[DTrace-devel] [PATCH v2] print() action: identify ctf object used for print
Alan Maguire
alan.maguire at oracle.com
Fri Apr 19 09:27:11 UTC 2024
[resending since appears to have bounced last time]
when generating code for print() action we need to identify source
of CTF; is it shared CTF, cdefs or ddefs or another module?
Use DTRACE_OBJ* values for the first three cases, falling back
to using module name pointer as a record argument if these fail.
Then when consuming records we can use either shared CTF,
cdef, ddef or module CTF as appropriate. Nick pointed out that
the initial solution will not work for module-defined types.
This fixes an issue encountered when using a shared kernel type
with alloca()ed memory; DTrace assumed the type was in ddefs
and it wasn't so it wasn't displayed. This change fixes that and
all tests continue to pass. Also tested that it works with
kernel module-defined types now:
dtrace: description 'fbt::ieee80211_rx_napi:entry ' matched 1 probe
CPU ID FUNCTION:NAME
7 123161 ieee80211_rx_napi:entry 0xffff9f8980fa08e0 = *
(struct ieee80211_hw) {
.conf = (struct
ieee80211_conf) {
.listen_interval = (u16)10,
.long_frame_max_tx_count =
(u8)4,
.short_frame_max_tx_count
= (u8)7,
},
Signed-off-by: Alan Maguire <alan.maguire at oracle.com>
---
libdtrace/dt_cg.c | 18 +++++++++++++++++-
libdtrace/dt_consume.c | 7 +++++--
libdtrace/dt_printf.c | 24 +++++++++++++++++++++---
libdtrace/dt_printf.h | 2 +-
4 files changed, 44 insertions(+), 7 deletions(-)
diff --git a/libdtrace/dt_cg.c b/libdtrace/dt_cg.c
index 27246a40..542fb887 100644
--- a/libdtrace/dt_cg.c
+++ b/libdtrace/dt_cg.c
@@ -20,6 +20,7 @@
#include <dt_dctx.h>
#include <dt_cg.h>
#include <dt_grammar.h>
+#include <dt_module.h>
#include <dt_parser.h>
#include <dt_printf.h>
#include <dt_provider.h>
@@ -2831,6 +2832,7 @@ dt_cg_act_print(dt_pcb_t *pcb, dt_node_t *dnp,
dtrace_actkind_t kind)
ctf_file_t *fp = addr->dn_ctfp;
ctf_id_t type = addr->dn_type;
char n[DT_TYPE_NAMELEN];
+ const char *ctf_obj;
size_t size;
type = ctf_type_reference(fp, type);
@@ -2842,9 +2844,23 @@ dt_cg_act_print(dt_pcb_t *pcb, dt_node_t *dnp,
dtrace_actkind_t kind)
"print( ) argument #1 reference has type '%s' with size 0; cannot
print( ) it.\n",
ctf_type_name(fp, type, n, sizeof(n)));
- /* reserve space for addr/type, data/size */
+ /* reserve space for addr/type, ctf file identification, data/size */
addr_off = dt_rec_add(dtp, dt_cg_fill_gap, DTRACEACT_PRINT,
sizeof(uint64_t), 8, NULL, type);
+ /* Use DTRACE_OBJ_* where possible, falling back to module name if
+ * none of these match.
