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-rw-r--r--kernel/fork.c67
1 files changed, 16 insertions, 51 deletions
diff --git a/kernel/fork.c b/kernel/fork.c
index 40996d2a56b9..b7da9000dfb1 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -2097,8 +2097,7 @@ static __latent_entropy struct task_struct *copy_process(
retval = copy_io(clone_flags, p);
if (retval)
goto bad_fork_cleanup_namespaces;
- retval = copy_thread_tls(clone_flags, args->stack, args->stack_size, p,
- args->tls);
+ retval = copy_thread(clone_flags, args->stack, args->stack_size, p, args->tls);
if (retval)
goto bad_fork_cleanup_io;
@@ -2417,6 +2416,20 @@ long _do_fork(struct kernel_clone_args *args)
long nr;
/*
+ * For legacy clone() calls, CLONE_PIDFD uses the parent_tid argument
+ * to return the pidfd. Hence, CLONE_PIDFD and CLONE_PARENT_SETTID are
+ * mutually exclusive. With clone3() CLONE_PIDFD has grown a separate
+ * field in struct clone_args and it still doesn't make sense to have
+ * them both point at the same memory location. Performing this check
+ * here has the advantage that we don't need to have a separate helper
+ * to check for legacy clone().
+ */
+ if ((args->flags & CLONE_PIDFD) &&
+ (args->flags & CLONE_PARENT_SETTID) &&
+ (args->pidfd == args->parent_tid))
+ return -EINVAL;
+
+ /*
* Determine whether and which event to report to ptracer. When
* called from kernel_thread or CLONE_UNTRACED is explicitly
* requested, no event is reported; otherwise, report if the event
@@ -2473,42 +2486,6 @@ long _do_fork(struct kernel_clone_args *args)
return nr;
}
-bool legacy_clone_args_valid(const struct kernel_clone_args *kargs)
-{
- /* clone(CLONE_PIDFD) uses parent_tidptr to return a pidfd */
- if ((kargs->flags & CLONE_PIDFD) &&
- (kargs->flags & CLONE_PARENT_SETTID))
- return false;
-
- return true;
-}
-
-#ifndef CONFIG_HAVE_COPY_THREAD_TLS
-/* For compatibility with architectures that call do_fork directly rather than
- * using the syscall entry points below. */
-long do_fork(unsigned long clone_flags,
- unsigned long stack_start,
- unsigned long stack_size,
- int __user *parent_tidptr,
- int __user *child_tidptr)
-{
- struct kernel_clone_args args = {
- .flags = (lower_32_bits(clone_flags) & ~CSIGNAL),
- .pidfd = parent_tidptr,
- .child_tid = child_tidptr,
- .parent_tid = parent_tidptr,
- .exit_signal = (lower_32_bits(clone_flags) & CSIGNAL),
- .stack = stack_start,
- .stack_size = stack_size,
- };
-
- if (!legacy_clone_args_valid(&args))
- return -EINVAL;
-
- return _do_fork(&args);
-}
-#endif
-
/*
* Create a kernel thread.
*/
@@ -2587,24 +2564,12 @@ SYSCALL_DEFINE5(clone, unsigned long, clone_flags, unsigned long, newsp,
.tls = tls,
};
- if (!legacy_clone_args_valid(&args))
- return -EINVAL;
-
return _do_fork(&args);
}
#endif
#ifdef __ARCH_WANT_SYS_CLONE3
-/*
- * copy_thread implementations handle CLONE_SETTLS by reading the TLS value from
- * the registers containing the syscall arguments for clone. This doesn't work
- * with clone3 since the TLS value is passed in clone_args instead.
- */
-#ifndef CONFIG_HAVE_COPY_THREAD_TLS
-#error clone3 requires copy_thread_tls support in arch
-#endif
-
noinline static int copy_clone_args_from_user(struct kernel_clone_args *kargs,
struct clone_args __user *uargs,
size_t usize)
@@ -2919,7 +2884,7 @@ static int unshare_fd(unsigned long unshare_flags, struct files_struct **new_fdp
/*
* unshare allows a process to 'unshare' part of the process
* context which was originally shared using clone. copy_*
- * functions used by do_fork() cannot be used here directly
+ * functions used by _do_fork() cannot be used here directly
* because they modify an inactive task_struct that is being
* constructed. Here we are modifying the current, active,
* task_struct.