History log of /haiku/src/system/libroot/posix/sys/mman.cpp
Revision Date Author Comments
# 140013f2 07-Dec-2022 Augustin Cavalier <waddlesplash@gmail.com>

libroot: Fix open flags in shm_open.

We need O_CLOEXEC here, not FD_CLOEXEC (which is equal to 0x1, which
in openflags is O_WRONLY and thus leads to the conflicts caught by
the previous commit.)

Fixes haikuports/haikuports#7524.
(cherry picked from commit 59e09f7bebcb8fa9d4ed82f501e6516c3d67d65b)

Change-Id: I5751822ac48ae7a865755494da241e4bfd34c45f
Reviewed-on: https://review.haiku-os.org/c/haiku/+/5853
Reviewed-by: waddlesplash <waddlesplash@gmail.com>


# a959262c 14-Dec-2019 Adrien Destugues <pulkomandy@pulkomandy.tk>

implement mlock(), munlock()

Change-Id: I2f04b8986d2ed32bb4d30d238d668e21a1505778
Reviewed-on: https://review.haiku-os.org/c/haiku/+/1991
Reviewed-by: Adrien Destugues <pulkomandy@gmail.com>


# b3bd6696 29-May-2020 Michael Lotz <mmlr@mlotz.ch>

libroot/kernel: Implement MADV_FREE madvise() extension.

It allows an application to signal that it no longer needs the data in
the given address range and the underlying pages can be discarded and
reused elsewhere. This is finer grained than working with full areas
or mappings at a time and enables unmapping sections of partially used
mappings without giving up its address space.

Compared with punching holes into a mapping by "mapping over" with
PROT_NONE and MAP_NORESERVE, this has the obvious advantage of not
producing a lot of unused extra areas and saves the corresponding
resources. It is also a lot "lighter" of an operation than cutting
existing areas.

This introduces madvise() alongside the existing posix_madvise() to
allow for OS specific extensions. The constants for both functions are
aliased, the POSIX_MADV_* being a subset of the MADV_* ones without the
non-POSIX extensions. Internally posix_madvise() simply calls madvise().

MADV_FREE is commonly supported in other OSes with various subtle
semantic differences as to when pages are actually freed/cleared and how
or whether the pages are counted against the memory use of a process.
In the variant implemented here, pages are always immediately discarded
and memory counting is not altered. This behaviour should be considered
an implementation detail and may be altered later. The actual unmap and
discard could for example be delayed until pages are needed elsewhere to
reduce overhead in case of repeated discarding and remapping.

Note that MADV_FREE doesn't really align with the rest of the madvise()
API as it works like a command (i.e. discard these pages) and does not
add an attribute to the pages in the given range (i.e. mark these pages
for quick access from now on). As such, an MADV_FREE does not need to be
undone by setting a different advice later on, unlike how the other
flags work. This discrepancy may be the reason why it is not part of
POSIX.

Change-Id: Icc093379125a43e465dc4409d8f5ae0f64e107e0
Reviewed-on: https://review.haiku-os.org/c/haiku/+/2844
Reviewed-by: waddlesplash <waddlesplash@gmail.com>


# b94221f3 08-May-2020 Michael Lotz <mmlr@mlotz.ch>

mmap: Use MAP_NORESERVE to request overcommit, not PROT_NONE.

This reverts hrev54120 and instead adds the commonly supported
MAP_NORESERVE flag to request overcommit.

Using PROT_NONE for overcommit is problematic as the protection of
individual pages can still be changed via mprotect to make them
accessible, but that won't change the commitment. An application
using such a pattern may then unexpectedly run into out of memory
conditions on random writes into the address space.

With MAP_NORESERVE the overcommit can explicitly be requested by
applications that want to reserve address space without producing
memory pressure.

Change-Id: Id213d2245c5e23103e8e0857f7902e0cd8a2c65d
Reviewed-on: https://review.haiku-os.org/c/haiku/+/2611
Reviewed-by: waddlesplash <waddlesplash@gmail.com>
Reviewed-by: Jérôme Duval <jerome.duval@gmail.com>


# 12bd6e12 02-May-2020 Jérôme Duval <jerome.duval@gmail.com>

mmap: using PROT_NONE usually means the memory isn't actually used.

A program can mmap virtual memory which will only trigger signal handlers.
This is for instance needed for ASAN.

Change-Id: I4a42b4860b5acab17465683e9cf73c486bea7d40
Reviewed-on: https://review.haiku-os.org/c/haiku/+/2554
Reviewed-by: waddlesplash <waddlesplash@gmail.com>


# ba390da3 18-May-2019 Augustin Cavalier <waddlesplash@gmail.com>

libroot: Name mmap areas by the name of the image that allocated them.

