Commit Graph

3306 Commits

Author SHA1 Message Date
Helge Deller
b8002058c4 linux-user: Fix openat() emulation to correctly detect accesses to /proc
In qemu we catch accesses to files like /proc/cpuinfo or /proc/net/route
and return to the guest contents which would be visible on a real system
(instead what the host would show).

This patch fixes a bug, where for example the accesses
    cat /proc////cpuinfo
or
    cd /proc && cat cpuinfo
will not be recognized by qemu and where qemu will wrongly show
the contents of the host's /proc/cpuinfo file.

Signed-off-by: Helge Deller <deller@gmx.de>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20230803214450.647040-2-deller@gmx.de>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2023-08-09 09:31:30 -07:00
Richard Henderson
a05cee93f4 linux-user: Use ARRAY_SIZE with bitmask_transtbl
Rather than using a zero tuple to end the table, use a macro
to apply ARRAY_SIZE and pass that on to the convert functions.

This fixes two bugs in which the conversion functions required
that both the target and host masks be non-zero in order to
continue, rather than require both target and host masks be
zero in order to terminate.

This affected mmap_flags_tbl when the host does not support
all of the flags we wish to convert (e.g. MAP_UNINITIALIZED).
Mapping these flags to zero is good enough, and matches how
the kernel ignores bits that are unknown.

Fixes: 4b840f96 ("linux-user: Populate more bits in mmap_flags_tbl")
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2023-08-09 07:17:42 -07:00
Richard Henderson
9ab8d07149 linux-user: Split out do_mmap
New function that rejects unsupported map types and flags.
In 4b840f96 we should not have accepted MAP_SHARED_VALIDATE
without actually validating the rest of the flags.

Fixes: 4b840f96 ("linux-user: Populate more bits in mmap_flags_tbl")
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2023-08-09 07:17:04 -07:00
Richard Henderson
32e07fddc6 linux-user: Adjust guest image layout vs reserved_va
linux-user: Do not adjust image mapping for host page size
 linux-user: Adjust initial brk when interpreter is close to executable
 util/selfmap: Rewrite using qemu/interval-tree.h
 linux-user: Rewrite probe_guest_base
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Merge tag 'pull-lu-20230808' of https://gitlab.com/rth7680/qemu into staging

linux-user: Adjust guest image layout vs reserved_va
linux-user: Do not adjust image mapping for host page size
linux-user: Adjust initial brk when interpreter is close to executable
util/selfmap: Rewrite using qemu/interval-tree.h
linux-user: Rewrite probe_guest_base

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* tag 'pull-lu-20230808' of https://gitlab.com/rth7680/qemu:
  linux-user: Rewrite non-fixed probe_guest_base
  linux-user: Rewrite fixed probe_guest_base
  linux-user: Consolidate guest bounds check in probe_guest_base
  linux-user: Remove duplicate CPU_LOG_PAGE from probe_guest_base
  util/selfmap: Rewrite using qemu/interval-tree.h
  linux-user: Use zero_bss for PT_LOAD with no file contents too
  linux-user: Do not adjust zero_bss for host page size
  linux-user: Do not adjust image mapping for host page size
  linux-user: Adjust initial brk when interpreter is close to executable
  linux-user: Use elf_et_dyn_base for ET_DYN with interpreter
  linux-user: Use MAP_FIXED_NOREPLACE for initial image mmap
  linux-user: Define ELF_ET_DYN_BASE in $guest/target_mman.h
  linux-user: Define TASK_UNMAPPED_BASE in $guest/target_mman.h
  linux-user: Adjust task_unmapped_base for reserved_va

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2023-08-08 14:10:07 -07:00
Richard Henderson
dd55885516 linux-user: Rewrite non-fixed probe_guest_base
Use pgb_addr_set to probe for all of the guest addresses,
not just the main executable.  Handle the identity map
specially and separately from the search.

If /proc/self/maps is available, utilize the full power
of the interval tree search, rather than a linear search
through the address list.

