Revision bce0b6c51ac76fc0e763262a6c2a9d05e486f0d8 authored by Steven Rostedt (Red Hat) on 21 August 2014, 03:57:04 UTC, committed by Steven Rostedt on 22 August 2014, 19:24:12 UTC
Now that a ftrace_hash can be shared by multiple ftrace_ops, they can dec
the rec->flags by more than once (one per those that share the ftrace_hash).
This means that the tramp_hash may not have a hash item when it was added.

For example, if two ftrace_ops share a hash for a ftrace record, and the
first ops has a trampoline, when it adds itself it will set the rec->flags
TRAMP flag and increments its nr_trampolines counter. When the second ops
is added, it must clear that tramp flag but also decrement the other ops
that shares its hash. As the update to the function callbacks has not yet
been performed, the other ops will not have the tramp hash set yet and it
can not be used to know to decrement its nr_trampolines.

Luckily, the tramp_hash does not need to be used. As the ftrace_mutex is
held, a ops with a trampoline to a record during an update of another ops
that shares the record will have its func_hash pointing to it. Since a
trampoline can only be set for a record if only one ops is attached to it,
we can just check if the record has a trampoline (the FTRACE_FL_TRAMP flag
is set) and then find the ops that has this record in its hashes.

Also added some output to help debug when things go wrong.

Cc: stable@vger.kernel.org # 3.16+ (apply after 3.17-rc4 is out)
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
1 parent 8426191
Raw File
Kconfig
#
# File system configuration
#

menu "File systems"

# Use unaligned word dcache accesses
config DCACHE_WORD_ACCESS
       bool

if BLOCK

source "fs/ext2/Kconfig"
source "fs/ext3/Kconfig"
source "fs/ext4/Kconfig"

config FS_XIP
# execute in place
	bool
	depends on EXT2_FS_XIP
	default y

source "fs/jbd/Kconfig"
source "fs/jbd2/Kconfig"

config FS_MBCACHE
# Meta block cache for Extended Attributes (ext2/ext3/ext4)
	tristate
	default y if EXT2_FS=y && EXT2_FS_XATTR
	default y if EXT3_FS=y && EXT3_FS_XATTR
	default y if EXT4_FS=y
	default m if EXT2_FS_XATTR || EXT3_FS_XATTR || EXT4_FS

source "fs/reiserfs/Kconfig"
source "fs/jfs/Kconfig"

source "fs/xfs/Kconfig"
source "fs/gfs2/Kconfig"
source "fs/ocfs2/Kconfig"
source "fs/btrfs/Kconfig"
source "fs/nilfs2/Kconfig"

endif # BLOCK

# Posix ACL utility routines
#
# Note: Posix ACLs can be implemented without these helpers.  Never use
# this symbol for ifdefs in core code.
#
config FS_POSIX_ACL
	def_bool n

config EXPORTFS
	tristate

config FILE_LOCKING
	bool "Enable POSIX file locking API" if EXPERT
	default y
	help
	  This option enables standard file locking support, required
          for filesystems like NFS and for the flock() system
          call. Disabling this option saves about 11k.

source "fs/notify/Kconfig"

source "fs/quota/Kconfig"

source "fs/autofs4/Kconfig"
source "fs/fuse/Kconfig"

menu "Caches"

source "fs/fscache/Kconfig"
source "fs/cachefiles/Kconfig"

endmenu

if BLOCK
menu "CD-ROM/DVD Filesystems"

source "fs/isofs/Kconfig"
source "fs/udf/Kconfig"

endmenu
endif # BLOCK

if BLOCK
menu "DOS/FAT/NT Filesystems"

source "fs/fat/Kconfig"
source "fs/ntfs/Kconfig"

endmenu
endif # BLOCK

menu "Pseudo filesystems"

source "fs/proc/Kconfig"
source "fs/kernfs/Kconfig"
source "fs/sysfs/Kconfig"

config TMPFS
	bool "Tmpfs virtual memory file system support (former shm fs)"
	depends on SHMEM
	help
	  Tmpfs is a file system which keeps all files in virtual memory.

	  Everything in tmpfs is temporary in the sense that no files will be
	  created on your hard drive. The files live in memory and swap
	  space. If you unmount a tmpfs instance, everything stored therein is
	  lost.

	  See <file:Documentation/filesystems/tmpfs.txt> for details.

config TMPFS_POSIX_ACL
	bool "Tmpfs POSIX Access Control Lists"
	depends on TMPFS
	select TMPFS_XATTR
	select FS_POSIX_ACL
	help
	  POSIX Access Control Lists (ACLs) support additional access rights
	  for users and groups beyond the standard owner/group/world scheme,
	  and this option selects support for ACLs specifically for tmpfs
	  filesystems.

