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authorLinus Torvalds <torvalds@linux-foundation.org>2019-10-04 19:18:56 +0200
committerLinus Torvalds <torvalds@linux-foundation.org>2019-10-04 19:18:56 +0200
commitaf0622f6ae416f9ac340d6d632be9879805c294a (patch)
tree4601536c7954fae49617041ab9c415bb86229677
parentMerge tag 'drm-fixes-2019-10-04' of git://anongit.freedesktop.org/drm/drm (diff)
parentsched: add kernel-doc for struct clone_args (diff)
downloadlinux-af0622f6ae416f9ac340d6d632be9879805c294a.tar.xz
linux-af0622f6ae416f9ac340d6d632be9879805c294a.zip
Merge tag 'for-linus-20191003' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux
Pull clone3/pidfd fixes from Christian Brauner: "This contains a couple of fixes: - Fix pidfd selftest compilation (Shuah Kahn) Due to a false linking instruction in the Makefile compilation for the pidfd selftests would fail on some systems. - Fix compilation for glibc on RISC-V systems (Seth Forshee) In some scenarios linux/uapi/linux/sched.h is included where __ASSEMBLY__ is defined causing a build failure because struct clone_args was not guarded by an #ifndef __ASSEMBLY__. - Add missing clone3() and struct clone_args kernel-doc (Christian Brauner) clone3() and struct clone_args were missing kernel-docs. (The goal is to use kernel-doc for any function or type where it's worth it.) For struct clone_args this also contains a comment about the fact that it's versioned by size" * tag 'for-linus-20191003' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux: sched: add kernel-doc for struct clone_args fork: add kernel-doc for clone3 selftests: pidfd: Fix undefined reference to pthread_create() sched: Add __ASSEMBLY__ guards around struct clone_args
-rw-r--r--include/uapi/linux/sched.h28
-rw-r--r--kernel/fork.c11
-rw-r--r--tools/testing/selftests/pidfd/Makefile2
3 files changed, 38 insertions, 3 deletions
diff --git a/include/uapi/linux/sched.h b/include/uapi/linux/sched.h
index b3105ac1381a..3d8f03bfd428 100644
--- a/include/uapi/linux/sched.h
+++ b/include/uapi/linux/sched.h
@@ -33,8 +33,31 @@
#define CLONE_NEWNET 0x40000000 /* New network namespace */
#define CLONE_IO 0x80000000 /* Clone io context */
-/*
- * Arguments for the clone3 syscall
+#ifndef __ASSEMBLY__
+/**
+ * struct clone_args - arguments for the clone3 syscall
+ * @flags: Flags for the new process as listed above.
+ * All flags are valid except for CSIGNAL and
+ * CLONE_DETACHED.
+ * @pidfd: If CLONE_PIDFD is set, a pidfd will be
+ * returned in this argument.
+ * @child_tid: If CLONE_CHILD_SETTID is set, the TID of the
+ * child process will be returned in the child's
+ * memory.
+ * @parent_tid: If CLONE_PARENT_SETTID is set, the TID of
+ * the child process will be returned in the
+ * parent's memory.
+ * @exit_signal: The exit_signal the parent process will be
+ * sent when the child exits.
+ * @stack: Specify the location of the stack for the
+ * child process.
+ * @stack_size: The size of the stack for the child process.
+ * @tls: If CLONE_SETTLS is set, the tls descriptor
+ * is set to tls.
+ *
+ * The structure is versioned by size and thus extensible.
+ * New struct members must go at the end of the struct and
+ * must be properly 64bit aligned.
*/
struct clone_args {
__aligned_u64 flags;
@@ -46,6 +69,7 @@ struct clone_args {
__aligned_u64 stack_size;
__aligned_u64 tls;
};
+#endif
/*
* Scheduling policies
diff --git a/kernel/fork.c b/kernel/fork.c
index f9572f416126..bf11cf39579a 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -2604,6 +2604,17 @@ static bool clone3_args_valid(const struct kernel_clone_args *kargs)
return true;
}
+/**
+ * clone3 - create a new process with specific properties
+ * @uargs: argument structure
+ * @size: size of @uargs
+ *
+ * clone3() is the extensible successor to clone()/clone2().
+ * It takes a struct as argument that is versioned by its size.
+ *
+ * Return: On success, a positive PID for the child process.
+ * On error, a negative errno number.
+ */
SYSCALL_DEFINE2(clone3, struct clone_args __user *, uargs, size_t, size)
{
int err;
diff --git a/tools/testing/selftests/pidfd/Makefile b/tools/testing/selftests/pidfd/Makefile
index 464c9b76148f..7550f08822a3 100644
--- a/tools/testing/selftests/pidfd/Makefile
+++ b/tools/testing/selftests/pidfd/Makefile
@@ -1,5 +1,5 @@
# SPDX-License-Identifier: GPL-2.0-only
-CFLAGS += -g -I../../../../usr/include/ -lpthread
+CFLAGS += -g -I../../../../usr/include/ -pthread
TEST_GEN_PROGS := pidfd_test pidfd_open_test pidfd_poll_test pidfd_wait