We updated flex output files in 4b314c89 ("libxl: update flex output
files") for DSA 3653-1 / CVE-2016-6354. But Debian security team
discovered the fix to flex was incomplete and issued DSA 3653-2. We need
to update our flex output files accordingly.
Signed-off-by: Wei Liu <wei.liu2@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
SMEP/SMAP is a security feature to prevent kernel executing/accessing
user address involuntarily, any such behavior will lead to a page fault.
SMEP/SMAP is open (in CR4) for both Xen and HVM guest in earlier code.
SMEP/SMAP bit set in Xen CR4 would enforce security checking for 32-bit
PV guest which will suffer unknown SMEP/SMAP page fault when guest
kernel attempt to access user address although SMEP/SMAP is close for
PV guests.
This patch introduces a new boot option value "hvm" for "sm{e,a}p", it
is going to diable SMEP/SMAP for Xen hypervisor while enable them for
HVM. In this way, 32-bit PV guest will not suffer SMEP/SMAP security
issue. Users can choose whether open SMEP/SMAP for Xen itself,
especially when they are going to run 32-bit PV guests.
Signed-off-by: He Chen <he.chen@linux.intel.com>
[jbeulich: doc and style adjustments]
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Both DEFINE_XEN_GUEST_HANDLE() and __DEFINE_XEN_GUEST_HANDLE()
each produce both const and non-const handles,
only DEFINE_COMPAT_HANDLE() does (__DEFINE_COMPAT_HANDLE()
does not). This patch has __DEFINE_COMPAT_HANDLE() also
produce a const handle.
Suggested-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Razvan Cojocaru <rcojocaru@bitdefender.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Extend the CPUID monitor event to include EAX and ECX values that were used
when CPUID was executed. This is useful in identifying which leaf was queried.
We also adjust the xen-access output format to more closely resemble the output
of the Linux cpuid tool's raw format.
Signed-off-by: Tamas K Lengyel <tamas.lengyel@zentific.com>
Acked-by: Razvan Cojocaru <rcojocaru@bitdefender.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
There has not been any substantial update to them since 2011. My quick
check shows that they don't work.
Just delete them. It would be easy to resurrect them from git log should
people still need them.
Signed-off-by: Wei Liu <wei.liu2@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
It only now occurred to me that there's no new hook needed to do so.
Eliminate the two work item comments.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Within compat_memory_op() this needs to be placed in the first switch()
statement, or it ends up being dead code (as that first switch() has a
default case chaining to compat_arch_memory_op()).
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Tested-by: Razvan Cojocaru <rcojocaru@bitdefender.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
So far accesses to Intel MSRs on an AMD system fall through to the
default case, while accesses to AMD MSRs on an Intel system bail (in
the RDMSR case without updating EAX and EDX). Make the "AMD MSRs on
Intel" case match the "Intel MSR on AMD" one.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
In the Credit1 hunk of 9f358ddd69 ("xen: Have
schedulers revise initial placement") csched_cpu_pick()
is called without taking the runqueue lock of the
(temporary) pCPU that the vCPU has been assigned to
(e.g., in XEN_DOMCTL_max_vcpus).
However, although 'hidden' in the IS_RUNQ_IDLE() macro,
that function does access the runq (for doing load
balancing calculations). Two scenarios are possible:
1) we are on cpu X, and IS_RUNQ_IDLE() peeks at cpu's
X own runq;
2) we are on cpu X, but IS_RUNQ_IDLE() peeks at some
other cpu's runq.
Scenario 2) absolutely requies that the appropriate
runq lock is taken. Scenario 1) works even without
taking the cpu's own runq lock. That is actually what
happens when when _csched_pick_cpu() is called from
csched_vcpu_acct() (in turn, called by csched_tick()).
Races have been observed and reported (by both XenServer
own testing and OSSTest [1]), in the form of
IS_RUNQ_IDLE() falling over LIST_POISON, because we're
not currently holding the proper lock, in
csched_vcpu_insert(), when scenario 1) occurs.
However, for better robustness, from now on we always
ask for the proper runq lock to be held when calling
IS_RUNQ_IDLE() (which is also becoming a static inline
function instead of macro).
