Re: [Kgdb-bugreport] [PATCH] kernel: convert switch/case fallthrough comments to fallthrough;
From: Daniel Thompson
Date: Mon Oct 21 2019 - 05:09:18 EST
On Fri, Oct 18, 2019 at 09:35:08AM -0700, Joe Perches wrote:
> Use the new pseudo keyword "fallthrough;" and not the
> various /* fallthrough */ style comments.
>
> Signed-off-by: Joe Perches <joe@xxxxxxxxxxx>
> ---
>
> This is a single patch for the kernel/ source tree,
> which would otherwise
> be sent through as separate
> patches to 19 maintainer sections.
For the kernel/debug/ files:
Acked-by: Daniel Thompson <daniel.thompson@xxxxxxxxxx>
Will you be putting this in an immutable branch once you've collected
enough acks?
[TBH I don't actually expect any conflict between this and the pending
kgdb changes for this kernel cycle anyway...]
Daniel.
>
> compilation tested only.
>
> Done by the script in this email:
> https://lore.kernel.org/lkml/9fe980f7e28242c2835ffae34914c5f68e8268a7.camel@xxxxxxxxxxx/
>
> kernel/auditfilter.c | 2 +-
> kernel/bpf/cgroup.c | 4 ++--
> kernel/bpf/verifier.c | 4 ++--
> kernel/capability.c | 2 +-
> kernel/compat.c | 6 +++---
> kernel/debug/gdbstub.c | 6 +++---
> kernel/debug/kdb/kdb_keyboard.c | 4 ++--
> kernel/debug/kdb/kdb_support.c | 6 +++---
> kernel/events/core.c | 3 +--
> kernel/futex.c | 4 ++--
> kernel/gcov/gcc_3_4.c | 6 +++---
> kernel/irq/handle.c | 3 +--
> kernel/irq/manage.c | 5 ++---
> kernel/kallsyms.c | 4 ++--
> kernel/pid.c | 2 +-
> kernel/power/hibernate.c | 2 +-
> kernel/power/qos.c | 4 ++--
> kernel/printk/printk.c | 2 +-
> kernel/sched/core.c | 2 +-
> kernel/sched/topology.c | 6 +++---
> kernel/signal.c | 2 +-
> kernel/sys.c | 3 +--
> kernel/time/hrtimer.c | 2 +-
> kernel/time/posix-timers.c | 4 ++--
> kernel/time/tick-broadcast.c | 2 +-
> kernel/time/timer.c | 2 +-
> kernel/trace/blktrace.c | 2 +-
> kernel/trace/trace_events_filter.c | 4 ++--
> 28 files changed, 47 insertions(+), 51 deletions(-)
>
> diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c
> index b0126e9c0743..471cd680479d 100644
> --- a/kernel/auditfilter.c
> +++ b/kernel/auditfilter.c
> @@ -674,7 +674,7 @@ static struct audit_rule_data *audit_krule_to_data(struct audit_krule *krule)
> data->values[i] = AUDIT_UID_UNSET;
> break;
> }
> - /* fall through - if set */
> + fallthrough; /* if set */
> default:
> data->values[i] = f->val;
> }
> diff --git a/kernel/bpf/cgroup.c b/kernel/bpf/cgroup.c
> index ddd8addcdb5c..955631f1b77d 100644
> --- a/kernel/bpf/cgroup.c
> +++ b/kernel/bpf/cgroup.c
> @@ -797,7 +797,7 @@ cgroup_base_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
> case BPF_FUNC_trace_printk:
> if (capable(CAP_SYS_ADMIN))
> return bpf_get_trace_printk_proto();
> - /* fall through */
> + fallthrough;
> default:
> return NULL;
> }
> @@ -1439,7 +1439,7 @@ static bool cg_sockopt_is_valid_access(int off, int size,
> return prog->expected_attach_type ==
> BPF_CGROUP_GETSOCKOPT;
> case offsetof(struct bpf_sockopt, optname):