If /proc/self/maps is not available, increase the skip
between probes so that we do not probe every single page
of the host address space.  Choose 1 MiB for 32-bit hosts
(max 4k probes) and 1 GiB for 64-bit hosts (possibly a
large number of probes, but the large step makes it more
likely to find empty space quicker).

Tested-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2023-08-08 13:41:55 -07:00
Richard Henderson
06f38c6688 linux-user: Rewrite fixed probe_guest_base
Create a set of subroutines to collect a set of guest addresses,
all of which must be mappable on the host.  Use this within the
renamed pgb_fixed subroutine to validate the user's choice of
guest_base specified by the -B command-line option.

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2023-08-08 13:33:22 -07:00
Richard Henderson
0c441aeb39 linux-user: Consolidate guest bounds check in probe_guest_base
The three sets of checks are identical, logically.

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2023-08-08 13:27:17 -07:00
Richard Henderson
435c042fdc linux-user: Remove duplicate CPU_LOG_PAGE from probe_guest_base
The proper logging for probe_guest_base is in the main function.
There is no need to duplicate that in the subroutines.

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2023-08-08 13:27:17 -07:00
Richard Henderson
3ce3dd8ca9 util/selfmap: Rewrite using qemu/interval-tree.h
We will want to be able to search the set of mappings.
For this patch, the two users iterate the tree in order.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2023-08-08 13:27:17 -07:00
Richard Henderson
5f4e5b3409 linux-user: Use zero_bss for PT_LOAD with no file contents too
If p_filesz == 0, then vaddr_ef == vaddr.  We can reuse the
code in zero_bss rather than incompletely duplicating it in
load_elf_image.

Tested-by: Helge Deller <deller@gmx.de>
Reviewed-by: Helge Deller <deller@gmx.de>
Reviewed-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2023-08-08 13:27:17 -07:00
Richard Henderson
2d385be615 linux-user: Do not adjust zero_bss for host page size
Rely on target_mmap to handle guest vs host page size mismatch.

Tested-by: Helge Deller <deller@gmx.de>
Reviewed-by: Helge Deller <deller@gmx.de>
Reviewed-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2023-08-08 13:27:17 -07:00
Richard Henderson
e3d97d5c5d linux-user: Do not adjust image mapping for host page size
Remove TARGET_ELF_EXEC_PAGESIZE, and 3 other TARGET_ELF_PAGE* macros
based off of that.  Rely on target_mmap to handle guest vs host page
size mismatch.

Tested-by: Helge Deller <deller@gmx.de>
Reviewed-by: Helge Deller <deller@gmx.de>
Reviewed-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2023-08-08 13:27:17 -07:00
Helge Deller
1f356e8c01 linux-user: Adjust initial brk when interpreter is close to executable
While we attempt to load a ET_DYN executable far away from
TASK_UNMAPPED_BASE, we are not completely in control of the
address space layout.  If the interpreter lands close to
the executable, leaving insufficient heap space, move brk.

Tested-by: Helge Deller <deller@gmx.de>
Signed-off-by: Helge Deller <deller@gmx.de>
[rth: Re-order after ELF_ET_DYN_BASE patch so that we do not
 "temporarily break" tsan, and also to minimize the changes required.
 Remove image_info.reserve_brk as unused.]
Reviewed-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2023-08-08 13:27:17 -07:00
Richard Henderson
1ea06ded0d linux-user: Use elf_et_dyn_base for ET_DYN with interpreter
Follow the lead of the linux kernel in fs/binfmt_elf.c,
in which an ET_DYN executable which uses an interpreter
(usually a PIE executable) is loaded away from where the
interpreter itself will be loaded.

Tested-by: Helge Deller <deller@gmx.de>
Reviewed-by: Helge Deller <deller@gmx.de>
Reviewed-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2023-08-08 13:27:17 -07:00
Richard Henderson
ad25051bae linux-user: Use MAP_FIXED_NOREPLACE for initial image mmap
Use this as extra protection for the guest mapping over
any qemu host mappings.

