when calculating the return PC of a newly created process. Instead of
creating a new PCState object from the next PC address, copy the old
PC and advance it.

Change-Id: Ice53831920bcb5d198865169ed2cca8d06e37cfe
Signed-off-by: Andreas Sandberg <andreas.sandberg@arm.com>
Cc: Giacomo Travaglini <giacomo.travaglini@arm.com>
Cc: Javier Setoain <javier.setoain@arm.com>
Cc: Brandon Potter <Brandon.Potter@amd.com>
Reviewed-on: https://gem5-review.googlesource.com/c/15417
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Brandon Potter <Brandon.Potter@amd.com>

sim-se: Use CONFIG_CLONE_BACKWARDS for Arm

Linxu on Arm users the CLONE_BACKWARDS argument order for the clone
syscall.

Change-Id: I48deb4f03140c9d4ef7a89e3e33813e76777f999
Signed-off-by: Andreas Sandberg <andreas.sandberg@arm.com>
Cc: Giacomo Travaglini <giacomo.travaglini@arm.com>
Cc: Javier Setoain <javier.setoain@arm.com>
Cc: Brandon Potter <Brandon.Potter@amd.com>
Reviewed-on: https://gem5-review.googlesource.com/c/15416
Reviewed-by: Brandon Potter <Brandon.Potter@amd.com>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Brandon Potter <Brandon.Potter@amd.com>

sim-se: only implement getdentsFunc on supported hosts

The implementation of the getdents syscall relies on SYS_getdents, which
is not available on all archs, because the getdents syscall has been
superseded by getdents64, and does not exist on newer archs such as
aarch64.

This leads the build to break on aarch64 hosts with error:

error: 'SYS_getdents' was not declared in this scope

Change-Id: I8701fb5b61c0418b14a9463ef135a391a7f7a9ba
Reviewed-on: https://gem5-review.googlesource.com/c/14596
Reviewed-by: Brandon Potter <Brandon.Potter@amd.com>
Maintainer: Brandon Potter <Brandon.Potter@amd.com>

syscall_emul: fix openat when directory does not end in "/"

Before this commit, the following code:

dir_fd = open(".", O_DIRECTORY);
file_fd = openat(dir_fd, "ble", O_CREAT, S_IRUSR | S_IWUSR);

would create a file called ".ble" in the current working directory,
instead of the correct "ble".

Change-Id: I1525a088d49744e29b760387afabef9f1ac98646
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/13005
Reviewed-by: Brandon Potter <Brandon.Potter@amd.com>
Maintainer: Brandon Potter <Brandon.Potter@amd.com>

syscall_emul: implement dir-related syscalls

Add getdents, rmdir, chdir, and mknod to SE mode for x86.

Change-Id: I387ea3066869e8999bc0064f74070f4e47c1e9a1
Reviewed-on: https://gem5-review.googlesource.com/12112
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Anthony Gutierrez <anthony.gutierrez@amd.com>

syscall_emul: adding symlink system call

Change-Id: Iebda05c130b4d2ee8434cad1e703933bfda486c8
Reviewed-on: https://gem5-review.googlesource.com/11490
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>

syscall_emul: adding link system call

Change-Id: If8922c2233bbe1f6fce35f64d1a44b91d2cfeed2
Reviewed-on: https://gem5-review.googlesource.com/11489
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Brandon Potter <Brandon.Potter@amd.com>

sim-se: Fix fallthrough in prlimit

Change-Id: Ieec4651000b3b4de05ba5ba11fdfa5392a5477e7
Signed-off-by: Jason Lowe-Power <jason@lowepower.com>
Reviewed-on: https://gem5-review.googlesource.com/8904
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Brandon Potter <Brandon.Potter@amd.com>

tarch, mem: Abstract the data stored in the SE page tables.

Rather than store the actual TLB entry that corresponds to a mapping,
we can just store some abstracted information (address, a few flags)
and then let the caller turn that into the appropriate entry. There
could potentially be some small amount of overhead from creating
entries vs. storing them and just installing them, but it's likely
pretty minimal since that only happens on a TLB miss (ideally rare),
and, if it is problematic, there could be some preallocated TLB
entries which are just minimally filled in as necessary.

This has the nice effect of finally making the page tables ISA
agnostic.

Change-Id: I11e630f60682f0a0029b0683eb8ff0135fbd4317
Reviewed-on: https://gem5-review.googlesource.com/7350
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>

arch-riscv,sim: Support clone syscall in RISC-V

(1) This patch sets a correct order of clone syscall's arguments for
RISC-V. Linux kernel 4.15 uses CLONE_BACKWARDS flag by default for
RISC-V. The flag in the Linux kernel defines the list of clone syscall's
arguments in the following order:

clone_flags (flags)
newsp (newStack)
parent_tidptr (ptidPtr)
tls (tlsPtr)
child_tidptr (ctidPtr)

Code reference:
https://github.com/riscv/riscv-linux/blob/master/kernel/fork.c
https://github.com/riscv/riscv-linux/blob/master/arch/riscv/Kconfig

(2) This patch copies a parent thread's register values to its child
thread in clone syscall.

Change-Id: I2eb1c8e80990861080ce7153503ed784fb2c7bdf
Reviewed-on: https://gem5-review.googlesource.com/6904
Maintainer: Brandon Potter <Brandon.Potter@amd.com>
Reviewed-by: Alec Roelke <ar4jc@virginia.edu>

sim: Fix a bug in prlimit syscall in SE mode

The old_limit pointer is supposed to be the 4th argument (index 3) of
the prlimit syscall. This patch sets old_limit pointer to the correct
argument.

Change-Id: I97808f7234cd2622cb3eb2f1e0beb7fc8cf492c1
Reviewed-on: https://gem5-review.googlesource.com/6903
Reviewed-by: Alec Roelke <ar4jc@virginia.edu>
Maintainer: Brandon Potter <Brandon.Potter@amd.com>

misc: Rename misc.(hh|cc) to logging.(hh|cc)

These files aren't a collection of miscellaneous stuff, they're the
definition of the Logger interface, and a few utility macros for
calling into that interface (panic, warn, etc.).

