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
Use the same scheme implemented to manage credentials.
Code needing to look at process's credentials (as opposed to thred's) is
provided with *_proc variants of relevant functions.
Places which possibly had to take the proc lock anyway still use the proc
pointer to access limits.
1. Linux sigset always 64 bit on all platforms. In order to move Linux
sigset code to the linux_common module define it as 64 bit int. Move
Linux sigset manipulation routines to the MI path.
2. Move Linux signal number definitions to the MI path. In general, they
are the same on all platforms except for a few signals.
3. Map Linux RT signals to the FreeBSD RT signals and hide signal conversion
tables to avoid conversion errors.
4. Emulate Linux SIGPWR signal via FreeBSD SIGRTMIN signal which is outside
of allowed on Linux signal numbers.
PR: 197216
argument is not a null pointer, and the ss_flags member pointed to by ss
contains flags other than SS_DISABLE. However, in fact, Linux also
allows SS_ONSTACK flag which is simply ignored.
For buggy apps (at least mono) ignore other than SS_DISABLE
flags as a Linux do.
While here move MI part of sigaltstack code to the appropriate place.
Reported by: abi at abinet dot ru
Use it in linux_wait4() system call and move linux_wait4() to the MI path.
While here add a prototype for the static bsd_to_linux_rusage().
Differential Revision: https://reviews.freebsd.org/D2138
Reviewed by: trasz
The reasons:
1. Get rid of the stubs/quirks with process dethreading,
process reparent when the process group leader exits and close
to this problems on wait(), waitpid(), etc.
2. Reuse our kernel code instead of writing excessive thread
managment routines in Linuxulator.
Implementation details:
1. The thread is created via kern_thr_new() in the clone() call with
the CLONE_THREAD parameter. Thus, everything else is a process.
2. The test that the process has a threads is done via P_HADTHREADS
bit p_flag of struct proc.
3. Per thread emulator state data structure is now located in the
struct thread and freed in the thread_dtor() hook.
Mandatory holdig of the p_mtx required when referencing emuldata
from the other threads.
4. PID mangling has changed. Now Linux pid is the native tid
and Linux tgid is the native pid, with the exception of the first
thread in the process where tid and pid are one and the same.
Ugliness:
In case when the Linux thread is the initial thread in the thread
group thread id is equal to the process id. Glibc depends on this
magic (assert in pthread_getattr_np.c). So for system calls that
take thread id as a parameter we should use the special method
to reference struct thread.
Differential Revision: https://reviews.freebsd.org/D1039
threads refactor kern_sched_rr_get_interval() and sys_sched_rr_get_interval().
Add a kern_sched_rr_get_interval() counterpart which takes a targettd
parameter to allow specify target thread directly by callee (new Linuxulator).
Linuxulator temporarily uses first thread in proc.
Move linux_sched_rr_get_interval() to the MI part.
Differential Revision: https://reviews.freebsd.org/D1032
Reviewed by: trasz
allocated from exec_map. If many threads try to perform execve(2) in
parallel, the exec map is exhausted and some threads sleep
uninterruptible waiting for the map space. Then, the thread which won
the race for the space allocation, cannot single-thread the process,
causing deadlock.
Reported and tested by: pho (previous version)
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
further refinement is required as some device drivers intended to be
portable over FreeBSD versions rely on __FreeBSD_version to decide whether
to include capability.h.
MFC after: 3 weeks
in the future in a backward compatible (API and ABI) way.
The cap_rights_t represents capability rights. We used to use one bit to
represent one right, but we are running out of spare bits. Currently the new
structure provides place for 114 rights (so 50 more than the previous
cap_rights_t), but it is possible to grow the structure to hold at least 285
rights, although we can make it even larger if 285 rights won't be enough.
The structure definition looks like this:
struct cap_rights {
uint64_t cr_rights[CAP_RIGHTS_VERSION + 2];
};
The initial CAP_RIGHTS_VERSION is 0.
The top two bits in the first element of the cr_rights[] array contain total
number of elements in the array - 2. This means if those two bits are equal to
0, we have 2 array elements.
The top two bits in all remaining array elements should be 0.
The next five bits in all array elements contain array index. Only one bit is
used and bit position in this five-bits range defines array index. This means
there can be at most five array elements in the future.
To define new right the CAPRIGHT() macro must be used. The macro takes two
arguments - an array index and a bit to set, eg.