Tested-by: Helge Deller <deller@gmx.de>
Reviewed-by: Helge Deller <deller@gmx.de>
Reviewed-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2023-08-08 13:27:17 -07:00
Richard Henderson
da2b71fab6 linux-user: Define ELF_ET_DYN_BASE in $guest/target_mman.h
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>
2023-08-08 13:27:15 -07:00
Richard Henderson
2d708164e0 linux-user: Define TASK_UNMAPPED_BASE in $guest/target_mman.h
Provide default values that are as close as possible to the
values used by the guest's kernel.

Tested-by: Helge Deller <deller@gmx.de>
Reviewed-by: Helge Deller <deller@gmx.de>
Reviewed-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2023-08-08 13:24:27 -07:00
Richard Henderson
c8fb5cf97d linux-user: Adjust task_unmapped_base for reserved_va
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>
2023-08-08 13:24:21 -07:00
Paolo Bonzini
50a0012227 linux-user: cleanup unused linux-user/include/host directories
Alpha and 31-bit s390 lack the assembly fragment to handle signals
occurring at the same time as system calls, so they cannot run
linux-user emulation anymore.  Drop the host-signal.h files for
them.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: Michael Tokarev <mjt@tls.msk.ru>
Tested-by: Ilya Leoshkevich <iii@linux.ibm.com>
Tested-by: Michael Tokarev <mjt@tls.msk.ru>
Message-ID: <20230808120303.585509-3-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-08-08 20:44:08 +02:00
Paolo Bonzini
f140823c56 configure: fix detection for x32 linux-user
x32 uses the same signal handling fragments as x86_64, since host_arch
is set to x86_64 when Meson runs.  Remove the unnecessary forwarder and
set the host_arch variable properly in configure.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Acked-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: Michael Tokarev <mjt@tls.msk.ru>
Tested-by: Ilya Leoshkevich <iii@linux.ibm.com>
Tested-by: Michael Tokarev <mjt@tls.msk.ru>
Message-ID: <20230808120303.585509-2-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-08-08 20:44:03 +02:00
Richard Henderson
62cbf08150 linux-user: Remove last_brk
This variable is unused.

Reviewed-by: Helge Deller <deller@gmx.de>
Reviewed-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2023-08-06 16:46:13 -07:00
Richard Henderson
0662a626a7 linux-user: Properly set image_info.brk in flatload
The heap starts at "brk" not "start_brk".  With this fixed,
image_info.start_brk is unused and may be removed.

Tested-by: Helge Deller <deller@gmx.de>
Reviewed-by: Helge Deller <deller@gmx.de>
Reviewed-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2023-08-06 16:46:13 -07:00
Akihiko Odaki
2aea137a42 linux-user: Do not align brk with host page size
do_brk() minimizes calls into target_mmap() by aligning the address
with host page size, which is potentially larger than the target page
size. However, the current implementation of this optimization has two
bugs:

- The start of brk is rounded up with the host page size while brk
  advertises an address aligned with the target page size as the
  beginning of brk. This makes the beginning of brk unmapped.
- Content clearing after mapping is flawed. The size to clear is
  specified as HOST_PAGE_ALIGN(brk_page) - brk_page, but brk_page is
  aligned with the host page size so it is always zero.

This optimization actually has no practical benefit. It makes difference
when brk() is called multiple times with values in a range of the host
page size. However, sophisticated memory allocators try to avoid to
make such frequent brk() calls. For example, glibc 2.37 calls brk() to
shrink the heap only when there is a room more than 128 KiB. It is
rare to have a page size larger than 128 KiB if it happens.

Let's remove the optimization to fix the bugs and make the code simpler.

Fixes: 86f04735ac ("linux-user: Fix brk() to release pages")
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1616
Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Message-Id: <20230802071754.14876-7-akihiko.odaki@daynix.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2023-08-06 16:46:03 -07:00
Akihiko Odaki
cb9d5d1fda linux-user: Do nothing if too small brk is specified
Linux 6.4.7 does nothing when a value smaller than the initial brk is
specified.