Change-Id: I84267ac3f45896a83c0ef027f8f19c5e9a5667d1
Reviewed-on: https://gem5-review.googlesource.com/6226
Reviewed-by: Brandon Potter <Brandon.Potter@amd.com>
Maintainer: Gabe Black <gabeblack@google.com>

sim-se: Add prlimit system call

Some ISAs (namely RISC-V) implement getrlimit and setrlimit using
prlimit. This patch adds an implementation for the prlimit system call.
Normally prlimit is supposed to provide the functionality of both
getrlimit and setrlimit, but because gem5 does not support setrlimit
this implementation of prlimit will simply display a warning and return
a failure code if the setrlimit mode is used. The same thing will happen
if a pid other than 0 is passed to it.

Change-Id: I653af2d5a60e716f4d6286196be7600409efcef8
Reviewed-on: https://gem5-review.googlesource.com/5321
Maintainer: Brandon Potter <Brandon.Potter@amd.com>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>

sim-se: Fix mremap for downward growing mmap regions

mremapFunc(...) did not respect Process::mmapGrowsDown(). This resulted
in an attempt to remap into an already allocated region and a panic in
FuncPageTable::allocate(...). This behavior can be observed in
435.gromacs.

Change-Id: Ib3ad33816126c76506d69679bdcefa7a98ef69f9
Reviewed-on: https://gem5-review.googlesource.com/4700
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Brandon Potter <Brandon.Potter@amd.com>

base, sim, arch: Fix clang 5.0 warnings

Compiling gem5 with recent version of clang (4 and 5) triggers
warnings that are treated as errors:

* Global templatized static functions result in a warning if they
are not used. These should either be declared as static inline or
without the static identifier to avoid the warning.

* Some templatized classes contain static variables. The
instantiated versions of these variables / templates need to be
explicitly declared to avoid a compiler warning.

Change-Id: Ie8261144836e94ebab7ea04ccccb90927672c257
Signed-off-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Curtis Dunham <curtis.dunham@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/3420
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>

syscall_emul: Fix undefined macro behavior

Clang's UBSAN implementation complains about macros that expand to
expressions that contain 'defined'. Explicitly set the various feature
macros to 1 or 0 to avoid this issue.

Change-Id: Iba239dacfe526c43ab9c5da5183a350fc4fdc57d
Signed-off-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Andreas Hansson <andreas.hansson@arm.com>
Reviewed-by: Curtis Dunham <curtis.dunham@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/3241

style: change NULL to nullptr in syscall files

Change-Id: I02719f3572f6665cace1eb5681f297dcde9e71ce
Reviewed-on: https://gem5-review.googlesource.com/2271
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Michael LeBeane <Michael.Lebeane@amd.com>
Reviewed-by: Tony Gutierrez <anthony.gutierrez@amd.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>

syscall-emul: Rewrite system call exit code

The changeset does a major refactor on the exit, exit_group, and
futex system calls regarding exit functionality.

A FutexMap class and related structures are added into a new
file. This increases code clarity by encapsulating the futex
operations and the futex state into an object.

Several exit conditions were added to allow the simulator to end
processes under certain conditions. Also, the simulation only
exits now when all processes have finished executing.

Change-Id: I1ee244caa9b5586fe7375e5b9b50fd3959b9655e
Reviewed-on: https://gem5-review.googlesource.com/2269
Maintainer: Jason Lowe-Power <jason@lowepower.com>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>

syscall-emul: Add the tgkill system call

This changeset adds support to kill a thread group by calling
the tgkill system call. The functionality is needed in some
pthread applications.

Change-Id: I0413a3331be69b74dfab30de95384113ec4efb63
Reviewed-on: https://gem5-review.googlesource.com/2268
Maintainer: Jason Lowe-Power <jason@lowepower.com>
Reviewed-by: Tony Gutierrez <anthony.gutierrez@amd.com>
Reviewed-by: Michael LeBeane <Michael.Lebeane@amd.com>

syscall-emul: Add or extend dup, dup2, and pipe

This changeset extends the pipe system call to work with
architectures other than Alpha (and enables the syscall for
x86). For the dup system call, it sets the clone-on-exec
flag by default. For the dup2 system call, the changeset
adds an implementation (and enables it for x86).

Change-Id: I00ddb416744ee7dd61a5cd02c4c3d97f30543878
Reviewed-on: https://gem5-review.googlesource.com/2266
Maintainer: Jason Lowe-Power <jason@lowepower.com>
Reviewed-by: Tony Gutierrez <anthony.gutierrez@amd.com>
Reviewed-by: Michael LeBeane <Michael.Lebeane@amd.com>

syscall-emul: Add functionality to open syscalls

This changeset adds refactors the existing open system call,
adds the openat variant (enabled for x86 builds), and adds
additional "special file" test cases for /proc/meminfo and
/etc/passwd.

Change-Id: I6f429db65bbf2a28ffa3fd12df518c2d0de49663
Reviewed-on: https://gem5-review.googlesource.com/2265
Maintainer: Jason Lowe-Power <jason@lowepower.com>
Reviewed-by: Tony Gutierrez <anthony.gutierrez@amd.com>
Reviewed-by: Michael LeBeane <Michael.Lebeane@amd.com>

style: Correct some style issues

This changeset fixes line alignment issues, spacing, spelling,
etc. for files that are used during SE Mode.

Change-Id: Ie61b8d0eb4ebb5af554d72f1297808027833616e
Reviewed-on: https://gem5-review.googlesource.com/2264
Maintainer: Jason Lowe-Power <jason@lowepower.com>
Reviewed-by: Tony Gutierrez <anthony.gutierrez@amd.com>
Reviewed-by: Michael LeBeane <Michael.Lebeane@amd.com>
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Pierre-Yves Péneau <pierre-yves.peneau@lirmm.fr>

syscall-emul: Move memState into its own file

The Process class is full of implementation details and
structures related to SE Mode. This changeset factors out an
internal class from Process and moves it into a separate file.
The purpose behind doing this is to clean up the code and make
it a bit more modular.

