Commit Graph

174 Commits

Author SHA1 Message Date
Richard Henderson 3e8f1628e8 exec: Use cpu_untagged_addr in g2h; split out g2h_untagged
Use g2h_untagged in contexts that have no cpu, e.g. the binary
loaders that operate before the primary cpu is created.  As a
colollary, target_mmap and friends must use untagged addresses,
since they are used by the loaders.

Use g2h_untagged on values returned from target_mmap, as the
kernel never applies a tag itself.

Use g2h_untagged on all pc values.  The only current user of
tags, aarch64, removes tags from code addresses upon branch,
so "pc" is always untagged.

Use g2h with the cpu context on hand wherever possible.

Use g2h_untagged in lock_user, which will be updated soon.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210212184902.1251044-13-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2021-02-16 11:04:53 +00:00
Richard Henderson 68f7766664 linux-user: Tidy VERIFY_READ/VERIFY_WRITE
These constants are only ever used with access_ok, and friends.
Rather than translating them to PAGE_* bits, let them equal
the PAGE_* bits to begin.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210212184902.1251044-8-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2021-02-16 11:04:53 +00:00
Richard Henderson 4feac83a9c linux-user: Check for overflow in access_ok
Verify that addr + size - 1 does not wrap around.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210212184902.1251044-7-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2021-02-16 11:04:53 +00:00
Keith Packard a10b9d93ec riscv: Add semihosting support
Adapt the arm semihosting support code for RISCV. This implementation
is based on the standard for RISC-V semihosting version 0.2 as
documented in

   https://github.com/riscv/riscv-semihosting-spec/releases/tag/0.2

Signed-off-by: Keith Packard <keithp@keithp.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20210107170717.2098982-6-keithp@keithp.com>
Message-Id: <20210108224256.2321-17-alex.bennee@linaro.org>
2021-01-18 10:05:06 +00:00
Richard Henderson 83f990eb5a linux-user/elfload: Parse NT_GNU_PROPERTY_TYPE_0 notes
This is generic support, with the code disabled for all targets.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20201021173749.111103-11-richard.henderson@linaro.org
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2020-10-27 10:44:02 +00:00
Stefan Hajnoczi d73415a315 qemu/atomic.h: rename atomic_ to qatomic_
clang's C11 atomic_fetch_*() functions only take a C11 atomic type
pointer argument. QEMU uses direct types (int, etc) and this causes a
compiler error when a QEMU code calls these functions in a source file
that also included <stdatomic.h> via a system header file:

  $ CC=clang CXX=clang++ ./configure ... && make
  ../util/async.c:79:17: error: address argument to atomic operation must be a pointer to _Atomic type ('unsigned int *' invalid)

Avoid using atomic_*() names in QEMU's atomic.h since that namespace is
used by <stdatomic.h>. Prefix QEMU's APIs with 'q' so that atomic.h
and <stdatomic.h> can co-exist. I checked /usr/include on my machine and
searched GitHub for existing "qatomic_" users but there seem to be none.

This patch was generated using:

  $ git grep -h -o '\<atomic\(64\)\?_[a-z0-9_]\+' include/qemu/atomic.h | \
    sort -u >/tmp/changed_identifiers
  $ for identifier in $(</tmp/changed_identifiers); do
        sed -i "s%\<$identifier\>%q$identifier%g" \
            $(git grep -I -l "\<$identifier\>")
    done

I manually fixed line-wrap issues and misaligned rST tables.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20200923105646.47864-1-stefanha@redhat.com>
2020-09-23 16:07:44 +01:00
Filip Bozuta 888468db94 linux-user: Add strace support for printing arguments for ioctls used for terminals and serial lines
Functions "print_ioctl()" and "print_syscall_ret_ioctl()" are used
to print arguments of "ioctl()" with "-strace". These functions
use "thunk_print()", which is defined in "thunk.c", to print the
contents of ioctl's third arguments that are not basic types.

However, this function doesn't handle ioctls of group ioctl_tty which
are used for terminals and serial lines. These ioctls use a type
"struct termios" which thunk type is defined in a non standard
way using "STRUCT_SPECIAL()". This means that this type is not decoded
regularly using "thunk_convert()" and uses special converting functions
"target_to_host_termios()" and "host_to_target_termios()", which are defined
in "syscall.c" to decode it's values.

For simillar reasons, this type is also not printed regularly using
"thunk_print()". That is the reason why a separate printing function
"print_termios()" is defined in file "strace.c". This function decodes
and prints flag values of the "termios" structure.

Implementation notes:

    Function "print_termios()" was implemented in "strace.c" using
    an existing function "print_flags()" to print flag values of
    "struct termios" fields. Also, recently implemented function
    "print_enums()" was also used to print enumareted values which
    are contained in the fields of 'struct termios'.

    These flag values were defined using an existing macro "FLAG_TARGET()"
    that generates aproppriate target flag values and string representations
    of these flags. Also, the recently defined macro "ENUM_TARGET()" was
    used to generate aproppriate enumarated values and their respective
    string representations.

    Function "print_termios()" was declared in "qemu.h" so that it can
    be accessed in "syscall.c". Type "StructEntry" defined in
    "exec/user/thunk.h" contains information that is used to decode
    structure values. Field "void print(void *arg)" was added in this
    structure as a special print function. Also, function "thunk_print()"
    was changed a little so that it uses this special print function
    in case it is defined. This printing function was instantiated with
    the defined "print_termios()" in "syscall.c" in "struct_termios_def".