Fixes: 86f04735ac ("linux-user: Fix brk() to release pages")
Reviewed-by: Helge Deller <deller@gmx.de>
Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Message-Id: <20230802071754.14876-6-akihiko.odaki@daynix.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2023-08-06 16:45:03 -07:00
Akihiko Odaki
e69e032d1a linux-user: Use MAP_FIXED_NOREPLACE for do_brk()
MAP_FIXED_NOREPLACE can ensure the mapped address is fixed without
concerning that the new mapping overwrites something else.

Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Message-Id: <20230802071754.14876-5-akihiko.odaki@daynix.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2023-08-06 16:44:52 -07:00
Akihiko Odaki
c6cc059eca linux-user: Do not call get_errno() in do_brk()
Later the returned value is compared with -1, and negated errno is not
expected.

Fixes: 00faf08c95 ("linux-user: Don't use MAP_FIXED in do_brk()")
Reviewed-by: Helge Deller <deller@gmx.de>
Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Message-Id: <20230802071754.14876-4-akihiko.odaki@daynix.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2023-08-06 16:39:00 -07:00
Akihiko Odaki
ddcdd8c48f linux-user: Fix MAP_FIXED_NOREPLACE on old kernels
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>
2023-08-06 10:10:11 -07:00
Akihiko Odaki
c3dd50da0f linux-user: Unset MAP_FIXED_NOREPLACE for host
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>
2023-08-06 10:10:11 -07:00
Nathan Egge
4333f0924c linux-user/elfload: Set V in ELF_HWCAP for RISC-V
Set V bit for hwcap if misa is set.

Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1793
Signed-off-by: Nathan Egge <negge@xiph.org>
Reviewed-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Tested-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Message-Id: <20230803131424.40744-1-negge@xiph.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2023-08-06 10:10:11 -07:00
Helge Deller
38dd78c41e linux-user/armeb: Fix __kernel_cmpxchg() for armeb
Commit 7f4f0d9ea8 ("linux-user/arm: Implement __kernel_cmpxchg with host
atomics") switched to use qatomic_cmpxchg() to swap a word with the memory
content, but missed to endianess-swap the oldval and newval values when
emulating an armeb CPU, which expects words to be stored in big endian in
the guest memory.

The bug can be verified with qemu >= v7.0 on any little-endian host, when
starting the armeb binary of the upx program, which just hangs without
this patch.

Cc: qemu-stable@nongnu.org
Signed-off-by: Helge Deller <deller@gmx.de>
Reported-by: "Markus F.X.J. Oberhumer" <markus@oberhumer.com>
Reported-by: John Reiser <jreiser@BitWagon.com>
Closes: https://github.com/upx/upx/issues/687
Message-Id: <ZMQVnqY+F+5sTNFd@p100>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2023-07-31 12:19:13 -07:00
Peter Maydell
a74e39f674 Revert "linux-user: Fix qemu-arm to run static armhf binaries"
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Merge tag 'pull-revert-armhf-brk-fix' of https://gitlab.com/mjt0k/qemu into staging

Revert "linux-user: Fix qemu-arm to run static armhf binaries"

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# gpg: Signature made Sat 22 Jul 2023 17:56:30 BST
# gpg:                using RSA key 7B73BAD68BE7A2C289314B22701B4F6B1A693E59
# gpg:                issuer "mjt@tls.msk.ru"
# gpg: Good signature from "Michael Tokarev <mjt@tls.msk.ru>" [full]
# gpg:                 aka "Michael Tokarev <mjt@corpit.ru>" [full]
# gpg:                 aka "Michael Tokarev <mjt@debian.org>" [full]
# Primary key fingerprint: 6EE1 95D1 886E 8FFB 810D  4324 457C E0A0 8044 65C5
#      Subkey fingerprint: 7B73 BAD6 8BE7 A2C2 8931  4B22 701B 4F6B 1A69 3E59

* tag 'pull-revert-armhf-brk-fix' of https://gitlab.com/mjt0k/qemu:
  Revert "linux-user: Fix qemu-arm to run static armhf binaries"

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2023-07-24 11:34:08 +01:00
Richard Henderson
990ef9182b include/exec: Add WITH_MMAP_LOCK_GUARD
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2023-07-23 17:57:10 +01:00
Michael Tokarev
4ea3fa99be Revert "linux-user: Fix qemu-arm to run static armhf binaries"
This reverts commit 518f32221a.

