From 3d3c376118b5f7ed7723c2b4fd7a0a1c1893d63e Mon Sep 17 00:00:00 2001 From: Nam Cao Date: Thu, 24 Jul 2025 19:33:28 +0200 Subject: [PATCH] rv: Merge struct rv_reactor_def into struct rv_reactor Each struct rv_reactor has a unique struct rv_reactor_def associated with it. struct rv_reactor is statically allocated, while struct rv_reactor_def is dynamically allocated. This makes the code more complicated than it should be: - Lookup is required to get the associated rv_reactor_def from rv_reactor - Dynamic memory allocation is required for rv_reactor_def. This is harder to get right compared to static memory. For instance, there is an existing mistake: rv_unregister_reactor() does not free the memory allocated by rv_register_reactor(). This is fortunately not a real memory leak problem as rv_unregister_reactor() is never called. Simplify and merge rv_reactor_def into rv_reactor. Cc: Masami Hiramatsu Cc: Mathieu Desnoyers Link: https://lore.kernel.org/71cb91c86cd40df5b8c492b788787f2a73c3eaa3.1753378331.git.namcao@linutronix.de Reviewed-by: Gabriele Monaco Signed-off-by: Nam Cao Signed-off-by: Steven Rostedt (Google) --- include/linux/rv.h | 5 +- kernel/trace/rv/rv.h | 9 ---- kernel/trace/rv/rv_reactors.c | 92 +++++++++++++++-------------------- 3 files changed, 43 insertions(+), 63 deletions(-) diff --git a/include/linux/rv.h b/include/linux/rv.h index dba53aecdfabc..c22c9b8c15673 100644 --- a/include/linux/rv.h +++ b/include/linux/rv.h @@ -90,6 +90,9 @@ struct rv_reactor { const char *name; const char *description; __printf(1, 2) void (*react)(const char *msg, ...); + struct list_head list; + /* protected by the monitor interface lock */ + int counter; }; #endif @@ -101,7 +104,7 @@ struct rv_monitor { void (*disable)(void); void (*reset)(void); #ifdef CONFIG_RV_REACTORS - struct rv_reactor_def *rdef; + struct rv_reactor *reactor; __printf(1, 2) void (*react)(const char *msg, ...); bool reacting; #endif diff --git a/kernel/trace/rv/rv.h b/kernel/trace/rv/rv.h index f039ec1c91563..8c38f9dd41bc4 100644 --- a/kernel/trace/rv/rv.h +++ b/kernel/trace/rv/rv.h @@ -23,15 +23,6 @@ struct rv_interface { extern struct mutex rv_interface_lock; extern struct list_head rv_monitors_list; -#ifdef CONFIG_RV_REACTORS -struct rv_reactor_def { - struct list_head list; - struct rv_reactor *reactor; - /* protected by the monitor interface lock */ - int counter; -}; -#endif - struct dentry *get_monitors_root(void); int rv_disable_monitor(struct rv_monitor *mon); int rv_enable_monitor(struct rv_monitor *mon); diff --git a/kernel/trace/rv/rv_reactors.c b/kernel/trace/rv/rv_reactors.c index 7cc620a1be1a8..2c7909e6d0e70 100644 --- a/kernel/trace/rv/rv_reactors.c +++ b/kernel/trace/rv/rv_reactors.c @@ -70,12 +70,12 @@ */ static LIST_HEAD(rv_reactors_list); -static struct rv_reactor_def *get_reactor_rdef_by_name(char *name) +static struct rv_reactor *get_reactor_rdef_by_name(char *name) { - struct rv_reactor_def *r; + struct rv_reactor *r; list_for_each_entry(r, &rv_reactors_list, list) { - if (strcmp(name, r->reactor->name) == 0) + if (strcmp(name, r->name) == 0) return r; } return NULL; @@ -86,9 +86,9 @@ static struct rv_reactor_def *get_reactor_rdef_by_name(char *name) */ static int reactors_show(struct seq_file *m, void *p) { - struct rv_reactor_def *rea_def = p; + struct rv_reactor *reactor = p; - seq_printf(m, "%s\n", rea_def->reactor->name); + seq_printf(m, "%s\n", reactor->name); return 0; } @@ -139,12 +139,12 @@ static const struct file_operations available_reactors_ops = { static int monitor_reactor_show(struct seq_file *m, void *p) { struct rv_monitor *mon = m->private; - struct rv_reactor_def *rdef = p; + struct rv_reactor *reactor = p; - if (mon->rdef == rdef) - seq_printf(m, "[%s]\n", rdef->reactor->name); + if (mon->reactor == reactor) + seq_printf(m, "[%s]\n", reactor->name); else - seq_printf(m, "%s\n", rdef->reactor->name); + seq_printf(m, "%s\n", reactor->name); return 0; } @@ -159,13 +159,13 @@ static const struct seq_operations monitor_reactors_seq_ops = { }; static void monitor_swap_reactors_single(struct rv_monitor *mon, - struct rv_reactor_def *rdef, + struct rv_reactor *reactor, bool reacting, bool nested) { bool monitor_enabled; /* nothing to do */ - if (mon->rdef == rdef) + if (mon->reactor == reactor) return; monitor_enabled = mon->enabled; @@ -173,12 +173,12 @@ static void monitor_swap_reactors_single(struct