Signed-off-by: Filip Bozuta <Filip.Bozuta@syrmia.com>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20200723210233.349690-4-Filip.Bozuta@syrmia.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
2020-08-27 12:29:50 +02:00
Filip Bozuta 7c89f34383 linux-user: Add strace support for printing arguments of truncate()/ftruncate() and getsid()
This patch implements strace argument printing functionality for following syscalls:

    * truncate, ftruncate - truncate a file to a specified length

        int truncate/truncate64(const char *path, off_t length)
        int ftruncate/ftruncate64(int fd, off_t length)
        man page: https://man7.org/linux/man-pages/man2/truncate.2.html

    * getsid - get session ID

        pid_t getsid(pid_t pid)
        man page: https://man7.org/linux/man-pages/man2/getsid.2.html

Implementation notes:

    Syscalls truncate/truncate64 take string argument types and thus a
    separate print function "print_truncate/print_truncate64" is stated in
    file "strace.list". This function is defined and implemented in "strace.c"
    by using an existing function used to print string arguments: "print_string()".
    For syscall ftruncate64, a separate printing function was also stated in
    "strace.c" as it requires a special kind of handling.
    The other syscalls have only primitive argument types, so the rest of the
    implementation was handled by stating an appropriate printing format in file
    "strace.list".
    Function "regpairs_aligned()" was cut & pasted from "syscall.c" to "qemu.h"
    as it is used by functions "print_truncate64()" and "print_ftruncate64()"
    to print the offset arguments of "truncate64()" and "ftruncate64()".

Signed-off-by: Filip Bozuta <Filip.Bozuta@syrmia.com>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20200811164553.27713-3-Filip.Bozuta@syrmia.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
2020-08-27 12:29:49 +02:00
Filip Bozuta e400e11941 linux-user: Make cpu_env accessible in strace.c
Variable "cpu_env" is used in file "syscall.c" to store
the information about the cpu environment. This variable
is used because values of some syscalls can vary between
cpu architectures. This patch makes the "cpu_env" accessible
in "strace.c" so it can enable aproppriate "-strace" argument
printing for these syscalls. This will be a useful addition
for future "-strace" implementation in QEMU.

Implementation notes:

    Functions "print_syscall()" and "print_syscall_ret()" which
    are stated and defined in "qemu.h" and "strace.c" respectively
    are used to print syscall arguments before and after syscall
    execution. These functions were changed with addition of a
    new argument "void *cpu_env". Strucute "struct syscallname"
    in "strace.c" is used to store the information about syscalls.
    Fields "call" and "result" represent pointers to functions which
    are used to print syscall arguments before and after execution.
    These fields were also changed with addition of a new "void *"
    argumetn.
    Also, all defined "print_*" and "print_syscall_ret*" functions
    in "strace.c" were changed to have the new "void *cpu_env".
    This was done to not cause build errors (even though none of
    these functions use this argument).

Signed-off-by: Filip Bozuta <Filip.Bozuta@syrmia.com>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20200811164553.27713-2-Filip.Bozuta@syrmia.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
2020-08-27 12:29:49 +02:00
Filip Bozuta 79482e5987 linux-user: Add strace support for printing arguments of ioctl()
This patch implements functionality for strace argument printing for ioctls.
When running ioctls through qemu with "-strace", they get printed in format:

    "ioctl(fd_num,0x*,0x*) = ret_value"

where the request code an the ioctl's third argument get printed in a hexadicemal
format. This patch changes that by enabling strace to print both the request code
name and the contents of the third argument. For example, when running ioctl
RTC_SET_TIME with "-strace", with changes from this patch, it gets printed in
this way:

    "ioctl(3,RTC_SET_TIME,{12,13,15,20,10,119,0,0,0}) = 0"

In case of IOC_R type ioctls, the contents of the third argument get printed
after the return value, and the argument inside the ioctl call gets printed
as pointer in hexadecimal format. For example, when running RTC_RD_TIME with
"-strace", with changes from this patch, it gets printed in this way:

    "ioctl(3,RTC_RD_TIME,0x40800374) = 0 ({22,9,13,11,5,120,0,0,0})"

In case of IOC_RW type ioctls, the contents of the third argument get printed
both inside the ioctl call and after the return value.

Implementation notes:

    Functions "print_ioctl()" and "print_syscall_ret_ioctl()", that are defined
    in "strace.c", are listed in file "strace.list" as "call" and "result"
    value for ioctl. Structure definition "IOCTLEntry" as well as predefined
    values for IOC_R, IOC_W and IOC_RW were cut and pasted from file "syscall.c"
    to file "qemu.h" so that they can be used by these functions to print the
    contents of the third ioctl argument. Also, the "static" identifier for array
    "ioctl_entries[]" was removed and this array was declared as "extern" in "qemu.h"
    so that it can also be used by these functions. To decode the structure type
    of the ioctl third argument, function "thunk_print()" was defined in file
    "thunk.c" and its definition is somewhat simillar to that of function
    "thunk_convert()".

Signed-off-by: Filip Bozuta <Filip.Bozuta@syrmia.com>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20200619124727.18080-3-filip.bozuta@syrmia.com>
[lv: fix close-bracket]
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
2020-07-04 18:08:51 +02:00
Filip Bozuta f4d92c5e9f linux-user: Add strace support for printing arguments of fallocate()
This patch implements strace argument printing functionality for following syscall:

    *fallocate - manipulate file space

        int fallocate(int fd, int mode, off_t offset, off_t len)
        man page: https://www.man7.org/linux/man-pages/man2/fallocate.2.html

Implementation notes:

    This syscall's second argument "mode" is composed of predefined values
    which represent flags that determine the type of operation that is
    to be performed on the file space. For that reason, a printing
    function "print_fallocate" was stated in file "strace.list". This printing
    function uses an already existing function "print_flags()" to print flags of
    the "mode" argument. These flags are stated inside an array "falloc_flags"
    that contains values of type "struct flags". These values are instantiated
    using an existing macro "FLAG_GENERIC()". Most of these flags are defined
    after kernel version 3.0 which is why they are enwrapped in an #ifdef
    directive.
    The syscall's third ant fourth argument are of type "off_t" which can
    cause variations between 32/64-bit architectures. To handle this variation,
    function "target_offset64()" was copied from file "strace.c" and used in
    "print_fallocate" to print "off_t" arguments for 32-bit architectures.

