[DTrace-devel] [PATCH v4 03/10] alloca: new bad-size fault

[Kris Van Hees]

On Tue, Apr 12, 2022 at 11:59:02AM +0100, Nick Alcock wrote:
> We'll use DTRACEFLT_BADSIZE to distinguish in error messages between
> out-of-bounds errors in bcopy and the like, and size-too-large errors.
> (Without this, it's hard to tell if a, say, 0x12 in the fault value
> is a nearly-NULL pointer or a wrong size.)
> 
> Signed-off-by: Nick Alcock <nick.alcock at oracle.com>

Reviewed-by: Kris Van Hees <kris.van.hees at oracle.com>

> ---
>  include/dtrace/faults_defines.h | 1 +
>  libdtrace/dt_error.c            | 1 +
>  libdtrace/dt_handle.c           | 1 +
>  3 files changed, 3 insertions(+)
> 
> diff --git a/include/dtrace/faults_defines.h b/include/dtrace/faults_defines.h
> index 20c57ad77499..3bef92d251ca 100644
> --- a/include/dtrace/faults_defines.h
> +++ b/include/dtrace/faults_defines.h
> @@ -32,6 +32,7 @@
>  #define DTRACEFLT_UPRIV			7	/* Illegal user access */
>  #define DTRACEFLT_TUPOFLOW		8	/* Tuple stack overflow */
>  #define DTRACEFLT_BADSTACK		9	/* Bad stack */
> +#define DTRACEFLT_BADSIZE		10	/* Bad size */
>  
>  #define DTRACEFLT_LIBRARY		1000	/* Library-level fault */
>  
> diff --git a/libdtrace/dt_error.c b/libdtrace/dt_error.c
> index 50229d271425..13713acb5f23 100644
> --- a/libdtrace/dt_error.c
> +++ b/libdtrace/dt_error.c
> @@ -206,6 +206,7 @@ dtrace_faultstr(dtrace_hdl_t *dtp, int fault)
>  		{ DTRACEFLT_UPRIV,	"invalid user access" },
>  		{ DTRACEFLT_TUPOFLOW,	"tuple stack overflow" },
>  		{ DTRACEFLT_BADSTACK,	"bad stack" },
> +		{ DTRACEFLT_BADSIZE,	"invalid size" },
>  		{ DTRACEFLT_LIBRARY,	"library-level fault" },
>  		{ 0,			NULL }
>  	};
> diff --git a/libdtrace/dt_handle.c b/libdtrace/dt_handle.c
> index bdc0365c47d8..e36c1619b81e 100644
> --- a/libdtrace/dt_handle.c
> +++ b/libdtrace/dt_handle.c
> @@ -183,6 +183,7 @@ dt_handle_err(dtrace_hdl_t *dtp, dtrace_probedata_t *data)
>  			goto no_addr;
>  	case DTRACEFLT_BADALIGN:
>  	case DTRACEFLT_BADSTACK:
> +	case DTRACEFLT_BADSIZE:
>  		sprintf(details, " (0x%llx)", (u_longlong_t)err.dteda_addr);
>  		break;
>  
> -- 
> 2.35.1