Commit Graph

18 Commits

Author SHA1 Message Date
Philippe Mathieu-Daudé
6b5fe13786 semihosting: Move include/hw/semihosting/ -> include/semihosting/
We want to move the semihosting code out of hw/ in the next patch.

This patch contains the mechanical steps, created using:

  $ git mv include/hw/semihosting/ include/
  $ sed -i s,hw/semihosting,semihosting, $(git grep -l hw/semihosting)

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20210226131356.3964782-2-f4bug@amsat.org>
Message-Id: <20210305135451.15427-2-alex.bennee@linaro.org>
2021-03-10 15:34:12 +00:00
Keith Packard
0bb446d8b0 semihosting: Change common-semi API to be architecture-independent
The public API is now defined in
hw/semihosting/common-semi.h. do_common_semihosting takes CPUState *
instead of CPUARMState *. All internal functions have been renamed
common_semi_ instead of arm_semi_ or arm_. Aside from the API change,
there are no functional changes in this patch.

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: <20210107170717.2098982-3-keithp@keithp.com>
Message-Id: <20210108224256.2321-14-alex.bennee@linaro.org>
2021-01-18 10:05:06 +00:00
Peter Maydell
acebed948c linux-user/arm: Deliver SIGTRAP for UDF patterns used as breakpoints
The Linux kernel doesn't use the official bkpt insn for breakpoints;
instead it uses three instructions in the guaranteed-to-UNDEF space,
and generates SIGTRAP for these rather than the SIGILL that most
UNDEF insns generate:

https://elixir.bootlin.com/linux/v5.9.8/source/arch/arm/kernel/ptrace.c#L197

Make QEMU treat these insns specially too.  The main benefit of this
is that if you're running a debugger on a guest program that runs
into a GCC __builtin_trap() or LLVM "trap because execution should
never reach here" then you'll get the expected signal rather than a
SIGILL.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20201117155634.6924-1-peter.maydell@linaro.org
2020-11-23 11:04:51 +00:00
Peter Maydell
3986a1721e linux-user/arm: Fix identification of syscall numbers
Our code to identify syscall numbers has some issues:
 * for Thumb mode, we never need the immediate value from the insn,
   but we always read it anyway
 * bad immediate values in the svc insn should cause a SIGILL, but we
   were abort()ing instead (via "goto error")

We can fix both these things by refactoring the code that identifies
the syscall number to more closely follow the kernel COMPAT_OABI code:
 * for Thumb it is always r7
 * for Arm, if the immediate value is 0, then this is an EABI call
   with the syscall number in r7
 * otherwise, we XOR the immediate value with 0x900000
   (ARM_SYSCALL_BASE for QEMU; __NR_OABI_SYSCALL_BASE in the kernel),
   which converts valid syscall immediates into the desired value,
   and puts all invalid immediates in the range 0x100000 or above
 * then we can just let the existing "value too large, deliver
   SIGILL" case handle invalid numbers, and drop the 'goto error'

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Message-id: 20200420212206.12776-5-peter.maydell@linaro.org
2020-05-21 20:00:18 +01:00
Peter Maydell
ab546bd238 linux-user/arm: Handle invalid arm-specific syscalls correctly
The kernel has different handling for syscalls with invalid
numbers that are in the "arm-specific" range 0x9f0000 and up:
 * 0x9f0000..0x9f07ff return -ENOSYS if not implemented
 * other out of range syscalls cause a SIGILL
(see the kernel's arch/arm/kernel/traps.c:arm_syscall())

Implement this distinction. (Note that our code doesn't look
quite like the kernel's, because we have removed the
0x900000 prefix by this point, whereas the kernel retains
it in arm_syscall().)

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-id: 20200420212206.12776-4-peter.maydell@linaro.org
2020-05-21 20:00:18 +01:00
Peter Maydell
62f141a426 linux-user/arm: Remove bogus SVC 0xf0002 handling
We incorrectly treat SVC 0xf0002 as a cacheflush request (which is a
NOP for QEMU).  This is the wrong syscall number, because in the
svc-immediate OABI syscall numbers are all offset by the
ARM_SYSCALL_BASE value and so the correct insn is SVC 0x9f0002.
(This is handled further down in the code with the other Arm-specific
syscalls like NR_breakpoint.)

When this code was initially added in commit 6f1f31c069 in
2004, ARM_NR_cacheflush was defined as (ARM_SYSCALL_BASE + 0xf0000 + 2)
so the value in the comparison took account of the extra 0x900000
offset. In commit fbb4a2e371 in 2008, the ARM_SYSCALL_BASE
was removed from the definition of ARM_NR_cacheflush and handling
for this group of syscalls was added below the point where we subtract
ARM_SYSCALL_BASE from the SVC immediate value. However that commit
forgot to remove the now-obsolete earlier handling code.

Remove the spurious ARM_NR_cacheflush condition.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Message-id: 20200420212206.12776-3-peter.maydell@linaro.org
2020-05-21 20:00:18 +01:00
Peter Maydell
13a0c21e64 linux-user/arm: BKPT should cause SIGTRAP, not be a syscall
In linux-user/arm/cpu-loop.c we incorrectly treat EXCP_BKPT similarly
to EXCP_SWI, which means that if the guest executes a BKPT insn then
QEMU will perform a syscall for it (which syscall depends on what
value happens to be in r7...). The correct behaviour is that the
guest process should take a SIGTRAP.

This code has been like this (more or less) since commit
06c949e62a in 2006 which added BKPT in the first place.  This is
probably because at the time the same code path was used to handle
both Linux syscalls and semihosting calls, and (on M profile) BKPT
with a suitable magic number is used for semihosting calls.  But
these days we've moved handling of semihosting out to an entirely
different codepath, so we can fix this bug by simply removing this
handling of EXCP_BKPT and instead making it deliver a SIGTRAP like
EXCP_DEBUG (as we do already on aarch64).