Signed-off-by: Filip Bozuta <Filip.Bozuta@syrmia.com>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20200619123331.17387-7-filip.bozuta@syrmia.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
2020-06-29 13:08:48 +02:00
Filip Bozuta c84be71f68 linux-user: Extend strace support to enable argument printing after syscall execution
Structure "struct syscallname" in file "strace.c" is used for "-strace"
    to print arguments and return values of syscalls. The last field of
    this structure "result" represents the calling function that prints the
    return values. This field was extended in this patch so that this function
    takes all syscalls arguments beside the return value. In this way, it enables
    "-strace" to print arguments of syscalls that have changed after the syscall
    execution. This extension will be useful as there are many syscalls that
    return values inside their arguments (i.e. listxattr() that returns the list
    of extended attributes inside the "list" argument).

Implementation notes:

    Since there are already three existing "print_syscall_ret*" functions inside
    "strace.c" ("print_syscall_ret_addr()", "print_syscall_ret_adjtimex()",
    "print_syscall_ret_newselect()"), they were changed to have all syscall arguments
    beside the return value. This was done so that these functions don't cause build
    errors (even though syscall arguments are not used in these functions).
    There is code repetition in these functions for checking the return value
    and printing the approppriate error message (this code is also located in
    print_syscall_ret() at the end of "strace.c"). That is the reason why a
    function "syscall_print_err()" was added for this code and put inside these
    functions. Functions "print_newselect()" and "print_syscall_ret_newselect()"
    were changed to use this new implemented functionality and not store the syscall
    argument values in separate static variables.

Signed-off-by: Filip Bozuta <Filip.Bozuta@syrmia.com>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20200619123331.17387-2-filip.bozuta@syrmia.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
2020-06-29 13:08:48 +02:00
Alex Bennée ee94743034 linux-user: completely re-write init_guest_space
First we ensure all guest space initialisation logic comes through
probe_guest_base once we understand the nature of the binary we are
loading. The convoluted init_guest_space routine is removed and
replaced with a number of pgb_* helpers which are called depending on
what requirements we have when loading the binary.

We first try to do what is requested by the host. Failing that we try
and satisfy the guest requested base address. If all those options
fail we fall back to finding a space in the memory map using our
recently written read_self_maps() helper.

There are some additional complications we try and take into account
when looking for holes in the address space. We try not to go directly
after the system brk() space so there is space for a little growth. We
also don't want to have to use negative offsets which would result in
slightly less efficient code on x86 when it's unable to use the
segment offset register.

Less mind-binding gotos and hopefully clearer logic throughout.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Acked-by: Laurent Vivier <laurent@vivier.eu>

Message-Id: <20200513175134.19619-5-alex.bennee@linaro.org>
2020-05-15 15:25:16 +01:00
Josh Kunz f63c9862ff linux-user: remove gemu_log from the linux-user tree
Now that all uses have been migrated to `qemu_log' it is no longer
needed.

Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Signed-off-by: Josh Kunz <jkz@google.com>
Message-Id: <20200204025416.111409-4-jkz@google.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
2020-02-19 11:17:40 +01:00
Josh Kunz 4b25a50674 linux-user: Use `qemu_log' for strace
This change switches linux-user strace logging to use the newer `qemu_log`
logging subsystem rather than the older `gemu_log` (notice the "g")
logger. `qemu_log` has several advantages, namely that it allows logging
to a file, and provides a more unified interface for configuration
of logging (via the QEMU_LOG environment variable or options).

This change introduces a new log mask: `LOG_STRACE` which is used for
logging of user-mode strace messages.

Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Signed-off-by: Josh Kunz <jkz@google.com>
Message-Id: <20200204025416.111409-3-jkz@google.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
2020-02-19 11:17:40 +01:00
Richard Henderson 6fd5944980 linux-user: Reserve space for brk
With bad luck, we can wind up with no space at all for brk,
which will generally cause the guest malloc to fail.

This bad luck is easier to come by with ET_DYN (PIE) binaries,
where either the stack or the interpreter (ld.so) gets placed
immediately after the main executable.

But there's nothing preventing this same thing from happening
with ET_EXEC (normal) binaries, during probe_guest_base().

In both cases, reserve some extra space via mmap and release
it back to the system after loading the interpreter and
allocating the stack.

The choice of 16MB is somewhat arbitrary.  It's enough for libc
to get going, but without being so large that 32-bit guests or
32-bit hosts are in danger of running out of virtual address space.
It is expected that libc will be able to fall back to mmap arenas
after the limited brk space is exhausted.

Launchpad: https://bugs.launchpad.net/qemu/+bug/1749393
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Tested-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20200117230245.5040-1-richard.henderson@linaro.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
2020-01-22 15:00:03 +01:00
Markus Armbruster dc5e9ac716 Include qemu/queue.h slightly less
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20190812052359.30071-20-armbru@redhat.com>
2019-08-16 13:31:52 +02:00
Peter Maydell 5bfce0b74f linux-user: Make sigaltstack stacks per-thread
The alternate signal stack set up by the sigaltstack syscall is
supposed to be per-thread.  We were incorrectly implementing it as
process-wide.  This causes problems for guest binaries that rely on
this.  Notably the Go runtime does, and so we were seeing crashes
caused by races where two guest threads might incorrectly both
execute on the same stack simultaneously.