> - /* fallthrough */
> + fallthrough;
> case offsetof(struct bpf_sockopt, level):
> if (size != size_default)
> return false;
> diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
> index ffc3e53f5300..d2b6fd8545e2 100644
> --- a/kernel/bpf/verifier.c
> +++ b/kernel/bpf/verifier.c
> @@ -2249,7 +2249,7 @@ static bool may_access_direct_pkt_data(struct bpf_verifier_env *env,
> case BPF_PROG_TYPE_CGROUP_SKB:
> if (t == BPF_WRITE)
> return false;
> - /* fallthrough */
> + fallthrough;
>
> /* Program types with direct read + write access go here! */
> case BPF_PROG_TYPE_SCHED_CLS:
> @@ -4381,7 +4381,7 @@ static int adjust_ptr_min_max_vals(struct bpf_verifier_env *env,
> off_reg == dst_reg ? dst : src);
> return -EACCES;
> }
> - /* fall-through */
> + fallthrough;
> default:
> break;
> }
> diff --git a/kernel/capability.c b/kernel/capability.c
> index 1444f3954d75..7c59b096c98a 100644
> --- a/kernel/capability.c
> +++ b/kernel/capability.c
> @@ -93,7 +93,7 @@ static int cap_validate_magic(cap_user_header_t header, unsigned *tocopy)
> break;
> case _LINUX_CAPABILITY_VERSION_2:
> warn_deprecated_v2();
> - /* fall through - v3 is otherwise equivalent to v2. */
> + fallthrough; /* v3 is otherwise equivalent to v2 */
> case _LINUX_CAPABILITY_VERSION_3:
> *tocopy = _LINUX_CAPABILITY_U32S_3;
> break;
> diff --git a/kernel/compat.c b/kernel/compat.c
> index a2bc1d6ceb57..d9c61f4317be 100644
> --- a/kernel/compat.c
> +++ b/kernel/compat.c
> @@ -343,11 +343,11 @@ get_compat_sigset(sigset_t *set, const compat_sigset_t __user *compat)
> return -EFAULT;
> switch (_NSIG_WORDS) {
> case 4: set->sig[3] = v.sig[6] | (((long)v.sig[7]) << 32 );
> - /* fall through */
> + fallthrough;
> case 3: set->sig[2] = v.sig[4] | (((long)v.sig[5]) << 32 );
> - /* fall through */
> + fallthrough;
> case 2: set->sig[1] = v.sig[2] | (((long)v.sig[3]) << 32 );
> - /* fall through */
> + fallthrough;
> case 1: set->sig[0] = v.sig[0] | (((long)v.sig[1]) << 32 );
> }
> #else
> diff --git a/kernel/debug/gdbstub.c b/kernel/debug/gdbstub.c
> index 4b280fc7dd67..b9d8b7248964 100644
> --- a/kernel/debug/gdbstub.c
> +++ b/kernel/debug/gdbstub.c
> @@ -1033,14 +1033,14 @@ int gdb_serial_stub(struct kgdb_state *ks)
> return DBG_PASS_EVENT;
> }
> #endif
> - /* Fall through */
> + fallthrough;
> case 'C': /* Exception passing */
> tmp = gdb_cmd_exception_pass(ks);
> if (tmp > 0)
> goto default_handle;
> if (tmp == 0)
> break;
> - /* Fall through - on tmp < 0 */
> + fallthrough; /* on tmp < 0 */
> case 'c': /* Continue packet */
> case 's': /* Single step packet */
> if (kgdb_contthread && kgdb_contthread != current) {
> @@ -1049,7 +1049,7 @@ int gdb_serial_stub(struct kgdb_state *ks)
> break;
> }
> dbg_activate_sw_breakpoints();
> - /* Fall through - to default processing */
> + fallthrough; /* to default processing */
> default:
> default_handle:
> error = kgdb_arch_handle_exception(ks->ex_vector,
> diff --git a/kernel/debug/kdb/kdb_keyboard.c b/kernel/debug/kdb/kdb_keyboard.c
