[DTrace-devel] [PATCH v4 1/5] usdt: have copy_args() count args while parsing them

[Alan Maguire]

stapsdt probes do not include an argument count, so the only
way to count them is to parse the parameter string.  Adjust
copy_args() to set upp->sargc while parsing upp->sargv.

Signed-off-by: Alan Maguire <alan.maguire at oracle.com>
---
 libdtrace/dt_prov_uprobe.c | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/libdtrace/dt_prov_uprobe.c b/libdtrace/dt_prov_uprobe.c
index cf5cfd43..2cbd8910 100644
--- a/libdtrace/dt_prov_uprobe.c
+++ b/libdtrace/dt_prov_uprobe.c
@@ -1145,9 +1145,9 @@ static void enable_usdt(dtrace_hdl_t *dtp, dt_probe_t *prp)
 }
 
 /*
- * Generate code that populates the probe arguments.
+ * Generate code that populates, counts the probe arguments.
  */
-static void copy_args(dt_pcb_t *pcb, const dt_uprobe_t *upp)
+static void copy_args(dt_pcb_t *pcb, dt_uprobe_t *upp)
 {
 	dtrace_hdl_t	*dtp = pcb->pcb_hdl;
 	dt_irlist_t	*dlp = &pcb->pcb_ir;
@@ -1158,7 +1158,7 @@ static void copy_args(dt_pcb_t *pcb, const dt_uprobe_t *upp)
 
 	assert(pvp != NULL);
 
-	for (i = 0; i < upp->sargc; i++) {
+	for (i = 0; strlen(p) > 0; i++) {
 		int	ssize, disp, len;
 		char	*reg = NULL;
 		int64_t	val = 0;
@@ -1425,6 +1425,7 @@ static void copy_args(dt_pcb_t *pcb, const dt_uprobe_t *upp)
 			usdt_error(pcb, "Unknown format in arg%d spec", i);
 #endif
 	}
+	upp->sargc = i;
 }
 
 /*
@@ -1445,7 +1446,7 @@ static int trampoline(dt_pcb_t *pcb, uint_t exitlbl)
 	dtrace_hdl_t		*dtp = pcb->pcb_hdl;
 	dt_irlist_t		*dlp = &pcb->pcb_ir;
 	const dt_probe_t	*uprp = pcb->pcb_probe;
-	const dt_uprobe_t	*upp = uprp->prv_data;
+	dt_uprobe_t		*upp = uprp->prv_data;
 	const list_probe_t	*pop;
 	uint_t			lbl_exit = pcb->pcb_exitlbl;
 	dt_ident_t		*usdt_prids = dt_dlib_get_map(dtp, "usdt_prids");
@@ -1519,7 +1520,7 @@ static int trampoline(dt_pcb_t *pcb, uint_t exitlbl)
 	if (upp->flags & PP_IS_RETURN)
 		goto out;
 
-	if (upp->sargc)
+	if (upp->sargv)
 		copy_args(pcb, upp);
 	else
 		dt_cg_tramp_copy_args_from_regs(pcb, 0);
-- 
2.43.5