Replace the global target_sigaltstack_used with a field
sigaltstack_used in the TaskState, and make all the references to the
old global instead get a pointer to the TaskState and use the field.

Fixes: https://bugs.launchpad.net/qemu/+bug/1696773
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Tested-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20190725131645.19501-1-peter.maydell@linaro.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
2019-07-26 19:24:33 +02:00
Rémi Denis-Courmont 0acd4ab849 linux-user: check valid address in access_ok()
Fix a crash with LTP testsuite and aarch64:

  tst_test.c:1015: INFO: Timeout per run is 0h 05m 00s
  qemu-aarch64: .../qemu/accel/tcg/translate-all.c:2522: page_check_range: Assertion `start < ((target_ulong)1 << L1_MAP_ADDR_SPACE_BITS)' failed.
  qemu:handle_cpu_signal received signal outside vCPU context @ pc=0x60001554

page_check_range() should never be called with address outside the guest
address space. This patch adds a guest_addr_valid() check in access_ok()
to only call page_check_range() with a valid address.

Fixes: f6768aa1b4 ("target/arm: fix AArch64 virtual address space size")
Signed-off-by: Rémi Denis-Courmont <remi@remlab.net>
Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Message-Id: <20190704084115.24713-1-lvivier@redhat.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
2019-07-18 13:57:28 +02:00
Laurent Vivier c6d0700f57 linux-user/m68k: remove simulator syscall interface
This interface has been introduced in 2005 with the
coldfire implementation (e6e5906b6e ColdFire target.)
and looks like to do what the linux-user interface already
does with the TRAP exception rather than the ILLEGAL
exception.

This interface has not been maintained since that.
The semi-hosting interface is not removed so coldfire kernel
with semi-hosting is always supported.

Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20190524162049.806-1-laurent@vivier.eu>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
2019-06-26 17:14:41 +02:00
Richard Henderson 30ab9ef296 linux-user: Fix shmat emulation by honoring host SHMLBA
For those hosts with SHMLBA > getpagesize, we don't automatically
select a guest address that is compatible with the host.  We can
achieve this by boosting the alignment of guest_base and by adding
an extra alignment argument to mmap_find_vma.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20190519201953.20161-13-richard.henderson@linaro.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
2019-05-24 13:16:21 +02:00
Thomas Huth 798b858130 linux-user: Fix compilation with clang 3.4
Clang version 3.4.2 does not know the -Wpragmas option yet and bails
out with an error when we try to disable it in linux-user/qemu.h.
Fortunately, clang has a __has_warning() macro which allows us to add
an explicit check for the option that we want to ignore. With that we
can check for the availability of "-Waddress-of-packed-member" properly
and do not need the "-Wpragmas" at all here.

Fixes: 850d5e330a
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Signed-off-by: Thomas Huth <thuth@redhat.com>
2019-01-22 06:26:31 +01:00
Paolo Bonzini 7d37435bd5 avoid TABs in files that only contain a few
Most files that have TABs only contain a handful of them.  Change
them to spaces so that we don't confuse people.

disas, standard-headers, linux-headers and libdecnumber are imported
from other projects and probably should be exempted from the check.
Outside those, after this patch the following files still contain both
8-space and TAB sequences at the beginning of the line.  Many of them
have a majority of TABs, or were initially committed with all tabs.

    bsd-user/i386/target_syscall.h
    bsd-user/x86_64/target_syscall.h
    crypto/aes.c
    hw/audio/fmopl.c
    hw/audio/fmopl.h
    hw/block/tc58128.c
    hw/display/cirrus_vga.c
    hw/display/xenfb.c
    hw/dma/etraxfs_dma.c
    hw/intc/sh_intc.c
    hw/misc/mst_fpga.c
    hw/net/pcnet.c
    hw/sh4/sh7750.c
    hw/timer/m48t59.c
    hw/timer/sh_timer.c
    include/crypto/aes.h
    include/disas/bfd.h
    include/hw/sh4/sh.h
    libdecnumber/decNumber.c
    linux-headers/asm-generic/unistd.h
    linux-headers/linux/kvm.h
    linux-user/alpha/target_syscall.h
    linux-user/arm/nwfpe/double_cpdo.c
    linux-user/arm/nwfpe/fpa11_cpdt.c
    linux-user/arm/nwfpe/fpa11_cprt.c
    linux-user/arm/nwfpe/fpa11.h
    linux-user/flat.h
    linux-user/flatload.c
    linux-user/i386/target_syscall.h
    linux-user/ppc/target_syscall.h
    linux-user/sparc/target_syscall.h
    linux-user/syscall.c
    linux-user/syscall_defs.h
    linux-user/x86_64/target_syscall.h
    slirp/cksum.c
    slirp/if.c
    slirp/ip.h
    slirp/ip_icmp.c
    slirp/ip_icmp.h
    slirp/ip_input.c
    slirp/ip_output.c
    slirp/mbuf.c
    slirp/misc.c
    slirp/sbuf.c
    slirp/socket.c
    slirp/socket.h
    slirp/tcp_input.c
    slirp/tcpip.h
    slirp/tcp_output.c
    slirp/tcp_subr.c
    slirp/tcp_timer.c
    slirp/tftp.c
    slirp/udp.c
    slirp/udp.h
    target/cris/cpu.h
    target/cris/mmu.c
    target/cris/op_helper.c
    target/sh4/helper.c
    target/sh4/op_helper.c
    target/sh4/translate.c
    tcg/sparc/tcg-target.inc.c
    tests/tcg/cris/check_addo.c
    tests/tcg/cris/check_moveq.c
    tests/tcg/cris/check_swap.c
    tests/tcg/multiarch/test-mmap.c
    ui/vnc-enc-hextile-template.h
    ui/vnc-enc-zywrle.h
    util/envlist.c
    util/readline.c

