sh4 uses gUSA (general UserSpace Atomicity) to provide atomicity on CPUs
that don't have atomic instructions. A gUSA region that adds 1 to an
atomic variable stored in @R2 looks like this:
4004b6: 03 c7 mova 4004c4 <gusa+0x10>,r0
4004b8: f3 61 mov r15,r1
4004ba: 09 00 nop
4004bc: fa ef mov #-6,r15
4004be: 22 63 mov.l @r2,r3
4004c0: 01 73 add #1,r3
4004c2: 32 22 mov.l r3,@r2
4004c4: 13 6f mov r1,r15
R0 contains a pointer to the end of the gUSA region
R1 contains the saved stack pointer
R15 contains negative length of the gUSA region
When this region is interrupted by a signal, the kernel detects if
R15 >= -128U. If yes, the kernel rolls back PC to the beginning of the
region and restores SP by copying R1 to R15.
The problem happens if we are interrupted by a signal at address 4004c4.
R15 still holds the value -6, but the atomic value was already written by
an instruction at address 4004c2. In this situation we can't undo the
gUSA. The function unwind_gusa does nothing, the signal handler attempts
to push a signal frame to the address -6 and crashes.
This patch fixes it, so that if we are interrupted at the last instruction
in a gUSA region, we copy R1 to R15 to restore the correct stack pointer
and avoid crashing.
There's another bug: if we are interrupted in a delay slot, we save the
address of the instruction in the delay slot. We must save the address of
the previous instruction.
Cc: qemu-stable@nongnu.org
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Reviewed-by: Yoshinori Sato <ysato@users.sourcefoege.jp>
Message-Id: <b16389f7-6c62-70b7-59b3-87533c0bcc@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Move the various open_cpuinfo functions into new files.
Move the m68k open_hardware function as well.
All other guest architectures get a boilerplate empty file.
Tested-by: Helge Deller <deller@gmx.de>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Copy each guest kernel's default value, then bound it
against reserved_va or the host address space.
Tested-by: Helge Deller <deller@gmx.de>
Reviewed-by: Helge Deller <deller@gmx.de>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
This makes target_flat.h behave like every other target_xxx.h header.
It also makes it actually work -- while the current header says adding
a header to the target subdir overrides the common one, it doesn't.
This is for two reasons:
* meson.build adds -Ilinux-user before -Ilinux-user/$arch
* the compiler search path for "target_flat.h" looks in the same dir
as the source file before searching -I paths.
This can be seen with the xtensa port -- the subdir settings aren't
used which breaks stack setup.
Move it to the generic/ subdir and add include stubs like every
other target_xxx.h header is handled.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20230129004625.11228-1-vapier@gentoo.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
The value previously chosen overlaps GUSA_MASK.
Rename all DELAY_SLOT_* and GUSA_* defines to emphasize
that they are included in TB_FLAGs. Add aliases for the
FPSCR and SR bits that are included in TB_FLAGS, so that
we don't accidentally reassign those bits.
Fixes: 4da06fb306 ("target/sh4: Implement prctl_unalign_sigbus")
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/856
Reviewed-by: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Seen while compiling on Alpine:
In file included from ../linux-user/strace.c:17:
In file included from ../linux-user/qemu.h:11:
In file included from ../linux-user/syscall_defs.h:1247:
../linux-user/sh4/termbits.h:276:10: warning: 'TIOCSER_TEMT' macro redefined
[-Wmacro-redefined]
# define TIOCSER_TEMT 0x01 /* Transmitter physically empty */
^
/usr/include/sys/ioctl.h:50:9: note: previous definition is here
#define TIOCSER_TEMT 1
^
1 warning generated.
Add the TARGET_ prefix here, too, like we do it on the other architectures.
Signed-off-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: Yoshinori Sato <ysato@users.sourceforge.jp>
Message-Id: <20220330134302.979686-1-thuth@redhat.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Leave TARGET_ALIGNED_ONLY set, but use the new CPUState
flag to set MO_UNALN for the instructions that the kernel
handles in the unaligned trap.
The Linux kernel does not handle all memory operations: no
floating-point and no MAC.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20211227150127.2659293-7-richard.henderson@linaro.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Since the prctl constants are supposed to be generic, supply
any that are not provided by the host.
Split out subroutines for PR_GET_FP_MODE, PR_SET_FP_MODE,
PR_GET_VL, PR_SET_VL, PR_RESET_KEYS, PR_SET_TAGGED_ADDR_CTRL,
PR_GET_TAGGED_ADDR_CTRL. Return EINVAL for guests that do
not support these options rather than pass them on to the host.
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20211227150127.2659293-2-richard.henderson@linaro.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
This value is fully internal to qemu, and so is not a TARGET define.
Reviewed-by: Warner Losh <imp@bsdimp.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
This value is fully internal to qemu, and so is not a TARGET define.
We use this as an extra marker for both host and target errno.
Reviewed-by: Warner Losh <imp@bsdimp.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
The fallback code in cpu_loop_exit_sigsegv is sufficient
for sh4 linux-user.
Remove the code from cpu_loop that raised SIGSEGV.
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
qemu.h is included in various non-linux-user files (which
mostly want the TaskState struct and the functions for
doing usermode access to guest addresses like lock_user(),
unlock_user(), get_user*(), etc).
Split out the parts that are only used in linux-user itself
into a new user-internals.h. This leaves qemu.h with basically
three things:
* the definition of the TaskState struct
* the user-access functions and macros
* do_brk()
all of which are needed by code outside linux-user that
includes qemu.h.
The addition of all the extra #include lines was done with
sed -i '/include.*qemu\.h/a #include "user-internals.h"' $(git grep -l 'include.*qemu\.h' linux-user)
(and then undoing the change to fpa11.h).
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210908154405.15417-8-peter.maydell@linaro.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