Change-Id: Ic6941a1657751e8d51d5b6b1dcc04f1195884280
Reviewed-on: https://gem5-review.googlesource.com/2263
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>

syscall_emul: [PATCH 15/22] add clone/execve for threading and multiprocess simulations

Modifies the clone system call and adds execve system call. Requires allowing
processes to steal thread contexts from other processes in the same system
object and the ability to detach pieces of process state (such as MemState)
to allow dynamic sharing.

syscall_emul: [patch 14/22] adds identifier system calls

This changeset add fields to the process object and adds the following
three system calls: setpgid, gettid, getpid.

syscall_emul: [patch 11/22] extend functionality of fcntl

This changeset adds the ability to set a close-on-exec flag for a given
file descriptor. It also reworks some of the logic surrounding setting and
retrieving flags from the file description.

syscall_emul: [patch 10/22] refactor fdentry and add fdarray class

Several large changes happen in this patch.

The FDEntry class is rewritten so that file descriptors now correspond to
types: 'File' which is normal file-backed file with the file open on the
host machine, 'Pipe' which is a pipe that has been opened on the host machine,
and 'Device' which does not have an open file on the host yet acts as a pseudo
device with which to issue ioctls. Other types which might be added in the
future are directory entries and sockets (off the top of my head).

The FDArray class was create to hold most of the file descriptor handling
that was stuffed into the Process class. It uses shared pointers and
the std::array type to hold the FDEntries mentioned above.

The changes to these two classes needed to be propagated out to the rest
of the code so there were quite a few changes for that. Also, comments were
added where I thought they were needed to help others and extend our
DOxygen coverage.

syscall_emul: [patch 5/22] remove LiveProcess class and use Process instead

The EIOProcess class was removed recently and it was the only other class
which derived from Process. Since every Process invocation is also a
LiveProcess invocation, it makes sense to simplify the organization by
combining the fields from LiveProcess into Process.

sim: Patch to fix the statfs build

See developers mailing list. Trying to unbreak statfs.

Testing Done:
Builds on FreeBSD now.

Reviewed at http://reviews.gem5.org/r/3803/

Signed-off-by: Jason Lowe-Power <jason@lowepower.com>

style: [patch 3/22] reduce include dependencies in some headers

Used cppclean to help identify useless includes and removed them. This
involved erroneously included headers, but also cases where forward
declarations could have been used rather than a full include.

syscall_emul: #ifdef new system calls to allow builds on OSX and BSD

syscall_emul: [patch 2/22] move SyscallDesc into its own .hh and .cc

The class was crammed into syscall_emul.hh which has tons of forward
declarations and template definitions. To clean it up a bit, moved the
class into separate files and commented the class with doxygen style
comments. Also, provided some encapsulation by adding some accessors and
a mutator.

The syscallreturn.hh file was renamed syscall_return.hh to make it consistent
with other similarly named files in the src/sim directory.

The DPRINTF_SYSCALL macro was moved into its own header file with the
include the Base and Verbose flags as well.

syscall_emul: implement fallocate

syscall_emul: add support for x86 statfs system calls

syscall_emul: extend sysinfo system call to include mem_unit

sim, syscall_emul: Add mmap to EmulatedDriver
Add support for calling mmap on an EmulatedDriver file descriptor.

sim: fix issues with pwrite(); don't enable fstatfs

this patch fixes issues with changeset 11593

use the host's pwrite() syscall for pwrite64Func(),
as opposed to pwrite64(), because pwrite64() does
not work well on all distros.

undo the enabling of fstatfs, as we will add this
in a separate pate.

x86, sim: add some syscalls to X86

this patch adds an implementation for the pwrite64 syscall and
enables it for x86_64, and enables fstatfs for x86_64.

base: add symbol support for dynamic libraries

Libraries are loaded into the process address space using the
mmap system call. Conveniently, this happens to be a good
time to update the process symbol table with the library's
incoming symbols so we handle the table update from within the
system call.

This works just like an application's normal symbols. The only
difference between a dynamic library and a main executable is
when the symbol table update occurs. The symbol table update for
an executable happens at program load time and is finished before
the process ever begins executing. Since dynamic linking happens
at runtime, the symbol loading happens after the library is
first loaded into the process address space. The library binary
is examined at this time for a symbol section and that section
is parsed for symbol types with specific bindings (global,
local, weak). Subsequently, these symbols are added to the table
and are available for use by gem5 for things like trace
generation.

Checkpointing should work just as it did previously. The address
space (and therefore the library) will be recorded and the symbol
table will be entirely recorded. (It's not possible to do anything
clever like checkpoint a program and then load the program back
with different libraries with LD_LIBRARY_PATH, because the
library becomes part of the address space after being loaded.)

syscall_emul: move mmapGrowsDown() to LiveProcess

The mmapGrowsDown() method was a static method on the OperatingSystem
class (and derived classes), which worked OK for the templated syscall
emulation methods, but made it hard to access elsewhere. This patch
moves the method to be a virtual function on the LiveProcess method,
where it can be overridden for specific platforms (for now, Alpha).

This patch also changes the value of mmapGrowsDown() from being false
by default and true only on X86Linux32 to being true by default and
false only on Alpha, which seems closer to reality (though in reality
most people use ASLR and this doesn't really matter anymore).

In the process, also got rid of the unused mmap_start field on
LiveProcess and OperatingSystem mmapGrowsUp variable.

syscall_emul: fix bugs for mmap2 system call and x86-32 syscalls

syscall_emul: extend mmap system call to support file backed mmaps

For O3, which has a stat that counts reg reads, there is an additional
reg read per mmap() call since there's an arg we no longer ignore.
Otherwise, stats should not be affected.

syscall_emul: add extra debug support for syscalls

Breaks the debug output from system calls into two levels: Base and Verbose.
A macro is added specifically for system calls which allows developers to
easily add new debug messages in a consistent manner. The macro also contains
a field to print thread IDs along with the CPU ID.

syscall_emul: Fix erroneous use of delete

clang correctly points out an erroneous use of delete.

syscall_emul: Implement clock_getres() system call

This patch implements the clock_getres() system call for arm and x86 in linux
SE mode.

style: fix missing spaces in control statements

Result of running 'hg m5style --skip-all --fix-control -a'.

style: change Process function calls to use camelCase

The Process class methods were using an improper style and this subsequently
bled into the system call code. The following regular expressions should be
helpful if someone transitions private system call patches on top of these
changesets:

s/alloc_fd/allocFD/
s/sim_fd(/simFD(/
s/sim_fd_obj/getFDEntry/
s/fix_file_offsets/fixFileOffsets/
s/find_file_offsets/findFileOffsets/

syscall_emul: standardized file descriptor name and add return checks.