The following have only TABs:

    bsd-user/i386/target_signal.h
    bsd-user/sparc64/target_signal.h
    bsd-user/sparc64/target_syscall.h
    bsd-user/sparc/target_signal.h
    bsd-user/sparc/target_syscall.h
    bsd-user/x86_64/target_signal.h
    crypto/desrfb.c
    hw/audio/intel-hda-defs.h
    hw/core/uboot_image.h
    hw/sh4/sh7750_regnames.c
    hw/sh4/sh7750_regs.h
    include/hw/cris/etraxfs_dma.h
    linux-user/alpha/termbits.h
    linux-user/arm/nwfpe/fpopcode.h
    linux-user/arm/nwfpe/fpsr.h
    linux-user/arm/syscall_nr.h
    linux-user/arm/target_signal.h
    linux-user/cris/target_signal.h
    linux-user/i386/target_signal.h
    linux-user/linux_loop.h
    linux-user/m68k/target_signal.h
    linux-user/microblaze/target_signal.h
    linux-user/mips64/target_signal.h
    linux-user/mips/target_signal.h
    linux-user/mips/target_syscall.h
    linux-user/mips/termbits.h
    linux-user/ppc/target_signal.h
    linux-user/sh4/target_signal.h
    linux-user/sh4/termbits.h
    linux-user/sparc64/target_syscall.h
    linux-user/sparc/target_signal.h
    linux-user/x86_64/target_signal.h
    linux-user/x86_64/termbits.h
    pc-bios/optionrom/optionrom.h
    slirp/mbuf.h
    slirp/misc.h
    slirp/sbuf.h
    slirp/tcp.h
    slirp/tcp_timer.h
    slirp/tcp_var.h
    target/i386/svm.h
    target/sparc/asi.h
    target/xtensa/core-dc232b/xtensa-modules.inc.c
    target/xtensa/core-dc233c/xtensa-modules.inc.c
    target/xtensa/core-de212/core-isa.h
    target/xtensa/core-de212/xtensa-modules.inc.c
    target/xtensa/core-fsf/xtensa-modules.inc.c
    target/xtensa/core-sample_controller/core-isa.h
    target/xtensa/core-sample_controller/xtensa-modules.inc.c
    target/xtensa/core-test_kc705_be/core-isa.h
    target/xtensa/core-test_kc705_be/xtensa-modules.inc.c
    tests/tcg/cris/check_abs.c
    tests/tcg/cris/check_addc.c
    tests/tcg/cris/check_addcm.c
    tests/tcg/cris/check_addoq.c
    tests/tcg/cris/check_bound.c
    tests/tcg/cris/check_ftag.c
    tests/tcg/cris/check_int64.c
    tests/tcg/cris/check_lz.c
    tests/tcg/cris/check_openpf5.c
    tests/tcg/cris/check_sigalrm.c
    tests/tcg/cris/crisutils.h
    tests/tcg/cris/sys.c
    tests/tcg/i386/test-i386-ssse3.c
    ui/vgafont.h

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20181213223737.11793-3-pbonzini@redhat.com>
Reviewed-by: Aleksandar Markovic <amarkovic@wavecomp.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Wainer dos Santos Moschetta <wainersm@redhat.com>
Acked-by: Richard Henderson <richard.henderson@linaro.org>
Acked-by: Eric Blake <eblake@redhat.com>
Acked-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Stefan Markovic <smarkovic@wavecomp.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-01-11 15:46:56 +01:00
Peter Maydell a2e002ff79 QEMU trivial patches collected between June and October 2018
(Thank you to Thomas Huth)
 
 v2: fix 32bit build with updated patch (v3) from Philippe Mathieu-Daudé
     built in a 32bit debian sid chroot
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Merge remote-tracking branch 'remotes/vivier2/tags/qemu-trivial-for-3.1-pull-request' into staging

QEMU trivial patches collected between June and October 2018
(Thank you to Thomas Huth)

v2: fix 32bit build with updated patch (v3) from Philippe Mathieu-Daudé
    built in a 32bit debian sid chroot

# gpg: Signature made Tue 30 Oct 2018 11:23:01 GMT
# gpg:                using RSA key F30C38BD3F2FBE3C
# gpg: Good signature from "Laurent Vivier <lvivier@redhat.com>"
# gpg:                 aka "Laurent Vivier <laurent@vivier.eu>"
# gpg:                 aka "Laurent Vivier (Red Hat) <lvivier@redhat.com>"
# Primary key fingerprint: CD2F 75DD C8E3 A4DC 2E4F  5173 F30C 38BD 3F2F BE3C

* remotes/vivier2/tags/qemu-trivial-for-3.1-pull-request:
  milkymist-minimac2: Use qemu_log_mask(GUEST_ERROR) instead of error_report
  ppc: move at24c to its own CONFIG_ symbol
  hw/intc/gicv3: Remove useless parenthesis around DIV_ROUND_UP macro
  hw/pci-host: Remove useless parenthesis around DIV_ROUND_UP macro
  tests/bios-tables-test: Remove an useless cast
  xen: Use the PCI_DEVICE macro
  qobject: Catch another straggler for use of qdict_put_str()
  configure: Support pkg-config for zlib
  tests: Fix typos in comments and help message (found by codespell)
  cpu.h: fix a typo in comment
  linux-user: fix comment s/atomic_write/atomic_set/
  qemu-iotests: make 218 executable
  scripts/qemu.py: remove trailing quotes on docstring
  scripts/decodetree.py: remove unused imports
  docs/devel/testing.rst: add missing newlines after code block
  qemu-iotests: fix filename containing checks
  tests/tcg/README: fix location for lm32 tests
  memory.h: fix typos in comments
  vga_int: remove unused function protype
  configs/alpha: Remove unused CONFIG_PARALLEL_ISA switch