It is causing similar segfaults at least on aarch64, ppc64el
and s390x. Let's revert this one for now and analyze what's
going on later.

Reopens: https://bugs.debian.org/1040981
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2023-07-22 19:54:22 +03:00
Peter Maydell
67d1f0a390 linux-user: brk() syscall fixes and armhf static binary fix
Commit 86f04735ac ("linux-user: Fix brk() to release pages") introduced
 the possibility for userspace applications to reduce memory footprint by
 calling brk() with a lower address and as such free up memory, the same
 way as the Linux kernel allows on physical machines.
 
 This change introduced some failures for applications with errors like
 - accesing bytes above the brk heap address on the same page,
 - freeing memory below the initial brk address,
 and introduced a behaviour which isn't done by the kernel (e.g. zeroing
 memory above brk).
 
 This patch series fixes those issues and has been tested with existing
 programs (e.g. upx).
 
 Additionally one patch fixes running static armhf executables (e.g. fstype)
 which was broken since qemu-8.0.
 
 Changes in v2:
 - dropped patch to revert d28b3c90cf ("linux-user: Make sure initial brk(0)
   is page-aligned")
 - rephrased some commit messages
 - fixed Cc email addresses, added new ones
 - added R-b tags
 
 Helge
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 =K3Va
 -----END PGP SIGNATURE-----

Merge tag 'linux-user-brk-fixes-pull-request' of https://github.com/hdeller/qemu-hppa into staging

linux-user: brk() syscall fixes and armhf static binary fix

Commit 86f04735ac ("linux-user: Fix brk() to release pages") introduced
the possibility for userspace applications to reduce memory footprint by
calling brk() with a lower address and as such free up memory, the same
way as the Linux kernel allows on physical machines.

This change introduced some failures for applications with errors like
- accesing bytes above the brk heap address on the same page,
- freeing memory below the initial brk address,
and introduced a behaviour which isn't done by the kernel (e.g. zeroing
memory above brk).

This patch series fixes those issues and has been tested with existing
programs (e.g. upx).

Additionally one patch fixes running static armhf executables (e.g. fstype)
which was broken since qemu-8.0.

Changes in v2:
- dropped patch to revert d28b3c90cf ("linux-user: Make sure initial brk(0)
  is page-aligned")
- rephrased some commit messages
- fixed Cc email addresses, added new ones
- added R-b tags

Helge

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# 4+eqW9vswjZwp1xm9bItLdnP2hkyUgI=
# =K3Va
# -----END PGP SIGNATURE-----
# gpg: Signature made Wed 19 Jul 2023 16:52:19 BST
# gpg:                using EDDSA key BCE9123E1AD29F07C049BBDEF712B510A23A0F5F
# gpg: Good signature from "Helge Deller <deller@gmx.de>" [unknown]
# gpg:                 aka "Helge Deller <deller@kernel.org>" [unknown]
# gpg: WARNING: This key is not certified with a trusted signature!
# gpg:          There is no indication that the signature belongs to the owner.
# Primary key fingerprint: 4544 8228 2CD9 10DB EF3D  25F8 3E5F 3D04 A7A2 4603
#      Subkey fingerprint: BCE9 123E 1AD2 9F07 C049  BBDE F712 B510 A23A 0F5F

* tag 'linux-user-brk-fixes-pull-request' of https://github.com/hdeller/qemu-hppa:
  linux-user: Fix qemu-arm to run static armhf binaries
  linux-user: Fix strace output for old_mmap
  linux-user: Fix signed math overflow in brk() syscall
  linux-user: Prohibit brk() to to shrink below initial heap address
  linux-user: Fix qemu brk() to not zero bytes on current page

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2023-07-20 09:53:52 +01:00
Helge Deller
518f32221a linux-user: Fix qemu-arm to run static armhf binaries
qemu-user crashes immediately when running static binaries on the armhf
architecture. The problem is the memory layout where the executable is
loaded before the interpreter library, in which case the reserved brk
region clashes with the interpreter code and is released before qemu
tries to start the program.

