Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Fix error output of boot instance creation failure

   Currently if a boot instance creation fails, instead of printing out
   the name of the instance that failed, it prints "(null)". That is
   because it prints "cur_str" that had already been processed by
   strsep(). Print the saved name instead.

   While at it, print the error code of the failure.

 - Fix use-after-free for same named historgrams

   Histograms can be named so that they can be used in multiple events.
   But if the named histogram has a variable attached, the second event
   that uses the named histogram which duplicates it and needs to free
   the original after duplication leaves the old variable in place and
   still visible. If another histogram uses than variable, it will use
   the stale one which will try to reference the freed duplicate
   histogram and crash the kernel.

   Free the duplicate variables along with the duplicated histogram
   data.

 - Check return value of kthread_run() in event self test

   The events self tests uses a kthread for testing but does not check
   if it succeeded in creating a kthread. If the kthread creation were
   to fail, the code will still try to call kthread_stop() on the error
   returned.

 - Fix race between reading trace_pipe and updating subbuffer size

   If a user is reading the trace_pipe file at the same time they update
   the ring buffer sub-buffer size, can cause the trace_pipe read to
   read stale data. Add trace_access_lock() around updating the ring
   buffer sub-buffer size.

 - Fix eventfs_inode on failure path in creation of the events directory

   In the creation of the "events" directory, if after allocating the
   eventfs_inode a failure is detected, it calls cleanup_ei() which
   calls free_ei(). The free_ei() will test if eventfs_inode being freed
   has no children. It is a bug if it does. But on the failure case of
   the creation of the "events" directory, the children lists have not
   yet been initialized and the free will trigger a warning because
   list_empty() on an uninitialized list returns false.

   Move the initialization into init_ei() where it makes more sense and
   makes sure that a created eventfs_inode has its lists initialized
   upon creation.

 - Check return value of kthread_run() in ftrace direct sample code

   The sample code that shows how to use the ftrace direct calls does
   not test the return of kthread_run() to see if it succeeds. Return a
   failure if the kthread_run() doesn't succeed.

 - Clear user events state on fork in case of alloc failure

   On fork, the child gets a pointer to the parent's user events state.
   It makes a copy of it then updates the child's pointer to it. But if
   the allocation fails, the duplication function leaves the child with
   a pointer to its parent's descriptor. When the child cleans up its
   data, it will free the parent's descriptor while the parent is still
   using it.

   In the duplication function, set the child's user_event_mm to NULL
   before testing if the allocation succeeded, and when it exits it will
   not free the parent's descriptor.

 - Fix retry exhaustion in simple ring buffer reader swap

   simple_ring_buffer_swap_reader_page() starts with retry set to 8 and
   post-decrements it only after a failed link replacement. On the final
   attempt, a successful replacement leaves retry at zero, while a
   failed replacement leaves it at -1.

   But the check for success expects the retry value to be non-zero and
   exits with an error on zero. This is the opposite result. Fix it.

 - Fail nicely when the remote swap_reader_page() returns an error

   Currently, if the swap_reader_page() of a remote buffer fails, it
   triggers a WARN_ON_ONCE() and continues normally. Instead, have it
   exit with an error and a pr_warn() print instead of a full WARNING.

* tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  ring-buffer: Stop remote reader update when page swap fails
  tracing: Fix retry exhaustion in simple ring buffer reader swap
  tracing/user_events: Clear copied tracing state before fork duplication
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify
  eventfs: Initialize ei->children and ei->list in init_ei()
  tracing: Fix use-after-free in trace_pipe read on sub-buffer order change
  tracing: Fix crash passing ERR_PTR to kthread_stop()
  tracing: Fix use-after-free with same-name named triggers
  tracing: Fix logged instance name on creation failure

