On 9/27/20 10:20 AM, Kele Huang wrote:
> Detect all MIPS store instructions in cpu_signal_handler for all available
> MIPS versions, and set is_write if encountering such store instructions.
>
> This fixed the error while dealing with self-modified code for MIPS.
>
> Reviewed-by: Richard Henderson <richard.hender...@linaro.org>
> Signed-off-by: Kele Huang <kele.hw...@gmail.com>
> Signed-off-by: Xu Zou <iwatchn...@gmail.com>
I already Cc'ed the TCG MIPS maintainers twice for you,
but you don't mind, so this time I won't insist.
> ---
> accel/tcg/user-exec.c | 39 ++++++++++++++++++++++++++++++++++++++-
> 1 file changed, 38 insertions(+), 1 deletion(-)
>
> diff --git a/accel/tcg/user-exec.c b/accel/tcg/user-exec.c
> index bb039eb32d..9ecda6c0d0 100644
> --- a/accel/tcg/user-exec.c
> +++ b/accel/tcg/user-exec.c
> @@ -702,6 +702,10 @@ int cpu_signal_handler(int host_signum, void *pinfo,
>
> #elif defined(__mips__)
>
> +#if defined(__misp16) || defined(__mips_micromips)
> +#error "Unsupported encoding"
> +#endif
> +
> int cpu_signal_handler(int host_signum, void *pinfo,
> void *puc)
> {
> @@ -709,9 +713,42 @@ int cpu_signal_handler(int host_signum, void *pinfo,
> ucontext_t *uc = puc;
> greg_t pc = uc->uc_mcontext.pc;
> int is_write;
> + uint32_t insn;
>
> - /* XXX: compute is_write */
> + /* Detect all store instructions at program counter. */
> is_write = 0;
> + insn = *(uint32_t *)pc;
> + switch((insn >> 26) & 077) {
> + case 050: /* SB */
> + case 051: /* SH */
> + case 052: /* SWL */
> + case 053: /* SW */
> + case 054: /* SDL */
> + case 055: /* SDR */
> + case 056: /* SWR */
> + case 070: /* SC */
> + case 071: /* SWC1 */
> + case 074: /* SCD */
> + case 075: /* SDC1 */
> + case 077: /* SD */
> +#if !defined(__mips_isa_rev) || __mips_isa_rev < 6
> + case 072: /* SWC2 */
> + case 076: /* SDC2 */
> +#endif
> + is_write = 1;
> + break;
> + case 023: /* COP1X */
> + /* Required in all versions of MIPS64 since
> + MIPS64r1 and subsequent versions of MIPS32r2. */
> + switch (insn & 077) {
> + case 010: /* SWXC1 */
> + case 011: /* SDXC1 */
> + case 015: /* SDXC1 */
> + is_write = 1;
> + }
> + break;
> + }
> +
> return handle_cpu_signal(pc, info, is_write, &uc->uc_sigmask);
> }
>
>
