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2022-04-26linux-user/nios2: Handle various SIGILL exceptionsRichard Henderson
We missed out on a couple of exception types that may legitimately be raised by a userland program. Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org> Message-Id: <20220421151735.31996-59-richard.henderson@linaro.org>
2022-04-26target/nios2: Advance pc when raising exceptionsRichard Henderson
The exception return address for nios2 is the instruction after the one that was executing at the time of the exception. We have so far implemented this by advancing the pc during the process of raising the exception. It is perhaps a little less confusing to do this advance in the translator (and helpers) when raising the exception in the first place, so that we may more closely match kernel sources. Signed-off-by: Richard Henderson <richard.henderson@linaro.org> Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Message-Id: <20220421151735.31996-58-richard.henderson@linaro.org>
2022-04-26target/nios2: Implement Misaligned destination exceptionRichard Henderson
Indirect branches, plus eret and bret optionally raise an exception when branching to a misaligned address. The exception is required when an mmu is enabled, but enable it always because the fallback behaviour is not documented (though presumably it discards low bits). For the purposes of the linux-user cpu loop, if EXCP_UNALIGN (misaligned data) were to arrive, it would be treated the same as EXCP_UNALIGND (misaligned destination). See the !defined(CONFIG_NIOS2_ALIGNMENT_TRAP) block in kernel/traps.c. Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org> Message-Id: <20220421151735.31996-53-richard.henderson@linaro.org>
2022-04-26target/nios2: Support division error exceptionRichard Henderson
Division may (optionally) raise a division exception. Since the linux kernel has been prepared for this for some time, enable it by default. Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org> Message-Id: <20220421151735.31996-42-richard.henderson@linaro.org>
2022-04-26linux-user/nios2: Only initialize SP and PC in target_cpu_copy_regsRichard Henderson
Drop the set of estatus in init_thread; it was clearly intended to be setting the value of CR_STATUS for the application, but we never actually performed that copy. However, the proper value is set in nios2_cpu_reset so we don't need to do anything here. We only initialize SP and EA in init_thread, there's no value in copying other uninitialized data into ENV. Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org> Message-Id: <20220421151735.31996-21-richard.henderson@linaro.org>
2022-04-26target/nios2: Split PC out of env->regs[]Richard Henderson
It is cleaner to have a separate name for this variable. Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org> Message-Id: <20220421151735.31996-17-richard.henderson@linaro.org>
2022-04-26linux-user/nios2: Use force_sig_fault for EXCP_DEBUGRichard Henderson
Use the simpler signal interface, which forces us to supply the missing PC value to si_addr. Signed-off-by: Richard Henderson <richard.henderson@linaro.org> Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Message-Id: <20220421151735.31996-13-richard.henderson@linaro.org>
2022-04-26target/nios2: Remove nios2_cpu_record_sigsegvRichard Henderson
Since f5ef0e518d0, we have a real page mapped for kuser, which means the special casing for SIGSEGV can go away. Signed-off-by: Richard Henderson <richard.henderson@linaro.org> Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Message-Id: <20220421151735.31996-11-richard.henderson@linaro.org>
2022-04-26linux-user/nios2: Handle special qemu syscall return valuesRichard Henderson
Honor QEMU_ESIGRETURN and QEMU_ERESTARTSYS. Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org> Message-Id: <20220421151735.31996-6-richard.henderson@linaro.org>
2022-04-26linux-user/nios2: Adjust error returnRichard Henderson
Follow the kernel assembly, which considers all negative return values to be errors. Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org> Message-Id: <20220421151735.31996-5-richard.henderson@linaro.org>
2022-04-26linux-user/nios2: Drop syscall 0 "workaround"Richard Henderson
Syscall 0 is __NR_io_setup for this target; there is nothing to work around. Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Fixes: a0a839b65b6 ("nios2: Add usermode binaries emulation") Signed-off-by: Richard Henderson <richard.henderson@linaro.org> Message-Id: <20220421151735.31996-4-richard.henderson@linaro.org>
2022-04-26linux-user/nios2: Hoist pc advance to the top of EXCP_TRAPRichard Henderson