This adds an average overhead of 10-15 us, which seems acceptable
(without the previous patch it adds 200-250 us, which is less so),
and it makes "listarea" output much more enlightening for applications
like app_server or WebKit which use a lot of them.

Change-Id: I48a4148e6e9fb0d1a8bbf67294deeafad9372f44
Reviewed-on: https://review.haiku-os.org/c/1462
Reviewed-by: Adrien Destugues <pulkomandy@gmail.com>


# f1fafe31 12-Apr-2019 Augustin Cavalier <waddlesplash@gmail.com>

kernel/OS.h: Include sys/types.h instead of pthread.h.

This avoids polluting the namespace significantly. Also adjust
all files which depended on this behavior to include pthread.h
directly.


# 0e900020 16-Nov-2017 Jérôme Duval <jerome.duval@gmail.com>

POSIX: shm_open: set the FD_CLOEXEC file descriptor flag...

on the new file descriptor.
Fixes #13774.


# 84ed99c2 30-Nov-2013 Ingo Weinhold <ingo_weinhold@gmx.de>

mmap(): Fix !MAP_FIXED with non-NULL address case

In that case the caller ideally wants to obtain an allocation at the
specified address, which was thwarted by using
B_RANDOMIZED_BASE_ADDRESS. Use B_BASE_ADDRESS instead.

This improves the experience with the gcc 4 pre-compiled headers
implementation (which expects to be able to map the PCH file at the same
address where it was located originally when it had been created), but
doesn't fix it completely. As long as ASLR is active, it is always
possible that something else (mapped shared objects, heap, stack) is in
the way.


# 537d84a0 05-Mar-2013 Pawel Dziepak <pdziepak@quarnos.org>

libroot: randomize position of areas created by mmap()

When mmap() is invoked without specifying address hint B_RANDOMIZED_ANY_ADDRESS
is used.
Otherwise, unless MAP_FIXED flag is set (which requires mmap() to return an area
positioned exactly at given address), B_RANDOMIZED_BASE_ADDRESS is used.


# 8d405928 25-Mar-2012 Hamish Morrison <hamish@lavabit.com>

mmap should try to honour the address hint


# ae901935 24-Nov-2011 Oliver Tappe <zooey@hirschkaefer.de>

Introduce __set_errno() throughout libroot.

* add errno_private.h, which defines the __set_errno() macro with
and without tracing
* instead of setting errno manually, all libroot's code now invokes
__set_errno(), which makes it much easier to trace changes to errno
* redirect glibc's use of __set_errno() to our own version


# 24df6592 11-Jun-2011 Ingo Weinhold <ingo_weinhold@gmx.de>

Merged signals-merge branch into trunk with the following changes:
* Reorganized the kernel locking related to threads and teams.
* We now discriminate correctly between process and thread signals. Signal
handlers have been moved to teams. Fixes #5679.
* Implemented real-time signal support, including signal queuing, SA_SIGINFO
support, sigqueue(), sigwaitinfo(), sigtimedwait(), waitid(), and the addition
of the real-time signal range. Closes #1935 and #2695.
* Gave SIGBUS a separate signal number. Fixes #6704.
* Implemented <time.h> clock and timer support, and fixed/completed alarm() and
[set]itimer(). Closes #5682.
* Implemented support for thread cancellation. Closes #5686.
* Moved send_signal() from <signal.h> to <OS.h>. Fixes #7554.
* Lots over smaller more or less related changes.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@42116 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 29ddbdbb 16-Jan-2010 Axel Dörfler <axeld@pinc-software.de>

* Moved the "var" directory to /boot/common/.
* Moved the "tmp" directory out of /var, and to /boot/common/cache/.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@35104 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 82db8a9e 19-Jun-2009 Axel Dörfler <axeld@pinc-software.de>

* Added an "unmapAddressRange" argument to the file mapping syscall. This is
the first part of making the runtime loader behave itself; it should already
make Clockwerk run okay with any number of translators (even if not all of
them will work yet).


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@31113 a95241bf-73f2-0310-859d-f6bbb57e9c96


# a9d7be07 07-Aug-2008 Ingo Weinhold <ingo_weinhold@gmx.de>

* Implemented mprotect(). A vm_area does now have an optional array
specifying the protection of each page (4 bits per page).
* Added no-op implementation of posix_madvise().
* Replaced a few "addr_t size" parameters by "size_t size".


