scftorture: Count single_rpc offline failures in statistics outputgrafted

scf_torture_stats_print() aggregates each invoker thread's counters
into a local scf_statistics structure before printing, but the
n_single_rpc_ofl field is missing from the aggregation loop.  As a
result, the "single_rpc_ofl" value printed in the statistics line is
always zero, even when smp_call_function_single() invocations for the
RPC test have failed due to offline CPUs and been counted by the
invoker threads.

Add the missing accumulation so that the printed value reflects the
actual counts.

Signed-off-by: Joel Fernandes <joelagnelf@nvidia.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

1 files changed, 216 insertions, 0 deletions

diff --git a/tools/perf/util/libdw.c b/tools/perf/util/libdw.c
new file mode 100644
index 000000000..d5d295890
--- /dev/null
+++ b/tools/perf/util/libdw.c
@@ -0,0 +1,216 @@
+// SPDX-License-Identifier: GPL-2.0
+#include "dso.h"
+#include "libdw.h"
+#include "srcline.h"
+#include "symbol.h"
+#include "dwarf-aux.h"
+#include "callchain.h"
+#include <fcntl.h>
+#include <unistd.h>
+#include <elfutils/libdwfl.h>
+
+static const Dwfl_Callbacks offline_callbacks = {
+	.find_debuginfo = dwfl_standard_find_debuginfo,
+	.section_address = dwfl_offline_section_address,
+	.find_elf = dwfl_build_id_find_elf,
+};
+
+void dso__free_libdw(struct dso *dso)
+{
+	Dwfl *dwfl = dso__libdw(dso);
+
+	if (dwfl) {
+		dwfl_end(dwfl);
+		dso__set_libdw(dso, NULL);
+	}
+}
+
+struct Dwfl *dso__libdw_dwfl(struct dso *dso)
+{
+	Dwfl *dwfl = dso__libdw(dso);
+	const char *dso_name;
+	Dwfl_Module *mod;
+	int fd;
+
+	if (dwfl)
+		return dwfl;
+
+	dso_name = dso__long_name(dso);
+	/*
+	 * Initialize Dwfl session.
+	 * We need to open the DSO file to report it to libdw.
+	 */
+	fd = open(dso_name, O_RDONLY);
+	if (fd < 0)
+		return NULL;
+
+	dwfl = dwfl_begin(&offline_callbacks);
+	if (!dwfl) {
+		close(fd);
+		return NULL;
+	}
+
+	/*
+	 * If the report is successful, the file descriptor fd is consumed
+	 * and closed by the Dwfl. If not, it is not closed.
+	 */
+	mod = dwfl_report_offline(dwfl, dso_name, dso_name, fd);
+	if (!mod) {
+		dwfl_end(dwfl);
+		close(fd);
+		return NULL;
+	}
+
+	if (dwfl_report_end(dwfl, /*removed=*/NULL, /*arg=*/NULL) != 0) {
+		dwfl_end(dwfl);
+		return NULL;
+	}
+	dso__set_libdw(dso, dwfl);
+
+	return dwfl;
+}
+
+struct libdw_a2l_cb_args {
+	struct dso *dso;
+	struct symbol *sym;
+	struct inline_node *node;
+	char *leaf_srcline;
+	bool leaf_srcline_used;
+	int err;
+};
+
+static int libdw_a2l_cb(Dwarf_Die *die, void *_args)
+{
+	struct libdw_a2l_cb_args *args  = _args;
+	struct symbol *inline_sym = new_inline_sym(args->dso, args->sym, die_name(die));
+	const char *call_fname = die_get_call_file(die);
+	int call_lineno = die_get_call_lineno(die);
+	char *call_srcline = srcline__unknown;
+
+	if (!inline_sym)
+		goto abort_enomem;
+
+	/* Assign caller information to the parent. */
+	if (call_fname)
+		call_srcline = srcline_from_fileline(call_fname, call_lineno >= 0 ? call_lineno : 0);
