Anthony reported that >4GB guests on Xen with 32bit QEMU broke after
commit 4ed023c ("Round up RAMBlock sizes to host page sizes", 2015-11-05).
In that patch sizes are masked against qemu_host_page_size/mask which
are uintptr_t, and thus 32bit on a 32bit QEMU, even though the ram space
might be bigger than 4GB on Xen.
Since ram_addr_t is not available on user-mode emulation targets, ensure
that we get a sign extension when masking away the low bits of the address.
Remove the ~10 year old scary comment that the type of these variables
is probably wrong, with another equally scary comment. The new comment
however does not have "???" in it, which is arguably an improvement.
For completeness use the alignment macros in linux-user and bsd-user
instead of manually doing an &. linux-user and bsd-user are not affected
by the Xen issue, however.
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reported-by: Anthony PERARD <anthony.perard@citrix.com>
Fixes: 4ed023ce2a
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
All error conditions that target_mprotect checks are also checked
by target_mmap. EACCESS cannot happen because we are just removing
PROT_WRITE. ENOMEM should not happen because we are modifying a
whole VMA (and we have bigger problems anyway if it happens).
Fixes a Coverity false positive, where Coverity complains about
target_mprotect's return value being passed to tb_invalidate_phys_range.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
As we have removed CONFIG_USE_GUEST_BASE, we always use a guest base
and the macros GUEST_BASE and RESERVED_VA become useless: replace
them by their values.
Reviewed-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <1440420834-8388-1-git-send-email-laurent@vivier.eu>
Signed-off-by: Richard Henderson <rth@twiddle.net>
All tcg host architectures now support the guest base and as
there is no real performance lost, it can be always enabled.
Anyway, guest base use can be disabled lively by setting guest
base to 0.
CONFIG_USE_GUEST_BASE is defined as (USE_GUEST_BASE && USER_ONLY),
it should have to be replaced by CONFIG_USER_ONLY in non CONFIG_USER_ONLY
parts, but as some other parts are using !CONFIG_SOFTMMU I have chosen to
use !CONFIG_SOFTMMU instead.
Reviewed-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <1440373328-9788-2-git-send-email-laurent@vivier.eu>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Remove them from the sundry exec-all.h header, since they are only used by
the TCG runtime in exec.c and user-exec.c.
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Now all linux-user targets support building with NPTL, we can make it
mandatory. This is a good idea because:
* NPTL is no longer new and experimental; it is completely standard
* in practice, linux-user without NPTL is nearly useless for
binaries built against non-ancient glibc
* it allows us to delete the rather untested code for handling
the non-NPTL configuration
Note that this patch leaves the CONFIG_USE_NPTL ifdefs in the
bsd-user codebase alone. This makes no change for bsd-user, since
our configure test for NPTL had a "#include <linux/futex.h>"
which means bsd-user would never have been compiled with
CONFIG_USE_NPTL defined, and it still is not.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
If we let the kernel handle the implementation of mmap_find_vma,
via an anon mmap, we must use the size as indicated by the user
and not the size truncated to the filesize.
This happens often in ld.so, where we initially mmap the file to
the size of the text+data+bss to reserve an area, then mmap+fixed
over the top to properly handle data and bss.
Signed-off-by: Richard Henderson <rth@twiddle.net>
If we execute linux-user code that does the following:
* A = mmap()
* execute code in A
* munmap(A)
* B = mmap(), but mmap returns the same address as A
* execute code in B
we end up executing a stale cached tb that contains translated code
from A, while we want new code from B.
This patch adds a TB flush for mmap'ed regions, before we return them,
avoiding the whole issue. It also adds a flush for munmap, so that we
don't execute stale TBs instead of getting a segfault.
Reported-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Acked-by: Riku Voipio <riku.voipio@linaro.org>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
After consulting with Paul Brook, we concluded that it's best to search
the VMA space downwards, so that we don't even get the chance to conflict
with the brk range.
This patch resolves a bunch of allocation conflicts when using -R.
