this contains still prototyped code, which if reached either
hangs (setjmp, longjmp), aborts (all that requires mmu::),
or implements differently (allocating with malloc instead of mmap)
This is enough libc AArch64 support for reaching the end of premain.

Signed-off-by: Claudio Fontana <claudio.fontana@huawei.com>

The current ballooning mechanism has a very serious design flaw, that became
obvious once the tests with it advanced: if we wait until memory is short to
release memory, it may be that the JVM itself may block. In particular, the
blocking thread can be running the Garbage Collector. More likely, it can
start running the GC to open up space for an object so big as the balloon.

I don't believe this is something we should fix with a quick hack, and I am
then pushing for a redesign: The solution is to use a reservation system, that
works by ballooning beforehand when the amount of reserved memory goes too low.

This system works by noting that when we balloon, we are effectively limiting
the maximum amount of memory java will ever use. We already have accounts of
both the amount of free memory and the amount of memory allocated to the heap.
With those figures, we can easily find out when the amount of used memory +
a full heap would go over the amount of available memory. When that happens,
we balloon.

Signed-off-by: Glauber Costa <glommer@cloudius-systems.com>

We can determine which mappings from the JVM are heap areas in a more
robust way by flipping a flag when we start JVM creation, and flipping
it back when we are finished. Doing this early is more robust and should
work better with a bigger set of GCs.

Although this is a heuristic, Calle agrees this is safe, and it has
been tested and confirmed to work with the following options:

    -XX:+UseSerialGC
    -XX:+UseG1GC
    -XX:+UseParallelGC
    -XX:+UseParallelOldGC
    -XX:+UseParNewGC
    -XX:+UseConcMarkSweepGC
    -XX:+UseConcMarkSweepGC

which pretty much covers all relevant GCs

Signed-off-by: Glauber Costa <glommer@cloudius-systems.com>

Implement __sysv_signal(), which is used by code using signal() when compiled
with _XOPEN_SOURCE, -std=..., or something similar (see signal(2) manual page
for a full discussion of the two variants of signal()).

Fixes #238.

Signed-off-by: Nadav Har'El <nyh@cloudius-systems.com>
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>

Instead of duplicating sigaction()'s code, let's just use it.

Signed-off-by: Nadav Har'El <nyh@cloudius-systems.com>
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>

Add signal number verification to sigaction().
Also add a FIXME comment that we don't support mode sa_flags.

Signed-off-by: Nadav Har'El <nyh@cloudius-systems.com>
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>

Add missing scandir() function from musl 1.0.0. Fixes #237.

Signed-off-by: Nadav Har'El <nyh@cloudius-systems.com>
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>

Add support for SA_RESETHAND signal handler flag, which means that the signal
handler is reset to the default one after handling the signal once.

I admit it's not a very useful feature (our default handler is powering off
the system...) but no reason not to support it.

Signed-off-by: Nadav Har'El <nyh@cloudius-systems.com>
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>

Don Martin writes:

  I'm experimenting with Capstan, trying to rule out some things for
  getting a bigger application working. I have a simple program to
  recursively list directory contents, here...

    https://github.com/dmarti/mini-ls



  It works on the host, but when I build the .so, the "capstan build" step
  works, and then when I do "capstan run"...

  $ capstan run
  OSv v0.05-501-gdbdf4f7
  Failed looking up symbol alphasort

This is missing libc functionality in OSv. To fix that, add the
alphasort function from musl.

Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>

Implement shmget/shmat/shmdt/shmctl function required by System V shared
memory interface.

Signed-off-by: Gleb Natapov <gleb@cloudius-systems.com>

This is required for '--interval' option on iperf.
The code was taken from musl-libc.

Reviewed-by: Nadav Har'El <nyh@cloudius-systems.com>
Signed-off-by: Takuya ASADA <syuu@cloudius-systems.com>
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>

We didn't notice this, but disabling the debugging messages also disabled
the assertion failure messages! The user only sees "Aborted" and you
can only tell what happened with a debugger.

Instead of using kprintf(), pass the message directly to abort(), which
will print its argument to the console as expected.