+ */
+ if (fp == dtp->dt_shared_ctf) {
+ ctf_obj = DTRACE_OBJ_KMODS;
+ } else if (fp == dtp->dt_cdefs->dm_ctfp) {
+ ctf_obj = DTRACE_OBJ_CDEFS;
+ } else if (fp == dtp->dt_ddefs->dm_ctfp) {
+ ctf_obj = DTRACE_OBJ_DDEFS;
+ } else {
+ ctf_obj = dt_module_lookup_by_ctf(dtp, fp)->dm_name;
+ }
+ dt_rec_add(dtp, dt_cg_fill_gap, DTRACEACT_PRINT,
+ sizeof(uint64_t), 8, NULL, (uint64_t)ctf_obj);
data_off = dt_rec_add(dtp, dt_cg_fill_gap, DTRACEACT_PRINT,
size, 8, NULL, size);
diff --git a/libdtrace/dt_consume.c b/libdtrace/dt_consume.c
index dec2314b..0d6f2642 100644
--- a/libdtrace/dt_consume.c
+++ b/libdtrace/dt_consume.c
@@ -1987,9 +1987,11 @@ static int
dt_print_print(dtrace_hdl_t *dtp, FILE *fp, dtrace_recdesc_t *rec,
const caddr_t buf)
{
- dtrace_recdesc_t *data_rec = rec + 1;
+ dtrace_recdesc_t *ctf_rec = rec + 1;
+ dtrace_recdesc_t *data_rec = rec + 2;
size_t max_size = dtp->dt_options[DTRACEOPT_PRINTSIZE];
size_t size = (size_t)data_rec->dtrd_arg;
+ const char *ctf_obj = (const char *)ctf_rec->dtrd_arg;
uint64_t printaddr;
if (size > max_size)
@@ -1998,7 +2000,8 @@ dt_print_print(dtrace_hdl_t *dtp, FILE *fp,
dtrace_recdesc_t *rec,
if (dt_read_scalar(buf, rec, &printaddr) < 0)
return dt_set_errno(dtp, EDT_PRINT);
- return dt_print_type(dtp, fp, printaddr, (ctf_id_t)rec->dtrd_arg,
+ return dt_print_type(dtp, fp, printaddr, ctf_obj,
+ (ctf_id_t)rec->dtrd_arg,
(caddr_t)buf + data_rec->dtrd_offset, size);
}
diff --git a/libdtrace/dt_printf.c b/libdtrace/dt_printf.c
index 50842216..2b5e4e0a 100644
--- a/libdtrace/dt_printf.c
+++ b/libdtrace/dt_printf.c
@@ -14,6 +14,7 @@
#include <limits.h>
#include <port.h>
+#include <dt_module.h>
#include <dt_printf.h>
#include <dt_string.h>
#include <dt_impl.h>
@@ -2236,13 +2237,30 @@ err:
int
dt_print_type(dtrace_hdl_t *dtp, FILE *fp, uint64_t printaddr,
- ctf_id_t type, caddr_t data, size_t size)
+ const char *ctf_obj, ctf_id_t type, caddr_t data, size_t size)
{
struct dt_visit_arg dva;
dva.dv_dtp = dtp;
dva.dv_fp = fp;
- dva.dv_ctfp = dtp->dt_ddefs->dm_ctfp;
+
+ if (ctf_obj == DTRACE_OBJ_KMODS) {
+ dva.dv_ctfp = dtp->dt_shared_ctf;
+ } else if (ctf_obj == DTRACE_OBJ_CDEFS) {
+ dva.dv_ctfp = dtp->dt_cdefs->dm_ctfp;
+ } else if (ctf_obj == DTRACE_OBJ_DDEFS) {
+ dva.dv_ctfp = dtp->dt_ddefs->dm_ctfp;
+ } else {
+ struct dt_module *dm = dt_module_lookup_by_name(dtp, ctf_obj);
+
+ if (dm)
+ dva.dv_ctfp = dt_module_getctf(dtp, dm);
+ if (!dm || !dva.dv_ctfp) {
+ dt_dprintf("error retrieving CTF for print() action\n");
+ return dt_set_errno(dtp, EDT_CTF);
+ }
+ }
+
dva.dv_data = data;
dva.dv_size = size;
dva.dv_last_depth = 0;
@@ -2260,5 +2278,5 @@ dt_print_type(dtrace_hdl_t *dtp, FILE *fp,
uint64_t printaddr,
if (dt_print_close_parens(&dva, 0) < 0)
return -1;
- return 2;
+ return 3;
}
diff --git a/libdtrace/dt_printf.h b/libdtrace/dt_printf.h
index 9771c4a8..b72ff55b 100644
--- a/libdtrace/dt_printf.h
+++ b/libdtrace/dt_printf.h
@@ -108,7 +108,7 @@ extern int dt_print_ustack(dtrace_hdl_t *, FILE *,
const char *, caddr_t, uint64_t);
extern int dt_print_mod(dtrace_hdl_t *, FILE *, const char *, caddr_t);
extern int dt_print_umod(dtrace_hdl_t *, FILE *, const char *, caddr_t);
-extern int dt_print_type(dtrace_hdl_t *, FILE *, uint64_t, ctf_id_t,
+extern int dt_print_type(dtrace_hdl_t *, FILE *, uint64_t, const char
*, ctf_id_t,
caddr_t, size_t);
#ifdef __cplusplus
--
2.39.3
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