In order to comply with that, we take the lock around
the call to _csched_cpu_pick() in csched_vcpu_acct().
[1] https://lists.xen.org/archives/html/xen-devel/2016-08/msg02144.html
Reported-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Dario Faggioli <dario.faggioli@citrix.com>
Reviewed-by: George Dunlap <george.dunlap@citrix.com>
This allows printf format checking to be performed, and for
debugtrace_printk() to evaluate its arguments, even if debugtrace is disabled
at compile time.
No intended change.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
* Use %pv or just d%d in preference to the multiple current ways of
presenting the same information.
* Use PRI_mfn instead of opencoding it.
* Drop all explicit use of __func__ from SHADOW_{PRINTK,DEBUG}() calls. The
wrappers already include it.
* Use hex rather than decimal for printing a pagefault error code.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Tim Deegan <tim@xen.org>
Mini-OS apps need to be compiled with the appropriate config settings
of Mini-OS, as there are various dependencies on those settings in
header files included by the apps.
Enhance stubdom Makefile to set the appropriate CPPFLAGS when calling
the apps' make.
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
[ wei: fold in change to Config.mk to update mini-os commit ]
Commit 03814de1d2 ("libxl: Do not trust
frontend for vusb") introduced an error in libxl_device_usbdev_list().
Fix it.
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
It is possible, when normalising a PV pagetable that the table has been freed
and reused for something else by the guest.
In such a case, data read might no longer be a pagetable, and fail the
truncation check. However, this should only be fatal if we encounter such a
page in the paused phase.
This check is now consistent with all other checks in the same area.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
cpufeat_mask() yields an unsigned integer constant. As a result, taking its
complement causes zero extention rather than sign extention.
The result is that, when a guest OS has OXSAVE disabled, all features in 1d
are hidden from native CPUID. Amongst other things, this causes the early
code in Linux to find no LAPIC, but for everything to appear fine later when
userspace is up and running.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Tested-by: Jan Beulich <jbeulich@suse.com>
- There's no 32-bit displacement in 16-bit addressing mode.
- It is wrong to ASSERT() anything on parts of an instruction fetched
from guest memory.
- The two scaling bits of a SIB byte don't affect whether there is a
scaled index register or not.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Non-debugging message text should be (and is in the cases here)
distinguishable without also logging function names. Debugging message
text, otoh, already includes file name and line number, so also
logging function names is redundant. One relatively pointless debugging
message gets removed altogether. In another case a missing log level
specifier gets added at once.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Recent enough binutils (2.25 onwards) support --build-id also for
COFF/PE output, and hence we should use that in favor of the original
hack when possible.
This gets complicated by the linker requiring at least one COFF object
file to attach the .buildid section to. Hence the patch introduces a
buildid.ihex (in order to avoid introducing binary files into the repo)
which then gets converted to a binary minimal COFF object (no sections,
no symbols).
Also (to avoid both code fragment going out of sync) remove an unneeded
ALIGN() from xen.lds.S: Adding an equivalent of it to the .buildid
section would cause the _erodata symbol to become associated with the
wrong section again (see commit 0970299de5 ["x86/EFI + Live Patch:
avoid symbol address truncation"]). And it's pointless because the
alignment already gets properly set by the input section(s).
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
Contrary to c/s b2507fe7 "x86/domctl: Update PV domain cpumasks when setting
cpuid policy", Intel CPUID masks are applied after fast forwarding hardware
state, rather than before. (All behaviour in this regard appears completely
undocumented by both Intel and AMD).
Therefore, a set bit in the MSR causes hardware to be fast-forwarded, while a
clear bit forces the guests view to 0, even if Xen's CR4.OSXSAVE is actually
set.
This allows Xen to provide an architectural view of a guest kernels
CR4.OSXSAVE setting to any native CPUID instruction issused by guest kernel or
userspace, even when masking is used.
The masking value defaults to 1 (if the guest has XSAVE available) to cause
fast-forwarding to occur for the HVM and idle vcpus.
When setting the MSRs, a PV guest kernel's choice of OXSAVE is taken into
account, and clobbered from the MSR if not set. This causes the
fast-forwarding of Xen's CR4 state not to happen.