At load time qemu calculates a brk value for interpreter and executable
each.  The fix is to choose the higher one of both.

Signed-off-by: Helge Deller <deller@gmx.de>
Cc: Andreas Schwab <schwab@suse.de>
Cc: qemu-stable@nongnu.org
Reported-by:  Venkata.Pyla@toshiba-tsip.com
Closes: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1040981
2023-07-18 20:42:05 +02:00
Helge Deller
d971040c2d linux-user: Fix strace output for old_mmap
The old_mmap syscall (e.g. on i386) hands over the parameters in
a struct. Adjust the strace output to print the correct values.

Signed-off-by: Helge Deller <deller@gmx.de>
Reported-by: John Reiser <jreiser@BitWagon.com>
Closes: https://gitlab.com/qemu-project/qemu/-/issues/1760
2023-07-18 20:42:05 +02:00
Helge Deller
eac78a4b0b linux-user: Fix signed math overflow in brk() syscall
Fix the math overflow when calculating the new_malloc_size.

new_host_brk_page and brk_page are unsigned integers. If userspace
reduces the heap, new_host_brk_page is lower than brk_page which results
in a huge positive number (but should actually be negative).

Fix it by adding a proper check and as such make the code more readable.

Signed-off-by: Helge Deller <deller@gmx.de>
Tested-by: "Markus F.X.J. Oberhumer" <markus@oberhumer.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Fixes: 86f04735ac ("linux-user: Fix brk() to release pages")
Cc: qemu-stable@nongnu.org
Buglink: https://github.com/upx/upx/issues/683
2023-07-18 20:42:05 +02:00
Helge Deller
dfe49864af linux-user: Prohibit brk() to to shrink below initial heap address
Since commit 86f04735ac ("linux-user: Fix brk() to release pages") it's
possible for userspace applications to reduce their memory footprint by
calling brk() with a lower address and free up memory. Before that commit
guest heap memory was never unmapped.

But the Linux kernel prohibits to reduce brk() below the initial memory
address which is set at startup by the set_brk() function in binfmt_elf.c.
Such a range check was missed in commit 86f04735ac.

This patch adds the missing check by storing the initial brk value in
initial_target_brk and verify any new brk addresses against that value.

Tested with the i386 upx binary from
https://github.com/upx/upx/releases/download/v4.0.2/upx-4.0.2-i386_linux.tar.xz

Signed-off-by: Helge Deller <deller@gmx.de>
Tested-by: "Markus F.X.J. Oberhumer" <markus@oberhumer.com>
Fixes: 86f04735ac ("linux-user: Fix brk() to release pages")
Cc: qemu-stable@nongnu.org
Buglink: https://github.com/upx/upx/issues/683
2023-07-18 20:42:05 +02:00
Helge Deller
15ad98536a linux-user: Fix qemu brk() to not zero bytes on current page
The qemu brk() implementation is too aggressive and cleans remaining bytes
on the current page above the last brk address.

But some existing applications are buggy and read/write bytes above their
current heap address. On a phyiscal machine this does not trigger a
runtime error as long as the access happens on the same page. Additionally
the Linux kernel allocates only full pages and does no zeroing on already
allocated pages, even if the brk address is lowered.

Fix qemu to behave the same way as the kernel does. Do not touch already
allocated pages, and - when running with different page sizes of guest and
host - zero out only those memory areas where the host page size is bigger
than the guest page size.

Signed-off-by: Helge Deller <deller@gmx.de>
Tested-by: "Markus F.X.J. Oberhumer" <markus@oberhumer.com>
Fixes: 86f04735ac ("linux-user: Fix brk() to release pages")
Cc: qemu-stable@nongnu.org
Buglink: https://github.com/upx/upx/issues/683
2023-07-18 20:42:05 +02:00
Ilya Leoshkevich
7f114a5807 linux-user/elfload: Fix /proc/cpuinfo features: on s390x
elf_hwcap_str() takes a bit number, but compares it for equality with
the HWCAP_S390_* masks. This causes /proc/cpuinfo to display incorrect
hwcaps.