#define CAP_PDKILL CAPRIGHT(1, 0x0000000000000800ULL)
We still support aliases that combine few rights, but the rights have to belong
to the same array element, eg:
#define CAP_LOOKUP CAPRIGHT(0, 0x0000000000000400ULL)
#define CAP_FCHMOD CAPRIGHT(0, 0x0000000000002000ULL)
#define CAP_FCHMODAT (CAP_FCHMOD | CAP_LOOKUP)
There is new API to manage the new cap_rights_t structure:
cap_rights_t *cap_rights_init(cap_rights_t *rights, ...);
void cap_rights_set(cap_rights_t *rights, ...);
void cap_rights_clear(cap_rights_t *rights, ...);
bool cap_rights_is_set(const cap_rights_t *rights, ...);
bool cap_rights_is_valid(const cap_rights_t *rights);
void cap_rights_merge(cap_rights_t *dst, const cap_rights_t *src);
void cap_rights_remove(cap_rights_t *dst, const cap_rights_t *src);
bool cap_rights_contains(const cap_rights_t *big, const cap_rights_t *little);
Capability rights to the cap_rights_init(), cap_rights_set(),
cap_rights_clear() and cap_rights_is_set() functions are provided by
separating them with commas, eg:
cap_rights_t rights;
cap_rights_init(&rights, CAP_READ, CAP_WRITE, CAP_FSTAT);
There is no need to terminate the list of rights, as those functions are
actually macros that take care of the termination, eg:
#define cap_rights_set(rights, ...) \
__cap_rights_set((rights), __VA_ARGS__, 0ULL)
void __cap_rights_set(cap_rights_t *rights, ...);
Thanks to using one bit as an array index we can assert in those functions that
there are no two rights belonging to different array elements provided
together. For example this is illegal and will be detected, because CAP_LOOKUP
belongs to element 0 and CAP_PDKILL to element 1:
cap_rights_init(&rights, CAP_LOOKUP | CAP_PDKILL);
Providing several rights that belongs to the same array's element this way is
correct, but is not advised. It should only be used for aliases definition.
This commit also breaks compatibility with some existing Capsicum system calls,
but I see no other way to do that. This should be fine as Capsicum is still
experimental and this change is not going to 9.x.
Sponsored by: The FreeBSD Foundation
but GNU libc used it without checking its kernel version, e. g., Fedora 10.
- Move pipe(2) implementation for Linuxulator from MD files to MI file,
sys/compat/linux/linux_file.c. There is no MD code for this syscall at all.
- Correct an argument type for pipe() from l_ulong * to l_int *. Probably
this was the source of MI/MD confusion.
Reviewed by: emulation
patch modifies makesyscalls.sh to prefix all of the non-compatibility
calls (e.g. not linux_, freebsd32_) with sys_ and updates the kernel
entry points and all places in the code that use them. It also
fixes an additional name space collision between the kernel function
psignal and the libc function of the same name by renaming the kernel
psignal kern_psignal(). By introducing this change now we will ease future
MFCs that change syscalls.
Reviewed by: rwatson
Approved by: re (bz)
kernel for FreeBSD 9.0:
Add a new capability mask argument to fget(9) and friends, allowing system
call code to declare what capabilities are required when an integer file
descriptor is converted into an in-kernel struct file *. With options
CAPABILITIES compiled into the kernel, this enforces capability
protection; without, this change is effectively a no-op.
Some cases require special handling, such as mmap(2), which must preserve
information about the maximum rights at the time of mapping in the memory
map so that they can later be enforced in mprotect(2) -- this is done by
narrowing the rights in the existing max_protection field used for similar
purposes with file permissions.
In namei(9), we assert that the code is not reached from within capability
mode, as we're not yet ready to enforce namespace capabilities there.
This will follow in a later commit.
Update two capability names: CAP_EVENT and CAP_KEVENT become
CAP_POST_KEVENT and CAP_POLL_KEVENT to more accurately indicate what they
represent.
Approved by: re (bz)
Submitted by: jonathan
Sponsored by: Google Inc
be used by linuxolator itself.
Move linux_wait4() to MD path as it requires native struct
rusage translation to struct l_rusage on linux32/amd64.
