In the h != g && shmaddr == NULL && !reserved_va case, target_shmat()
incorrectly mmap()s the initial anonymous range with
MAP_FIXED_NOREPLACE, even though the earlier mmap_find_vma() has
already reserved the respective address range.
Fix by using MAP_FIXED when "mapped", which is set after
mmap_find_vma(), is true.
Fixes: 78bc8ed9a8 ("linux-user: Rewrite target_shmat")
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Message-Id: <20240325192436.561154-4-iii@linux.ibm.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Work much harder to get alignment and mapping beyond the end
of the file correct. Both of which are excercised by our
test-mmap for alpha (8k pages) on any 4k page host.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Acked-by: Helge Deller <deller@gmx.de>
Message-Id: <20240102015808.132373-23-richard.henderson@linaro.org>
For the cases for which the host mmap succeeds, but does
not yield the desired address, use do_munmap to restore
the reserved_va memory reservation.
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
For reserved_va, place all non-fixed maps then proceed
as for MAP_FIXED.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Reviewed-by: Ilya Leoshkevich <iii@linux.ibm.com>
Acked-by: Helge Deller <deller@gmx.de>
Message-Id: <20240102015808.132373-21-richard.henderson@linaro.org>
Use a subroutine instead of a goto within target_mmap__locked.
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Ilya Leoshkevich <iii@linux.ibm.com>
Acked-by: Helge Deller <deller@gmx.de>
Message-Id: <20240102015808.132373-20-richard.henderson@linaro.org>
We cannot skip over the_end1 to the_end, because we fail to
record the validity of the guest page with the interval tree.
Remove "the_end" and rename "the_end1" to "the_end".
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Reviewed-by: Ilya Leoshkevich <iii@linux.ibm.com>
Acked-by: Helge Deller <deller@gmx.de>
Message-Id: <20240102015808.132373-19-richard.henderson@linaro.org>
Basic validation of operands does not require the lock.
Hoist them from target_mmap__locked back into target_mmap.
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Ilya Leoshkevich <iii@linux.ibm.com>
Acked-by: Helge Deller <deller@gmx.de>
Message-Id: <20240102015808.132373-18-richard.henderson@linaro.org>
This removes a hidden use of qemu_host_page_size, using instead
the existing host_page_size local within each function.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Reviewed-by: Ilya Leoshkevich <iii@linux.ibm.com>
Acked-by: Helge Deller <deller@gmx.de>
Message-Id: <20240102015808.132373-11-richard.henderson@linaro.org>
We already have qemu_real_host_page_size() in a local variable.
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Ilya Leoshkevich <iii@linux.ibm.com>
Acked-by: Helge Deller <deller@gmx.de>
Message-Id: <20240102015808.132373-10-richard.henderson@linaro.org>
The feature test functions isar_feature_*() now take up nearly
a thousand lines in target/arm/cpu.h. This header file is included
by a lot of source files, most of which don't need these functions.
Move the feature test functions to their own header file.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20231024163510.2972081-2-peter.maydell@linaro.org
Do not assert success, but return any failure received.
Additionally, fix the method of earlier error return in target_munmap.
Reported-by: Andreas Schwab <schwab@suse.de>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Fix following warnings:
.../linux-user/mmap.c: In function 'target_mremap':
.../linux-user/mmap.c:913:13: warning: declaration of 'prot' shadows a previous local [-Wshadow=compatible-local]
913 | int prot = 0;
| ^~~~
../../../Projects/qemu/linux-user/mmap.c:871:9: note: shadowed declaration is here
871 | int prot;
| ^~~~
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Message-ID: <20230925151029.461358-3-laurent@vivier.eu>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Remove the fixed size shm_regions[] array.
Remove references when other mappings completely remove
or replace a region.
Tested-by: Helge Deller <deller@gmx.de>
Reviewed-by: Helge Deller <deller@gmx.de>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
If the shm region is not mapped at shmaddr, EINVAL.
