Replace all uses of kern_mmap with kern_mmap_req move the old kern_mmap.
Reand rename kern_mmap_req to kern_mmap .
The helper saved some code churn initially, but having multiple
interfaces is sub-optimal.
Obtained from: CheriBSD
Reviewed by: kib
Differential Revision: https://reviews.freebsd.org/D28292
vm_object_madvise() is a no-op for unmanaged objects, but we should also
limit the scope of mappings on which pmap_remove() is called. In
particular, with the WIP largepage shm objects patch the kernel must
remove mappings of such objects along superpage boundaries, and without
this check Linux madvise(MADV_DONTNEED) could violate that requirement.
Reviewed by: alc, kib
MFC with: r362631
Sponsored by: Juniper Networks, Klara Inc.
Differential Revision: https://reviews.freebsd.org/D26084
Linux MADV_DONTNEED is not advisory: it has side effects for anonymous
memory, and some system software depends on that. In particular,
MADV_DONTNEED causes anonymous pages to be discarded. If the mapping is
a private mapping of a named object then subsequent faults are to
repopulate the range from that object, otherwise pages will be
zero-filled. For mappings of non-anonymous objects, Linux MADV_DONTNEED
can be implemented in the same way as our MADV_DONTNEED.
This implementation differs from Linux semantics in its handling of
private mappings, inherited through fork(), of non-anonymous objects.
After applying MADV_DONTNEED, subsequent faults will repopulate the
mapping from the parent object rather than the root of the shadow chain.
PR: 230160
Reviewed by: alc, kib
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D25330
FreeBSD madvise(2) directly. While some of the flag values match,
most don't.
PR: kern/230160
Reported by: markj
Reviewed by: markj
Discussed with: brooks, kib
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D25272
This presents an extensible interface to the generic mmap(2)
implementation via a struct pointer intended to use a designated
initializer or compount literal. We take advantage of the mandatory
zeroing of fields not listed in the initializer.
Remove kern_mmap_fpcheck() and use kern_mmap_req().
The motivation for this change is a desire to keep the core
implementation from growing an ever-increasing number of arguments
that must be specified in the correct order for the lowest-level
implementations. In CheriBSD we have already added two more arguments.
Reviewed by: kib
Discussed with: kevans
Obtained from: CheriBSD
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D23164
This unbreaks Mono (mono-devel-4.6.2.7+dfsg-1ubuntu1 from Ubuntu Bionic);
previously would crash on "amd64_is_imm32" assert.
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D23306
This unbreaks Mono (mono-devel-4.6.2.7+dfsg-1ubuntu1 from Ubuntu Bionic);
previously would crash on "amd64_is_imm32" assert.
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Linux mmap rejects mmap() on a write-only file with EACCES.
linux_mmap_common currently does a fun dance to grab the fp associated with
the passed in fd, validates it, then drops the reference and calls into
kern_mmap(). Doing so is perhaps both fragile and premature; there's still
plenty of chance for the request to get rejected with a more appropriate
error, and it's prone to a race where the file we ultimately mmap has
changed after it drops its referenced.
This change alleviates the need to do this by providing a kern_mmap variant
that allows the caller to inspect the fp just before calling into the fileop
layer. The callback takes flags, prot, and maxprot as one could imagine
scenarios where any of these, in conjunction with the file itself, may
influence a caller's decision.
The file type check in the linux compat layer has been removed; EINVAL is
seemingly not an appropriate response to the file not being a vnode or
device. The fileop layer will reject the operation with ENODEV if it's not
supported, which more closely matches the common linux description of
mmap(2) return values.
If we discover that we're allowing an mmap() on a file type that Linux
normally wouldn't, we should restrict those explicitly.
Reviewed by: kib
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D22977
After r349240 kern_mprotect returns EINVAL for unsupported bits in the prot
argument. Linux rtld uses PROT_GROWSDOWN and PROT_GROWS_UP when marking the
stack executable. Mask these bits like kern_mprotect used to do. For other
unsupported bits EINVAL is returned like Linux does.
Reviewed by: trasz, brooks
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D20864
- Add macros to allow preinitialization of cap_rights_t.
- Convert most commonly used code paths to use preinitialized cap_rights_t.
A 3.6% speedup in fstat was measured with this change.
Reported by: mjg
Reviewed by: oshogbo
Approved by: sbruno
MFC after: 1 month
binary mode user-space emulation layer. This is a regression issue after
r328436, when LinuxKPI character devices started to use DTYPE_DEV in
the "f_type" field of the associated file structure(s).
MFC after: 3 days
Found by: Johannes Lundberg <johalun0@gmail.com>
Sponsored by: Mellanox Technologies
parameter to mmap(2), even if MAP_FIXED is not explicitly specified.
Android ART is one example. Implement bug compatibility for this case
in linuxulator.
Reviewed by: dchagin@
MFC after: 2 weeks
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D9373
Rename kern_vm_* functions to kern_*. Move the prototypes to
syscallsubr.h. Also change Mach VM types to uintptr_t/size_t as
needed, to avoid headers pollution.
Requested by: alc, jhb
Reviewed by: alc
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
Differential revision: https://reviews.freebsd.org/D9535
kern_vm_munmap(), and kern_vm_madvise(), and use them in various compats
instead of their sys_*() counterparts.
Reviewed by: ed, dchagin, kib
MFC after: 2 weeks
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D9378
FreeBSD support NX bit on X86_64 processors out of the box, for i386 emulation
use READ_IMPLIES_EXEC flag, introduced in r302515.
While here move common part of mmap() and mprotect() code to the files in compat/linux
to reduce code dupcliation between Linuxulator's.
Reported by: Johannes Jost Meixner, Shawn Webb
MFC after: 1 week
XMFC with: r302515, r302516
