Re: [PATCH] linux-user/riscv: Propagate fault address

[Palmer Dabbelt]

On Tue, 01 Oct 2019 09:39:52 PDT (-0700), address@hidden wrote:
> The CPU loop tagged all the queued signals as QEMU_SI_KILL while it was
> filling the `_sigfault` part of `siginfo`: this caused QEMU to copy the
> wrong fields over to the userspace program.
>
> Make sure the fault address recorded by the MMU is is stored in the CPU
> environment structure.
>
> In case of memory faults store the exception address into `siginfo`.
>
> Signed-off-by: Giuseppe Musacchio <address@hidden>
> ---
>  linux-user/riscv/cpu_loop.c | 3 ++-
>  target/riscv/cpu_helper.c   | 5 ++++-
>  2 files changed, 6 insertions(+), 2 deletions(-)
>
> diff --git a/linux-user/riscv/cpu_loop.c b/linux-user/riscv/cpu_loop.c
> index 12aa3c0f16..aa9e437875 100644
> --- a/linux-user/riscv/cpu_loop.c
> +++ b/linux-user/riscv/cpu_loop.c
> @@ -89,6 +89,7 @@ void cpu_loop(CPURISCVState *env)
>          case RISCV_EXCP_STORE_PAGE_FAULT:
>              signum = TARGET_SIGSEGV;
>              sigcode = TARGET_SEGV_MAPERR;
> +            sigaddr = env->badaddr;
>              break;
>          case EXCP_DEBUG:
>          gdbstep:
> @@ -108,7 +109,7 @@ void cpu_loop(CPURISCVState *env)
>                  .si_code = sigcode,
>                  ._sifields._sigfault._addr = sigaddr
>              };
> -            queue_signal(env, info.si_signo, QEMU_SI_KILL, &info);
> +            queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info);
>          }
>
>          process_pending_signals(env);
> diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
> index 87dd6a6ece..58e40e9824 100644
> --- a/target/riscv/cpu_helper.c
> +++ b/target/riscv/cpu_helper.c
> @@ -446,9 +446,9 @@ bool riscv_cpu_tlb_fill(CPUState *cs, vaddr address, int 
> size,
>                          MMUAccessType access_type, int mmu_idx,
>                          bool probe, uintptr_t retaddr)
>  {
> -#ifndef CONFIG_USER_ONLY
>      RISCVCPU *cpu = RISCV_CPU(cs);
>      CPURISCVState *env = &cpu->env;
> +#ifndef CONFIG_USER_ONLY
>      hwaddr pa = 0;
>      int prot;
>      bool pmp_violation = false;
> @@ -499,7 +499,10 @@ bool riscv_cpu_tlb_fill(CPUState *cs, vaddr address, int 
> size,
>      case MMU_DATA_STORE:
>          cs->exception_index = RISCV_EXCP_STORE_PAGE_FAULT;
>          break;
> +    default:
> +        g_assert_not_reached();
>      }
> +    env->badaddr = address;
>      cpu_loop_exit_restore(cs, retaddr);
>  #endif
>  }

Reviewed-by: Palmer Dabbelt <address@hidden>

I fixed up your Author tag and added this to for-master.  Thanks!