Guard, requested by the MAP_GUARD mmap(2) flag, prevents the reuse of
the allocated address space, but does not allow instantiation of the
pages in the range. It is useful for more explicit support for usual
two-stage reserve then commit allocators, since it prevents accidental
instantiation of the mapping, e.g. by mprotect(2).
Use guards to reimplement stack grow code. Explicitely track stack
grow area with the guard, including the stack guard page. On stack
grow, trivial shift of the guard map entry and stack map entry limits
makes the stack expansion. Move the code to detect stack grow and
call vm_map_growstack(), from vm_fault() into vm_map_lookup().
As result, it is impossible to get random mapping to occur in the
stack grow area, or to overlap the stack guard page.
Enable stack guard page by default.
Reviewed by: alc, markj
Man page update reviewed by: alc, bjk, emaste, markj, pho
Tested by: pho, Qualys
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D11306 (man pages)
o Separate fields of struct socket that belong to listening from
fields that belong to normal dataflow, and unionize them. This
shrinks the structure a bit.
- Take out selinfo's from the socket buffers into the socket. The
first reason is to support braindamaged scenario when a socket is
added to kevent(2) and then listen(2) is cast on it. The second
reason is that there is future plan to make socket buffers pluggable,
so that for a dataflow socket a socket buffer can be changed, and
in this case we also want to keep same selinfos through the lifetime
of a socket.
- Remove struct struct so_accf. Since now listening stuff no longer
affects struct socket size, just move its fields into listening part
of the union.
- Provide sol_upcall field and enforce that so_upcall_set() may be called
only on a dataflow socket, which has buffers, and for listening sockets
provide solisten_upcall_set().
o Remove ACCEPT_LOCK() global.
- Add a mutex to socket, to be used instead of socket buffer lock to lock
fields of struct socket that don't belong to a socket buffer.
- Allow to acquire two socket locks, but the first one must belong to a
listening socket.
- Make soref()/sorele() to use atomic(9). This allows in some situations
to do soref() without owning socket lock. There is place for improvement
here, it is possible to make sorele() also to lock optionally.
- Most protocols aren't touched by this change, except UNIX local sockets.
See below for more information.
o Reduce copy-and-paste in kernel modules that accept connections from
listening sockets: provide function solisten_dequeue(), and use it in
the following modules: ctl(4), iscsi(4), ng_btsocket(4), ng_ksocket(4),
infiniband, rpc.
o UNIX local sockets.
- Removal of ACCEPT_LOCK() global uncovered several races in the UNIX
local sockets. Most races exist around spawning a new socket, when we
are connecting to a local listening socket. To cover them, we need to
hold locks on both PCBs when spawning a third one. This means holding
them across sonewconn(). This creates a LOR between pcb locks and
unp_list_lock.
- To fix the new LOR, abandon the global unp_list_lock in favor of global
unp_link_lock. Indeed, separating these two locks didn't provide us any
extra parralelism in the UNIX sockets.
- Now call into uipc_attach() may happen with unp_link_lock hold if, we
are accepting, or without unp_link_lock in case if we are just creating
a socket.
- Another problem in UNIX sockets is that uipc_close() basicly did nothing
for a listening socket. The vnode remained opened for connections. This
is fixed by removing vnode in uipc_close(). Maybe the right way would be
to do it for all sockets (not only listening), simply move the vnode
teardown from uipc_detach() to uipc_close()?
Sponsored by: Netflix
Differential Revision: https://reviews.freebsd.org/D9770
INHERIT_ZERO is an OpenBSD feature.
When a page is marked as such, it would be zeroed
upon fork().
This would be used in new arc4random(3) functions.
PR: 182610
Reviewed by: kib (earlier version)
MFC after: 1 month
Differential Revision: https://reviews.freebsd.org/D427
Renumber cluase 4 to 3, per what everybody else did when BSD granted
them permission to remove clause 3. My insistance on keeping the same
numbering for legal reasons is too pedantic, so give up on that point.
Submitted by: Jan Schaumann <jschauma@stevens.edu>
Pull Request: https://github.com/freebsd/freebsd/pull/96
Our mprotect() function seems to take a "const void *" address to the
pages whose permissions need to be adjusted. POSIX uses "void *". Simply
stick to the POSIX one to prevent us from writing unportable code.