As a side effect however, levelling potentially need updating on all PV CR4
changes.
Reported-by: Jan Beulich <JBeulich@suse.com>
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
A subsequent change needs to special-case OSXSAVE handling, which is per-vcpu
rather than per-domain.
No functional change.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
There is no need to extend the workaround to the faulted CPUID view, as
Linux's dependence on the workaround is stricly via the emulated view.
This causes a guest kernel faulted CPUID to observe architectural behaviour
with respect to its CR4.OSXSAVE setting.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
* Drop one piece of trailing whitespace
* Reposition LATE_HWDOM so it sits properly nested inside XSM in menuconfig
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Doug Goldstein <cardoe@cardoe.com>
Most of the comments are duplicated from the help text, and those without help
provide no useful additional input.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Julien Grall <julien.grall@arm.com>
Reviewed-by: Doug Goldstein <cardoe@cardoe.com>
Currently enabling gcov in hypervisor won't build because although
26c9d03d ("gcov: Adding support for coverage information") claimed that
%.init.o files were excluded from applying compilation options, it was
in fact not true.
Fix that by filtering out the options correctly. Because the dependency
of stub.o in x86 EFI build can't be eliminated easily and we prefer a
generalised method going forward, we introduce nogcov-y to explicitly
mark objects that don't need to build with gcov support.
Signed-off-by: Wei Liu <wei.liu2@citrix.com>
Signed-off-by: Jan Beulich <JBeulich@suse.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
The cbz instruction has range limitation. When compiled with gcov
support the object is larger so cbz can't handle that anymore. The error
message is like:
aarch64-linux-gnu-ld -EL -T xen.lds -N prelink.o \
/local/work/xen.git/xen/common/symbols-dummy.o -o /local/work/xen.git/xen/.xen-syms.0
prelink.o: In function `launch':
/local/work/xen.git/xen/arch/arm/arm64/head.S:602:(.text+0x408): relocation truncated to fit: R_AARCH64_CONDBR19 against symbol `start_xen' defined in .init.text section in prelink.o
Use "b" instead.
Signed-off-by: Wei Liu <wei.liu2@citrix.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: Julien Grall <julien.grall@arm.com>
That file should contain code and data used during initialisation only.
Mark it as such in build system and correctly annotate enabled_cpus.
Signed-off-by: Wei Liu <wei.liu2@citrix.com>
Reviewed-by: Julien Grall <julien.grall@arm.com>
Libxl ships output files from flex (libxlu_*_l.{c,h}). We use the flex
shipped in Debian to generate those files. Debian just patched their
flex (DSA 3653-1) to fix CVE-2016-6354, which is a buffer overrun bug.
Note that libxl is _NOT_ vulnerable to that CVE. See below for Ian's
analysis to security@xen.
It would still be nice that we update our shipped flex output files to
avoid confusion.
===QUOTE===
The bug is that with input >16K[1] flex would usually fail to resize
the input buffer, and then overrun it.
I have read the code in libxlu_cfg_l.c to try to understand the
implications for libxl.
AFAICT
- libxl always does config file reading _from the file_ itself, and
provides flex with a string or buffer.
- so we always call whatever_yy_scan_bytes, not any other flex setup
function to set up a `buffer' (as flex calls it)
- yy_scan_bytes calls yy_scan_buffer to set up the buffer
- yy_scan_buffer sets b->yy_fill_buffer
- The effect of this is that yy_get_next_buffer will always
return early, rather than continuing on to the vulnerable code.
So I think libxl is not vulnerable, regardless of the contents of the
configuration file.
[1] the default buffer size, or whatever other buffer size is
configured (but we don't change it)
===ENDQUOTE===
Signed-off-by: Wei Liu <wei.liu2@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Commit 91e204d37f ("libxc: try to find
last used pfn when migrating") introduced a bug for the case of a
domain supporting the virtual mapped linear p2m list: the maximum pfn
of the domain calculated from the p2m memory allocation might be too
low.
Correct this.
Reported-by: Stefan Bader <stefan.bader@canonical.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Tested-by: Stefan Bader <stefan.bader@canonical.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
The struct hvm_domain.vmx is defined in a union along with the svm.
