[PATCH AUTOSEL 5.4 1/2] rcu: Fix __this_cpu_read() lockdep warning in rcu_force_quiescent_state()
From: Zqiang qiang1.zhang@intel.com
[ Upstream commit ceb1c8c9b8aa9199da46a0f29d2d5f08d9b44c15 ]
Running rcutorture with non-zero fqs_duration module parameter in a kernel built with CONFIG_PREEMPTION=y results in the following splat:
BUG: using __this_cpu_read() in preemptible [00000000] code: rcu_torture_fqs/398 caller is __this_cpu_preempt_check+0x13/0x20 CPU: 3 PID: 398 Comm: rcu_torture_fqs Not tainted 6.0.0-rc1-yoctodev-standard+ Call Trace: <TASK> dump_stack_lvl+0x5b/0x86 dump_stack+0x10/0x16 check_preemption_disabled+0xe5/0xf0 __this_cpu_preempt_check+0x13/0x20 rcu_force_quiescent_state.part.0+0x1c/0x170 rcu_force_quiescent_state+0x1e/0x30 rcu_torture_fqs+0xca/0x160 ? rcu_torture_boost+0x430/0x430 kthread+0x192/0x1d0 ? kthread_complete_and_exit+0x30/0x30 ret_from_fork+0x22/0x30 </TASK>
The problem is that rcu_force_quiescent_state() uses __this_cpu_read() in preemptible code instead of the proper raw_cpu_read(). This commit therefore changes __this_cpu_read() to raw_cpu_read().
Signed-off-by: Zqiang qiang1.zhang@intel.com Reviewed-by: Joel Fernandes (Google) joel@joelfernandes.org Signed-off-by: Paul E. McKenney paulmck@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- kernel/rcu/tree.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index 5797cf2909b0..615283404d9d 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -2317,7 +2317,7 @@ void rcu_force_quiescent_state(void) struct rcu_node *rnp_old = NULL;
/* Funnel through hierarchy to reduce memory contention. */ - rnp = __this_cpu_read(rcu_data.mynode); + rnp = raw_cpu_read(rcu_data.mynode); for (; rnp != NULL; rnp = rnp->parent) { ret = (READ_ONCE(rcu_state.gp_flags) & RCU_GP_FLAG_FQS) || !raw_spin_trylock(&rnp->fqslock);
From: Liu Shixin liushixin2@huawei.com
[ Upstream commit 6a46bf558803dd2b959ca7435a5c143efe837217 ]
UBSAN reported a shift-out-of-bounds warning:
left shift of 1 by 31 places cannot be represented in type 'int' Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x8d/0xcf lib/dump_stack.c:106 ubsan_epilogue+0xa/0x44 lib/ubsan.c:151 __ubsan_handle_shift_out_of_bounds+0x1e7/0x208 lib/ubsan.c:322 check_special_flags fs/binfmt_misc.c:241 [inline] create_entry fs/binfmt_misc.c:456 [inline] bm_register_write+0x9d3/0xa20 fs/binfmt_misc.c:654 vfs_write+0x11e/0x580 fs/read_write.c:582 ksys_write+0xcf/0x120 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x34/0x80 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x4194e1
Since the type of Node's flags is unsigned long, we should define these macros with same type too.
Signed-off-by: Liu Shixin liushixin2@huawei.com Signed-off-by: Kees Cook keescook@chromium.org Link: https://lore.kernel.org/r/20221102025123.1117184-1-liushixin2@huawei.com Signed-off-by: Sasha Levin sashal@kernel.org --- fs/binfmt_misc.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/fs/binfmt_misc.c b/fs/binfmt_misc.c index 056a68292e15..23b563ff0dd7 100644 --- a/fs/binfmt_misc.c +++ b/fs/binfmt_misc.c @@ -44,10 +44,10 @@ static LIST_HEAD(entries); static int enabled = 1;
enum {Enabled, Magic}; -#define MISC_FMT_PRESERVE_ARGV0 (1 << 31) -#define MISC_FMT_OPEN_BINARY (1 << 30) -#define MISC_FMT_CREDENTIALS (1 << 29) -#define MISC_FMT_OPEN_FILE (1 << 28) +#define MISC_FMT_PRESERVE_ARGV0 (1UL << 31) +#define MISC_FMT_OPEN_BINARY (1UL << 30) +#define MISC_FMT_CREDENTIALS (1UL << 29) +#define MISC_FMT_OPEN_FILE (1UL << 28)
typedef struct { struct list_head list;
linux-stable-mirror@lists.linaro.org
-
Sasha Levin