PR: 211423 (exp-run)
Tested by: antoine@ (Thanks!)
for libthr.so.3, without breaking the ABI. Special value is stored in
the lock pointer to indicate shared lock, and offline page in the shared
memory is allocated to store the actual lock.
Reviewed by: vangyzen (previous version)
Discussed with: deischen, emaste, jhb, rwatson,
Martin Simmons <martin@lispworks.com>
Tested by: pho
Sponsored by: The FreeBSD Foundation
operations. File type-specific logic is now placed in the mmap hook
implementation rather than requiring it to be placed in
sys/vm/vm_mmap.c. This hook allows new file types to support mmap() as
well as potentially allowing mmap() for existing file types that do not
currently support any mapping.
The vm_mmap() function is now split up into two functions. A new
vm_mmap_object() function handles the "back half" of vm_mmap() and accepts
a referenced VM object to map rather than a (handle, handle_type) tuple.
vm_mmap() is now reduced to converting a (handle, handle_type) tuple to a
a VM object and then calling vm_mmap_object() to handle the actual mapping.
The vm_mmap() function remains for use by other parts of the kernel
(e.g. device drivers and exec) but now only supports mapping vnodes,
character devices, and anonymous memory.
The mmap() system call invokes vm_mmap_object() directly with a NULL object
for anonymous mappings. For mappings using a file descriptor, the
descriptors fo_mmap() hook is invoked instead. The fo_mmap() hook is
responsible for performing type-specific checks and adjustments to
arguments as well as possibly modifying mapping parameters such as flags
or the object offset. The fo_mmap() hook routines then call
vm_mmap_object() to handle the actual mapping.
The fo_mmap() hook is optional. If it is not set, then fo_mmap() will
fail with ENODEV. A fo_mmap() hook is implemented for regular files,
character devices, and shared memory objects (created via shm_open()).
While here, consistently use the VM_PROT_* constants for the vm_prot_t
type for the 'prot' variable passed to vm_mmap() and vm_mmap_object()
as well as the vm_mmap_vnode() and vm_mmap_cdev() helper routines.
Previously some places were using the mmap()-specific PROT_* constants
instead. While this happens to work because PROT_xx == VM_PROT_xx,
using VM_PROT_* is more correct.
Differential Revision: https://reviews.freebsd.org/D2658
Reviewed by: alc (glanced over), kib
MFC after: 1 month
Sponsored by: Chelsio
and MAP_NORESERVE flags to mmap(2). Older binaries are still permitted
to use these flags.
PR: 193961 (exp-run in ports)
Differential Revision: https://reviews.freebsd.org/D848
Reviewed by: kib
to add type-specific information to struct kinfo_file. - Move the
various fill_*_info() methods out of kern_descrip.c and into the various
file type implementations. - Rework the support for kinfo_ofile to
generate a suitable kinfo_file object for each file and then convert
that to a kinfo_ofile structure rather than keeping a second, different
set of code that directly manipulates type-specific file information. -
Remove the shm_path() and ksem_info() layering violations.
Differential Revision: https://reviews.freebsd.org/D775
Reviewed by: kib, glebius (earlier version)
It should be combined with MAP_FIXED, and prevents the request from
deleting existing mappings in the region, failing instead.
Reviewed by: alc
Discussed with: jhb
Tested by: markj, pho (previous version, as part of the bigger patch)
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
to request that a mapping use an address in the first 2GB of the
process's address space. This flag should have the same semantics as the
same flag on Linux.
To facilitate this, add a new parameter to vm_map_find() that specifies an
optional maximum virtual address. While here, fix several callers of
vm_map_find() to use a VMFS_* constant for the findspace argument instead of
TRUE and FALSE.
Reviewed by: alc
Approved by: re (kib)
for posix shmfd. Add MAC framework entries for posix shm read and write.
Do not allow implicit extension of the underlying memory segment past
the limit set by ftruncate(2) by either of the syscalls. Read and
write returns short i/o, lseek(2) fails with EINVAL when resulting
offset does not fit into the limit.
Discussed with: alc
Tested by: pho
Sponsored by: The FreeBSD Foundation
Add __nl_item to <sys/_types.h> for FreeBSD compatibility. Use it in
<langinfo.h> and the Cygwin <nl_types.h>. Make the enum __nl_item in
<langinfo.h> anonymous.