> index 750497b0003a..f877a0a0d7cf 100644
> --- a/kernel/debug/kdb/kdb_keyboard.c
> +++ b/kernel/debug/kdb/kdb_keyboard.c
> @@ -173,11 +173,11 @@ int kdb_get_kbd_char(void)
> case KT_LATIN:
> if (isprint(keychar))
> break; /* printable characters */
> - /* fall through */
> + fallthrough;
> case KT_SPEC:
> if (keychar == K_ENTER)
> break;
> - /* fall through */
> + fallthrough;
> default:
> return -1; /* ignore unprintables */
> }
> diff --git a/kernel/debug/kdb/kdb_support.c b/kernel/debug/kdb/kdb_support.c
> index b8e6306e7e13..d636506f695a 100644
> --- a/kernel/debug/kdb/kdb_support.c
> +++ b/kernel/debug/kdb/kdb_support.c
> @@ -432,7 +432,7 @@ int kdb_getphysword(unsigned long *word, unsigned long addr, size_t size)
> *word = w8;
> break;
> }
> - /* fall through */
> + fallthrough;
> default:
> diag = KDB_BADWIDTH;
> kdb_printf("kdb_getphysword: bad width %ld\n", (long) size);
> @@ -481,7 +481,7 @@ int kdb_getword(unsigned long *word, unsigned long addr, size_t size)
> *word = w8;
> break;
> }
> - /* fall through */
> + fallthrough;
> default:
> diag = KDB_BADWIDTH;
> kdb_printf("kdb_getword: bad width %ld\n", (long) size);
> @@ -525,7 +525,7 @@ int kdb_putword(unsigned long addr, unsigned long word, size_t size)
> diag = kdb_putarea(addr, w8);
> break;
> }
> - /* fall through */
> + fallthrough;
> default:
> diag = KDB_BADWIDTH;
> kdb_printf("kdb_putword: bad width %ld\n", (long) size);
> diff --git a/kernel/events/core.c b/kernel/events/core.c
> index 9ec0b0bfddbd..04e75b1144c5 100644
> --- a/kernel/events/core.c
> +++ b/kernel/events/core.c
> @@ -9361,8 +9361,7 @@ perf_event_parse_addr_filter(struct perf_event *event, char *fstr,
> case IF_SRC_KERNELADDR:
> case IF_SRC_KERNEL:
> kernel = 1;
> - /* fall through */
> -
> + fallthrough;
> case IF_SRC_FILEADDR:
> case IF_SRC_FILE:
> if (state != IF_STATE_SOURCE)
> diff --git a/kernel/futex.c b/kernel/futex.c
> index bd18f60e4c6c..ab12b6229d2d 100644
> --- a/kernel/futex.c
> +++ b/kernel/futex.c
> @@ -3639,12 +3639,12 @@ long do_futex(u32 __user *uaddr, int op, u32 val, ktime_t *timeout,
> switch (cmd) {
> case FUTEX_WAIT:
> val3 = FUTEX_BITSET_MATCH_ANY;
> - /* fall through */
> + fallthrough;
> case FUTEX_WAIT_BITSET:
> return futex_wait(uaddr, flags, val, timeout, val3);
> case FUTEX_WAKE:
> val3 = FUTEX_BITSET_MATCH_ANY;
> - /* fall through */
> + fallthrough;
> case FUTEX_WAKE_BITSET:
> return futex_wake(uaddr, flags, val, val3);
> case FUTEX_REQUEUE:
> diff --git a/kernel/gcov/gcc_3_4.c b/kernel/gcov/gcc_3_4.c
> index 801ee4b0b969..32fc3278166f 100644
> --- a/kernel/gcov/gcc_3_4.c
> +++ b/kernel/gcov/gcc_3_4.c
> @@ -455,7 +455,7 @@ int gcov_iter_next(struct gcov_iterator *iter)
> case RECORD_COUNT:
> /* Advance to next count */
> iter->count++;
> - /* fall through */
> + fallthrough;
> case RECORD_COUNT_LEN:
> if (iter->count < get_func(iter)->n_ctrs[iter->type]) {
> iter->record = 9;
> @@ -465,7 +465,7 @@ int gcov_iter_next(struct gcov_iterator *iter)
