[PATCH] utils: add args output to showUSDT.c

[PATCH] utils: add args output to showUSDT.c

[Kris Van Hees]

The showUSDT utility now reports argument type (native and translated)
and mapping data for probes.

Signed-off-by: Kris Van Hees <kris.van.hees@oracle.com>
---
 test/utils/showUSDT.c | 21 +++++++++++++++++++--
 1 file changed, 19 insertions(+), 2 deletions(-)

diff --git a/test/utils/showUSDT.c b/test/utils/showUSDT.c
index f42aaa21..a1116bbf 100644
--- a/test/utils/showUSDT.c
+++ b/test/utils/showUSDT.c
@@ -104,15 +104,32 @@ static void processECB(dof_hdr_t *dof, int size) {
 
 static void processProbe(int id, dof_probe_t *probe, const char *name,
 			 const char *strtab, unsigned int *offtab,
-			 unsigned int *enotab, unsigned char *argtab) {
+			 unsigned int *enotab, const unsigned char *argtab) {
     int			i;
+    const char		*str;
     unsigned int	*offs;
+    const unsigned char	*map;
 
     printf("      Probe %d: %s:%s:%s:%s\n",
 	   id, name, "",
 	   strtab + probe->dofpr_func, strtab + probe->dofpr_name);
     printf("        argc %d noffs %d nenoffs %d\n",
-	   probe->dofpr_nargc, probe->dofpr_noffs, probe->dofpr_nenoffs);
+	   probe->dofpr_xargc, probe->dofpr_noffs, probe->dofpr_nenoffs);
+
+    str = strtab + probe->dofpr_nargv;
+    for (i = 0; i < probe->dofpr_nargc; i++) {
+	printf("          (native) argv[%d]: %s\n",
+	       i, str);
+	str += strlen(str) + 1;
+    }
+
+    str = strtab + probe->dofpr_xargv;
+    map = argtab + probe->dofpr_argidx;
+    for (i = 0; i < probe->dofpr_xargc; i++) {
+	printf("          (translated) argv[%d] (from native argv[%hhd]): %s\n",
+	       i, map[i], str);
+	str += strlen(str) + 1;
+    }
 
     offs = &offtab[probe->dofpr_offidx];
     for (i = 0; i < probe->dofpr_noffs; i++)
-- 
2.45.2

Re: [DTrace-devel] [PATCH] utils: add args output to showUSDT.c

[Nick Alcock]

On 1 Nov 2024, Kris Van Hees via DTrace-devel verbalised:

> The showUSDT utility now reports argument type (native and translated)
> and mapping data for probes.
>
> Signed-off-by: Kris Van Hees <kris.van.hees@oracle.com>

Nice! Dropped my corresponding one.

Reviewed-by: Nick Alcock <nick.alcock@oracle.com>

One caveat:

>      printf("      Probe %d: %s:%s:%s:%s\n",
>  	   id, name, "",
>  	   strtab + probe->dofpr_func, strtab + probe->dofpr_name);
>      printf("        argc %d noffs %d nenoffs %d\n",
> -	   probe->dofpr_nargc, probe->dofpr_noffs, probe->dofpr_nenoffs);
> +	   probe->dofpr_xargc, probe->dofpr_noffs, probe->dofpr_nenoffs);

I think you shuld still print dofpr_nargc here too, because if it's
wrong we don't want the loop beyond to overrun and crash without any
previous indication of why :)

-- 
NULL && (void)