+
+	if (!list_empty(&args->node->val)) {
+		struct inline_list *parent;
+
+		if (callchain_param.order == ORDER_CALLEE)
+			parent = list_first_entry(&args->node->val, struct inline_list, list);
+		else
+			parent = list_last_entry(&args->node->val, struct inline_list, list);
+
+		if (args->leaf_srcline == parent->srcline)
+			args->leaf_srcline_used = false;
+		else if (parent->srcline != srcline__unknown)
+			free(parent->srcline);
+		parent->srcline = call_srcline;
+		call_srcline = NULL;
+	}
+	if (call_srcline && call_srcline != srcline__unknown)
+		free(call_srcline);
+
+	/* Add this symbol to the chain as the leaf. */
+	if (!args->leaf_srcline_used) {
+		if (inline_list__append_tail(inline_sym, args->leaf_srcline, args->node) != 0)
+			goto abort_delete_sym;
+		args->leaf_srcline_used = true;
+	} else {
+		char *srcline = strdup(args->leaf_srcline);
+
+		if (!srcline)
+			goto abort_delete_sym;
+		if (inline_list__append_tail(inline_sym, srcline, args->node) != 0) {
+			free(srcline);
+			goto abort_delete_sym;
+		}
+	}
+	return 0;
+
+abort_delete_sym:
+	if (symbol__inlined(inline_sym))
+		symbol__delete(inline_sym);
+abort_enomem:
+	args->err = -ENOMEM;
+	return DWARF_CB_ABORT;
+}
+
+int libdw__addr2line(u64 addr, char **file, unsigned int *line_nr,
+		     struct dso *dso, bool unwind_inlines,
+		     struct inline_node *node, struct symbol *sym)
+{
+	Dwfl *dwfl = dso__libdw_dwfl(dso);
+	Dwfl_Module *mod;
+	Dwfl_Line *dwline;
+	Dwarf_Addr bias;
+	const char *src;
+	int lineno = 0;
+
+	if (!dwfl)
+		return 0;
+
+	mod = dwfl_addrmodule(dwfl, addr);
+	if (!mod)
+		return 0;
+
+	/*
+	 * Get/ignore the dwarf information. Determine the bias, difference
+	 * between the regular ELF addr2line addresses and those to use with
+	 * libdw.
+	 */
+	if (!dwfl_module_getdwarf(mod, &bias))
+		return 0;
+
+	/* Find source line information for the address. */
+	dwline = dwfl_module_getsrc(mod, addr + bias);
+	if (!dwline)
+		return 0;
+
+	/* Get line information. */
+	src = dwfl_lineinfo(dwline, /*addr=*/NULL, &lineno, /*col=*/NULL, /*mtime=*/NULL,
+			    /*length=*/NULL);
+
+	if (file)
+		*file = src ? strdup(src) : NULL;
+	if (line_nr)
+		*line_nr = lineno;
+
+	/* Optionally unwind inline function call chain. */
+	if (unwind_inlines && node) {
+		Dwarf_Addr unused_bias;
+		Dwarf_Die *cudie = dwfl_module_addrdie(mod, addr + bias, &unused_bias);
+		struct libdw_a2l_cb_args args = {
+			.dso = dso,
+			.sym = sym,
+			.node = node,
+			.leaf_srcline = srcline_from_fileline(src ?: "<unknown>", lineno),
+		};
+
+		if (!args.leaf_srcline) {
+			if (file && *file) {
+				free(*file);
+				*file = NULL;
+			}
+			return 0;
+		}
+
+		/* Walk from the parent down to the leaf. */
+		if (cudie)
+			cu_walk_functions_at(cudie, addr, libdw_a2l_cb, &args);
+
+		if (!args.leaf_srcline_used)
+			free(args.leaf_srcline);
+
+		if (args.err) {
+			if (file && *file) {
+				free(*file);
+				*file = NULL;
+			}
+			inline_node__clear_frames(node);
+			return 0;
+		}
+	}
+	return 1;
+}