The patch clarifies whether file descriptors are host file descriptors or
target file descriptors in the system call code. (Host file descriptors
are file descriptors which have been allocated through real system calls
where target file descriptors are allocated from an array in the Process
class.)

base: refactor process class (specifically FdMap and friends)

This patch extends the previous patch's alterations around fd_map. It cleans
up some of the uglier code in the process file and replaces it with a more
concise C++11 version. As part of the changes, the FdMap class is pulled out
of the Process class and receives its own file.

arm: Implement some missing syscalls (SE mode)

Adding a few syscalls that were previously considered unimplemented.

syscall_emul: fix warn_once behavior

The current ignoreWarnOnceFunc doesn't really work as expected,
since it will only generate one warning total, for whichever
"warn-once" syscall is invoked first. This patch fixes that
behavior by keeping a "warned" flag in the SyscallDesc object,
allowing suitably flagged syscalls to warn exactly once per
syscall.

syscall_emul: implement clock_gettime system call

syscall_emul: update getrlimit to use warn
Don't use std::cerr directly, and just return EINVAL instead of aborting.

syscall_emul: fix warning with wrong syscall name
Also nix extra whitespace.

arm: Add unlinkat syscall implementation

added ARM aarch64 unlinkat syscall support, modeled on other <xxx>at syscalls.
This gets all of the cpu2006 int workloads passing in SE mode on aarch64.

Committed by: Nilay Vaish <nilay@cs.wisc.edu>

syscall_emul: Return correct writev value

According to Linux man pages, if writev is successful, it returns the total
number of bytes written. Otherwise, it returns an error code. Instead of
returning 0, return the result from the actual call to writev in the system
call.

syscall_emul: Put BufferArg classes in a separate header.

Move the BufferArg classes that support syscall buffer args
(i.e., pointers into simulated user space) out of syscall_emul.hh
and into a new header syscall_emul_buf.hh so they are accessible
to emulated driver implementations.

Take the opportunity to add some comments as well.

syscall_emul: add EmulatedDriver object

Fake SE-mode device drivers can now be added by
deriving from this abstract object.

sim: revert 6709bbcf564d
The identifier SYS_getdents is not available on Mac OS X. Therefore, its use
results in compilation failure. It seems there is no straight forward way to
implement the system call getdents using readdir() or similar C functions.
Hence the commit 6709bbcf564d is being rolled back.

sim: invalid alignment checks in mmap and mremap
Presently, the alignment checks in the mmap and mremap implementations
in syscall_emul.hh are wrong. The checks are implemented as:

if ((start % TheISA::PageBytes) != 0 ||
(length % TheISA::PageBytes) != 0) {
warn("mmap failing: arguments not page-aligned: "
"start 0x%x length 0x%x",
start, length);
return -EINVAL;
}

This checks that both the start and the length arguments of the mmap
syscall are checked for page-alignment. However, the POSIX specification says:

The off argument is constrained to be aligned and sized according to the value
returned by sysconf() when passed _SC_PAGESIZE or _SC_PAGE_SIZE. When MAP_FIXED
is specified, the application shall ensure that the argument addr also meets
these constraints. The implementation performs mapping operations over whole
pages. Thus, while the argument len need not meet a size or alignment
constraint, the implementation shall include, in any mapping operation, any
partial page specified by the range [pa,pa+len).

So the length parameter should not be checked for page-alignment. By contrast,
the current implementation fails to check the offset argument, which must be
page aligned.

Committed by: Nilay Vaish <nilay@cs.wisc.edu>

sim: mmap: correct behavior for fixed address
Change mmap fixed address request to return an error if the mapping is
impossible due to conflict instead of what I believe used to be silent
corruption.

Committed by: Nilay Vaish <nilay@cs.wisc.edu>

sim: implement getdents/getdents64 in user mode

Has been tested only for alpha.
Committed by: Nilay Vaish <nilay@cs.wisc.edu>

arch: Cleanup unused ISA traits constants

This patch prunes unused values, and also unifies how the values are
defined (not using an enum for ALPHA), aligning the use of int vs Addr
etc.

The patch also removes the duplication of PageBytes/PageShift and
VMPageSize/LogVMPageSize. For all ISAs the two pairs had identical
values and the latter has been removed.

sim, arm: implement more of the at variety syscalls

Needed for new AArch64 binaries

sim: Add openat/fstatat syscalls and fix mremap

This patch adds support for the openat and fstatat syscalls and
broadens the support for mremap to make it work on OS X.

arm: add access syscall for ARM SE mode

This patch adds the "access" syscall for ARM SE as required by some spec2006
benchmarks.

SE: Ignore FUTEX_PRIVATE_FLAG of sys_futex

This patch ignores the FUTEX_PRIVATE_FLAG of the sys_futex system call
in SE mode.

With this patch, when sys_futex with the options FUTEX_WAIT_PRIVATE or
FUTEX_WAKE_PRIVATE is emulated, the FUTEX_PRIVATE_FLAG is ignored and
so their behaviours are the regular FUTEX_WAIT and FUTEX_WAKE.

Emulating FUTEX_WAIT_PRIVATE and FUTEX_WAKE_PRIVATE as if they were
non-private is safe from a functional point of view. The
FUTEX_PRIVATE_FLAG does not change the semantics of the futex, it's
just a mechanism to improve performance under certain circunstances
that can be ignored in SE mode.

NetBSD: Build on NetBSD

Minor patch against so building on NetBSD is possible.

syscall_emul: clean up open() code a bit.

str: add an overloaded startswith() utility method
for various string types and use it in a few places.

syscall emulation: Clean up ioctl handling, and implement for x86.