Signed-off-by: Alexander Graf <agraf@suse.de>
[minor changes to get it to apply -- PMM]
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
If CONFIG_USE_GUEST_BASE is not defined, gcc complains:
linux-user/mmap.c:235: error: comparison of unsigned expression >= 0 is always true
because RESERVED_VA is #defined to 0. Since mmap_find_vma_reserved()
will never be called anyway if RESERVED_VA is always 0, fix this by
simply #ifdef'ing away the function and its callsite.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
mmap_reserve() should be called only when RESERVED_VA is enabled.
Otherwise, unmaped virtual address space will never be reusable. This
bug will exhaust virtual address space in extreme conditions.
Signed-off-by: Riku Voipio <riku.voipio@nokia.com>
-1ul is unsigned long, which does not necessarily match abi_ulong
type.
Fix by using abi_long instead.
This also avoids a warning with GCC flag -Wtype-limits.
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
Commit 68a1c81686 broke qemu on hosts not
using guest base. It uses reserved_va unconditionally in mmap.c. To
avoid to many #ifdef #endif blocks, define RESERVED_VA as either
reserved_va or 0ul, and use it instead of reserved_va, similarly to what
has been done with guest_base/GUEST_BASE.
Since we're no longer setting PAGE_RESERVED, there's no need to
implement qemu_malloc via mmap.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
The usermode PAGE_RESERVED code is not required by the current mmap
implementation, and is already broken when guest_base != 0.
Unfortunately the bsd emulation still uses the old mmap implementation,
so we can't rip it out altogether.
Signed-off-by: Paul Brook <paul@codesourcery.com>
Don't return addresses that aren't properly aligned for the guest,
e.g. when the guest has a larger page size than the host. Don't
return addresses that are outside the virtual address space for the
target, by paying proper attention to the h2g/g2h macros.
At the same time, place the default mapping base for 64-bit guests
(on 64-bit hosts) outside the low 4G. Consistently interpret
mmap_next_start in the guest address space.
Signed-off-by: Richard Henderson <rth@twiddle.net>
CC i386-linux-user/mmap.o
cc1: warnings being treated as errors
/usr/src/RPM/BUILD/qemu-0.11.92/linux-user/mmap.c: In function 'mmap_frag':
/usr/src/RPM/BUILD/qemu-0.11.92/linux-user/mmap.c:253: error: ignoring return value of 'pread', declared with attribute warn_unused_result
/usr/src/RPM/BUILD/qemu-0.11.92/linux-user/mmap.c: In function 'target_mmap':
/usr/src/RPM/BUILD/qemu-0.11.92/linux-user/mmap.c:477: error: ignoring return value of 'pread', declared with attribute warn_unused_result
make[1]: *** [mmap.o] Error 1
Signed-off-by: Kirill A. Shutemov <kirill@shutemov.name>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
qemu's page table can be incomple if /proc/self/maps is unavailable or
host allocating a memory with mmap(), so we can't use it to find free
memory area.
New version mmap_find_vma() uses mmap() without MAP_FIXED to find free
memory.
Tested-by: Martin Mohring <martin.mohring@opensuse.org> :
quite some time ago this patch had been sent by Kirill to the QEMU ml.
At that time, the patch was rejected. Now we found out why the current
user mode memory allocator sometimes fails:
- Kernel Bug linux/fs/proc/task_mmu.c (fixed after 2.6.27)
http://bugzilla.kernel.org/attachment.cgi?id=17219
- use of proc file system to find memory mappings => bad idea
So I please apply the attached patch from Kirill to qemu to fix this
longstanding bug, because it causes all older linux distros (using
kernel 2.6.26 or older) to fail the QEMU memory allocator in user mode.
Signed-off-by: Kirill A. Shutemov <kirill@shutemov.name>
Signed-off-by: Riku Voipio <riku.voipio@iki.fi>
I used the following command to enable debugging:
perl -p -i -e 's/^\/\/#define DEBUG/#define DEBUG/g' * */* */*/*
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
We initialize mmap_mutex in any child threads/processes, but we need to
correctly statically initialize it for the original process.
Signed-off-by: Nathan Froyd <froydnj@codesourcery.com>
Signed-off-by: Riku Voipio <riku.voipio@iki.fi>
Signed-off-by: Edgar E. Iglesias <edgar.iglesias@gmail.com>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6510 c046a42c-6fe2-441c-8c8c-71466251a162