MFC after: 1 Month.
for manipulating pcb_flags. These inline functions are very similar to
atomic_set_char(9) and atomic_clear_char(9) but without unnecessary LOCK
prefix for SMP. Add comments about the rationale[1]. Use these functions
wherever possible. Although there are some places where it is not strictly
necessary (e.g., a PCB is copied to create a new PCB), it is done across
the board for sake of consistency. Turn pcb_full_iret into a PCB flag as
it is safe now. Move rarely used fields before pcb_flags and reduce size
of pcb_flags to one byte. Fix some style(9) nits in pcb.h while I am in
the neighborhood.
Reviewed by: kib
Submitted by: kib[1]
MFC after: 2 months
in Linux emulation layer. Linux seems to only require that pos is
page-aligned, but otherwise ignores it. Default FreeBSD mmap parameter
checking is too strict to allow some Linux binaries to run. tsMuxeR is
one example of such a binary.
Discussed with: jhb
MFC after: 1 week
partially fixed on amd64 earlier. Rather than forcing linux_mmap_common()
to use a 32-bit offset, have it accept a 64-bit file offset. This offset
is then passed to the real mmap() call. Rather than inventing a structure
to hold the normal linux_mmap args that has a 64-bit offset, just pass
each of the arguments individually to linux_mmap_common() since that more
closes matches the existing style of various kern_foo() functions.
Submitted by: Christian Zander @ Nvidia
MFC after: 1 week
the kernel on amd64. Fill and read segment registers for mcontext and
signals. Handle traps caused by restoration of the
invalidated selectors.
Implement user-mode creation and manipulation of the process-specific
LDT descriptors for amd64, see sysarch(2).
Implement support for TSS i/o port access permission bitmap for amd64.
Context-switch LDT and TSS. Do not save and restore segment registers on
the context switch, that is handled by kernel enter/leave trampolines
now. Remove segment restore code from the signal trampolines for
freebsd/amd64, freebsd/ia32 and linux/i386 for the same reason.
Implement amd64-specific compat shims for sysarch.
Linuxolator (temporary ?) switched to use gsbase for thread_area pointer.
TODO:
Currently, gdb is not adapted to show segment registers from struct reg.
Also, no machine-depended ptrace command is added to set segment
registers for debugged process.
In collaboration with: pho
Discussed with: peter
Reviewed by: jhb
Linuxolator tested by: dchagin
Add a custom version of copyiniov() to deal with the 32-bit iovec
pointers from userland (to be used later).
Adjust prototypes for linux_readv() and linux_writev() to use new
l_iovec32 definition and to match actual linux code. In particular,
use ulong for fd (why ?).
Submitted by: dchagin
- Use `fildes[2]' instead of `*fildes' to make more clear that pipe(2)
fills an array with two descriptors.
- Remove EFAULT from the manual page. Because of the current calling
convention, pipe(2) raises a segmentation fault when an invalid
address is passed.
- Introduce kern_pipe() to make it easier for binary emulations to
implement pipe(2).
- Make Linux binary emulation use kern_pipe(), which means we don't have
to recover td_retval after calling the FreeBSD system call.
Approved by: rdivacky
Discussed on: arch
location in GDT where the segment descriptor from pcb_gs32sd is
copied, and the location is in GDT local to CPU.
Noted and reviewed by: peter
MFC after: 1 week
the 32bit images on amd64.
Change the semantic of the PCB_32BIT pcb flag to request the context
switch code to operate on the segment registers. Its previous meaning
of saving or restoring the %gs base offset is assigned to the new
PCB_GS32BIT flag.
FreeBSD 32bit image activator sets the PCB_32BIT flag, while Linux 32bit
emulation sets PCB_32BIT | PCB_GS32BIT.
Reviewed by: peter
MFC after: 2 weeks
- Use thread_lock() rather than sched_lock for per-thread scheduling
sychronization.
- Use the per-process spinlock rather than the sched_lock for per-process
scheduling synchronization.
Tested by: kris, current@
Tested on: i386, amd64, ULE, 4BSD, libthr, libkse, PREEMPTION, etc.
Discussed with: kris, attilio, kmacy, jhb, julian, bde (small parts each)
passed zero as exit signal.
GCC 4.2 changes the kernel data segment layout not to have 0
in that memory location. This code ran by luck before and now
the luck has run out.
Dont "return" in linux_clone() after we forked the new process in a case
of problems. Move the copyout of p2->p_pid outside the emul_lock coverage.
Submitted by: Roman Divacky
