From bf8bddbf1971d40549f33bc6f70623cf53bbfa2f Mon Sep 17 00:00:00 2001 From: Arnaldo Carvalho de Melo Date: Thu, 19 May 2016 11:14:15 -0300 Subject: [PATCH] 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 Cc: Alexander Shishkin Cc: Alexei Starovoitov Cc: Brendan Gregg Cc: David Ahern Cc: Frederic Weisbecker Cc: He Kuang Cc: Jiri Olsa Cc: Masami Hiramatsu Cc: Milian Wolff Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Stephane Eranian Cc: Thomas Gleixner Cc: Vince Weaver Cc: Wang Nan Cc: Zefan Li Link: http://lkml.kernel.org/n/tip-2995bt2g5yq2m05vga4kip6m@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/machine.c | 25 +++++-------------------- 1 file changed, 5 insertions(+), 20 deletions(-) diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c index bdc33ce40bdc..205d27017361 100644 --- a/tools/perf/util/machine.c +++ b/tools/perf/util/machine.c @@ -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; @@ -1830,8 +1825,7 @@ 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); + skip_idx = arch_skip_callchain_idx(thread, chain); /* * Add branches to call stack for easier browsing. This gives @@ -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)