Enable different whitelists for different OS/arch combinations,
since some use the generic Linux definitions only, and others
use definitions inherited from earlier Unix flavors on those
architectures.

Also update x86 function pointers so ioctl is no longer
unimplemented on that platform.

This patch is a revised version of Vince Weaver's earlier patch.

syscall emulation: Add the futex system call.

Syscalls: warn when the length argument to mmap is excessive.

If the length argument to mmap is larger than the arbitrary but reasonable
limit of 4GB, there's a good chance that the value is nonsense and not
intentional. Rather than attempting to satisfy the mmap anyway, this change
makes gem5 warn to make it more apparent what's going wrong.

MEM: Make port proxies use references rather than pointers

This patch is adding a clearer design intent to all objects that would
not be complete without a port proxy by making the proxies members
rathen than dynamically allocated. In essence, if NULL would not be a
valid value for the proxy, then we avoid using a pointer to make this
clear.

The same approach is used for the methods using these proxies, such as
loadSections, that now use references rather than pointers to better
reflect the fact that NULL would not be an acceptable value (in fact
the code would break and that is how this patch started out).

Overall the concept of "using a reference to express unconditional
composition where a NULL pointer is never valid" could be done on a
much broader scale throughout the code base, but for now it is only
done in the locations affected by the proxies.

Merge with head, hopefully the last time for this batch.

Merge with the main repo.

Merge with main repository.

SE/FS: Build the base process class in FS.

clang: Enable compiling gem5 using clang 2.9 and 3.0

This patch adds the necessary flags to the SConstruct and SConscript
files for compiling using clang 2.9 and later (on Ubuntu et al and OSX
XCode 4.2), and also cleans up a bunch of compiler warnings found by
clang. Most of the warnings are related to hidden virtual functions,
comparisons with unsigneds >= 0, and if-statements with empty
bodies. A number of mismatches between struct and class are also
fixed. clang 2.8 is not working as it has problems with class names
that occur in multiple namespaces (e.g. Statistics in
kernel_stats.hh).

clang has a bug (http://llvm.org/bugs/show_bug.cgi?id=7247) which
causes confusion between the container std::set and the function
Packet::set, and this is currently addressed by not including the
entire namespace std, but rather selecting e.g. "using std::vector" in
the appropriate places.

MEM: Add port proxies instead of non-structural ports

Port proxies are used to replace non-structural ports, and thus enable
all ports in the system to correspond to a structural entity. This has
the advantage of accessing memory through the normal memory subsystem
and thus allowing any constellation of distributed memories, address
maps, etc. Most accesses are done through the "system port" that is
used for loading binaries, debugging etc. For the entities that belong
to the CPU, e.g. threads and thread contexts, they wrap the CPU data
port in a port proxy.

The following replacements are made:
FunctionalPort > PortProxy
TranslatingPort > SETranslatingPortProxy
VirtualPort > FSTranslatingPortProxy

SE: move page allocation from PageTable to Process

PageTable supported an allocate() call that called back
through the Process to allocate memory, but did not have
a method to map addresses without allocating new pages.
It makes more sense for Process to do the allocation, so
this method was renamed allocateMem() and moved to Process,
and uses a new map() call on PageTable.

The remaining uses of the process pointer in PageTable
were only to get the name and the PID, so by passing these
in directly in the constructor, we can make PageTable
completely independent of Process.

syscall_emul: implement MAP_FIXED option to mmap()

syscall emul: fix Power Linux mmap constant, plus other cleanup

We were getting a spurious warning in the regressions that turned
out to be due to having the wrong value for TGT_MAP_ANONYMOUS for
Power Linux, but in the process of tracking it down I ended up
doing some cleanup of the mmap handling in general.

trace: reimplement the DTRACE function so it doesn't use a vector
At the same time, rename the trace flags to debug flags since they
have broader usage than simply tracing. This means that
--trace-flags is now --debug-flags and --trace-help is now --debug-help

includes: sort all includes

ARM: Add minimal ARM_SE support for m5threads.

Updated some of the assembly code sequences to use armv7 instructions and
coprocessor 15 for storing the TLS pointer.

Replace curTick global variable with accessor functions.
This step makes it easy to replace the accessor functions
(which still access a global variable) with ones that access
per-thread curTick values.

ISA,CPU,etc: Create an ISA defined PC type that abstracts out ISA behaviors.



This change is a low level and pervasive reorganization of how PCs are managed
in M5. Back when Alpha was the only ISA, there were only 2 PCs to worry about,
the PC and the NPC, and the lsb of the PC signaled whether or not you were in
PAL mode. As other ISAs were added, we had to add an NNPC, micro PC and next
micropc, x86 and ARM introduced variable length instruction sets, and ARM
started to keep track of mode bits in the PC. Each CPU model handled PCs in
its own custom way that needed to be updated individually to handle the new
dimensions of variability, or, in the case of ARMs mode-bit-in-the-pc hack,
the complexity could be hidden in the ISA at the ISA implementation's expense.
Areas like the branch predictor hadn't been updated to handle branch delay
slots or micropcs, and it turns out that had introduced a significant (10s of
percent) performance bug in SPARC and to a lesser extend MIPS. Rather than
perpetuate the problem by reworking O3 again to handle the PC features needed
by x86, this change was introduced to rework PC handling in a more modular,
transparent, and hopefully efficient way.


PC type:

Rather than having the superset of all possible elements of PC state declared
in each of the CPU models, each ISA defines its own PCState type which has
exactly the elements it needs. A cross product of canned PCState classes are
defined in the new "generic" ISA directory for ISAs with/without delay slots
and microcode. These are either typedef-ed or subclassed by each ISA. To read
or write this structure through a *Context, you use the new pcState() accessor
which reads or writes depending on whether it has an argument. If you just
want the address of the current or next instruction or the current micro PC,
you can get those through read-only accessors on either the PCState type or
the *Contexts. These are instAddr(), nextInstAddr(), and microPC(). Note the
move away from readPC. That name is ambiguous since it's not clear whether or
not it should be the actual address to fetch from, or if it should have extra
bits in it like the PAL mode bit. Each class is free to define its own
functions to get at whatever values it needs however it needs to to be used in
ISA specific code. Eventually Alpha's PAL mode bit could be moved out of the
PC and into a separate field like ARM.