Signed-off-by: Sebastian Huber <sebastian.huber@embedded-brains.de>
Add __tls_get_addr() for all targets to crt0. This is not only used on
ARM. In particular, it is used on RISC-V. This helps to adequately
support the GCC libgomp.
Signed-off-by: Sebastian Huber <sebastian.huber@embedded-brains.de
This reverts commit 8a32c24a7b.
Replacing page_size() with allocation_granularity() was incorrect.
The values returned by get_mem_values() are # of pages of size
page_size(). Multiplying with allocation_granularity() here
results in values 16 times too big.
strtof ("-nan") returned positive NaN instead of negative NaN.
strtod ("-nan") and strtold ("-nan") return negative NaN.
Linux glibc has been fixed
that strto{f|d|ld} ("-nan") returns negative NaN.
https://sourceware.org/bugzilla/show_bug.cgi?id=23007
This commit makes strtof preserves the negative sign bit
when parsing "-nan" like glibc.
By previous commit, strto{d|ld} ("nan")
does not use the definition of NaN.
There is no other function that uses the definitions.
This commit remove the definitions.
The definition of qNaN for x86_64 and i386 was wrong.
strto{d|ld} ("nan") returned wrong negative NaN
instead of correct positive NaN
since it used the wrong definition.
On the other hand, strtof ("nan") returns correct positive NaN
since it uses nanf ("") instead of the wrong definition.
This commit makes strto{d|ld} ("nan") uses {nan|nanl} ("")
like strtof ("nan") using.
So strto{d|ld} ("nan") returns positive NaN.
Improve comments in sincosf implementation to make the code easier
to understand. Rename the constant pi64 to pi63 since it's actually
PI * 2^-63. Add comments for fields of sincos_t structure. Add comments
describing implementation details to reduce_fast.
By excluding the denormal-operand exception from FE_ALL_EXCEPT, it will not
be possible anymore to UNmask this exception by means of the API defined by
/usr/include/fenv.h
Note: terminology has changed since IEEE Std 854-1987; denormalized numbers
are called subnormal numbers nowadays.
This modification has basically been motivated by the fact that it is also
not possible on Linux to manipulate the denormal-operand exception by means
of the interface as defined by /usr/include/fenv.h. This has been the state
of affairs on Linux since 2001 (Andreas Jaeger).
The exceptions required by the standard (IEEE Std 754), in case they can be
supported by the implementation, are:
FE_INEXACT, FE_UNDERFLOW, FE_OVERFLOW, FE_DIVBYZERO and FE_INVALID.
Although it is allowed to define additional exceptions, there is no reason
to support the "denormal-operand exception" in this case (fenv.h), because
the subnormal numbers can be handled almost as fast the normalized numbers
by the hardware of the x86/x86_64 architecture. Said differently, a reason
to trap on the input of subnormal numbers does not exist. At least that is
what William Kahan and others at Intel asserted around 2000.
(that is William Kahan of the K-C-S draft, the precursor to the standard)
This commit modifies winsup/cygwin/include/fenv.h as follows:
- redefines FE_ALL_EXCEPT from 0x3f to 0x3d
- removes the definition for FE_DENORMAL
- introduces __FE_DENORM (0x2) (enum in Linux also uses __FE_DENORM)
- introduces FE_ALL_EXCEPT_X86 (0x3f), i.e. ALL x86/x86_64 FP exceptions
wordexp uses fprintf in a dangerous way. It uses an unchecked
input string as format string, rather than as parameter to a %s.
Replace fprintf with fputs.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
* create new function __get_cpus_per_group to evaluate # of CPU groups
* Call from format_proc_cpuinfo and sched_getcpu
* Bump API minor version
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
fnstenv MUST be followed by fldenv in fegetenv(), as the former disables all
exceptions in the x87 FPU, which is not appropriate here (fegetenv() ).
fldenv after fnstenv should reload the x87 FPU w/ the configuration that was
saved by fnstenv, i.e. a configuration that might have exceptions enabled.
Note: x86_64 uses SSE for floating-point, not the x87 FPU. However, because
feraiseexcept() attempts to provoke an exception using the x87 FPU, the bug
in fegetenv() will make this attempt futile here (x86_64).
Note: WoW uses the x87 FPU for floating-point, not SSE. Here anything that
would normally result in triggering an exception, not only feraiseexcept(),
will not be able to, as result of the bug in fegetenv().
kib