The old link has moved but it seems the document is now hosted on
Arm's github along with a license update to CC-BY-SA-4.0.
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220929114231.583801-42-alex.bennee@linaro.org>
Currently our semihosting implementations generally prohibit use of
semihosting calls in system emulation from the guest userspace. This
is a very long standing behaviour justified originally "to provide
some semblance of security" (since code with access to the
semihosting ABI can do things like read and write arbitrary files on
the host system). However, it is sometimes useful to be able to run
trusted guest code which performs semihosting calls from guest
userspace, notably for test code. Add a command line suboption to
the existing semihosting-config option group so that you can
explicitly opt in to semihosting from guest userspace with
-semihosting-config userspace=on
(There is no equivalent option for the user-mode emulator, because
there by definition all code runs in userspace and has access to
semihosting already.)
This commit adds the infrastructure for the command line option and
adds a bool 'is_user' parameter to the function
semihosting_userspace_enabled() that target code can use to check
whether it should be permitting the semihosting call for userspace.
It mechanically makes all the callsites pass 'false', so they
continue checking "is semihosting enabled in general". Subsequent
commits will make each target that implements semihosting honour the
userspace=on option by passing the correct value and removing
whatever "don't do this for userspace" checking they were doing by
hand.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Acked-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220822141230.3658237-2-peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
The TARGET_SYS_TMPNAM implementation has two bugs spotted by
Coverity:
* confusion about whether 'len' has the length of the string
including or excluding the terminating NUL means we
lock_user() len bytes of memory but memcpy() len + 1 bytes
* In the error-exit cases we forget to free() the buffer
that asprintf() returned to us
Resolves: Coverity CID 1490285, 1490289
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220719121110.225657-5-peter.maydell@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20220725140520.515340-10-alex.bennee@linaro.org>
The SET_ARG() macro returns an error indication; we check this in the
TARGET_SYS_GET_CMDLINE case but not when we use it in implementing
TARGET_SYS_ELAPSED. Check for and handle the errors via the do_fault
codepath, and update the comment documenting the SET_ARG() and
GET_ARG() macros to note how they handle memory access errors.
Resolves: Coverity CID 1490287
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220719121110.225657-4-peter.maydell@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20220725140520.515340-9-alex.bennee@linaro.org>
The console_write() semihosting function outputs guest data from a
buffer; it doesn't update that buffer. It therefore doesn't need to
pass a length value to unlock_user(), but can pass 0, meaning "do not
copy any data back to the guest memory".
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220719121110.225657-3-peter.maydell@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20220725140520.515340-8-alex.bennee@linaro.org>
The documentation comment for qemu_semihosting_console_write() says
* Returns: number of bytes written -- this should only ever be short
* on some sort of i/o error.
and the callsites rely on this. However, the implementation code
path which sends console output to a chardev doesn't honour this,
and will return negative values on error. Bring it into line with
the other implementation codepaths and the documentation, so that
it returns 0 on error.
Spotted by Coverity, because console_write() passes the return value
to unlock_user(), which doesn't accept a negative length.
Resolves: Coverity CID 1490288
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220719121110.225657-2-peter.maydell@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20220725140520.515340-7-alex.bennee@linaro.org>
The function is no longer used.
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220628111701.677216-7-richard.henderson@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
This will be used for implementing the xtensa select_one
system call. Choose "poll" over "select" so that we can
reuse Glib's g_poll constants and to avoid struct timeval.
Reviewed-by: Luc Michel <lmichel@kalray.eu>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
This function has been replaced by *_write.
Reviewed-by: Luc Michel <lmichel@kalray.eu>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
This function has been replaced by *_write.
Reviewed-by: Luc Michel <lmichel@kalray.eu>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
For arm-compat, initialize console_{in,out}_gf;
otherwise, initialize stdio file descriptors.
This will go some way to cleaning up arm-compat, and
will allow other semihosting to use normal stdio.
Reviewed-by: Luc Michel <lmichel@kalray.eu>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Add a GuestFDType for connecting to the semihosting console.
Hook up to read, write, isatty, and fstat syscalls.
Note that the arm-specific syscall flen cannot be applied
to the console, because the console is not a descriptor
exposed to the guest.
Reviewed-by: Luc Michel <lmichel@kalray.eu>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Will replace qemu_semihosting_console_{outs,outc},
but we need more plumbing first.
Reviewed-by: Luc Michel <lmichel@kalray.eu>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Rename qemu_semihosting_connect_chardevs to
qemu_semihosting_chardev_init; pass the result
directly to qemu_semihosting_console_init.
Store the chardev in SemihostingConsole instead
of SemihostingConfig, which lets us drop
semihosting_get_chardev.
Reviewed-by: Luc Michel <lmichel@kalray.eu>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Allow more than one character to be read at one time.
Will be used by m68k and nios2 semihosting for stdio.
Reviewed-by: Luc Michel <lmichel@kalray.eu>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
We don't need CPUArchState, and we do want the CPUState of the
thread performing the operation -- use this instead of current_cpu.
Reviewed-by: Luc Michel <lmichel@kalray.eu>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Change 'ret' to uint64_t. This resolves a FIXME in the
m68k and nios2 semihosting that we've lost data.
Change 'err' to int. There is nothing target-specific
about the width of the errno value.
Reviewed-by: Luc Michel <lmichel@kalray.eu>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
This syscall will be used by m68k and nios2 semihosting.
