On 9/18/21 20:45, Richard Henderson wrote:
> Record cr2, error_code, and exception_index. That last means
> that we must exit to cpu_loop ourselves, instead of letting
> exception_index being overwritten.
>
> Use the maperr parameter to properly set PG_ERROR_P_MASK.
>
> Signed-off-by: Richard Henderson <[email protected]>
> ---
> target/i386/tcg/helper-tcg.h | 6 ++++++
> target/i386/tcg/tcg-cpu.c | 3 ++-
> target/i386/tcg/user/excp_helper.c | 23 +++++++++++++++++------
> 3 files changed, 25 insertions(+), 7 deletions(-)
> diff --git a/target/i386/tcg/user/excp_helper.c
> b/target/i386/tcg/user/excp_helper.c
> index a89b5228fd..cd507e2a1b 100644
> --- a/target/i386/tcg/user/excp_helper.c
> +++ b/target/i386/tcg/user/excp_helper.c
> @@ -22,18 +22,29 @@
> #include "exec/exec-all.h"
> #include "tcg/helper-tcg.h"
>
> -bool x86_cpu_tlb_fill(CPUState *cs, vaddr addr, int size,
> - MMUAccessType access_type, int mmu_idx,
> - bool probe, uintptr_t retaddr)
> +void x86_cpu_record_sigsegv(CPUState *cs, vaddr addr,
> + MMUAccessType access_type,
> + bool maperr, uintptr_t ra)
> {
> X86CPU *cpu = X86_CPU(cs);
> CPUX86State *env = &cpu->env;
>
> + /*
> + * The error_code that hw reports as part of the exception frame
> + * is copied to linux sigcontext.err. The exception_index is
> + * copied to linux sigcontext.trapno. Short of inventing a new
> + * place to store the trapno, we cannot let our caller raise the
> + * signal and set exception_index to EXCP_INTERRUPT.
> + */
> env->cr[2] = addr;
> - env->error_code = (access_type == MMU_DATA_STORE) << PG_ERROR_W_BIT;
> - env->error_code |= PG_ERROR_U_MASK;
> + env->error_code = ((access_type == MMU_DATA_STORE) << PG_ERROR_W_BIT)
> + | (maperr ? 0 : PG_ERROR_P_MASK)
> + | PG_ERROR_U_MASK;
> cs->exception_index = EXCP0E_PAGE;
> +
> + /* Disable do_interrupt_user. */
> env->exception_is_int = 0;
> env->exception_next_eip = -1;
> - cpu_loop_exit_restore(cs, retaddr);
> +
> + cpu_loop_exit_restore(cs, ra);
> }
>
Better have an x86 expert also review this, but to the best
of my knowledge:
Reviewed-by: Philippe Mathieu-Daudé <[email protected]>
And YAY! btw, thanks :>