Note that this advance *should* be done by the translator, as that's the pc value that's supposed to be generated by hardware. However, that's a much larger change across sysemu as well. In the meantime, produce the correct PC for any signals raised by the trap instruction. Note the special case of TRAP_BRKPT, which itself is special cased within the kernel. Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org> Message-Id: <20220421151735.31996-2-richard.henderson@linaro.org>
2022-01-06linux-user/nios2: Fix EA vs PC confusionRichard Henderson
The real kernel will talk about the user PC as EA, because that's where the hardware will have copied it, and where it expects to put it to then use ERET. But qemu does not emulate all of the exception stuff while emulating user-only. Manipulate PC directly. This fixes signal entry and return, and eliminates some slight confusion from target_cpu_copy_regs. Signed-off-by: Richard Henderson <richard.henderson@linaro.org> Reviewed-by: Laurent Vivier <laurent@vivier.eu> Message-Id: <20211221025012.1057923-6-richard.henderson@linaro.org> Signed-off-by: Laurent Vivier <laurent@vivier.eu>
2022-01-06linux-user/nios2: Map a real kuser pageRichard Henderson
The first word of page1 is data, so the whole thing can't be implemented with emulation of addresses. Use init_guest_commpage for the allocation. Hijack trap number 16 to implement cmpxchg. Signed-off-by: Richard Henderson <richard.henderson@linaro.org> Reviewed-by: Laurent Vivier <laurent@vivier.eu> Message-Id: <20211221025012.1057923-5-richard.henderson@linaro.org> Signed-off-by: Laurent Vivier <laurent@vivier.eu>
2022-01-06linux-user/nios2: Properly emulate EXCP_TRAPRichard Henderson
The real kernel has to load the instruction and extract the imm5 field; for qemu, modify the translator to do this. The use of R_AT for this in cpu_loop was a bug. Handle the other trap numbers as per the kernel's trap_table. Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org> Reviewed-by: Laurent Vivier <laurent@vivier.eu> Message-Id: <20211221025012.1057923-2-richard.henderson@linaro.org> Signed-off-by: Laurent Vivier <laurent@vivier.eu>
2021-09-13linux-user: Split linux-user internals out of qemu.hPeter Maydell
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>
2021-09-13linux-user: Split signal-related prototypes into signal-common.hPeter Maydell
Split the signal related prototypes into the existing header file signal-common.h, and include it in those places that now require it. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Message-Id: <20210908154405.15417-4-peter.maydell@linaro.org> Signed-off-by: Laurent Vivier <laurent@vivier.eu>
2019-06-10cpu: Replace ENV_GET_CPU with env_cpuRichard Henderson
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>
2019-03-07Fix breakpoint support in Nios II user-mode emulation.Sandra Loosemore
Nios II user-mode emulation was missing handling for EXCP_DEBUG, making the gdb stub essentially useless. This patch adds the missing piece. The new code was copied from the existing EXCP_TRAP handling and is also similar to what other targets (e.g., arm) do with EXCP_DEBUG. Signed-off-by: Sandra Loosemore <sandra@codesourcery.com> Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Message-Id: <1550076626-7202-1-git-send-email-sandra@codesourcery.com> Signed-off-by: Laurent Vivier <laurent@vivier.eu>
2018-11-12linux-user: Clean up nios2 main loop signal handlingPeter Maydell
The nios2 main loop code's code does some odd things with gdb_handlesig() that no other target CPU does: it has some signals that are delivered to gdb and only to gdb. Stop doing this, and instead behave like all the other targets: * a trap instruction becomes a SIGTRAP * an unhandled exception type returned from cpu_exec() causes us to abort(), not to try to hand gdb a SIGILL This fixes in passing Coverity issue CID 1390853, which was a complaint that the old code failed to check the return value from gdb_handlesig(). Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Message-Id: <20181019174958.26616-3-peter.maydell@linaro.org> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> [lv: removed gdbsig unused variable] Signed-off-by: Laurent Vivier <laurent@vivier.eu>
2018-04-30linux-user: move nios2 cpu loop to nios2 directoryLaurent Vivier
No code change, only move code from main.c to nios2/cpu_loop.c. Signed-off-by: Laurent Vivier <laurent@vivier.eu> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Message-Id: <20180411185651.21351-9-laurent@vivier.eu>
2018-04-30linux-user: create a dummy per arch cpu_loop.cLaurent Vivier
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>