Hi Tyler,

On 01/02/17 17:16, Tyler Baicar wrote:
> SEA exceptions are often caused by an uncorrected hardware
> error, and are handled when data abort and instruction abort
> exception classes have specific values for their Fault Status
> Code.
> When SEA occurs, before killing the process, report the error
> in the kernel logs.
> Update fault_info[] with specific SEA faults so that the
> new SEA handler is used.

> diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c
> index 156169c..9ae7e65 100644
> --- a/arch/arm64/mm/fault.c
> +++ b/arch/arm64/mm/fault.c
> @@ -487,6 +487,31 @@ static int do_bad(unsigned long addr, unsigned int esr, 
> struct pt_regs *regs)
>       return 1;
>  }
>  
> +#define SEA_FnV_MASK 0x00000400

There are a glut of ESR_ELx_ macros in arch/arm64/include/asm/esr.h, could this
be fitted in there in a similar format?


--- a/arch/arm64/include/asm/esr.h
+++ b/arch/arm64/include/asm/esr.h
@@ -83,6 +83,7 @@
 #define ESR_ELx_WNR            (UL(1) << 6)

 /* Shared ISS field definitions for Data/Instruction aborts */
+#define ESR_ELx_FnV            (UL(1) << 10)
 #define ESR_ELx_EA             (UL(1) << 9)
 #define ESR_ELx_S1PTW          (UL(1) << 7)


> +
> +/*
> + * This abort handler deals with Synchronous External Abort.
> + * It calls notifiers, and then returns "fault".
> + */
> +static int do_sea(unsigned long addr, unsigned int esr, struct pt_regs *regs)
> +{
> +     struct siginfo info;
> +
> +     pr_err("Synchronous External Abort: %s (0x%08x) at 0x%016lx\n",
> +              fault_name(esr), esr, addr);
> +
> +     info.si_signo = SIGBUS;
> +     info.si_errno = 0;
> +     info.si_code  = 0;
> +     if (esr & SEA_FnV_MASK)
> +             info.si_addr = 0;
> +     else
> +             info.si_addr  = (void __user *)addr;
> +     arm64_notify_die("", regs, &info, esr);
> +
> +     return 0;
> +}
> +
>  static const struct fault_info {
>       int     (*fn)(unsigned long addr, unsigned int esr, struct pt_regs 
> *regs);
>       int     sig;
> @@ -509,22 +534,22 @@ static int do_bad(unsigned long addr, unsigned int esr, 
> struct pt_regs *regs)
>       { do_page_fault,        SIGSEGV, SEGV_ACCERR,   "level 1 permission 
> fault"      },
>       { do_page_fault,        SIGSEGV, SEGV_ACCERR,   "level 2 permission 
> fault"      },
>       { do_page_fault,        SIGSEGV, SEGV_ACCERR,   "level 3 permission 
> fault"      },
> -     { do_bad,               SIGBUS,  0,             "synchronous external 
> abort"    },
> +     { do_sea,               SIGBUS,  0,             "synchronous external 
> abort"    },

This will print:
> Synchronous External Abort: synchronous external abort

It looks odd, but I can't think of anything better to put there.


>       { do_bad,               SIGBUS,  0,             "unknown 17"            
>         },
>       { do_bad,               SIGBUS,  0,             "unknown 18"            
>         },
>       { do_bad,               SIGBUS,  0,             "unknown 19"            
>         },
> -     { do_bad,               SIGBUS,  0,             "synchronous external 
> abort (translation table walk)" },
> -     { do_bad,               SIGBUS,  0,             "synchronous external 
> abort (translation table walk)" },
> -     { do_bad,               SIGBUS,  0,             "synchronous external 
> abort (translation table walk)" },
> -     { do_bad,               SIGBUS,  0,             "synchronous external 
> abort (translation table walk)" },
> -     { do_bad,               SIGBUS,  0,             "synchronous parity 
> error"      },
> +     { do_sea,               SIGBUS,  0,             "level 0 (translation 
> table walk)"      },
> +     { do_sea,               SIGBUS,  0,             "level 1 (translation 
> table walk)"      },
> +     { do_sea,               SIGBUS,  0,             "level 2 (translation 
> table walk)"      },
> +     { do_sea,               SIGBUS,  0,             "level 3 (translation 
> table walk)"      },
> +     { do_sea,               SIGBUS,  0,             "synchronous parity or 
> ECC error" },
>       { do_bad,               SIGBUS,  0,             "unknown 25"            
>         },
>       { do_bad,               SIGBUS,  0,             "unknown 26"            
>         },
>       { do_bad,               SIGBUS,  0,             "unknown 27"            
>         },
> -     { do_bad,               SIGBUS,  0,             "synchronous parity 
> error (translation table walk)" },
> -     { do_bad,               SIGBUS,  0,             "synchronous parity 
> error (translation table walk)" },
> -     { do_bad,               SIGBUS,  0,             "synchronous parity 
> error (translation table walk)" },
> -     { do_bad,               SIGBUS,  0,             "synchronous parity 
> error (translation table walk)" },
> +     { do_sea,               SIGBUS,  0,             "level 0 synchronous 
> parity error (translation table walk)"     },
> +     { do_sea,               SIGBUS,  0,             "level 1 synchronous 
> parity error (translation table walk)"     },
> +     { do_sea,               SIGBUS,  0,             "level 2 synchronous 
> parity error (translation table walk)"     },
> +     { do_sea,               SIGBUS,  0,             "level 3 synchronous 
> parity error (translation table walk)"     },
>       { do_bad,               SIGBUS,  0,             "unknown 32"            
>         },
>       { do_alignment_fault,   SIGBUS,  BUS_ADRALN,    "alignment fault"       
>         },
>       { do_bad,               SIGBUS,  0,             "unknown 34"            
>         },
> 


With the ESR_ELx_FnV change above,
Reviewed-by: James Morse <james.mo...@arm.com>


Thanks,

James


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