	  If you've selected TMPFS, it's possible that you'll also need
	  this option as there are a number of Linux distros that require
	  POSIX ACL support under /dev for certain features to work properly.
	  For example, some distros need this feature for ALSA-related /dev
	  files for sound to work properly.  In short, if you're not sure,
	  say Y.

	  To learn more about Access Control Lists, visit the POSIX ACLs for
	  Linux website <http://acl.bestbits.at/>.

config TMPFS_XATTR
	bool "Tmpfs extended attributes"
	depends on TMPFS
	default n
	help
	  Extended attributes are name:value pairs associated with inodes by
	  the kernel or by users (see the attr(5) manual page, or visit
	  <http://acl.bestbits.at/> for details).

	  Currently this enables support for the trusted.* and
	  security.* namespaces.

	  You need this for POSIX ACL support on tmpfs.

	  If unsure, say N.

config HUGETLBFS
	bool "HugeTLB file system support"
	depends on X86 || IA64 || SPARC64 || (S390 && 64BIT) || \
		   SYS_SUPPORTS_HUGETLBFS || BROKEN
	help
	  hugetlbfs is a filesystem backing for HugeTLB pages, based on
	  ramfs. For architectures that support it, say Y here and read
	  <file:Documentation/vm/hugetlbpage.txt> for details.

	  If unsure, say N.

config HUGETLB_PAGE
	def_bool HUGETLBFS

source "fs/configfs/Kconfig"

endmenu

menuconfig MISC_FILESYSTEMS
	bool "Miscellaneous filesystems"
	default y
	---help---
	  Say Y here to get to see options for various miscellaneous
	  filesystems, such as filesystems that came from other
	  operating systems.

	  This option alone does not add any kernel code.

	  If you say N, all options in this submenu will be skipped and
	  disabled; if unsure, say Y here.

if MISC_FILESYSTEMS

source "fs/adfs/Kconfig"
source "fs/affs/Kconfig"
source "fs/ecryptfs/Kconfig"
source "fs/hfs/Kconfig"
source "fs/hfsplus/Kconfig"
source "fs/befs/Kconfig"
source "fs/bfs/Kconfig"
source "fs/efs/Kconfig"
source "fs/jffs2/Kconfig"
# UBIFS File system configuration
source "fs/ubifs/Kconfig"
source "fs/logfs/Kconfig"
source "fs/cramfs/Kconfig"
source "fs/squashfs/Kconfig"
source "fs/freevxfs/Kconfig"
source "fs/minix/Kconfig"
source "fs/omfs/Kconfig"
source "fs/hpfs/Kconfig"
source "fs/qnx4/Kconfig"
source "fs/qnx6/Kconfig"
source "fs/romfs/Kconfig"
source "fs/pstore/Kconfig"
source "fs/sysv/Kconfig"
source "fs/ufs/Kconfig"
source "fs/exofs/Kconfig"
source "fs/f2fs/Kconfig"
source "fs/efivarfs/Kconfig"

endif # MISC_FILESYSTEMS

source "fs/exofs/Kconfig.ore"

menuconfig NETWORK_FILESYSTEMS
	bool "Network File Systems"
	default y
	depends on NET
	---help---
	  Say Y here to get to see options for network filesystems and
	  filesystem-related networking code, such as NFS daemon and
	  RPCSEC security modules.

	  This option alone does not add any kernel code.

	  If you say N, all options in this submenu will be skipped and
	  disabled; if unsure, say Y here.

if NETWORK_FILESYSTEMS

source "fs/nfs/Kconfig"
source "fs/nfsd/Kconfig"

config LOCKD
	tristate
	depends on FILE_LOCKING

config LOCKD_V4
	bool
	depends on NFSD_V3 || NFS_V3
	depends on FILE_LOCKING
	default y

config NFS_ACL_SUPPORT
	tristate
	select FS_POSIX_ACL

config NFS_COMMON
	bool
	depends on NFSD || NFS_FS
	default y

source "net/sunrpc/Kconfig"
source "fs/ceph/Kconfig"
source "fs/cifs/Kconfig"
source "fs/ncpfs/Kconfig"
source "fs/coda/Kconfig"
source "fs/afs/Kconfig"
source "fs/9p/Kconfig"

endif # NETWORK_FILESYSTEMS

source "fs/nls/Kconfig"
source "fs/dlm/Kconfig"

endmenu
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