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Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195// SPDX-License-Identifier: GPL-2.0/* * Userspace indexing of printk formats */
#include <linux/debugfs.h>#include <linux/module.h>#include <linux/printk.h>#include <linux/slab.h>#include <linux/string_helpers.h>
#include "internal.h"
extern struct pi_entry *__start_printk_index[];extern struct pi_entry *__stop_printk_index[];
/* The base dir for module formats, typically debugfs/printk/index/ */static struct dentry *dfs_index;
static struct pi_entry *pi_get_entry(const struct module *mod, loff_t pos){ struct pi_entry **entries; unsigned int nr_entries;
#ifdef CONFIG_MODULES if (mod) { entries = mod->printk_index_start; nr_entries = mod->printk_index_size; } else#endif { /* vmlinux, comes from linker symbols */ entries = __start_printk_index; nr_entries = __stop_printk_index - __start_printk_index; }
if (pos >= nr_entries) return NULL;
return entries[pos];}
static void *pi_next(struct seq_file *s, void *v, loff_t *pos){ const struct module *mod = s->file->f_inode->i_private; struct pi_entry *entry = pi_get_entry(mod, *pos);
(*pos)++;
return entry;}
static void *pi_start(struct seq_file *s, loff_t *pos){ /* * Make show() print the header line. Do not update *pos because * pi_next() still has to return the entry at index 0 later. */ if (*pos == 0) return SEQ_START_TOKEN;
return pi_next(s, NULL, pos);}
/* * We need both ESCAPE_ANY and explicit characters from ESCAPE_SPECIAL in @only * because otherwise ESCAPE_NAP will cause double quotes and backslashes to be * ignored for quoting. */#define seq_escape_printf_format(s, src) \ seq_escape_str(s, src, ESCAPE_ANY | ESCAPE_NAP | ESCAPE_APPEND, "\"\\")
static int pi_show(struct seq_file *s, void *v){ const struct pi_entry *entry = v; int level = LOGLEVEL_DEFAULT; enum printk_info_flags flags = 0; u16 prefix_len = 0;
if (v == SEQ_START_TOKEN) { seq_puts(s, "# <level/flags> filename:line function \"format\"\n"); return 0; }
if (!entry->fmt) return 0;
if (entry->level) printk_parse_prefix(entry->level, &level, &flags); else prefix_len = printk_parse_prefix(entry->fmt, &level, &flags);
if (flags & LOG_CONT) { /* * LOGLEVEL_DEFAULT here means "use the same level as the * message we're continuing from", not the default message * loglevel, so don't display it as such. */ if (level == LOGLEVEL_DEFAULT) seq_puts(s, "<c>"); else seq_printf(s, "<%d,c>", level); } else seq_printf(s, "<%d>", level);
seq_printf(s, " %s:%d %s \"", entry->file, entry->line, entry->func); if (entry->subsys_fmt_prefix) seq_escape_printf_format(s, entry->subsys_fmt_prefix); seq_escape_printf_format(s, entry->fmt + prefix_len); seq_puts(s, "\"\n");
return 0;}
static void pi_stop(struct seq_file *p, void *v) { }
static const struct seq_operations dfs_index_sops = { .start = pi_start, .next = pi_next, .show = pi_show, .stop = pi_stop,};
DEFINE_SEQ_ATTRIBUTE(dfs_index);
#ifdef CONFIG_MODULESstatic const char *pi_get_module_name(struct module *mod){ return mod ? mod->name : "vmlinux";}#elsestatic const char *pi_get_module_name(struct module *mod){ return "vmlinux";}#endif
static void pi_create_file(struct module *mod){ debugfs_create_file(pi_get_module_name(mod), 0444, dfs_index, mod, &dfs_index_fops);}
#ifdef CONFIG_MODULESstatic void pi_remove_file(struct module *mod){ debugfs_lookup_and_remove(pi_get_module_name(mod), dfs_index);}
static int pi_module_notify(struct notifier_block *nb, unsigned long op, void *data){ struct module *mod = data;
switch (op) { case MODULE_STATE_COMING: pi_create_file(mod); break; case MODULE_STATE_GOING: pi_remove_file(mod); break; default: /* we don't care about other module states */ break; }
return NOTIFY_OK;}
static struct notifier_block module_printk_fmts_nb = { .notifier_call = pi_module_notify,};
static void __init pi_setup_module_notifier(void){ register_module_notifier(&module_printk_fmts_nb);}#elsestatic inline void __init pi_setup_module_notifier(void) { }#endif
static int __init pi_init(void){ struct dentry *dfs_root = debugfs_create_dir("printk", NULL);
dfs_index = debugfs_create_dir("index", dfs_root); pi_setup_module_notifier(); pi_create_file(NULL);
return 0;}
/* debugfs comes up on core and must be initialised first */postcore_initcall(pi_init);