1 files changed, 211 insertions, 0 deletions

diff --git a/ipc/syscall.c b/ipc/syscall.c
new file mode 100644
index 000000000..dfb0e988d
--- /dev/null
+++ b/ipc/syscall.c
@@ -0,0 +1,211 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * sys_ipc() is the old de-multiplexer for the SysV IPC calls.
+ *
+ * This is really horribly ugly, and new architectures should just wire up
+ * the individual syscalls instead.
+ */
+#include <linux/unistd.h>
+#include <linux/syscalls.h>
+#include <linux/security.h>
+#include <linux/ipc_namespace.h>
+#include "util.h"
+
+#ifdef __ARCH_WANT_SYS_IPC
+#include <linux/errno.h>
+#include <linux/ipc.h>
+#include <linux/shm.h>
+#include <linux/uaccess.h>
+
+int ksys_ipc(unsigned int call, int first, unsigned long second,
+	unsigned long third, void __user * ptr, long fifth)
+{
+	int version, ret;
+
+	version = call >> 16; /* hack for backward compatibility */
+	call &= 0xffff;
+
+	switch (call) {
+	case SEMOP:
+		return ksys_semtimedop(first, (struct sembuf __user *)ptr,
+				       second, NULL);
+	case SEMTIMEDOP:
+		if (IS_ENABLED(CONFIG_64BIT))
+			return ksys_semtimedop(first, ptr, second,
+			        (const struct __kernel_timespec __user *)fifth);
+		else if (IS_ENABLED(CONFIG_COMPAT_32BIT_TIME))
+			return compat_ksys_semtimedop(first, ptr, second,
+			        (const struct old_timespec32 __user *)fifth);
+		else
+			return -ENOSYS;
+
+	case SEMGET:
+		return ksys_semget(first, second, third);
+	case SEMCTL: {
+		unsigned long arg;
+		if (!ptr)
+			return -EINVAL;
+		if (get_user(arg, (unsigned long __user *) ptr))
+			return -EFAULT;
+		return ksys_old_semctl(first, second, third, arg);
+	}
+
+	case MSGSND:
+		return ksys_msgsnd(first, (struct msgbuf __user *) ptr,
+				  second, third);
+	case MSGRCV:
+		switch (version) {
+		case 0: {
+			struct ipc_kludge tmp;
+			if (!ptr)
+				return -EINVAL;
+
+			if (copy_from_user(&tmp,
+					   (struct ipc_kludge __user *) ptr,
+					   sizeof(tmp)))
+				return -EFAULT;
+			return ksys_msgrcv(first, tmp.msgp, second,
+					   tmp.msgtyp, third);
+		}
+		default:
+			return ksys_msgrcv(first,
+					   (struct msgbuf __user *) ptr,
+					   second, fifth, third);
+		}
+	case MSGGET:
+		return ksys_msgget((key_t) first, second);
+	case MSGCTL:
+		return ksys_old_msgctl(first, second,
+				   (struct msqid_ds __user *)ptr);
+
+	case SHMAT:
+		switch (version) {
+		default: {
+			unsigned long raddr;
+			ret = do_shmat(first, (char __user *)ptr,
+				       second, &raddr, SHMLBA);
+			if (ret)
+				return ret;
+			return put_user(raddr, (unsigned long __user *) third);
+		}
+		case 1:
+			/*
+			 * This was the entry point for kernel-originating calls
+			 * from iBCS2 in 2.2 days.
+			 */
+			return -EINVAL;
+		}
+	case SHMDT:
+		return ksys_shmdt((char __user *)ptr);
+	case SHMGET:
+		return ksys_shmget(first, second, third);
+	case SHMCTL:
+		return ksys_old_shmctl(first, second,
+				   (struct shmid_ds __user *) ptr);
+	default:
+		return -ENOSYS;
+	}
+}
+
+SYSCALL_DEFINE6(ipc, unsigned int, call, int, first, unsigned long, second,
+		unsigned long, third, void __user *, ptr, long, fifth)
+{
+	return ksys_ipc(call, first, second, third, ptr, fifth);
+}
+#endif
+
+#ifdef CONFIG_COMPAT
+#include <linux/compat.h>
+
+#ifndef COMPAT_SHMLBA
+#define COMPAT_SHMLBA	SHMLBA
+#endif
+
+struct compat_ipc_kludge {
+	compat_uptr_t msgp;
+	compat_long_t msgtyp;
+};
+
+#ifdef CONFIG_ARCH_WANT_OLD_COMPAT_IPC
+int compat_ksys_ipc(u32 call, int first, int second,
+	u32 third, compat_uptr_t ptr, u32 fifth)
+{
+	int version;
+	u32 pad;
+
+	version = call >> 16; /* hack for backward compatibility */
+	call &= 0xffff;
+
+	switch (call) {
+	case SEMOP:
+		/* struct sembuf is the same on 32 and 64bit :)) */
+		return ksys_semtimedop(first, compat_ptr(ptr), second, NULL);
+	case SEMTIMEDOP:
+		if (!IS_ENABLED(CONFIG_COMPAT_32BIT_TIME))
+			return -ENOSYS;
+		return compat_ksys_semtimedop(first, compat_ptr(ptr), second,
+						compat_ptr(fifth));
+	case SEMGET:
+		return ksys_semget(first, second, third);
+	case SEMCTL:
+		if (!ptr)
+			return -EINVAL;
+		if (get_user(pad, (u32 __user *) compat_ptr(ptr)))
+			return -EFAULT;
+		return compat_ksys_old_semctl(first, second, third, pad);
+
+	case MSGSND:
+		return compat_ksys_msgsnd(first, ptr, second, third);
+
+	case MSGRCV: {
+		void __user *uptr = compat_ptr(ptr);
+
+		if (first < 0 || second < 0)
+			return -EINVAL;
+
+		if (!version) {
+			struct compat_ipc_kludge ipck;
+			if (!uptr)
+				return -EINVAL;
+			if (copy_from_user(&ipck, uptr, sizeof(ipck)))
+				return -EFAULT;
+			return compat_ksys_msgrcv(first, ipck.msgp, second,
+						 ipck.msgtyp, third);
+		}
+		return compat_ksys_msgrcv(first, ptr, second, fifth, third);
+	}
+	case MSGGET:
+		return ksys_msgget(first, second);
+	case MSGCTL:
+		return compat_ksys_old_msgctl(first, second, compat_ptr(ptr));
+
+	case SHMAT: {
+		int err;
+		unsigned long raddr;
+
+		if (version == 1)
+			return -EINVAL;
+		err = do_shmat(first, compat_ptr(ptr), second, &raddr,
+			       COMPAT_SHMLBA);
+		if (err < 0)
+			return err;
+		return put_user(raddr, (compat_ulong_t __user *)compat_ptr(third));
+	}
+	case SHMDT:
+		return ksys_shmdt(compat_ptr(ptr));
+	case SHMGET:
+		return ksys_shmget(first, (unsigned int)second, third);
+	case SHMCTL:
+		return compat_ksys_old_shmctl(first, second, compat_ptr(ptr));
+	}
+
+	return -ENOSYS;
+}
+
+COMPAT_SYSCALL_DEFINE6(ipc, u32, call, int, first, int, second,
+	u32, third, compat_uptr_t, ptr, u32, fifth)
+{
+	return compat_ksys_ipc(call, first, second, third, ptr, fifth);
+}
+#endif
+#endif