> get_type(iter)->offset += iter->count;
> iter->count = 0;
> iter->type++;
> - /* fall through */
> + fallthrough;
> case RECORD_FUNCTION_CHECK:
> if (iter->type < iter->num_types) {
> iter->record = 7;
> @@ -474,7 +474,7 @@ int gcov_iter_next(struct gcov_iterator *iter)
> /* Advance to next function */
> iter->type = 0;
> iter->function++;
> - /* fall through */
> + fallthrough;
> case RECORD_TIME_STAMP:
> if (iter->function < iter->info->n_functions)
> iter->record = 3;
> diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c
> index a4ace611f47f..b38d2fd70fe1 100644
> --- a/kernel/irq/handle.c
> +++ b/kernel/irq/handle.c
> @@ -165,8 +165,7 @@ irqreturn_t __handle_irq_event_percpu(struct irq_desc *desc, unsigned int *flags
> }
>
> __irq_wake_thread(desc, action);
> -
> - /* Fall through - to add to randomness */
> + fallthrough; /* to add to randomness */
> case IRQ_HANDLED:
> *flags |= action->flags;
> break;
> diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
> index 1753486b440c..baa86020f243 100644
> --- a/kernel/irq/manage.c
> +++ b/kernel/irq/manage.c
> @@ -222,7 +222,7 @@ int irq_do_set_affinity(struct irq_data *data, const struct cpumask *mask,
> case IRQ_SET_MASK_OK:
> case IRQ_SET_MASK_OK_DONE:
> cpumask_copy(desc->irq_common_data.affinity, mask);
> - /* fall through */
> + fallthrough;
> case IRQ_SET_MASK_OK_NOCOPY:
> irq_validate_effective_affinity(data);
> irq_set_thread_affinity(desc);
> @@ -792,8 +792,7 @@ int __irq_set_trigger(struct irq_desc *desc, unsigned long flags)
> case IRQ_SET_MASK_OK_DONE:
> irqd_clear(&desc->irq_data, IRQD_TRIGGER_MASK);
> irqd_set(&desc->irq_data, flags);
> - /* fall through */
> -
> + fallthrough;
> case IRQ_SET_MASK_OK_NOCOPY:
> flags = irqd_get_trigger_type(&desc->irq_data);
> irq_settings_set_trigger_mask(desc, flags);
> diff --git a/kernel/kallsyms.c b/kernel/kallsyms.c
> index 136ce049c4ad..05ce8a4d4729 100644
> --- a/kernel/kallsyms.c
> +++ b/kernel/kallsyms.c
> @@ -651,11 +651,11 @@ int kallsyms_show_value(void)
> case 0:
> if (kallsyms_for_perf())
> return 1;
> - /* fallthrough */
> + fallthrough;
> case 1:
> if (has_capability_noaudit(current, CAP_SYSLOG))
> return 1;
> - /* fallthrough */
> + fallthrough;
> default:
> return 0;
> }
> diff --git a/kernel/pid.c b/kernel/pid.c
> index 0a9f2e437217..b2a005a6dea1 100644
> --- a/kernel/pid.c
> +++ b/kernel/pid.c
> @@ -144,7 +144,7 @@ void free_pid(struct pid *pid)
> /* Handle a fork failure of the first process */
> WARN_ON(ns->child_reaper);
> ns->pid_allocated = 0;
> - /* fall through */
> + fallthrough;
> case 0:
> schedule_work(&ns->proc_work);
> break;
> diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c
> index 3c0a5a8170b0..d091dcd57557 100644
> --- a/kernel/power/hibernate.c
> +++ b/kernel/power/hibernate.c
> @@ -647,7 +647,7 @@ static void power_down(void)
> break;
> case HIBERNATION_PLATFORM:
> hibernation_platform_enter();
> - /* Fall through */
> + fallthrough;