These types can be reset to a particular pc (where npc = pc +
sizeof(MachInst), nnpc = npc + sizeof(MachInst), upc = 0, nupc = 1 as
appropriate), printed, serialized, and compared. There is a branching()
function which encapsulates code in the CPU models that checked if an
instruction branched or not. Exactly what that means in the context of branch
delay slots which can skip an instruction when not taken is ambiguous, and
ideally this function and its uses can be eliminated. PCStates also generally
know how to advance themselves in various ways depending on if they point at
an instruction, a microop, or the last microop of a macroop. More on that
later.

Ideally, accessing all the PCs at once when setting them will improve
performance of M5 even though more data needs to be moved around. This is
because often all the PCs need to be manipulated together, and by getting them
all at once you avoid multiple function calls. Also, the PCs of a particular
thread will have spatial locality in the cache. Previously they were grouped
by element in arrays which spread out accesses.


Advancing the PC:

The PCs were previously managed entirely by the CPU which had to know about PC
semantics, try to figure out which dimension to increment the PC in, what to
set NPC/NNPC, etc. These decisions are best left to the ISA in conjunction
with the PC type itself. Because most of the information about how to
increment the PC (mainly what type of instruction it refers to) is contained
in the instruction object, a new advancePC virtual function was added to the
StaticInst class. Subclasses provide an implementation that moves around the
right element of the PC with a minimal amount of decision making. In ISAs like
Alpha, the instructions always simply assign NPC to PC without having to worry
about micropcs, nnpcs, etc. The added cost of a virtual function call should
be outweighed by not having to figure out as much about what to do with the
PCs and mucking around with the extra elements.

One drawback of making the StaticInsts advance the PC is that you have to
actually have one to advance the PC. This would, superficially, seem to
require decoding an instruction before fetch could advance. This is, as far as
I can tell, realistic. fetch would advance through memory addresses, not PCs,
perhaps predicting new memory addresses using existing ones. More
sophisticated decisions about control flow would be made later on, after the
instruction was decoded, and handed back to fetch. If branching needs to
happen, some amount of decoding needs to happen to see that it's a branch,
what the target is, etc. This could get a little more complicated if that gets
done by the predecoder, but I'm choosing to ignore that for now.


Variable length instructions:

To handle variable length instructions in x86 and ARM, the predecoder now
takes in the current PC by reference to the getExtMachInst function. It can
modify the PC however it needs to (by setting NPC to be the PC + instruction
length, for instance). This could be improved since the CPU doesn't know if
the PC was modified and always has to write it back.


ISA parser:

To support the new API, all PC related operand types were removed from the
parser and replaced with a PCState type. There are two warts on this
implementation. First, as with all the other operand types, the PCState still
has to have a valid operand type even though it doesn't use it. Second, using
syntax like PCS.npc(target) doesn't work for two reasons, this looks like the
syntax for operand type overriding, and the parser can't figure out if you're
reading or writing. Instructions that use the PCS operand (which I've
consistently called it) need to first read it into a local variable,
manipulate it, and then write it back out.


Return address stack:

The return address stack needed a little extra help because, in the presence
of branch delay slots, it has to merge together elements of the return PC and
the call PC. To handle that, a buildRetPC utility function was added. There
are basically only two versions in all the ISAs, but it didn't seem short
enough to put into the generic ISA directory. Also, the branch predictor code
in O3 and InOrder were adjusted so that they always store the PC of the actual
call instruction in the RAS, not the next PC. If the call instruction is a
microop, the next PC refers to the next microop in the same macroop which is
probably not desirable. The buildRetPC function advances the PC intelligently
to the next macroop (in an ISA specific way) so that that case works.


Change in stats:

There were no change in stats except in MIPS and SPARC in the O3 model. MIPS
runs in about 9% fewer ticks. SPARC runs with 30%-50% fewer ticks, which could
likely be improved further by setting call/return instruction flags and taking
advantage of the RAS.


TODO:

Add != operators to the PCState classes, defined trivially to be !(a==b).
Smooth out places where PCs are split apart, passed around, and put back
together later. I think this might happen in SPARC's fault code. Add ISA
specific constructors that allow setting PC elements without calling a bunch
of accessors. Try to eliminate the need for the branching() function. Factor
out Alpha's PAL mode pc bit into a separate flag field, and eliminate places
where it's blindly masked out or tested in the PC.

Faults: Pass the StaticInst involved, if any, to a Fault's invoke method.

Also move the "Fault" reference counted pointer type into a separate file,
sim/fault.hh. It would be better to name this less similarly to sim/faults.hh
to reduce confusion, but fault.hh matches the name of the type. We could change
Fault to FaultPtr to match other pointer types, and then changing the name of
the file would make more sense.

compile: don't #include unnecessary stuff
Time from base/time.hh has a name clash with Time from Ruby's
TypeDefines.hh. Eventually Ruby's Time should go away, so instead of
fixing this properly just try to avoid the clash.

tick: rename Clock namespace to SimClock

SE: Fix SE mode OS X compilation.

SysCalls: Implement truncate64 system call

This uses the new stack-based argument infrastructure.

Tested on x86 and x86_64.

Syscalls: Make system calls access arguments like a stack, not an array.

When accessing arguments for a syscall, the position of an argument depends on
the policies of the ISA, how much space preceding arguments took up, and the
"alignment" of the index for this particular argument into the number of
possible storate locations. This change adjusts getSyscallArg to take its
index parameter by reference instead of value and to adjust it to point to the
possible location of the next argument on the stack, basically just after the
current one. This way, the rules for the new argument can be applied locally
without knowing about other arguments since those have already been taken into
account implicitly.

