Grygorii Strashko 11ce4b33ae ARM: 8672/1: mm: remove tasklist locking from update_sections_early() ... The below backtrace can be observed on -rt kernel with CONFIG_DEBUG_MODULE_RONX (4.9 kernel CONFIG_DEBUG_RODATA) option enabled: BUG: sleeping function called from invalid context at kernel/locking/rtmutex.c:993 in_atomic(): 1, irqs_disabled(): 128, pid: 14, name: migration/0 1 lock held by migration/0/14: #0: (tasklist_lock){+.+...}, at: [<c01183e8>] update_sections_early+0x24/0xdc irq event stamp: 38 hardirqs last enabled at (37): [<c08f6f7c>] _raw_spin_unlock_irq+0x24/0x68 hardirqs last disabled at (38): [<c01fdfe8>] multi_cpu_stop+0xd8/0x138 softirqs last enabled at (0): [<c01303ec>] copy_process.part.5+0x238/0x1b64 softirqs last disabled at (0): [< (null)>] (null) Preemption disabled at: [<c01fe244>] cpu_stopper_thread+0x80/0x10c CPU: 0 PID: 14 Comm: migration/0 Not tainted 4.9.21-rt16-02220-g49e319c #15 Hardware name: Generic DRA74X (Flattened Device Tree) [<c0112014>] (unwind_backtrace) from [<c010d370>] (show_stack+0x10/0x14) [<c010d370>] (show_stack) from [<c049beb8>] (dump_stack+0xa8/0xd4) [<c049beb8>] (dump_stack) from [<c01631a0>] (___might_sleep+0x1bc/0x2ac) [<c01631a0>] (___might_sleep) from [<c08f7244>] (__rt_spin_lock+0x1c/0x30) [<c08f7244>] (__rt_spin_lock) from [<c08f77a4>] (rt_read_lock+0x54/0x68) [<c08f77a4>] (rt_read_lock) from [<c01183e8>] (update_sections_early+0x24/0xdc) [<c01183e8>] (update_sections_early) from [<c01184b0>] (__fix_kernmem_perms+0x10/0x1c) [<c01184b0>] (__fix_kernmem_perms) from [<c01fe010>] (multi_cpu_stop+0x100/0x138) [<c01fe010>] (multi_cpu_stop) from [<c01fe24c>] (cpu_stopper_thread+0x88/0x10c) [<c01fe24c>] (cpu_stopper_thread) from [<c015edc4>] (smpboot_thread_fn+0x174/0x31c) [<c015edc4>] (smpboot_thread_fn) from [<c015a988>] (kthread+0xf0/0x108) [<c015a988>] (kthread) from [<c0108818>] (ret_from_fork+0x14/0x3c) Freeing unused kernel memory: 1024K (c0d00000 - c0e00000) The stop_machine() is called with cpus = NULL from fix_kernmem_perms() and mark_rodata_ro() which means only one CPU will execute update_sections_early() while all other CPUs will spin and wait. Hence, it's safe to remove tasklist locking from update_sections_early(). As part of this change also mark functions which are local to this module as static. Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com> Acked-by: Laura Abbott <labbott@redhat.com> Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>		2017-04-26 10:59:36 +01:00
..
alpha	sched/headers: Move task->mm handling methods to <linux/sched/mm.h>	2017-03-03 01:43:28 +01:00
arc	sched/headers: Move task->mm handling methods to <linux/sched/mm.h>	2017-03-03 01:43:28 +01:00
arm	ARM: 8672/1: mm: remove tasklist locking from update_sections_early()	2017-04-26 10:59:36 +01:00
arm64	ARM: SoC: late DT updates for v4.11	2017-03-03 16:15:48 -08:00
avr32	sched/headers: Prepare to remove the <linux/mm_types.h> dependency from <linux/sched.h>	2017-03-02 08:42:37 +01:00
blackfin	sched/headers: Move task->mm handling methods to <linux/sched/mm.h>	2017-03-03 01:43:28 +01:00
c6x	sched/headers: Prepare for new header dependencies before moving code to <linux/sched/task_stack.h>	2017-03-02 08:42:36 +01:00
cris	sched/headers: Prepare to remove the <linux/mm_types.h> dependency from <linux/sched.h>	2017-03-02 08:42:37 +01:00
frv	sched/headers: Prepare to move 'init_task' and 'init_thread_union' from <linux/sched.h> to <linux/sched/task.h>	2017-03-02 08:42:38 +01:00
h8300	sched/headers: Prepare to remove the <linux/mm_types.h> dependency from <linux/sched.h>	2017-03-02 08:42:37 +01:00
hexagon	sched/headers: Move task->mm handling methods to <linux/sched/mm.h>	2017-03-03 01:43:28 +01:00
ia64	sched/core: Remove unused prefetch_stack()	2017-03-03 01:45:38 +01:00
m32r	sched/headers: Move task->mm handling methods to <linux/sched/mm.h>	2017-03-03 01:43:28 +01:00
m68k	sched/headers: Prepare to remove the <linux/mm_types.h> dependency from <linux/sched.h>	2017-03-02 08:42:37 +01:00
metag	sched/headers: Move task->mm handling methods to <linux/sched/mm.h>	2017-03-03 01:43:28 +01:00
microblaze	sched/headers: Prepare to remove the <linux/mm_types.h> dependency from <linux/sched.h>	2017-03-02 08:42:37 +01:00
mips	sched/headers: Remove the <linux/topology.h> include from <linux/sched.h>	2017-03-03 01:45:41 +01:00
mn10300	sched/headers: Prepare to remove the <linux/mm_types.h> dependency from <linux/sched.h>	2017-03-02 08:42:37 +01:00
nios2	sched/headers: Prepare to move 'init_task' and 'init_thread_union' from <linux/sched.h> to <linux/sched/task.h>	2017-03-02 08:42:38 +01:00
openrisc	sched/headers: Prepare to move kstack_end() from <linux/sched.h> to <linux/sched/task_stack.h>	2017-03-02 08:42:39 +01:00
parisc	Merge branch 'parisc-4.11-1' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux	2017-03-03 16:20:06 -08:00
powerpc	Second batch of KVM changes for 4.11 merge window	2017-03-04 11:36:19 -08:00
s390	sched/headers: Move task statistics APIs from <linux/sched.h> to <linux/sched/stat.h>	2017-03-03 01:43:43 +01:00
score	sched/headers: Move task->mm handling methods to <linux/sched/mm.h>	2017-03-03 01:43:28 +01:00
sh	sched/headers: Remove <asm/ptrace.h> from <linux/sched.h>	2017-03-03 01:45:33 +01:00
sparc	sched/headers: Move task->mm handling methods to <linux/sched/mm.h>	2017-03-03 01:43:28 +01:00
tile	sched/headers: Move task->mm handling methods to <linux/sched/mm.h>	2017-03-03 01:43:28 +01:00
um	sched/headers: Prepare to move kstack_end() from <linux/sched.h> to <linux/sched/task_stack.h>	2017-03-02 08:42:39 +01:00
unicore32	sched/headers: Prepare for new header dependencies before moving code to <linux/sched/task_stack.h>	2017-03-02 08:42:36 +01:00
x86	Second batch of KVM changes for 4.11 merge window	2017-03-04 11:36:19 -08:00
xtensa	Xtensa improvements for v4.11:	2017-03-03 16:17:55 -08:00
.gitignore
Kconfig	scripts/spelling.txt: add "an user" pattern and fix typo instances	2017-02-27 18:43:46 -08:00