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@26871 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 0f448d21 22-May-2008 Ingo Weinhold <ingo_weinhold@gmx.de>

* Added vm_page_write_modified_page_range(), which is similar to
vm_page_write_modified_pages(), save that it only writes pages in the
given range.
* Added vm_page_schedule_write_page_range() which schedules all modified
pages in the given cache's range for writing by the page writer.
* Added _kern_sync_memory() syscall and the msync() POSIX function.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@25620 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 6b202f4e 13-May-2008 Ingo Weinhold <ingo_weinhold@gmx.de>

* Introduced new header directory headers/private/system which is supposed
to contain headers shared by kernel and userland (mainly libroot).
* Moved quite a few private kernel headers to the new location. Split
several kernel headers into a shared part and one that is still kernel
private. Adjusted all affected Jamfiles and source in the standard x86
build accordingly. The build for other architectures and for test code
may be broken.
* Quite a bit of userland code still includes private kernel headers.
Mostly those are <util/*> headers. The ones that aren't strictly
kernel-only should be moved to some other place (maybe
headers/private/shared/util).


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@25486 a95241bf-73f2-0310-859d-f6bbb57e9c96


# f23d0a62 08-May-2008 Ingo Weinhold <ingo_weinhold@gmx.de>

Implement shm_open() and shm_unlink(). The shared memory objects are
simply created as files in /boot/var/shared_memory/. The Bootscript
clears the directory.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@25374 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 9b293bf6 15-Apr-2008 Ingo Weinhold <ingo_weinhold@gmx.de>

mmap() was a little strict: The length parameter need not be page
aligned. It shall be rounded up by the implementation.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@24967 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 3cf7ecd1 13-Apr-2008 Ingo Weinhold <ingo_weinhold@gmx.de>

* Added <sys/mman.h> header. It declares only mmap() and munmap() yet
and defines the macros needed by them.
* Renamed syscall sys_vm_map_file() to _kern_map_file() and changed the
path to an FD parameter. Changed vm_map_file() accordingly and
adjusted the kernel ELF loader and the runtime loader.
* Added syscall _kern_unmap_memory().
* Added bool unmapAddressRange parameter to vm_create_anonymous_area()
and map_backing_store(). If true and the address specification is
B_EXACT_ADDRESS, all areas in the specified address range will be
deleted (unless an area is covered only partially).
* Introduced B_SHARED_AREA flag, which is set on areas that have been
created by {vm,_user}_map_file() with REGION_NO_PRIVATE_MAP. When
fork()ing those areas won't be copied CoW, but rather be cloned. This
is needed for mmap() MAP_SHARED.
* {vm,_user}_map_file() also accept an FD argument < 0, in which case an
anonymous area is created.
* Implemented mmap() and munmap(). Currently there's the restriction
that we can't partially unmap areas. Otherwise the functions should be
rather compliant. We also support the non-POSIX extension
MAP_ANONYMOUS.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@24964 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 84ed99c2aadf0a4fd233e134f8205a17219101d8 30-Nov-2013 Ingo Weinhold <ingo_weinhold@gmx.de>

mmap(): Fix !MAP_FIXED with non-NULL address case

In that case the caller ideally wants to obtain an allocation at the
specified address, which was thwarted by using
B_RANDOMIZED_BASE_ADDRESS. Use B_BASE_ADDRESS instead.

This improves the experience with the gcc 4 pre-compiled headers
implementation (which expects to be able to map the PCH file at the same
address where it was located originally when it had been created), but
doesn't fix it completely. As long as ASLR is active, it is always
possible that something else (mapped shared objects, heap, stack) is in
the way.


# 537d84a07cab3152554ed0608a704958a979120f 05-Mar-2013 Pawel Dziepak <pdziepak@quarnos.org>

libroot: randomize position of areas created by mmap()

When mmap() is invoked without specifying address hint B_RANDOMIZED_ANY_ADDRESS
is used.
Otherwise, unless MAP_FIXED flag is set (which requires mmap() to return an area
positioned exactly at given address), B_RANDOMIZED_BASE_ADDRESS is used.


# 8d405928217c529dc48673cc8b29000ea2a24452 25-Mar-2012 Hamish Morrison <hamish@lavabit.com>

mmap should try to honour the address hint


# ae9019359606f1db67632ef51a77ce70001d3770 24-Nov-2011 Oliver Tappe <zooey@hirschkaefer.de>

Introduce __set_errno() throughout libroot.

* add errno_private.h, which defines the __set_errno() macro with
and without tracing
* instead of setting errno manually, all libroot's code now invokes
__set_errno(), which makes it much easier to trace changes to errno
* redirect glibc's use of __set_errno() to our own version