Reported-by: <omerg681@gmail.com>
Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 20200420212206.12776-2-peter.maydell@linaro.org
Fixes: https://bugs.launchpad.net/qemu/+bug/1873898
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2020-05-21 20:00:18 +01:00
Josh Kunz
39be535008 linux-user: Use `qemu_log' for non-strace logging
Since most calls to `gemu_log` are actually logging unimplemented features,
this change replaces most non-strace calls to `gemu_log` with calls to
`qemu_log_mask(LOG_UNIMP, ...)`.  This allows the user to easily log to
a file, and to mask out these log messages if they desire.

Note: This change is slightly backwards incompatible, since now these
"unimplemented" log messages will not be logged by default.

Signed-off-by: Josh Kunz <jkz@google.com>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20200204025416.111409-2-jkz@google.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
2020-02-19 11:17:40 +01:00
Alex Bennée
4ff5ef9e91 target/arm: only update pc after semihosting completes
Before we introduce blocking semihosting calls we need to ensure we
can restart the system on semi hosting exception. To be able to do
this the EXCP_SEMIHOST operation should be idempotent until it finally
completes. Practically this means ensureing we only update the pc
after the semihosting call has completed.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Keith Packard <keithp@keithp.com>
Tested-by: Keith Packard <keithp@keithp.com>
2020-01-09 11:41:29 +00:00
Richard Henderson
37bf16c645 linux-user/arm: Rebuild hflags for TARGET_WORDS_BIGENDIAN
Continue setting, but not relying upon, env->hflags.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20191023150057.25731-24-richard.henderson@linaro.org
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-10-24 17:16:28 +01:00
Alex Bennée
e267255957 target/arm: remove run-time semihosting checks for linux-user
Now we do all our checking at translate time we can make cpu_loop a
little bit simpler. We also introduce a simple linux-user semihosting
test case to defend the functionality. The out-of-tree softmmu based
semihosting tests are still more comprehensive.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-id: 20190913151845.12582-6-alex.bennee@linaro.org
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-09-27 11:41:32 +01:00
Markus Armbruster
a8d2532645 Include qemu-common.h exactly where needed
No header includes qemu-common.h after this commit, as prescribed by
qemu-common.h's file comment.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20190523143508.25387-5-armbru@redhat.com>
[Rebased with conflicts resolved automatically, except for
include/hw/arm/xlnx-zynqmp.h hw/arm/nrf51_soc.c hw/arm/msf2-soc.c
block/qcow2-refcount.c block/qcow2-cluster.c block/qcow2-cache.c
target/arm/cpu.h target/lm32/cpu.h target/m68k/cpu.h target/mips/cpu.h
target/moxie/cpu.h target/nios2/cpu.h target/openrisc/cpu.h
target/riscv/cpu.h target/tilegx/cpu.h target/tricore/cpu.h
target/unicore32/cpu.h target/xtensa/cpu.h; bsd-user/main.c and
net/tap-bsd.c fixed up]
2019-06-12 13:20:20 +02:00
Richard Henderson
2fc0cc0e1e target/arm: Use env_cpu, env_archcpu
Cleanup in the boilerplate that each target must define.
Replace arm_env_get_cpu with env_archcpu.  The combination
CPU(arm_env_get_cpu) should have used ENV_GET_CPU to begin;
use env_cpu now.

Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2019-06-10 07:03:34 -07:00
Richard Henderson
29a0af618d cpu: Replace ENV_GET_CPU with env_cpu
Now that we have both ArchCPU and CPUArchState, we can define
this generically instead of via macro in each target's cpu.h.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Acked-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2019-06-10 07:03:34 -07:00
Peter Maydell
b10089a14c linux-user: Don't call gdb_handlesig() before queue_signal()
The CPU main-loop routines for linux-user generally
call gdb_handlesig() when they're about to queue a
SIGTRAP signal. This is wrong, because queue_signal()
will cause us to pend a signal, and process_pending_signals()
will then call gdb_handlesig() itself. So the effect is that
we notify gdb of the SIGTRAP, and then if gdb says "OK,
continue with signal X" we will incorrectly notify
gdb of the signal X as well. We don't do this double-notify
for anything else, only SIGTRAP.

Remove this unnecessary and incorrect code from all
the targets except for nios2 (whose main loop is
doing something different and broken, and will be handled
in a separate patch).

This bug only manifests if the user responds to the reported
SIGTRAP using "signal SIGFOO" rather than "continue"; since
the latter is the overwhelmingly common thing to do after a
breakpoint most people won't have hit this.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20181019174958.26616-2-peter.maydell@linaro.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
2018-11-12 15:48:00 +01:00
Christophe Lyon
62aaa51464 linux-user: Add ARM get_tls syscall support
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: <20180416091845.7315-1-christophe.lyon@st.com>
[lv: moved the change to linux-user/arm/cpu_loop.c]
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
2018-04-30 09:51:31 +02:00
Laurent Vivier
d967351226 linux-user: move arm cpu loop to arm directory
No code change, only move code from main.c to
arm/cpu_loop.c and duplicate some macro
defined for both arm and aarch64.

Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20180411185651.21351-5-laurent@vivier.eu>
2018-04-30 09:48:01 +02:00
Laurent Vivier
cd71c08964 linux-user: create a dummy per arch cpu_loop.c
Create a cpu_loop-common.h for future use by
these new files and use it in the existing
main.c

Introduce target_cpu_copy_regs():
declare the function in cpu_loop-common.h
and an empty function for each target,
to move all the cpu_loop prologues to this function.

Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20180411185651.21351-2-laurent@vivier.eu>
2018-04-30 09:47:55 +02:00