Hi Wang,

>From: Wang Nan [mailto:wangn...@huawei.com]
>
>To prevent futher commits calling machine__delete() on non-allocated
>'struct machine' (which would cause memory corruption), this patch
>enforces machine__init(), record whether a machine structure is
>dynamically allocated or not, and warn if machine__delete() is called
>on incorrect object.

Looks good to me :D

Reviewed-by: Masami Hiramatsu <masami.hiramatsu...@hitachi.com>

Thanks!

>
>Signed-off-by: Wang Nan <wangn...@huawei.com>
>Cc: Arnaldo Carvalho de Melo <a...@redhat.com>
>Cc: Jiri Olsa <jo...@kernel.org>
>Cc: Masami Hiramatsu <masami.hiramatsu...@hitachi.com>
>Cc: Namhyung Kim <namhy...@kernel.org>
>---
>
>v1 -> v2: Remove incorrect '!'.
>
>---
> tools/perf/tests/vmlinux-kallsyms.c |  4 ++--
> tools/perf/util/machine.c           | 14 +++++++++-----
> tools/perf/util/machine.h           |  3 ++-
> 3 files changed, 13 insertions(+), 8 deletions(-)
>
>diff --git a/tools/perf/tests/vmlinux-kallsyms.c 
>b/tools/perf/tests/vmlinux-kallsyms.c
>index f0bfc9e..441e93d 100644
>--- a/tools/perf/tests/vmlinux-kallsyms.c
>+++ b/tools/perf/tests/vmlinux-kallsyms.c
>@@ -35,8 +35,8 @@ int test__vmlinux_matches_kallsyms(int subtest 
>__maybe_unused)
>        * Init the machines that will hold kernel, modules obtained from
>        * both vmlinux + .ko files and from /proc/kallsyms split by modules.
>        */
>-      machine__init(&kallsyms, "", HOST_KERNEL_ID);
>-      machine__init(&vmlinux, "", HOST_KERNEL_ID);
>+      machine__init(&kallsyms, "", HOST_KERNEL_ID, false);
>+      machine__init(&vmlinux, "", HOST_KERNEL_ID, false);
>
>       /*
>        * Step 2:
>diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c
>index f5882b8..ac64e5a 100644
>--- a/tools/perf/util/machine.c
>+++ b/tools/perf/util/machine.c
>@@ -23,7 +23,7 @@ static void dsos__init(struct dsos *dsos)
>       pthread_rwlock_init(&dsos->lock, NULL);
> }
>
>-int machine__init(struct machine *machine, const char *root_dir, pid_t pid)
>+int machine__init(struct machine *machine, const char *root_dir, pid_t pid, 
>bool allocated)
> {
>       map_groups__init(&machine->kmaps, machine);
>       RB_CLEAR_NODE(&machine->rb_node);
>@@ -64,6 +64,7 @@ int machine__init(struct machine *machine, const char 
>*root_dir, pid_t pid)
>       }
>
>       machine->current_tid = NULL;
>+      machine->allocated = allocated;
>
>       return 0;
> }
>@@ -73,7 +74,7 @@ struct machine *machine__new_host(void)
>       struct machine *machine = malloc(sizeof(*machine));
>
>       if (machine != NULL) {
>-              machine__init(machine, "", HOST_KERNEL_ID);
>+              machine__init(machine, "", HOST_KERNEL_ID, true);
>
>               if (machine__create_kernel_maps(machine) < 0)
>                       goto out_delete;
>@@ -136,12 +137,15 @@ void machine__exit(struct machine *machine)
> void machine__delete(struct machine *machine)
> {
>       machine__exit(machine);
>-      free(machine);
>+      if (machine->allocated)
>+              free(machine);
>+      else
>+              pr_warning("WARNING: delete a non-allocated machine. Skip.\n");
> }
>
> void machines__init(struct machines *machines)
> {
>-      machine__init(&machines->host, "", HOST_KERNEL_ID);
>+      machine__init(&machines->host, "", HOST_KERNEL_ID, false);
>       machines->guests = RB_ROOT;
>       machines->symbol_filter = NULL;
> }
>@@ -162,7 +166,7 @@ struct machine *machines__add(struct machines *machines, 
>pid_t pid,
>       if (machine == NULL)
>               return NULL;
>
>-      if (machine__init(machine, root_dir, pid) != 0) {
>+      if (machine__init(machine, root_dir, pid, true) != 0) {
>               free(machine);
>               return NULL;
>       }
>diff --git a/tools/perf/util/machine.h b/tools/perf/util/machine.h
>index 2c2b443..24dfd46 100644
>--- a/tools/perf/util/machine.h
>+++ b/tools/perf/util/machine.h
>@@ -28,6 +28,7 @@ struct machine {
>       pid_t             pid;
>       u16               id_hdr_size;
>       bool              comm_exec;
>+      bool              allocated;
>       char              *root_dir;
>       struct rb_root    threads;
>       pthread_rwlock_t  threads_lock;
>@@ -131,7 +132,7 @@ void machines__set_symbol_filter(struct machines *machines,
> void machines__set_comm_exec(struct machines *machines, bool comm_exec);
>
> struct machine *machine__new_host(void);
>-int machine__init(struct machine *machine, const char *root_dir, pid_t pid);
>+int machine__init(struct machine *machine, const char *root_dir, pid_t pid, 
>bool allocated);
> void machine__exit(struct machine *machine);
> void machine__delete_threads(struct machine *machine);
> void machine__delete(struct machine *machine);
>--
>1.8.3.4

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