From b7b4eebdba7b6aea6b34dc29691b71c39d1dbd6a Mon Sep 17 00:00:00 2001 From: Jim Cromie Date: Sun, 4 Sep 2022 15:40:48 -0600 Subject: dyndbg: gather __dyndbg[] state into struct _ddebug_info This new struct composes the linker provided (vector,len) section, and provides a place to add other __dyndbg[] state-data later: descs - the vector of descriptors in __dyndbg section. num_descs - length of the data/section. Use it, in several different ways, as follows: In lib/dynamic_debug.c: ddebug_add_module(): Alter params-list, replacing 2 args (array,index) with a struct _ddebug_info * containing them both, with room for expansion. This helps future-proof the function prototype against the looming addition of class-map info into the dyndbg-state, by providing a place to add more member fields later. NB: later add static struct _ddebug_info builtins_state declaration, not needed yet. ddebug_add_module() is called in 2 contexts: In dynamic_debug_init(), declare, init a struct _ddebug_info di auto-var to use as a cursor. Then iterate over the prdbg blocks of the builtin modules, and update the di cursor before calling _add_module for each. Its called from kernel/module/main.c:load_info() for each loaded module: In internal.h, alter struct load_info, replacing the dyndbg array,len fields with an embedded _ddebug_info containing them both; and populate its members in find_module_sections(). The 2 calling contexts differ in that _init deals with contiguous subranges of __dyndbgs[] section, packed together, while loadable modules are added one at a time. So rename ddebug_add_module() into outer/__inner fns, call __inner from _init, and provide the offset into the builtin __dyndbgs[] where the module's prdbgs reside. The cursor provides start, len of the subrange for each. The offset will be used later to pack the results of builtin __dyndbg_sites[] de-duplication, and is 0 and unneeded for loadable modules, Note: kernel/module/main.c includes for struct _ddeubg_info. This might be prone to include loops, since its also included by printk.h. Nothing has broken in robot-land on this. cc: Luis Chamberlain Signed-off-by: Jim Cromie Link: https://lore.kernel.org/r/20220904214134.408619-12-jim.cromie@gmail.com Signed-off-by: Greg Kroah-Hartman --- lib/dynamic_debug.c | 40 +++++++++++++++++++++++++++++++--------- 1 file changed, 31 insertions(+), 9 deletions(-) (limited to 'lib/dynamic_debug.c') diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c index 2e8ebef3bd0d..c358ccdf4a39 100644 --- a/lib/dynamic_debug.c +++ b/lib/dynamic_debug.c @@ -923,14 +923,20 @@ static const struct proc_ops proc_fops = { * Allocate a new ddebug_table for the given module * and add it to the global list. */ -int ddebug_add_module(struct _ddebug *tab, unsigned int n, - const char *name) +static int __ddebug_add_module(struct _ddebug_info *di, unsigned int base, + const char *modname) { struct ddebug_table *dt; + v3pr_info("add-module: %s.%d sites\n", modname, di->num_descs); + if (!di->num_descs) { + v3pr_info(" skip %s\n", modname); + return 0; + } + dt = kzalloc(sizeof(*dt), GFP_KERNEL); if (dt == NULL) { - pr_err("error adding module: %s\n", name); + pr_err("error adding module: %s\n", modname); return -ENOMEM; } /* @@ -939,18 +945,25 @@ int ddebug_add_module(struct _ddebug *tab, unsigned int n, * member of struct module, which lives at least as long as * this struct ddebug_table. */ - dt->mod_name = name; - dt->num_ddebugs = n; - dt->ddebugs = tab; + dt->mod_name = modname; + dt->ddebugs = di->descs; + dt->num_ddebugs = di->num_descs; + + INIT_LIST_HEAD(&dt->link); mutex_lock(&ddebug_lock); list_add_tail(&dt->link, &ddebug_tables); mutex_unlock(&ddebug_lock); - vpr_info("%3u debug prints in module %s\n", n, dt->mod_name); + vpr_info("%3u debug prints in module %s\n", di->num_descs, modname); return 0; } +int ddebug_add_module(struct _ddebug_info *di, const char *modname) +{ + return __ddebug_add_module(di, 0, modname); +} + /* helper for ddebug_dyndbg_(boot|module)_param_cb */ static int ddebug_dyndbg_param_cb(char *param, char *val, const char *modname, int on_err) @@ -1064,6 +1077,11 @@ static int __init dynamic_debug_init(void) const char *modname; char *cmdline; + struct _ddebug_info di = { + .descs = __start___dyndbg, + .num_descs = __stop___dyndbg - __start___dyndbg, + }; + if (&__start___dyndbg == &__stop___dyndbg) { if (IS_ENABLED(CONFIG_DYNAMIC_DEBUG)) { pr_warn("_ddebug table is empty in a CONFIG_DYNAMIC_DEBUG build\n"); @@ -1082,7 +1100,9 @@ static int __init dynamic_debug_init(void) if (strcmp(modname, iter->modname)) { mod_ct++; - ret = ddebug_add_module(iter_mod_start, mod_sites, modname); + di.num_descs = mod_sites; + di.descs = iter_mod_start; + ret = __ddebug_add_module(&di, i - mod_sites, modname); if (ret) goto out_err; @@ -1091,7 +1111,9 @@ static int __init dynamic_debug_init(void) iter_mod_start = iter; } } - ret = ddebug_add_module(iter_mod_start, mod_sites, modname); + di.num_descs = mod_sites; + di.descs = iter_mod_start; + ret = __ddebug_add_module(&di, i - mod_sites, modname); if (ret) goto out_err; -- cgit