All system calls have also been changed to reflect the new interface. In a
number of cases this made the implementation clearer since it encourages
arguments to be collected in one place in order and then used as necessary
later, as opposed to scattering them throughout the function or using them in
place in long expressions. It also discourages using getSyscallArg over and
over to retrieve the same value when a temporary would do the job.

syscall: Addition of an ioctl command code for Power.

syscall: Fix conversion of the stat64 buffer during system calls.

syscall: Implementation of the ftruncate64 system call.

syscall: Implementation of the time system call.

syscall: Implementation of the times system call

SE mode: Make the direction anonymous mmaps move through memory configurable.

arch: nuke arch/isa_specific.hh and move stuff to generated config/the_isa.hh

Syscalls: Implement sysinfo() syscall.

types: clean up types, especially signed vs unsigned

includes: sort includes again

types: Move stuff for global types into src/base/types.hh

Commit m5threads package.

This patch adds limited multithreading support in syscall-emulation
mode, by using the clone system call. The clone system call works
for Alpha, SPARC and x86, and multithreaded applications run
correctly in Alpha and SPARC.

Processes: Make getting and setting system call arguments part of a process object.

sycalls: implement mremap() and add DATA flag for getrlimit(). mremap has been tested on Alpha, compiles for the rest but not tested. I don't see why it wouldn't work though.

Fix issue 326: glibc non-deterministic because it reads /proc

syscalls: fix latent brk/obreak bug.
Bogus calls to ChunkGenerator with negative size were triggering
a new assertion that was added there.
Also did a little renaming and cleanup in the process.

style: Remove non-leading tabs everywhere they shouldn't be. Developers should configure their editors to not insert tabs

syscall: Fix TTY emulation in fstat() user-mode simulation for fd 1 (stdout).
The code didn't set S_IFCHR in the st_mode

syscalls: Add a bunch of missing system calls.
readlink, umask, truncate, ftruncate, mkdir, and getcwd.

Serialization: Fix serialization of file descriptors. Make sure open
file descriptors are reopened and the file pointer is in the same
place as when the checkpoint occured.

Signed-off by: Ali Saidi

SE: fix stat64 syscall on os x

Syscall Emulation: Add stat64 syscall.

Patch submitted by: Jonas Diemer [diemer (a) ida.ing.tu-bs.de]

Use the TheISA namespace in case we're coming from a file that doesn't do that for us. This should be contained in the scope of the function and not leak elsewhere.

Don't use the exact same name as a system header #define

Implement the _llseek syscall. It's Linux only, so we'll actually use the lseek syscall.

Force the st_blksize field of a stat call to be 8k.

implement RUSAGE_CHILDREN for getrusage since it's trivial

Implement current working directory for LiveProcesses

Added in missing portions of the stat structure copying function.

Finished changing how stat structures are translated, fixed the handling of various ids as LiveProcess parameters.

src/arch/alpha/linux/process.cc:
src/arch/alpha/linux/process.hh:
src/arch/alpha/process.cc:
src/arch/alpha/process.hh:
src/arch/alpha/tru64/process.cc:
src/arch/alpha/tru64/process.hh:
src/arch/mips/linux/process.cc:
src/arch/mips/linux/process.hh:
src/arch/mips/process.cc:
src/arch/mips/process.hh:
src/arch/sparc/linux/process.cc:
src/arch/sparc/linux/process.hh:
src/arch/sparc/process.cc:
src/arch/sparc/process.hh:
src/arch/sparc/solaris/process.cc:
src/arch/sparc/solaris/process.hh:
src/sim/process.cc:
src/sim/process.hh:
src/sim/syscall_emul.cc:
src/sim/syscall_emul.hh:
Changed Process to LiveProcess in syscall handlers and fixed the implementation of uid, euid, gid, egid, pid and ppid as LiveProcess parameters.
src/kern/tru64/tru64.hh:
Changed Process to LiveProcess in syscall handlers and fixed the implementation of uid, euid, gid, egid, pid and ppid as LiveProcess parameters. Also fit tru64 in with the new way to handle stat calls.

Changes to correct stat behavior

Add dup() support (from Antti Miettinen).

Fix so that O3CPU doesnt segfault on exit.
Major thing was to not execute commit if there are no active threads in CPU.

src/cpu/o3/alpha/thread_context.hh:
call deallocate instead of deallocateContext
src/cpu/o3/commit_impl.hh:
dont run commit stage if there are no instructions
src/cpu/o3/cpu.cc:
add deallocate event, deactivateThread function, and edit deallocateContext.
src/cpu/o3/cpu.hh:
add deallocate event and add optional delay to deallocateContext
src/cpu/o3/thread_context.hh:
optional delay for deallocate
src/cpu/o3/thread_context_impl.hh:
edit DPRINTFs to say Thread Context instead of Alpha TC
src/cpu/thread_context.hh:
optional delay
src/sim/syscall_emul.hh:
name stuff

Fixes to compile under Cygwin.

src/kern/linux/linux.hh:
src/kern/solaris/solaris.hh:
Rename BSD_HOST to the more specific NO_STAT64.
src/sim/byteswap.hh:
Replace set of swap_byte functions with a single
templated version. Hope this fixes compiler issues
with e.g. int32_t vs int disambiguation.
src/sim/syscall_emul.hh:
Rename BSD_HOST to the more specific NO_STAT64.
Set this for __CYGWIN__.

Authorship stuff

src/sim/syscall_emul.cc:
Authorship Stuff

add fcntl64Func

use ThreadContext rename

src/arch/mips/isa/formats/branch.isa:
src/arch/mips/isa/formats/fp.isa:
src/arch/mips/isa/includes.isa:
Use ThreadContext
src/sim/syscall_emul.cc:
fcntl64 function using TC
src/sim/syscall_emul.hh:
Add fcntl64func

Change ExecContext to ThreadContext. This is being renamed to differentiate between the interface used objects outside of the CPU, and the interface used by the ISA. ThreadContext is used by objects outside of the CPU and is specifically defined in thread_context.hh. ExecContext is more implicit, and is defined by files such as base_dyn_inst.hh or cpu/simple/base.hh.