Since we using the overloading abort(...), it now needs to be done in a
C++ source file. So move this function from libc/exit/assert.c, to
runtime.cc.

Reviewed-by: Glauber Costa <glommer@cloudius-systems.com>
Signed-off-by: Nadav Har'El <nyh@cloudius-systems.com>
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>

It's needed by openssl. It supposed to return NULL if the environemnt is not
trusted. Our implementation just delegates to getenv().

Signed-off-by: Tomasz Grabiec <tgrabiec@cloudius-systems.com>
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>

This patch addresses the bugs of *use* of the dynamic linker - looking
up symbols or iterating the list of loaded objects - in parallel with new
libraries being loaded with get_library().

The underlying problem is that we have an unprotected "_modules" vector
of loaded objects, which we need to iterate to look up symbols, but this
list of modules can change when a new shared object is loaded.

We decided *not* to solve this problem by using the same mutex protecting
object load/unload: _mutex. That would make boot slower, as threads using
new symbols are blocked just because another thread is concurrently loading
some unrelated shared object (not a big problem with demand-paged file
mmaps). Using a mutex can also cause deadlocks in the leak detector,
because of lock order reversal between malloc's and elf'c mutexes: malloc()
takes a lock first and then backtrace() will take elf's lock, and on the
other hand elf can take its lock and then call malloc taking malloc's lock.

Instead, this patch uses RCU to allow lock-free reading of the modules
list. As in RCU, writing (adding or removing an object from the list)
manufactures a new list, defering the freeing of the old one, allowing
reads to continue using the old object list.

Note that after this patch, concurrent lookups and get_library() will
work correctly, but concurrent lookups and object *unload* still will
still not be correct because we need to defer an object's unloading from
memory while lookups are in progress. This will be solved in a following
patch.

Signed-off-by: Nadav Har'El <nyh@cloudius-systems.com>
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>

Useful for debugging.

Signed-off-by: Avi Kivity <avi@cloudius-systems.com>

Signed-off-by: Avi Kivity <avi@cloudius-systems.com>

Remove unused #include of <drivers/clock.hh>.
Except the clock drivers and <osv/clock.hh>, no source file now now
include this header. Rather, <osv/clock.hh> should be used. Code including
<sched.hh> will also get <osv/clock.hh> automatically.

Reviewed-by: Glauber Costa <glommer@cloudius-systems.com>
Signed-off-by: Nadav Har'El <nyh@cloudius-systems.com>
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>

Fix pthread_cond_timedwait to set the absolute timer using a timepoint,
instead of the old s64.

Moreover, now that we have both a wall-clock and monotonic clock, we
can support pthread_condattr_setclock, so this patch also adds this
support. OpenJDK 8, for example, cannot run without this support (it
assumes that if the OS supports CLOCK_MONOTONIC, it can also configure
condition variables to use it).

Unfortunately supporting pthread_condattr_setclock - the only condition-
variable attribute that really exists - grows the pthread condition
variable structure :(

Fixes #168.

Reviewed-by: Glauber Costa <glommer@cloudius-systems.com>
Signed-off-by: Nadav Har'El <nyh@cloudius-systems.com>
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>

Drop the s64 literals _ms, _ns, etc., from <drivers/clock.hh>.
Fix a few places which still use the old literals.

The std:chrono::duration version from <osv/clock.hh> remains -
but remember you need to "using namespace osv::clock::literals"
to use them.

Reviewed-by: Glauber Costa <glommer@cloudius-systems.com>
Signed-off-by: Nadav Har'El <nyh@cloudius-systems.com>
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>

Change alarm() implementation to use the new <osv/clock.hh> APIs and the
monotonic clock.

Reviewed-by: Glauber Costa <glommer@cloudius-systems.com>
Signed-off-by: Nadav Har'El <nyh@cloudius-systems.com>
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>

Delete the sched::thread::sleep_until() function. All users of this
function actually wanted a relative time, not absolute time, and can
use the simpler new sched::thread::sleep() instead.

