The patch titled
Subject: mm, vmstat: Make sure mutex is a global static
has been added to the -mm tree. Its filename is
mm-sysctl-make-numa-stats-configurable-v5-fix.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/mm-sysctl-make-numa-stats-configurable-v5-fix.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/mm-sysctl-make-numa-stats-configurable-v5-fix.patch
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From: Kees Cook <keescook@xxxxxxxxxxxx>
Subject: mm, vmstat: Make sure mutex is a global static
The mutex in sysctl_vm_numa_stat_handler() needs to be a global static,
not a stack variable, otherwise it doesn't serve any purpose. Also,
reading the file with CONFIG_LOCKDEP=y will complain:
[ 63.258593] INFO: trying to register non-static key.
[ 63.259113] the code is fine but needs lockdep annotation.
[ 63.259596] turning off the locking correctness validator.
[ 63.260073] CPU: 1 PID: 4102 Comm: perl Not tainted 4.14.0-rc8-next-20171107+ #419
[ 63.260769] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014
[ 63.261570] Call Trace:
[ 63.261783] dump_stack+0x5f/0x86
[ 63.262062] register_lock_class+0xe4/0x550
[ 63.262408] ? __lock_acquire+0x308/0x1170
[ 63.262746] __lock_acquire+0x7e/0x1170
[ 63.263063] lock_acquire+0x9d/0x1d0
[ 63.263363] ? sysctl_vm_numa_stat_handler+0x8f/0x2d0
[ 63.263777] ? sysctl_vm_numa_stat_handler+0x8f/0x2d0
[ 63.264192] __mutex_lock+0xb8/0x9a0
[ 63.264488] ? sysctl_vm_numa_stat_handler+0x8f/0x2d0
[ 63.264942] ? sysctl_vm_numa_stat_handler+0x8f/0x2d0
[ 63.265398] ? sysctl_vm_numa_stat_handler+0x8f/0x2d0
[ 63.265840] sysctl_vm_numa_stat_handler+0x8f/0x2d0
[ 63.266270] proc_sys_call_handler+0xe3/0x100
[ 63.266655] __vfs_read+0x33/0x1b0
[ 63.266957] vfs_read+0xa6/0x150
[ 63.267244] SyS_read+0x55/0xc0
[ 63.267525] do_syscall_64+0x56/0x140
[ 63.267850] entry_SYSCALL64_slow_path+0x25/0x25
Link: http://lkml.kernel.org/r/20171107213809.GA4314@beast
Fixes: 920d5f77d1a25 ("mm, sysctl: make NUMA stats configurable")
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
Cc: Jesper Dangaard Brouer <brouer@xxxxxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxx>
Cc: Ying Huang <ying.huang@xxxxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/vmstat.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff -puN mm/vmstat.c~mm-sysctl-make-numa-stats-configurable-v5-fix mm/vmstat.c
--- a/mm/vmstat.c~mm-sysctl-make-numa-stats-configurable-v5-fix
+++ a/mm/vmstat.c
@@ -72,11 +72,12 @@ static void invalid_numa_statistics(void
zero_global_numa_counters();
}
+static DEFINE_MUTEX(vm_numa_stat_lock);
+
int sysctl_vm_numa_stat_handler(struct ctl_table *table, int write,
void __user *buffer, size_t *length, loff_t *ppos)
{
int ret, oldval;
- DEFINE_MUTEX(vm_numa_stat_lock);
mutex_lock(&vm_numa_stat_lock);
if (write)
_
Patches currently in -mm which might be from keescook@xxxxxxxxxxxx are
writeback-convert-timers-to-use-timer_setup.patch
mm-sysctl-make-numa-stats-configurable-v5-fix.patch
sh-boot-add-static-stack-protector-to-pre-kernel.patch
lkdtm-include-warn-format-string.patch
bug-define-the-cut-here-string-in-a-single-place.patch
bug-fix-cut-here-location-for-__warn_taint-architectures.patch
fs-nilfs2-convert-timers-to-use-timer_setup.patch
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