Further renames/reorganization will be coming shortly; what is currently CPUExecContext (the old ExecContext from m5) will be renamed to SimpleThread or something similar.

src/arch/alpha/arguments.cc:
src/arch/alpha/arguments.hh:
src/arch/alpha/ev5.cc:
src/arch/alpha/faults.cc:
src/arch/alpha/faults.hh:
src/arch/alpha/freebsd/system.cc:
src/arch/alpha/freebsd/system.hh:
src/arch/alpha/isa/branch.isa:
src/arch/alpha/isa/decoder.isa:
src/arch/alpha/isa/main.isa:
src/arch/alpha/linux/process.cc:
src/arch/alpha/linux/system.cc:
src/arch/alpha/linux/system.hh:
src/arch/alpha/linux/threadinfo.hh:
src/arch/alpha/process.cc:
src/arch/alpha/regfile.hh:
src/arch/alpha/stacktrace.cc:
src/arch/alpha/stacktrace.hh:
src/arch/alpha/tlb.cc:
src/arch/alpha/tlb.hh:
src/arch/alpha/tru64/process.cc:
src/arch/alpha/tru64/system.cc:
src/arch/alpha/tru64/system.hh:
src/arch/alpha/utility.hh:
src/arch/alpha/vtophys.cc:
src/arch/alpha/vtophys.hh:
src/arch/mips/faults.cc:
src/arch/mips/faults.hh:
src/arch/mips/isa_traits.cc:
src/arch/mips/isa_traits.hh:
src/arch/mips/linux/process.cc:
src/arch/mips/process.cc:
src/arch/mips/regfile/float_regfile.hh:
src/arch/mips/regfile/int_regfile.hh:
src/arch/mips/regfile/misc_regfile.hh:
src/arch/mips/regfile/regfile.hh:
src/arch/mips/stacktrace.hh:
src/arch/sparc/faults.cc:
src/arch/sparc/faults.hh:
src/arch/sparc/isa_traits.hh:
src/arch/sparc/linux/process.cc:
src/arch/sparc/linux/process.hh:
src/arch/sparc/process.cc:
src/arch/sparc/regfile.hh:
src/arch/sparc/solaris/process.cc:
src/arch/sparc/stacktrace.hh:
src/arch/sparc/ua2005.cc:
src/arch/sparc/utility.hh:
src/arch/sparc/vtophys.cc:
src/arch/sparc/vtophys.hh:
src/base/remote_gdb.cc:
src/base/remote_gdb.hh:
src/cpu/base.cc:
src/cpu/base.hh:
src/cpu/base_dyn_inst.hh:
src/cpu/checker/cpu.cc:
src/cpu/checker/cpu.hh:
src/cpu/checker/exec_context.hh:
src/cpu/cpu_exec_context.cc:
src/cpu/cpu_exec_context.hh:
src/cpu/cpuevent.cc:
src/cpu/cpuevent.hh:
src/cpu/exetrace.hh:
src/cpu/intr_control.cc:
src/cpu/memtest/memtest.hh:
src/cpu/o3/alpha_cpu.hh:
src/cpu/o3/alpha_cpu_impl.hh:
src/cpu/o3/alpha_dyn_inst_impl.hh:
src/cpu/o3/commit.hh:
src/cpu/o3/commit_impl.hh:
src/cpu/o3/cpu.cc:
src/cpu/o3/cpu.hh:
src/cpu/o3/fetch_impl.hh:
src/cpu/o3/regfile.hh:
src/cpu/o3/thread_state.hh:
src/cpu/ozone/back_end.hh:
src/cpu/ozone/cpu.hh:
src/cpu/ozone/cpu_impl.hh:
src/cpu/ozone/front_end.hh:
src/cpu/ozone/front_end_impl.hh:
src/cpu/ozone/inorder_back_end.hh:
src/cpu/ozone/lw_back_end.hh:
src/cpu/ozone/lw_back_end_impl.hh:
src/cpu/ozone/lw_lsq.hh:
src/cpu/ozone/lw_lsq_impl.hh:
src/cpu/ozone/thread_state.hh:
src/cpu/pc_event.cc:
src/cpu/pc_event.hh:
src/cpu/profile.cc:
src/cpu/profile.hh:
src/cpu/quiesce_event.cc:
src/cpu/quiesce_event.hh:
src/cpu/simple/atomic.cc:
src/cpu/simple/base.cc:
src/cpu/simple/base.hh:
src/cpu/simple/timing.cc:
src/cpu/static_inst.cc:
src/cpu/static_inst.hh:
src/cpu/thread_state.hh:
src/dev/alpha_console.cc:
src/dev/ns_gige.cc:
src/dev/sinic.cc:
src/dev/tsunami_cchip.cc:
src/kern/kernel_stats.cc:
src/kern/kernel_stats.hh:
src/kern/linux/events.cc:
src/kern/linux/events.hh:
src/kern/system_events.cc:
src/kern/system_events.hh:
src/kern/tru64/dump_mbuf.cc:
src/kern/tru64/tru64.hh:
src/kern/tru64/tru64_events.cc:
src/kern/tru64/tru64_events.hh:
src/mem/vport.cc:
src/mem/vport.hh:
src/sim/faults.cc:
src/sim/faults.hh:
src/sim/process.cc:
src/sim/process.hh:
src/sim/pseudo_inst.cc:
src/sim/pseudo_inst.hh:
src/sim/syscall_emul.cc:
src/sim/syscall_emul.hh:
src/sim/system.cc:
src/cpu/thread_context.hh:
src/sim/system.hh:
src/sim/vptr.hh:
Change ExecContext to ThreadContext.

Updated Authors from bk prs info

New directory structure:
- simulator source now in 'src' subdirectory
- imported files from 'ext' repository
- support building in arbitrary places, including
outside of the source tree. See comment at top
of SConstruct file for more details.
Regression tests are temporarily disabled; that
syetem needs more extensive revisions.

SConstruct:
Update for new directory structure.
Modify to support build trees that are not subdirectories
of the source tree. See comment at top of file for
more details.
Regression tests are temporarily disabled.
src/arch/SConscript:
src/arch/isa_parser.py:
src/python/SConscript:
Update for new directory structure.