Make stack trace use dctx->mem to store stack trace data

The stack trace implementation was using an offset into the dctx->buf memory space to store the stack trace data. Now that we have a generic scratch memory area that can be referenced as dctx->mem, the stack trace implementation has been adjusted to make use of that. This patch also contains a tiny fix to the tst.stack_fbt.x script to use /bin/bash because it depends on bash specific features. Signed-off-by: Kris Van Hees <kris.van.hees@oracle.com>
oracle · Aug 27, 2021 · 55902ec · 55902ec
1 parent 1e19a7a
commit 55902ec
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Showing 5 changed files with 4 additions and 10 deletions.
diff --git a/bpf/get_bvar.c b/bpf/get_bvar.c
@@ -25,7 +25,6 @@ extern struct bpf_map_def probes;
 extern struct bpf_map_def state;
 
 extern uint64_t STBSZ;
-extern uint64_t STKOFF;
 extern uint64_t STKSIZ;
 extern uint64_t BOOTTM;
 
@@ -60,7 +59,7 @@ noinline uint64_t dt_get_bvar(dt_dctx_t *dctx, uint32_t id)
 	case DIF_VAR_USTACKDEPTH: {
 		uint32_t bufsiz = (uint32_t) (uint64_t) (&STKSIZ);
 		uint64_t flags = 0 & BPF_F_SKIP_FIELD_MASK;
-		char *buf = ((char *) dctx->buf) + ((uint64_t) &STKOFF);
+		char *buf = dctx->mem;
 		uint64_t stacksize;
 
 		if (id == DIF_VAR_USTACKDEPTH)

diff --git a/libdtrace/dt_bpf.h b/libdtrace/dt_bpf.h
@@ -24,9 +24,8 @@ extern "C" {
 #define DT_CONST_ARGC	4
 #define DT_CONST_STBSZ	5
 #define DT_CONST_STRSZ	6
-#define DT_CONST_STKOFF	7
-#define DT_CONST_STKSIZ	8
-#define DT_CONST_BOOTTM	9
+#define DT_CONST_STKSIZ	7
+#define DT_CONST_BOOTTM	8
 
 extern int perf_event_open(struct perf_event_attr *attr, pid_t pid, int cpu,
 			   int group_fd, unsigned long flags);

diff --git a/libdtrace/dt_cc.c b/libdtrace/dt_cc.c
@@ -2352,9 +2352,6 @@ dt_link_construct(dtrace_hdl_t *dtp, const dt_probe_t *prp, dtrace_difo_t *dp,
 				nrp->dofr_data =
 					dtp->dt_options[DTRACEOPT_STRSIZE];
 				continue;
-			case DT_CONST_STKOFF:
-				nrp->dofr_data = roundup(dtp->dt_maxreclen, 8);
-				continue;
 			case DT_CONST_STKSIZ:
 				nrp->dofr_data = sizeof(uint64_t)
 				    * dtp->dt_options[DTRACEOPT_MAXFRAMES];

diff --git a/libdtrace/dt_dlibs.c b/libdtrace/dt_dlibs.c
@@ -78,7 +78,6 @@ static const dt_ident_t		dt_bpf_symbols[] = {
 	DT_BPF_SYMBOL_ID(ARGC, DT_IDENT_SCALAR, DT_CONST_ARGC),
 	DT_BPF_SYMBOL_ID(STBSZ, DT_IDENT_SCALAR, DT_CONST_STBSZ),
 	DT_BPF_SYMBOL_ID(STRSZ, DT_IDENT_SCALAR, DT_CONST_STRSZ),
-	DT_BPF_SYMBOL_ID(STKOFF, DT_IDENT_SCALAR, DT_CONST_STKOFF),
 	DT_BPF_SYMBOL_ID(STKSIZ, DT_IDENT_SCALAR, DT_CONST_STKSIZ),
 	DT_BPF_SYMBOL_ID(BOOTTM, DT_IDENT_SCALAR, DT_CONST_BOOTTM),
 	/* End-of-list marker */

diff --git a/test/unittest/stack/tst.stack_fbt.x b/test/unittest/stack/tst.stack_fbt.x
@@ -1,4 +1,4 @@
-#!/bin/sh
+#!/bin/bash
 
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