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2018-10-30 15:49:55 +00:00
Stefan Markovic 74cfc704e5 linux-user: Extend image_info struct with MIPS fp_abi and interp_fp_abi fields
Add MIPS specific image_info struct fields fp_abi and interp_fp_abi
to store executable and interpreter fp_abi values (based on kernel
struct arch_elf_state in mips/include/asm/elf.h).

Reviewed-by: Aleksandar Markovic <amarkovic@wavecomp.com>
Signed-off-by: Stefan Markovic <smarkovic@wavecomp.com>
2018-10-29 15:50:23 +01:00
Emilio G. Cota 83f164bd5a linux-user: fix comment s/atomic_write/atomic_set/
Signed-off-by: Emilio G. Cota <cota@braap.org>
Message-Id: <20180811211011.6277-1-cota@braap.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
2018-10-26 17:17:32 +02:00
Peter Maydell 850d5e330a linux-user: Suppress address-of-packed-member warnings in __get/put_user_e
Our __get_user_e() and __put_user_e() macros cause newer versions
of clang to generate false-positive -Waddress-of-packed-member
warnings if they are passed the address of a member of a packed
struct (see https://bugs.llvm.org/show_bug.cgi?id=39113).
Suppress these using the _Pragma() operator. Unfortunately
_Pragma() support in gcc is broken in some gcc versions and
in some usage contexts, so we limit the pragma usage here to clang.

To put in the pragmas we need to convert the macros from
expressions to statements, but all the callsites effectively
treat them as statements already so this is OK.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20181009161814.21257-1-peter.maydell@linaro.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
2018-10-18 20:17:49 +02:00
Richard Henderson fa97e38eed linux-user/ppc: Implement swapcontext syscall
This allows the tests generated by debian-powerpc-user-cross
to function properly, especially tests/test-coroutine.

Technically this syscall is available to both ppc32 and ppc64,
but only ppc32 glibc actually uses it.  Thus the ppc64 path is
untested.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Tested-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20180718200648.22529-1-richard.henderson@linaro.org>
2018-07-22 21:33:45 +02:00
Laurent Vivier 33143c446e linux-user: fix ELF load alignment error
When we try to use some targets on ppc64, it can happen the target
doesn't support the host page size to align ELF load sections and
fails with:

  ELF load command alignment not page-aligned

Since commit a70daba377 ("linux-user: Tell guest about big host
page sizes") the host page size is used to align ELF sections, but
this doesn't work if the alignment required by the load section is
smaller than the host one.  For these cases, we continue to use the
TARGET_PAGE_SIZE instead of the host one.

I have tested this change on ppc64, and it fixes qemu linux-user for:
  s390x, m68k, i386, arm, aarch64, hppa
and I have tested it doesn't break the following targets:
  x86_64, mips64el, sh4
mips and mipsel abort, but I think for another reason.

Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
[lv: fixed "info->alignment = 0"]
Message-Id: <20180716195349.29959-1-laurent@vivier.eu>
2018-07-22 21:32:50 +02:00
Alex Bennée 708b6a643c linux-user: introduce preexit_cleanup
To avoid repeating ourselves move our preexit clean-up code into a
helper function. I figured the continuing effort to split of the
syscalls made it worthwhile creating a new file for it now.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
2018-07-05 15:59:41 +01:00
Philippe Mathieu-Daudé 1129dd7121 linux-user: Export use is_error(), use it to avoid warnings
This fixes:

  linux-user/flatload.c:740:9: warning: Loss of sign in implicit conversion
      if (res > (unsigned long)-4096)
          ^~~

Reported-by: Clang Static Analyzer
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20180604153722.24956-2-f4bug@amsat.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
2018-06-11 14:40:11 +02:00
Laurent Vivier 9850f9f63a linux-user: move get_sp_from_cpustate() to target_cpu.h
Remove useless includes
Fix HPPA include guard.

Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Acked-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20180529194207.31503-9-laurent@vivier.eu>
2018-06-04 01:30:44 +02:00
Christophe Lyon 3cb10cfafd linux-user: ARM-FDPIC: Add support of FDPIC for ARM.
Add FDPIC info into image_info structure since interpreter info is on
stack and needs to be saved to be accessed later on.

Co-Authored-By:  Mickaël Guêné <mickael.guene@st.com>
Signed-off-by: Christophe Lyon <christophe.lyon@st.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <20180430080404.7323-4-christophe.lyon@st.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
2018-05-03 18:25:29 +02:00
Christophe Lyon a99856cd7f Remove CONFIG_USE_FDPIC.
We want to avoid code disabled by default, because it ends up less
tested. This patch removes all instances of #ifdef CONFIG_USE_FDPIC,
most of which can be safely kept. For the ones that should be
conditionally executed, we define elf_is_fdpic(). Without this patch,
defining CONFIG_USE_FDPIC would prevent QEMU from building precisely
because elf_is_fdpic is not defined.

Signed-off-by: Christophe Lyon <christophe.lyon@st.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <20180430080404.7323-2-christophe.lyon@st.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
2018-05-03 18:25:29 +02:00
Max Filippov 41c97cc022 linux-user: drop unused target_msync function
target_msync is not used, remove its declaration and implementation.