Fix by introducing the HWCAP_S390_NR_* constants and using them in
elf_hwcap_str() instead of the HWCAP_S390_*. While at it, add the
missing nnpa, pcimio and sie hwcaps from the latest kernel.

Output before:

	features	: esan3 zarch stfle msa

Output after:

	features	: esan3 zarch stfle msa ldisp eimm etf3eh highgprs vx vxe

Fixes: e19807bee3 ("linux-user/elfload: Introduce elf_hwcap_str() on s390x")
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Message-Id: <20230627151356.273259-1-iii@linux.ibm.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Thomas Huth <thuth@redhat.com>
2023-07-18 09:36:27 +02:00
Peter Maydell
aab746106c linux-user: Remove pointless NULL check in clock_adjtime handling
In the code for TARGET_NR_clock_adjtime, we set the pointer phtx to
the address of the local variable htx.  This means it can never be
NULL, but later in the code we check it for NULL anyway.  Coverity
complains about this (CID 1507683) because the NULL check comes after
a call to clock_adjtime() that assumes it is non-NULL.

Since phtx is always &htx, and is used only in three places, it's not
really necessary.  Remove it, bringing the code structure in to line
with that for TARGET_NR_clock_adjtime64, which already uses a simple
'&htx' when it wants a pointer to 'htx'.

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: 20230623144410.1837261-1-peter.maydell@linaro.org
2023-07-17 11:05:07 +01:00
Philippe Mathieu-Daudé
d713cf4d6c linux-user/arm: Do not allocate a commpage at all for M-profile CPUs
Since commit fbd3c4cff6 ("linux-user/arm: Mark the commpage
executable") executing bare-metal (linked with rdimon.specs)
cortex-M code fails as:

  $ qemu-arm -cpu cortex-m3 ~/hello.exe.m3
  qemu-arm: ../../accel/tcg/user-exec.c:492: page_set_flags: Assertion `last <= GUEST_ADDR_MAX' failed.
  Aborted (core dumped)

Commit 4f5c67f8df ("linux-user/arm: Take more care allocating
commpage") already took care of not allocating a commpage for
M-profile CPUs, however it had to be reverted as commit 6cda41daa2.

Re-introduce the M-profile fix from commit 4f5c67f8df.

Fixes: fbd3c4cff6 ("linux-user/arm: Mark the commpage executable")
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1755
Reported-by: Christophe Lyon <christophe.lyon@linaro.org>
Suggested-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Anton Johansson <anjo@rev.ng>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20230711153408.68389-1-philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2023-07-15 08:02:33 +01:00
Juan Quintela
ac42f44310 linux-user: Drop uint and ulong
These are types not used anymore anywhere else.

Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-id: <20230511085056.13809-1-quintela@redhat.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2023-07-15 08:02:33 +01:00
Richard Henderson
e230ec090b linux-user: Simplify target_madvise
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>
2023-07-15 08:02:33 +01:00
Richard Henderson
ecb796db03 linux-user: Remove can_passthrough_madvise
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>
2023-07-15 08:02:32 +01:00
Richard Henderson
bef6f008b9 accel/tcg: Return bool from page_check_range
Replace the 0/-1 result with true/false.
Invert the sense of the test of all callers.
Document the function.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20230707204054.8792-25-richard.henderson@linaro.org>
2023-07-15 08:02:32 +01:00
Richard Henderson
d7b0c5d013 linux-user: Simplify target_munmap
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>
2023-07-15 08:02:32 +01:00
Richard Henderson
558a4411c2 linux-user: Rename mmap_reserve to mmap_reserve_or_unmap
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>
2023-07-15 08:02:32 +01:00
Richard Henderson
260561d873 linux-user: Rewrite mmap_reserve
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>
2023-07-15 08:02:32 +01:00
Richard Henderson
f9cd8f5eca linux-user: Use 'last' instead of 'end' in target_mmap
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>
2023-07-15 08:02:32 +01:00