Reviewed-by: Luc Michel <lmichel@kalray.eu>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
These syscalls will be used by m68k and nios2 semihosting.
Reviewed-by: Luc Michel <lmichel@kalray.eu>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Split out the non-ARM specific portions of SYS_SYSTEM to a
reusable function.
Reviewed-by: Luc Michel <lmichel@kalray.eu>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Split out the non-ARM specific portions of SYS_RENAME to a
reusable function.
Reviewed-by: Luc Michel <lmichel@kalray.eu>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Split out the non-ARM specific portions of SYS_REMOVE to a
reusable function.
Reviewed-by: Luc Michel <lmichel@kalray.eu>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
The ARM-specific SYS_FLEN isn't really something that can be
reused by other semihosting apis, but there are parts that can
reused for the implementation of semihost_sys_fstat.
Reviewed-by: Luc Michel <lmichel@kalray.eu>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Split out the non-ARM specific portions of SYS_ISTTY to a
reusable function. This handles all GuestFD.
Add a common_semi_istty_cb helper to translate the Posix
error return, 0+ENOTTY, to the Arm semihosting not-a-file
success result.
Reviewed-by: Luc Michel <lmichel@kalray.eu>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Split out the non-ARM specific portions of SYS_SEEK to a
reusable function. This handles all GuestFD. Isolate the
curious ARM-specific return value processing to a new
callback, common_semi_seek_cb.
Expand the internal type of the offset to int64_t, and
provide the whence argument, which will be required by
m68k and nios2 semihosting.
Note that gdb_do_syscall %x reads target_ulong, not int.
Reviewed-by: Luc Michel <lmichel@kalray.eu>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Fixes a minor bug in which a 64-bit guest on a 32-bit host could
truncate the length. This would only ever cause a problem if
there were no bits set in the low 32, so that it truncates to 0.
Reviewed-by: Luc Michel <lmichel@kalray.eu>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Split out the non-ARM specific portions of SYS_WRITE to a
reusable function. This handles all GuestFD. This removes
the last use of common_semi_syscall_len.
Note that gdb_do_syscall %x reads target_ulong, not int.
Reviewed-by: Luc Michel <lmichel@kalray.eu>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Split out the non-ARM specific portions of SYS_READ to a
reusable function. This handles all GuestFD. Isolate the
curious ARM-specific return value processing to a new
callback, common_semi_rw_cb.
Note that gdb_do_syscall %x reads target_ulong, not int.
Reviewed-by: Luc Michel <lmichel@kalray.eu>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Split out the non-ARM specific portions of SYS_CLOSE to a
reusable function. This handles all GuestFD.
Note that gdb_do_syscall %x reads target_ulong, not int.
Reviewed-by: Luc Michel <lmichel@kalray.eu>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Split out the non-ARM specific portions of SYS_OPEN to a
reusable function. This handles gdb and host file i/o.
Add helpers to validate the length of the filename string.
Prepare for usage by other semihosting by allowing the
filename length parameter to be 0, and calling strlen.
Reviewed-by: Luc Michel <lmichel@kalray.eu>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Moving this to be useful for another function
besides do_common_semihosting.
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
We've already loaded cs->env_ptr into a local variable; use it.
Since env is unconditionally used, we don't need a dummy use.
Reviewed-by: Luc Michel <lmichel@kalray.eu>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Move the ARM and RISCV specific helpers into
their own header file.
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Luc Michel <lmichel@kalray.eu>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
We already have some larger ifdef blocks for ARM and RISCV;
split out a boolean test for SYS_SYNCCACHE.
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
We already have some larger ifdef blocks for ARM and RISCV;
split out common_semi_stack_bottom per target.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
We already have some larger ifdef blocks for ARM and RISCV;
split the function into multiple implementations per arch.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Load the entire 64-bit size value. While we're at it,
use offsetof instead of an integer constant.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
There were 3 copies of these flags. Place them in the
file with gdb_do_syscall, with which they belong.
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
The value is zero, and gdb always opens files in binary mode.
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
This header is not private to the top-level semihosting directory,
so place it in the public include directory.
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Perform the cleanup in the FIXME comment in common_semi_gdb_syscall.
Do not modify guest registers until the syscall is complete,
which in the gdbstub case is asynchronous.
In the synchronous non-gdbstub case, use common_semi_set_ret
to set the result. Merge set_swi_errno into common_semi_cb.
Rely on the latter for combined return value / errno setting.
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Use common_semi_cb to return results instead of calling
set_swi_errno and common_semi_set_ret directly.
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Do not read from the gdb struct stat buffer if the callback is
reporting an error. Use common_semi_cb to finish returning results.
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
The err parameter is non-zero if and only if an error occured.
Use this instead of ret == -1 for determining if we need to
update the saved errno.
This fixes the errno setting of SYS_ISTTY, which returns 0 on
error, not -1.
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Do not store 'err' into errno only to read it back immediately.
Use 'ret' for the return value, not 'reg0'.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
In arm-compat-semi.c, we have more advanced treatment of
guest file descriptors than we do in other implementations.
Split out GuestFD and related functions to a new file so
that they can be shared.
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
We are not currently bounding the search to the 1024 bytes
that we allocated, possibly overrunning the buffer.
Use softmmu_strlen_user to find the length and allocate the
correct size from the beginning.
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