Do not unmap the region until the syscall succeeds.
Use mmap_reserve_or_unmap to preserve reserved_va semantics.
Tested-by: Helge Deller <deller@gmx.de>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Rename from do_* to target_*. Fix some minor checkpatch errors.
Tested-by: Helge Deller <deller@gmx.de>
Tested-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Warner Losh <imp@bsdimp.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Copy each guest kernel's default value, then bound it
against reserved_va or the host address space.
Tested-by: Helge Deller <deller@gmx.de>
Reviewed-by: Helge Deller <deller@gmx.de>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Ensure that the chosen values for mmap_next_start and
task_unmapped_base are within the guest address space.
Tested-by: Helge Deller <deller@gmx.de>
Reviewed-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
The man page states:
> Note that older kernels which do not recognize the MAP_FIXED_NOREPLACE
> flag will typically (upon detecting a collision with a preexisting
> mapping) fall back to a “non-MAP_FIXED” type of behavior: they will
> return an address that is different from the requested address.
> Therefore, backward-compatible software should check the returned
> address against the requested address.
https://man7.org/linux/man-pages/man2/mmap.2.html
Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Message-Id: <20230802071754.14876-3-akihiko.odaki@daynix.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Passing MAP_FIXED_NOREPLACE to host will fail for reserved_va because
the address space is reserved with mmap. Replace it with MAP_FIXED
in that case.
Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Message-Id: <20230802071754.14876-2-akihiko.odaki@daynix.com>
[rth: Expand inline commentary.]
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
The trivial length 0 check can be moved up, simplifying some
of the other cases. The end < start test is handled by
guest_range_valid_untagged.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20230707204054.8792-27-richard.henderson@linaro.org>
Use page_check_range instead, which uses the interval tree
instead of checking each page individually.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20230707204054.8792-26-richard.henderson@linaro.org>
All of the guest to host page adjustment is handled by
mmap_reserve_or_unmap; there is no need to duplicate that.
There are no failure modes for munmap after alignment and
guest address range have been validated.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20230707204054.8792-23-richard.henderson@linaro.org>
If !reserved_va, munmap instead and assert success.
Update all callers.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20230707204054.8792-22-richard.henderson@linaro.org>
Use 'last' variables instead of 'end' variables; be careful
about avoiding overflow. Assert that the mmap succeeded.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20230707204054.8792-21-richard.henderson@linaro.org>
Complete the transition within the mmap functions to a formulation
that does not overflow at the end of the address space.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-Id: <20230707204054.8792-20-richard.henderson@linaro.org>
Use the interval tree to find empty space, rather than
probing each page in turn.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20230707204054.8792-19-richard.henderson@linaro.org>
Use 'last' variables instead of 'end' variables.
Always zero MAP_ANONYMOUS fragments, which we previously
failed to do if they were not writable; early exit in case
we allocate a new page from the kernel, known zeros.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20230707204054.8792-16-richard.henderson@linaro.org>
Use 'last' variables instead of 'end' variables.
When host page size > guest page size, detect when
adjacent host pages have the same protection and
merge that expanded host range into fewer syscalls.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20230707204054.8792-15-richard.henderson@linaro.org>
We build with _FILE_OFFSET_BITS=64, so off_t = off64_t = uint64_t.
With an extra cast, this fixes emulation of mmap2, which could
overflow the computation of the full value of offset.
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20230707204054.8792-14-richard.henderson@linaro.org>
Split out from validate_prot_to_pageflags, as there is not
one single host_prot for the entire range. We need to adjust
prot for every host page that overlaps multiple guest pages.
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20230707204054.8792-13-richard.henderson@linaro.org>
Fix all checkpatch.pl errors within mmap.c.
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20230707204054.8792-5-richard.henderson@linaro.org>
There is an overflow problem in mmap_find_vma_reserved:
when reserved_va == UINT32_MAX, end may overflow to 0.
Rather than a larger rewrite at this time, simply avoid
the final byte of the VA, which avoids searching the
final page, which avoids the overflow.
