[tip:perf/urgent] perf c2c: Keep struct hist_entry at the end of struct c2c_hist_entry

From: tip-bot for Jiri Olsa
Date: Thu Jun 14 2018 - 02:24:32 EST


Commit-ID: 4c8205273626f27b9e5a64bdc194ab483a8cce66
Gitweb: https://git.kernel.org/tip/4c8205273626f27b9e5a64bdc194ab483a8cce66
Author: Jiri Olsa <jolsa@xxxxxxxxxx>
AuthorDate: Fri, 8 Jun 2018 02:22:11 +0200
Committer: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
CommitDate: Fri, 8 Jun 2018 13:35:53 -0300

perf c2c: Keep struct hist_entry at the end of struct c2c_hist_entry

Exactly as the comment just before 'struct c2c_hist_entry" says, i.e.
the last entry in struct hist_entry is a zero length array, that when
allocating space for hist_entry gets extra space if callchains are in
use, which, if hist_entry is not at the end of c2c_hist_entry, the
members after it gets corrupted when callchains get added to the rb
trees collecting them, etc.

Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
Reported-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Cc: Jin Yao <yao.jin@xxxxxxxxxxxxxxx>
Fixes: 7f834c2e84bb ("perf c2c report: Display node for cacheline address")
Link: http://lkml.kernel.org/n/tip-bh0ke4fh2ygpj3yowna7o1di@xxxxxxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
tools/perf/builtin-c2c.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/tools/perf/builtin-c2c.c b/tools/perf/builtin-c2c.c
index 307b3594525f..6a8738f7ead3 100644
--- a/tools/perf/builtin-c2c.c
+++ b/tools/perf/builtin-c2c.c
@@ -56,16 +56,16 @@ struct c2c_hist_entry {

struct compute_stats cstats;

+ unsigned long paddr;
+ unsigned long paddr_cnt;
+ bool paddr_zero;
+ char *nodestr;
+
/*
* must be at the end,
* because of its callchain dynamic entry
*/
struct hist_entry he;
-
- unsigned long paddr;
- unsigned long paddr_cnt;
- bool paddr_zero;
- char *nodestr;
};

static char const *coalesce_default = "pid,iaddr";