Cc: Riku Voipio <riku.voipio@iki.fi>
Cc: Laurent Vivier <laurent@vivier.eu>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20180228221609.11265-9-jcmvbkbc@gmail.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
2018-03-09 19:23:38 +01:00
Peter Maydell daa4374a04 linux-user: Drop unicore32 code
We dropped the unicore32-linux-user target in commit 5e2b40f727
in 2016. Nobody has made any attempt to fix the issues that
caused us to drop it, so remove the associated code.
(The system emulation parts of unicore32 remain.)

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20180308144733.25615-2-peter.maydell@linaro.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
2018-03-09 19:17:27 +01:00
YunQiang Su 768fe76e92 linux-user: introduce functions to detect CPU type
Add a function to return ELF e_flags and use it
to select the CPU model.

Signed-off-by: YunQiang Su <syq@debian.org>
[lv: split the patch and some cleanup in get_elf_eflags()]
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20180220173307.25125-3-laurent@vivier.eu>
2018-02-25 17:28:49 +01:00
Peter Maydell b44316fb36 linux-user: Remove THREAD macro
Back when we used to support compiling either with or without
NPTL threading library support, we used a macro THREAD which would
expand either to nothing (no thread support) or to __thread (threads
supported). For a long time now we have required thread support,
so remove the macro and just use __thread directly as other parts
of QEMU do.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20180213132246.26844-1-peter.maydell@linaro.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
2018-02-18 18:52:32 +01:00
Richard Henderson 7c4ee5bcc8 linux-user: Support stack-grows-up in elfload.c
HPPA is a (the) stack-grows-up target, and supporting that requires
rearranging how we compute addresses while laying out the initial
program stack.  In addition, hppa32 requires 64-byte stack alignment
so parameterize that as well.

Signed-off-by: Richard Henderson <rth@twiddle.net>
2017-01-22 18:14:10 -08:00
Peter Maydell 9d2803f720 linux-user: Pass si_type information to queue_signal() explicitly
Instead of assuming in queue_signal() that all callers are passing
a siginfo structure which uses the _sifields._sigfault part of the
union (and thus a si_type of QEMU_SI_FAULT), make callers pass
the si_type they require in as an argument.

[RV adjusted to apply]
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
2016-09-21 22:01:28 +03:00
Peter Maydell 0cb581d6bd linux-user: report signals being taken in strace output
Native strace reports when the process being traced takes a signal:
   --- SIGSEGV {si_signo=SIGSEGV, si_code=SI_KERNEL, si_addr=0} ---

Report something similar when QEMU is doing its internal strace of
the guest process and is about to deliver it a signal.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
2016-09-21 14:25:59 +03:00
Md Haris Iqbal 38e826de00 linux-user/qemu.h: change malloc to g_malloc, free to g_free
Signed-off-by: Md Haris Iqbal <haris.phnx@gmail.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2016-09-15 15:32:22 +03:00
Igor Mammedov 1bc7e522d9 exec: Reduce CONFIG_USER_ONLY ifdeffenery
Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
2016-07-26 15:31:58 -03:00
Peter Maydell d317091d5e linux-user: Make semihosting heap/stack fields abi_ulongs
The fields in the TaskState heap_base, heap_limit and stack_base
are all guest addresses (representing the locations of the heap
and stack for the guest binary), so they should be abi_ulong
rather than uint32_t. (This only in practice affects ARM AArch64
since all the other semihosting implementations are 32-bit.)

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Laurent Desnogues <laurent.desnogues@gmail.com>
Message-id: 1466783381-29506-2-git-send-email-peter.maydell@linaro.org
2016-07-04 13:06:35 +01:00
Peter Maydell 1d48fdd9d8 linux-user: Don't use sigfillset() on uc->uc_sigmask
The kernel and libc have different ideas about what a sigset_t
is -- for the kernel it is only _NSIG / 8 bytes in size (usually
8 bytes), but for libc it is much larger, 128 bytes. In most
situations the difference doesn't matter, because if you pass a
pointer to a libc sigset_t to the kernel it just acts on the first
8 bytes of it, but for the ucontext_t* argument to a signal handler
it trips us up. The kernel allocates this ucontext_t on the stack
according to its idea of the sigset_t type, but the type of the
ucontext_t defined by the libc headers uses the libc type, and
so do the manipulator functions like sigfillset(). This means that
 (1) sizeof(uc->uc_sigmask) is much larger than the actual
     space used on the stack
 (2) sigfillset(&uc->uc_sigmask) will write garbage 0xff bytes
     off the end of the structure, which can trash data that
     was on the stack before the signal handler was invoked,
     and may result in a crash after the handler returns

To avoid this, we use a memset() of the correct size to fill
the signal mask rather than using the libc function.

This fixes a problem where we would crash at least some of the
time on an i386 host when a signal was taken.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
2016-06-26 13:17:20 +03:00
Peter Maydell 7dcdaeafe0 linux-user: Make target_strerror() return 'const char *'
Make target_strerror() return 'const char *' rather than just 'char *';
this will allow us to return constant strings from it for some special
cases.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
2016-06-08 12:06:57 +03:00
Timothy E Baldwin 655ed67c2a linux-user: Queue synchronous signals separately
If a synchronous signal and an asynchronous signal arrive near simultaneously,
and the signal number of the asynchronous signal is lower than that of the
synchronous signal the the handler for the asynchronous would be called first,
and then the handler for the synchronous signal would be called within or
after the first handler with an incorrect context.