This can causes issue for SVM since this code is used in the common
scheduling code for x86. The logic must check for cpu_has_vmx before
accessing the hvm_domain.vmx sturcture.
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Non-debugging message text should be (and is in the cases here)
distinguishable without also logging function names. Additionally log
the PCI device coordinates for alloc_pdev() failure.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Use %ecx instead of %eax to store low memory upper limit from EBDA.
This way we do not wipe multiboot protocol identifier. It is needed
in reloc() to differentiate between multiboot (v1) and
multiboot2 protocol.
Signed-off-by: Daniel Kiper <daniel.kiper@oracle.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Current reloc() call method makes confusion and does not scale well
for more arguments. And subsequent patch adding multiboot2 protocol
support have to pass 3 arguments instead of 2. Hence, move reloc()
call to stdcall calling convention. One may argue that we should use
standard cdecl calling convention. However, stdcall is better here
than cdecl because we do not need to remove "manually" arguments from
stack in xen/arch/x86/boot/head.S assembly file.
Suggested-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Daniel Kiper <daniel.kiper@oracle.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Newer GCC (e.g. gcc version 5.1.1 20150618 (Red Hat 5.1.1-4) (GCC)) does
some code optimizations by creating data sections (e.g. jump addresses
for C switch/case are calculated using data in .rodata section). This
thing is not accepted by *.lnk build recipe which requires that only .text
section lives in output. Potentially we can inhibit this GCC behavior by
using special options, e.g. -fno-tree-switch-conversion. However, this
does not guarantee that in the future new similar optimizations or anything
else which creates not accepted sections will not break our build recipes
again. I do not mention that probably this is not good idea to just disable
random optimizations. So, take over full control on *.lnk linking process
by using linker script and merge all text and data sections into one
.text section.
Additionally, remove .got.plt section which is not used in our final code.
Signed-off-by: Daniel Kiper <daniel.kiper@oracle.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Debugging message text already includes file name and line number, so
also logging function names is redundant.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: Kevin Tian <kevin.tian@intel.com>
Non-debugging message text should be (and is in the cases here)
distinguishable without also logging function names.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Daniel De Graaf <dgdegra@tycho.nsa.gov>
The uart generates an interrupt whenever the transmit holding register is
empty and UART_IER_ETHREI is set in UART_IER. Currently, Xen's ns16550
driver does not currently mask this interrupt when transmit is stopped,
unlike other platforms such as Linux [1].
Toggle UART_IER_ETHREI flag in the UART_IER according to the state dictated
by stop_tx and start_tx hooks.
On the Tegra platform (forthcoming series), the reset via reading IIR does not
prevent re-assertion of THRE. This causes Xen to hang in the interrupt
handler's while loop whenever there is no data to transmit. This behavior (bug?)
is addressed by utilizing the start & stop tx hooks.
This has been tested on various x86 PCs for any obvious signs of regressions.
[1] https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/drivers/tty/serial/8250/8250_port.c?id=refs/tags/v4.8-rc2#n1518
Signed-off-by: Chris Patterson <pattersonc@ainfosec.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
In addition:
- fixed a reference, which was incorrect
Signed-off-by: Lars Kurth <lars.kurth@citrix.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
[ wei: remove one trailing space while committing ]
Coverity complains:
overflow_before_widen: Potentially overflowing expression
info->nr_modules * 32U with type unsigned int (32 bits, unsigned) is
evaluated using 32-bit arithmetic, and then used in a context that
expects an expression of type uint64_t (64 bits, unsigned).
The overflow is unlikely to happen in reality because we only expect a
few modules.
Fix that by converting the check to use bound checking to placate
Coverity.
Signed-off-by: Wei Liu <wei.liu2@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
The original code used sizeof(info->signature) as the size parameter for
memcpy, which was wrong.
Fix that by using structure assignment.
Signed-off-by: Wei Liu <wei.liu2@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Wei Liu
He Chen
Razvan Cojocaru
Tamas K Lengyel
Luwei Kang
Jan Beulich
Dario Faggioli
Andrew Cooper
Juergen Gross
Feng Wu
Suravee Suthikulpanit
Daniel Kiper
Chris Patterson
Lars Kurth