From 667ac92a1a72b6038f0fae4acfc6a280fd69697b Mon Sep 17 00:00:00 2001 From: Ignat Korchagin Date: Mon, 16 Sep 2019 10:30:23 -0600 Subject: [PATCH] btreplay: fix device IO remap functionality Commit dd093eb1c48e ("Fix warnings on newer gcc") moved string buffers holding device names during map file parse stage to stack. However, only pointers to them are being stored in the allocated "struct map_dev" structure. These pointers are invalid outside of scope of this function and in a different thread context. Also "release_map_devs" function still tries to "free" them later as if they were allocated on the heap. Moving the buffers back to the heap by instructing "fscanf" to allocate them while parsing the file. Alternatively, we could redefine the "struct map_dev" to include the whole buffers instead of just pointers to them and free them as part of releasing the whole "struct map_dev". Fixes: dd093eb1c48e ("Fix warnings on newer gcc") Signed-off-by: Ignat Korchagin Signed-off-by: Jens Axboe --- btreplay/btreplay.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/btreplay/btreplay.c b/btreplay/btreplay.c index edaf81f..23cc2a9 100644 --- a/btreplay/btreplay.c +++ b/btreplay/btreplay.c @@ -645,7 +645,7 @@ static void find_input_devs(char *idir) static void read_map_devs(char *file_name) { FILE *fp; - char from_dev[256], to_dev[256]; + char *from_dev, *to_dev; fp = fopen(file_name, "r"); if (!fp) { @@ -653,7 +653,7 @@ static void read_map_devs(char *file_name) /*NOTREACHED*/ } - while (fscanf(fp, "%s %s", from_dev, to_dev) == 2) { + while (fscanf(fp, "%ms %ms", &from_dev, &to_dev) == 2) { struct map_dev *mdp = malloc(sizeof(*mdp)); mdp->from_dev = from_dev; -- 2.25.1