Cc: qemu-stable@nongnu.org
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1741
Fixes: 95059f9c ("include/exec: Change reserved_va semantics to last byte")
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Tested-by: Michael Tokarev <mjt@tls.msk.ru>
Reviewed-by: Michael Tokarev <mjt@tls.msk.ru>
Message-Id: <20230629080835.71371-1-richard.henderson@linaro.org>
Change the semantics to be the last byte of the guest va, rather
than the following byte. This avoids some overflow conditions.
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Pass the address of the last byte to be changed, rather than
the first address past the last byte. This avoids overflow
when the last page of the address space is involved.
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Pass the address of the last byte to be changed, rather than
the first address past the last byte. This avoids overflow
when the last page of the address space is involved.
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1528
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Both parameters have a different value on the parisc platform, so first
translate the target value into a host value for usage in the native
madvise() syscall.
Those parameters are often used by security sensitive applications (e.g.
tor browser, boringssl, ...) which expect the call to return a proper
return code on failure, so return -EINVAL if qemu fails to forward the
syscall to the host OS.
While touching this code, enhance the comments about MADV_DONTNEED.
Tested with testcase of tor browser when running hppa-linux guest on
x86-64 host.
Signed-off-by: Helge Deller <deller@gmx.de>
Acked-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <Y5iwTaydU7i66K/i@p100>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
When PAGE_RESET is set, we are replacing pages with new
content, which means that we need to invalidate existing
cached data, such as TranslationBlocks. Perform the
reset invalidate while we're doing other invalidates,
which allows us to remove the separate invalidates from
the user-only mmap/munmap/mprotect routines.
In addition, restrict invalidation to PAGE_EXEC pages.
Since cdf7130851, we have validated PAGE_EXEC is present
before translation, which means we can assume that if the
bit is not present, there are no translations to invalidate.
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
The hppa platform uses an upwards-growing stack and required in Linux
kernels < 5.18 an executable stack for signal processing. For that some
executables and libraries are marked to have an executable stack, for
which glibc uses the mprotect() syscall to mark the stack like this:
mprotect(xfa000000,4096,PROT_EXEC|PROT_READ|PROT_WRITE|PROT_GROWSUP).
Currently qemu will return -TARGET_EINVAL for this syscall because of the
checks in validate_prot_to_pageflags(), which doesn't allow the
PROT_GROWSUP or PROT_GROWSDOWN flags and thus triggers this error in the
guest:
error while loading shared libraries: libc.so.6: cannot enable executable stack as shared object requires: Invalid argument
Allow mprotect() to handle both flags and thus fix the guest.
The glibc tst-execstack testcase can be used to reproduce the issue.
Signed-off-by: Helge Deller <deller@gmx.de>
Message-Id: <20220924114501.21767-7-deller@gmx.de>
[lvivier: s/elif TARGET_HPPA/elif defined(TARGET_HPPA)/]
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
This is a follow-up for commit 892a4f6a75 ("linux-user: Add partial
support for MADV_DONTNEED"), which added passthrough for anonymous
mappings. File mappings can be handled in a similar manner.
In order to do that, mark pages, for which mmap() was passed through,
with PAGE_PASSTHROUGH, and then allow madvise() passthrough for these
pages. Drop the explicit PAGE_ANON check, since anonymous mappings are
expected to have PAGE_PASSTHROUGH anyway.
Add PAGE_PASSTHROUGH to PAGE_STICKY in order to keep it on mprotect().
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220725125043.43048-1-iii@linux.ibm.com>
Message-Id: <20220906000839.1672934-5-iii@linux.ibm.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
MADV_DONTNEED has a different value on alpha, compared to all the other
architectures. Fix by using TARGET_MADV_DONTNEED instead of
MADV_DONTNEED.
Fixes: 892a4f6a75 ("linux-user: Add partial support for MADV_DONTNEED")
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220906000839.1672934-3-iii@linux.ibm.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