Reviewed-by: Glauber Costa <glommer@cloudius-systems.com>
Signed-off-by: Nadav Har'El <nyh@cloudius-systems.com>
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>

Switch the timerfd to use std::chrono types, and add support also for the
monotonic clock.

Fixes #142.

Reviewed-by: Glauber Costa <glommer@cloudius-systems.com>
Signed-off-by: Nadav Har'El <nyh@cloudius-systems.com>
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>

Switch the thread scheduler from using the s64 type for durations and
the wall time, to the osv::clock::uptime::duration type (which is
std::chrono::nanoseconds) and monotonic clock.

Also, now that the per-thread CPU-time clock (thread::thread_clock())
returns an std::chrono::duration instead of s64, we no longer need the
fill_ts(s64) variant in libc/time.cc (if we leave it unused, we'll get a
compilation warning).

Reviewed-by: Glauber Costa <glommer@cloudius-systems.com>
Signed-off-by: Nadav Har'El <nyh@cloudius-systems.com>
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>

Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>

Move definitions from <debug.h> to <osv/debug.h> and update includes to
use the latter.

Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>

Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>

Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>

Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>

Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>

Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>

Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>

Reviewed-by: Nadav Har'El <nyh@cloudius-systems.com>
Signed-off-by: Vlad Zolotarov <vladz@cloudius-systems.com>
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>

Reviewed-by: Nadav Har'El <nyh@cloudius-systems.com>
Signed-off-by: Vlad Zolotarov <vladz@cloudius-systems.com>
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>

Reviewed-by: Nadav Har'El <nyh@cloudius-systems.com>
Signed-off-by: Vlad Zolotarov <vladz@cloudius-systems.com>
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>

sysinfo() until now was a stub. This patches fills some of the information
we can already provide, namely the uptime in seconds (through the recently
added osv::clock::uptime()), the total and free memory (through the recently
added memory::stats::free()/total() functions), and number of processes
(always 1 on OSv).

This patch also changes a couple of types from unsized names (like "unsigned")
to fixed-sized ones (like "u32"), to match the definition of this structure
on Linux. It won't make any difference on x86_64, but perhaps in some future
architecture it will.

Tested-by: Amnon Heiman <amnon@cloudius-systems.com>
Signed-off-by: Nadav Har'El <nyh@cloudius-systems.com>
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>

Currently, RLIMIT_STACK is 64 KB.  This is too small for the JVM which
limits stack size to RLIMIT_STACK if a VMA range that covers address
found in '__libc_stack_end' in /proc/self/maps.

In preparation for procfs support, switch to pthread_attr_getstacksize()
for RLIMIT_STACK.

Reviewed-by: Nadav Har'El <nyh@cloudius-systems.com>
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>

Add pthread_attr_getstacksize() in preparation for fixing RLIMIT_STACK.

Reviewed-by: Glauber Costa <glommer@cloudius-systems.com>
Reviewed-by: Nadav Har'El <nyh@cloudius-systems.com>
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>

Output to stdout normally goes to file descriptor 1. However, during
early boot, before the console is opened on file descriptor 1, we also
want printf() to work. So this case is specially treated in
libc/stdio/__stdout_write.cc, where in this early case, we used debug_write
directly, instead of write to the file descriptor.

However, recent patches changed debug_write to write to a memory buffer,
instead of to screen (unless "--verbose" option is given to the loader).
This made early printf() break too.

This patch changes __stdout_write to use console::write(), not
debug_write(). To use console::write(), I had to convert that source
file to C++.

Signed-off-by: Nadav Har'El <nyh@cloudius-systems.com>
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>

Add a type-safe std::chrono interface to the wall-clock time. E.g., use
use osv::clock::wall::now() to get an std::chrono::time_point instead
of clock::get()->time() which returns an s64.

This patch also changes clock_gettime(CLOCK_REALTIME) and gettimeofday()
to use the new osv::clock::wall::now() interface.

Signed-off-by: Nadav Har'El <nyh@cloudius-systems.com>
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>

Signed-off-by: Dmitry Fleytman <dmitry@daynix.com>
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>