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Commit bf8bddbf authored by Arnaldo Carvalho de Melo's avatar Arnaldo Carvalho de Melo
Browse files

perf callchain: Stop validating callchains by the max_stack sysctl 

As thread__resolve_callchain_sample can be used for handling perf.data
files, that could've been recorded with a large max_stack sysctl setting
than what the system used for analysis has set.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: Wang Nan <wangnan0@huawei.com>
Cc: Zefan Li <lizefan@huawei.com>
Link: http://lkml.kernel.org/n/tip-2995bt2g5yq2m05vga4kip6m@git.kernel.org


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent c008f78f

tools/perf/util/machine.c

+5 −20
Original line number Diff line number Diff line
@@ -1771,11 +1771,6 @@ static int resolve_lbr_callchain_sample(struct thread *thread, 
		 */

		int mix_chain_nr = i + 1 + lbr_nr + 1;



		if (mix_chain_nr > (int)sysctl_perf_event_max_stack + PERF_MAX_BRANCH_DEPTH) {

			pr_warning("corrupted callchain. skipping...\n");

			return 0;

		}



		for (j = 0; j < mix_chain_nr; j++) {

			if (callchain_param.order == ORDER_CALLEE) {

				if (j < i + 1)
@@ -1815,7 +1810,7 @@ static int thread__resolve_callchain_sample(struct thread *thread, 
	struct ip_callchain *chain = sample->callchain;

	int chain_nr = chain->nr;

	u8 cpumode = PERF_RECORD_MISC_USER;

	int i, j, err, nr_entries, nr_contexts;

	int i, j, err, nr_entries;

	int skip_idx = -1;

	int first_call = 0;
@@ -1830,7 +1825,6 @@ static int thread__resolve_callchain_sample(struct thread *thread, 
	 * Based on DWARF debug information, some architectures skip

	 * a callchain entry saved by the kernel.

	 */

	if (chain_nr < sysctl_perf_event_max_stack)

	skip_idx = arch_skip_callchain_idx(thread, chain);



	/*
@@ -1891,7 +1885,7 @@ static int thread__resolve_callchain_sample(struct thread *thread, 
	}



check_calls:

	for (i = first_call, nr_entries = 0, nr_contexts = 0;

	for (i = first_call, nr_entries = 0;

	     i < chain_nr && nr_entries < max_stack; i++) {

		u64 ip;
@@ -1906,13 +1900,8 @@ static int thread__resolve_callchain_sample(struct thread *thread, 
#endif

		ip = chain->ips[j];



		if (ip >= PERF_CONTEXT_MAX) {

			if (++nr_contexts > sysctl_perf_event_max_contexts_per_stack)

				goto out_corrupted_callchain;

		} else {

			if (++nr_entries > sysctl_perf_event_max_stack)

				goto out_corrupted_callchain;

		}

		if (ip < PERF_CONTEXT_MAX)

                       ++nr_entries;



		err = add_callchain_ip(thread, cursor, parent, root_al, &cpumode, ip);
@@ -1921,10 +1910,6 @@ static int thread__resolve_callchain_sample(struct thread *thread, 
	}



	return 0;



out_corrupted_callchain:

	pr_warning("corrupted callchain. skipping...\n");

	return 0;

}



static int unwind_entry(struct unwind_entry *entry, void *arg)