rv_monitor *mon, rv_disable_monitor(mon); /* swap reactor's usage */ - mon->rdef->counter--; - rdef->counter++; + mon->reactor->counter--; + reactor->counter++; - mon->rdef = rdef; + mon->reactor = reactor; mon->reacting = reacting; - mon->react = rdef->reactor->react; + mon->react = reactor->react; /* enable only once if iterating through a container */ if (monitor_enabled && !nested) @@ -186,7 +186,7 @@ static void monitor_swap_reactors_single(struct rv_monitor *mon, } static void monitor_swap_reactors(struct rv_monitor *mon, - struct rv_reactor_def *rdef, bool reacting) + struct rv_reactor *reactor, bool reacting) { struct rv_monitor *p = mon; @@ -194,7 +194,7 @@ static void monitor_swap_reactors(struct rv_monitor *mon, list_for_each_entry_continue(p, &rv_monitors_list, list) { if (p->parent != mon) break; - monitor_swap_reactors_single(p, rdef, reacting, true); + monitor_swap_reactors_single(p, reactor, reacting, true); } /* * This call enables and disables the monitor if they were active. @@ -202,7 +202,7 @@ static void monitor_swap_reactors(struct rv_monitor *mon, * All nested monitors are enabled also if they were off, we may refine * this logic in the future. */ - monitor_swap_reactors_single(mon, rdef, reacting, false); + monitor_swap_reactors_single(mon, reactor, reacting, false); } static ssize_t @@ -211,7 +211,7 @@ monitor_reactors_write(struct file *file, const char __user *user_buf, { char buff[MAX_RV_REACTOR_NAME_SIZE + 2]; struct rv_monitor *mon; - struct rv_reactor_def *rdef; + struct rv_reactor *reactor; struct seq_file *seq_f; int retval = -EINVAL; bool enable; @@ -243,16 +243,16 @@ monitor_reactors_write(struct file *file, const char __user *user_buf, retval = -EINVAL; - list_for_each_entry(rdef, &rv_reactors_list, list) { - if (strcmp(ptr, rdef->reactor->name) != 0) + list_for_each_entry(reactor, &rv_reactors_list, list) { + if (strcmp(ptr, reactor->name) != 0) continue; - if (rdef == get_reactor_rdef_by_name("nop")) + if (strcmp(reactor->name, "nop")) enable = false; else enable = true; - monitor_swap_reactors(mon, rdef, enable); + monitor_swap_reactors(mon, reactor, enable); retval = count; break; @@ -299,23 +299,16 @@ static const struct file_operations monitor_reactors_ops = { static int __rv_register_reactor(struct rv_reactor *reactor) { - struct rv_reactor_def *r; + struct rv_reactor *r; list_for_each_entry(r, &rv_reactors_list, list) { - if (strcmp(reactor->name, r->reactor->name) == 0) { + if (strcmp(reactor->name, r->name) == 0) { pr_info("Reactor %s is already registered\n", reactor->name); return -EINVAL; } } - r = kzalloc(sizeof(struct rv_reactor_def), GFP_KERNEL); - if (!r) - return -ENOMEM; - - r->reactor = reactor; - r->counter = 0; - - list_add_tail(&r->list, &rv_reactors_list); + list_add_tail(&reactor->list, &rv_reactors_list); return 0; } @@ -350,26 +343,19 @@ int rv_register_reactor(struct rv_reactor *reactor) */ int rv_unregister_reactor(struct rv_reactor *reactor) { - struct rv_reactor_def *ptr, *next; int ret = 0; mutex_lock(&rv_interface_lock); - list_for_each_entry_safe(ptr, next, &rv_reactors_list, list) { - if (strcmp(reactor->name, ptr->reactor->name) == 0) { - - if (!ptr->counter) { - list_del(&ptr->list); - } else { - printk(KERN_WARNING - "rv: the rv_reactor %s is in use by %d monitor(s)\n", - ptr->reactor->name, ptr->counter); - printk(KERN_WARNING "rv: the rv_reactor %s cannot be removed\n", - ptr->reactor->name); - ret = -EBUSY; - break; - } - } + if (!reactor->counter) { + list_del(&reactor->list); + } else { + printk(KERN_WARNING + "rv: the rv_reactor %s is in use by %d monitor(s)\n", + reactor->name, reactor->counter); + printk(KERN_WARNING "rv: the rv_reactor %s cannot be removed\n", + reactor->name); + ret = -EBUSY; } mutex_unlock(&rv_interface_lock); @@ -469,8 +455,8 @@ int reactor_populate_monitor(struct rv_monitor *mon) /* * Configure as the rv_nop reactor. */ - mon->rdef = get_reactor_rdef_by_name("nop"); - mon->rdef->counter++; + mon->reactor = get_reactor_rdef_by_name("nop"); + mon->reactor->counter++; mon->reacting = false; return 0; @@ -483,8 +469,8 @@ int reactor_populate_monitor(struct rv_monitor *mon) void reactor_cleanup_monitor(struct rv_monitor *mon) { lockdep_assert_held(&rv_interface_lock); - mon->rdef->counter--; - WARN_ON_ONCE(mon->rdef->counter < 0); + mon->reactor->counter--; + WARN_ON_ONCE(mon->reactor->counter < 0); } /* -- 2.47.2