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Subject[RESEND PATCH 2/4] um: remove uses of variable length arrays
Date
From: Bartosz Golaszewski <bgolaszewski@baylibre.com>

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 <bgolaszewski@baylibre.com>
---
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);
--
2.21.0
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