> case HIBERNATION_SHUTDOWN:
> if (pm_power_off)
> kernel_power_off();
> diff --git a/kernel/power/qos.c b/kernel/power/qos.c
> index 9568a2fe7c11..6bf5295b2ade 100644
> --- a/kernel/power/qos.c
> +++ b/kernel/power/qos.c
> @@ -236,7 +236,7 @@ int pm_qos_update_target(struct pm_qos_constraints *c, struct plist_node *node,
> * changed
> */
> plist_del(node, &c->list);
> - /* fall through */
> + fallthrough;
> case PM_QOS_ADD_REQ:
> plist_node_init(node, new_value);
> plist_add(node, &c->list);
> @@ -309,7 +309,7 @@ bool pm_qos_update_flags(struct pm_qos_flags *pqf,
> break;
> case PM_QOS_UPDATE_REQ:
> pm_qos_flags_remove_req(pqf, req);
> - /* fall through */
> + fallthrough;
> case PM_QOS_ADD_REQ:
> req->flags = val;
> INIT_LIST_HEAD(&req->node);
> diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
> index ca65327a6de8..6b3d7c68e6fe 100644
> --- a/kernel/printk/printk.c
> +++ b/kernel/printk/printk.c
> @@ -1531,7 +1531,7 @@ int do_syslog(int type, char __user *buf, int len, int source)
> /* Read/clear last kernel messages */
> case SYSLOG_ACTION_READ_CLEAR:
> clear = true;
> - /* FALL THRU */
> + fallthrough;
> /* Read last kernel messages */
> case SYSLOG_ACTION_READ_ALL:
> if (!buf || len < 0)
> diff --git a/kernel/sched/core.c b/kernel/sched/core.c
> index dd05a378631a..050b728728f4 100644
> --- a/kernel/sched/core.c
> +++ b/kernel/sched/core.c
> @@ -2068,7 +2068,7 @@ static int select_fallback_rq(int cpu, struct task_struct *p)
> state = possible;
> break;
> }
> - /* Fall-through */
> + fallthrough;
> case possible:
> do_set_cpus_allowed(p, cpu_possible_mask);
> state = fail;
> diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c
> index b5667a273bf6..7d6b84e0caca 100644
> --- a/kernel/sched/topology.c
> +++ b/kernel/sched/topology.c
> @@ -1224,13 +1224,13 @@ static void __free_domain_allocs(struct s_data *d, enum s_alloc what,
> case sa_rootdomain:
> if (!atomic_read(&d->rd->refcount))
> free_rootdomain(&d->rd->rcu);
> - /* Fall through */
> + fallthrough;
> case sa_sd:
> free_percpu(d->sd);
> - /* Fall through */
> + fallthrough;
> case sa_sd_storage:
> __sdt_free(cpu_map);
> - /* Fall through */
> + fallthrough;
> case sa_none:
> break;
> }
> diff --git a/kernel/signal.c b/kernel/signal.c
> index c4da1ef56fdf..73bdcc1f2561 100644
> --- a/kernel/signal.c
> +++ b/kernel/signal.c
> @@ -846,7 +846,7 @@ static int check_kill_permission(int sig, struct kernel_siginfo *info,
> */
> if (!sid || sid == task_session(current))
> break;
> - /* fall through */
> + fallthrough;
> default:
> return -EPERM;
> }
> diff --git a/kernel/sys.c b/kernel/sys.c
> index a611d1d58c7d..bad4f30e7f37 100644
> --- a/kernel/sys.c
> +++ b/kernel/sys.c
> @@ -1737,8 +1737,7 @@ void getrusage(struct task_struct *p, int who, struct rusage *r)
>
> if (who == RUSAGE_CHILDREN)
> break;
> - /* fall through */
> -
> + fallthrough;
> case RUSAGE_SELF:
> thread_group_cputime_adjusted(p, &tgutime, &tgstime);
> utime += tgutime;
> diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c
> index 0d4dc241c0fb..8060a35682e1 100644
> --- a/kernel/time/hrtimer.c
> +++ b/kernel/time/hrtimer.c
> @@ -373,7 +373,7 @@ static bool hrtimer_fixup_activate(void *addr, enum debug_obj_state state)
> switch (state) {
> case ODEBUG_STATE_ACTIVE:
> WARN_ON(1);
> - /* fall through */
> + fallthrough;
> default:
> return false;
> }
> diff --git a/kernel/time/posix-timers.c b/kernel/time/posix-timers.c
> index 0ec5b7a1d769..6cc658391702 100644
> --- a/kernel/time/posix-timers.c
> +++ b/kernel/time/posix-timers.c
> @@ -413,12 +413,12 @@ static struct pid *good_sigevent(sigevent_t * event)
> rtn = pid_task(pid, PIDTYPE_PID);
> if (!rtn || !same_thread_group(rtn, current))
> return NULL;
> - /* FALLTHRU */
> + fallthrough;
> case SIGEV_SIGNAL:
> case SIGEV_THREAD:
> if (event->sigev_signo <= 0 || event->sigev_signo > SIGRTMAX)
> return NULL;
> - /* FALLTHRU */
> + fallthrough;
> case SIGEV_NONE:
> return pid;
> default:
> diff --git a/kernel/time/tick-broadcast.c b/kernel/time/tick-broadcast.c
> index e51778c312f1..36d7464c8962 100644
> --- a/kernel/time/tick-broadcast.c
> +++ b/kernel/time/tick-broadcast.c
> @@ -381,7 +381,7 @@ void tick_broadcast_control(enum tick_broadcast_mode mode)
> switch (mode) {
> case TICK_BROADCAST_FORCE:
> tick_broadcast_forced = 1;
> - /* fall through */
> + fallthrough;
> case TICK_BROADCAST_ON:
> cpumask_set_cpu(cpu, tick_broadcast_on);
> if (!cpumask_test_and_set_cpu(cpu, tick_broadcast_mask)) {
> diff --git a/kernel/time/timer.c b/kernel/time/timer.c
> index 4820823515e9..6512d721ef57 100644
> --- a/kernel/time/timer.c
> +++ b/kernel/time/timer.c
> @@ -653,7 +653,7 @@ static bool timer_fixup_activate(void *addr, enum debug_obj_state state)
>
> case ODEBUG_STATE_ACTIVE:
> WARN_ON(1);
> - /* fall through */
> + fallthrough;
> default:
> return false;
> }
> diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
> index 2d6e93ab0478..0a1753dc69d3 100644
> --- a/kernel/trace/blktrace.c
> +++ b/kernel/trace/blktrace.c
> @@ -717,7 +717,7 @@ int blk_trace_ioctl(struct block_device *bdev, unsigned cmd, char __user *arg)
> #endif
> case BLKTRACESTART:
> start = 1;
> - /* fall through */
> + fallthrough;
> case BLKTRACESTOP:
> ret = __blk_trace_startstop(q, start);
> break;
> diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c
> index c9a74f82b14a..78b0bfc4d72e 100644
> --- a/kernel/trace/trace_events_filter.c
> +++ b/kernel/trace/trace_events_filter.c
> @@ -499,7 +499,7 @@ predicate_parse(const char *str, int nr_parens, int nr_preds,
> ptr++;
> break;
> }
> - /* fall through */
> + fallthrough;
> default:
> parse_error(pe, FILT_ERR_TOO_MANY_PREDS,
> next - str);
> @@ -1273,7 +1273,7 @@ static int parse_pred(const char *str, void *data,
> switch (op) {
> case OP_NE:
> pred->not = 1;
> - /* Fall through */
> + fallthrough;
> case OP_GLOB:
> case OP_EQ:
> break;
>
>
>
>
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