This is fixed by queuing synchronous signals separately. Note that this does
risk delaying a asynchronous signal until the synchronous signal handler
returns rather than handling the signal on another thread, but this seems
unlikely to cause problems for real guest programs and is unavoidable unless
we could guarantee to roll back and reexecute whatever guest instruction
caused the synchronous signal (which would be a bit odd if we've already
logged its execution, for instance, and would require careful analysis of
all guest CPUs to check it was possible in all cases).

Signed-off-by: Timothy Edward Baldwin <T.E.Baldwin99@members.leeds.ac.uk>
Message-id: 1441497448-32489-24-git-send-email-T.E.Baldwin99@members.leeds.ac.uk
[PMM: added a comment]
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
2016-06-07 16:39:07 +03:00
Timothy E Baldwin 907f5fddaa linux-user: Remove real-time signal queuing
As host signals are now blocked whenever guest signals are blocked, the
queue of realtime signals is now in Linux. The QEMU queue is now
redundant and can be removed. (We already did not queue non-RT signals, and
none of the calls to queue_signal() except the one in host_signal_handler()
pass an RT signal number.)

Signed-off-by: Timothy Edward Baldwin <T.E.Baldwin99@members.leeds.ac.uk>
Message-id: 1441497448-32489-23-git-send-email-T.E.Baldwin99@members.leeds.ac.uk
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
[PMM: minor commit message tweak]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
2016-06-07 16:39:07 +03:00
Peter Maydell 3d3efba020 linux-user: Fix race between multiple signals
If multiple host signals are received in quick succession they would
be queued in TaskState then delivered to the guest in spite of
signals being supposed to be blocked by the guest signal handler's
sa_mask. Fix this by decoupling the guest signal mask from the
host signal mask, so we can have protected sections where all
host signals are blocked. In particular we block signals from
when host_signal_handler() queues a signal from the guest until
process_pending_signals() has unqueued it. We also block signals
while we are manipulating the guest signal mask in emulation of
sigprocmask and similar syscalls.

Blocking host signals also ensures the correct behaviour with respect
to multiple threads and the overrun count of timer related signals.
Alas blocking and queuing in qemu is still needed because of virtual
processor exceptions, SIGSEGV and SIGBUS.

Blocking signals inside process_pending_signals() protects against
concurrency problems that would otherwise happen if host_signal_handler()
ran and accessed the signal data structures while process_pending_signals()
was manipulating them.

Since we now track the guest signal mask separately from that
of the host, the sigsuspend system calls must track the signal
mask passed to them, because when we process signals as we leave
the sigsuspend the guest signal mask in force is that passed to
sigsuspend.

Signed-off-by: Timothy Edward Baldwin <T.E.Baldwin99@members.leeds.ac.uk>
Message-id: 1441497448-32489-19-git-send-email-T.E.Baldwin99@members.leeds.ac.uk
[PMM: make signal_pending a simple flag rather than a word with two flag bits;
 ensure we don't call block_signals() twice in sigreturn codepaths;
 document and assert() the guarantee that using do_sigprocmask() to
 get the current mask never fails;  use the qemu atomics.h functions
 rather than raw volatile variable access; add extra commentary and
 documentation; block SIGSEGV/SIGBUS in block_signals() and in
 process_pending_signals() because they can't occur synchronously here;
 check the right do_sigprocmask() call for errors in ssetmask syscall;
 expand commit message; fixed sigsuspend() hanging]
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
2016-06-07 16:39:07 +03:00
Timothy E Baldwin 4d330cee37 linux-user: Provide safe_syscall for fixing races between signals and syscalls
If a signal is delivered immediately before a blocking system call the
handler will only be called after the system call returns, which may be a
long time later or never.

This is fixed by using a function (safe_syscall) that checks if a guest
signal is pending prior to making a system call, and if so does not call the
system call and returns -TARGET_ERESTARTSYS. If a signal is received between
the check and the system call host_signal_handler() rewinds execution to
before the check. This rewinding has the effect of closing the race window
so that safe_syscall will reliably either (a) go into the host syscall
with no unprocessed guest signals pending or or (b) return
-TARGET_ERESTARTSYS so that the caller can deal with the signals.
Implementing this requires a per-host-architecture assembly language
fragment.

This will also resolve the mishandling of the SA_RESTART flag where
we would restart a host system call and not call the guest signal handler
until the syscall finally completed -- syscall restarting now always
happens at the guest syscall level so the guest signal handler will run.
(The host syscall will never be restarted because if the host kernel
rewinds the PC to point at the syscall insn for a restart then our
host_signal_handler() will see this and arrange the guest PC rewind.)

This commit contains the infrastructure for implementing safe_syscall
and the assembly language fragment for x86-64, but does not change any
syscalls to use it.

Signed-off-by: Timothy Edward Baldwin <T.E.Baldwin99@members.leeds.ac.uk>
Message-id: 1441497448-32489-14-git-send-email-T.E.Baldwin99@members.leeds.ac.uk
[PMM:
 * Avoid having an architecture if-ladder in configure by putting
   linux-user/host/$(ARCH) on the include path and including
   safe-syscall.inc.S from it
 * Avoid ifdef ladder in signal.c by creating new hostdep.h to hold
   host-architecture-specific things
 * Added copyright/license header to safe-syscall.inc.S
 * Rewrote commit message
 * Added comments to safe-syscall.inc.S
 * Changed calling convention of safe_syscall() to match syscall()
   (returns -1 and host error in errno on failure)
 * Added a long comment in qemu.h about how to use safe_syscall()
   to implement guest syscalls.
]
RV: squashed Peters "fixup! linux-user: compile on non-x86-64 hosts"
patch
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2016-05-27 14:49:51 +03:00