From 0d4e5ac7e78035950d564e65c38ce148cb9af681 Mon Sep 17 00:00:00 2001 From: Bartosz Golaszewski Date: Thu, 11 Apr 2019 11:49:42 +0200 Subject: [PATCH] um: remove uses of variable length arrays While the affected code is run in user-mode, the build still warns about it. Convert all uses of VLA to dynamic allocations. Signed-off-by: Bartosz Golaszewski Signed-off-by: Richard Weinberger --- arch/um/os-Linux/umid.c | 36 +++++++++++++++++++++++++++--------- 1 file changed, 27 insertions(+), 9 deletions(-) diff --git a/arch/um/os-Linux/umid.c b/arch/um/os-Linux/umid.c index 998fbb445458..e261656fe9d7 100644 --- a/arch/um/os-Linux/umid.c +++ b/arch/um/os-Linux/umid.c @@ -135,12 +135,18 @@ static int remove_files_and_dir(char *dir) */ static inline int is_umdir_used(char *dir) { - char file[strlen(uml_dir) + UMID_LEN + sizeof("/pid\0")]; - char pid[sizeof("nnnnn\0")], *end; + char pid[sizeof("nnnnn\0")], *end, *file; int dead, fd, p, n, err; + size_t filelen; - n = snprintf(file, sizeof(file), "%s/pid", dir); - if (n >= sizeof(file)) { + err = asprintf(&file, "%s/pid", dir); + if (err < 0) + return 0; + + filelen = strlen(file); + + n = snprintf(file, filelen, "%s/pid", dir); + if (n >= filelen) { printk(UM_KERN_ERR "is_umdir_used - pid filename too long\n"); err = -E2BIG; goto out; @@ -185,6 +191,7 @@ static inline int is_umdir_used(char *dir) out_close: close(fd); out: + free(file); return 0; } @@ -210,18 +217,21 @@ static int umdir_take_if_dead(char *dir) static void __init create_pid_file(void) { - char file[strlen(uml_dir) + UMID_LEN + sizeof("/pid\0")]; - char pid[sizeof("nnnnn\0")]; + char pid[sizeof("nnnnn\0")], *file; int fd, n; - if (umid_file_name("pid", file, sizeof(file))) + file = malloc(strlen(uml_dir) + UMID_LEN + sizeof("/pid\0")); + if (!file) return; + if (umid_file_name("pid", file, sizeof(file))) + goto out; + fd = open(file, O_RDWR | O_CREAT | O_EXCL, 0644); if (fd < 0) { printk(UM_KERN_ERR "Open of machine pid file \"%s\" failed: " "%s\n", file, strerror(errno)); - return; + goto out; } snprintf(pid, sizeof(pid), "%d\n", getpid()); @@ -231,6 +241,8 @@ static void __init create_pid_file(void) errno); close(fd); +out: + free(file); } int __init set_umid(char *name) @@ -385,13 +397,19 @@ __uml_setup("uml_dir=", set_uml_dir, static void remove_umid_dir(void) { - char dir[strlen(uml_dir) + UMID_LEN + 1], err; + char *dir, err; + + dir = malloc(strlen(uml_dir) + UMID_LEN + 1); + if (!dir) + return; sprintf(dir, "%s%s", uml_dir, umid); err = remove_files_and_dir(dir); if (err) os_warn("%s - remove_files_and_dir failed with err = %d\n", __func__, err); + + free(dir); } __uml_exitcall(remove_umid_dir);