linux-kernel - [PATCH 01/12] perf machine: Set main kernel end address properly

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Date:   Wed, 25 Apr 2018 12:59:57 -0300
From:   Arnaldo Carvalho de Melo <acme@...nel.org>
To:     Ingo Molnar <mingo@...nel.org>
Cc:     Clark Williams <williams@...hat.com>, linux-kernel@...r.kernel.org,
        linux-perf-users@...r.kernel.org,
        Namhyung Kim <namhyung@...nel.org>,
        Jiri Olsa <jolsa@...nel.org>,
        Peter Zijlstra <peterz@...radead.org>, kernel-team@....com,
        Arnaldo Carvalho de Melo <acme@...hat.com>
Subject: [PATCH 01/12] perf machine: Set main kernel end address properly

From: Namhyung Kim <namhyung@...nel.org>

map_groups__fixup_end() was called to set the end addresses of kernel
and module maps.  But now since machine__create_modules() sets the end
address of modules properly, the only remaining piece is the kernel map.

We can set it with adjacent module's address directly instead of calling
map_groups__fixup_end().  If there's no module after the kernel map, the
end address will be ~0ULL.

Since it also changes the start address of the kernel map, it needs to
re-insert the map to the kmaps in order to keep a correct ordering.  Kim
reported that it caused problems on ARM64.

Reported-by: Kim Phillips <kim.phillips@....com>
Tested-by: Kim Phillips <kim.phillips@....com>
Signed-off-by: Namhyung Kim <namhyung@...nel.org>
Cc: Jiri Olsa <jolsa@...nel.org>
Cc: Peter Zijlstra <peterz@...radead.org>
Cc: kernel-team@....com
Link: http://lkml.kernel.org/r/20180419235915.GA19067@sejong
Signed-off-by: Arnaldo Carvalho de Melo <acme@...hat.com>
---
 tools/perf/util/machine.c | 30 ++++++++++++++++++------------
 1 file changed, 18 insertions(+), 12 deletions(-)

diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c
index 2eca8478e24f..32d50492505d 100644
--- a/tools/perf/util/machine.c
+++ b/tools/perf/util/machine.c
@@ -1019,13 +1019,6 @@ int machine__load_vmlinux_path(struct machine *machine, enum map_type type)
 	return ret;
 }
 
-static void map_groups__fixup_end(struct map_groups *mg)
-{
-	int i;
-	for (i = 0; i < MAP__NR_TYPES; ++i)
-		__map_groups__fixup_end(mg, i);
-}
-
 static char *get_kernel_version(const char *root_dir)
 {
 	char version[PATH_MAX];
@@ -1233,6 +1226,7 @@ int machine__create_kernel_maps(struct machine *machine)
 {
 	struct dso *kernel = machine__get_kernel(machine);
 	const char *name = NULL;
+	struct map *map;
 	u64 addr = 0;
 	int ret;
 
@@ -1259,13 +1253,25 @@ int machine__create_kernel_maps(struct machine *machine)
 			machine__destroy_kernel_maps(machine);
 			return -1;
 		}
-		machine__set_kernel_mmap(machine, addr, 0);
+
+		/* we have a real start address now, so re-order the kmaps */
+		map = machine__kernel_map(machine);
+
+		map__get(map);
+		map_groups__remove(&machine->kmaps, map);
+
+		/* assume it's the last in the kmaps */
+		machine__set_kernel_mmap(machine, addr, ~0ULL);
+
+		map_groups__insert(&machine->kmaps, map);
+		map__put(map);
 	}
 
-	/*
-	 * Now that we have all the maps created, just set the ->end of them:
-	 */
-	map_groups__fixup_end(&machine->kmaps);
+	/* update end address of the kernel map using adjacent module address */
+	map = map__next(machine__kernel_map(machine));
+	if (map)
+		machine__set_kernel_mmap(machine, addr, map->start);
+
 	return 0;
 }
 
-- 
2.14.3