# 24df65921befcd0ad0c5c7866118f922da61cb96 11-Jun-2011 Ingo Weinhold <ingo_weinhold@gmx.de>

Merged signals-merge branch into trunk with the following changes:
* Reorganized the kernel locking related to threads and teams.
* We now discriminate correctly between process and thread signals. Signal
handlers have been moved to teams. Fixes #5679.
* Implemented real-time signal support, including signal queuing, SA_SIGINFO
support, sigqueue(), sigwaitinfo(), sigtimedwait(), waitid(), and the addition
of the real-time signal range. Closes #1935 and #2695.
* Gave SIGBUS a separate signal number. Fixes #6704.
* Implemented <time.h> clock and timer support, and fixed/completed alarm() and
[set]itimer(). Closes #5682.
* Implemented support for thread cancellation. Closes #5686.
* Moved send_signal() from <signal.h> to <OS.h>. Fixes #7554.
* Lots over smaller more or less related changes.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@42116 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 29ddbdbb53af79445de933b590598e4342a34ae9 16-Jan-2010 Axel Dörfler <axeld@pinc-software.de>

* Moved the "var" directory to /boot/common/.
* Moved the "tmp" directory out of /var, and to /boot/common/cache/.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@35104 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 82db8a9e159b60e775b4cab31d54ac40fe95de53 19-Jun-2009 Axel Dörfler <axeld@pinc-software.de>

* Added an "unmapAddressRange" argument to the file mapping syscall. This is
the first part of making the runtime loader behave itself; it should already
make Clockwerk run okay with any number of translators (even if not all of
them will work yet).


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@31113 a95241bf-73f2-0310-859d-f6bbb57e9c96


# a9d7be0708b660121608c1b916862ab6d664ba07 07-Aug-2008 Ingo Weinhold <ingo_weinhold@gmx.de>

* Implemented mprotect(). A vm_area does now have an optional array
specifying the protection of each page (4 bits per page).
* Added no-op implementation of posix_madvise().
* Replaced a few "addr_t size" parameters by "size_t size".


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@26871 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 0f448d21e52dfbde6ebd029af30d19542224c16d 22-May-2008 Ingo Weinhold <ingo_weinhold@gmx.de>

* Added vm_page_write_modified_page_range(), which is similar to
vm_page_write_modified_pages(), save that it only writes pages in the
given range.
* Added vm_page_schedule_write_page_range() which schedules all modified
pages in the given cache's range for writing by the page writer.
* Added _kern_sync_memory() syscall and the msync() POSIX function.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@25620 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 6b202f4e3da73d4c131355fcd82b792d153f84f6 13-May-2008 Ingo Weinhold <ingo_weinhold@gmx.de>

* Introduced new header directory headers/private/system which is supposed
to contain headers shared by kernel and userland (mainly libroot).
* Moved quite a few private kernel headers to the new location. Split
several kernel headers into a shared part and one that is still kernel
private. Adjusted all affected Jamfiles and source in the standard x86
build accordingly. The build for other architectures and for test code
may be broken.
* Quite a bit of userland code still includes private kernel headers.
Mostly those are <util/*> headers. The ones that aren't strictly
kernel-only should be moved to some other place (maybe
headers/private/shared/util).


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@25486 a95241bf-73f2-0310-859d-f6bbb57e9c96


# f23d0a624287b6d275610e71d7c329323a565975 08-May-2008 Ingo Weinhold <ingo_weinhold@gmx.de>

Implement shm_open() and shm_unlink(). The shared memory objects are
simply created as files in /boot/var/shared_memory/. The Bootscript
clears the directory.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@25374 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 9b293bf65318dde200b1bb1e3487f5f76cde97b5 15-Apr-2008 Ingo Weinhold <ingo_weinhold@gmx.de>

mmap() was a little strict: The length parameter need not be page
aligned. It shall be rounded up by the implementation.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@24967 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 3cf7ecd1e49db0ad531a6d81ad1945c4a6235010 13-Apr-2008 Ingo Weinhold <ingo_weinhold@gmx.de>

* Added <sys/mman.h> header. It declares only mmap() and munmap() yet
and defines the macros needed by them.
* Renamed syscall sys_vm_map_file() to _kern_map_file() and changed the
path to an FD parameter. Changed vm_map_file() accordingly and
adjusted the kernel ELF loader and the runtime loader.
* Added syscall _kern_unmap_memory().
* Added bool unmapAddressRange parameter to vm_create_anonymous_area()
and map_backing_store(). If true and the address specification is
B_EXACT_ADDRESS, all areas in the specified address range will be
deleted (unless an area is covered only partially).
* Introduced B_SHARED_AREA flag, which is set on areas that have been
created by {vm,_user}_map_file() with REGION_NO_PRIVATE_MAP. When
fork()ing those areas won't be copied CoW, but rather be cloned. This
is needed for mmap() MAP_SHARED.
* {vm,_user}_map_file() also accept an FD argument < 0, in which case an
anonymous area is created.
* Implemented mmap() and munmap(). Currently there's the restriction
that we can't partially unmap areas. Otherwise the functions should be
rather compliant. We also support the non-POSIX extension
MAP_ANONYMOUS.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@24964 a95241bf-73f2-0310-859d-f6bbb57e9c96