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[73.78.62.130]) by smtp.googlemail.com with ESMTPSA id n9-20020a056638110900b003435e8635bbsm27928jal.77.2022.08.11.10.36.03 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 11 Aug 2022 10:36:04 -0700 (PDT) From: Jim Cromie To: linux-kernel@vger.kernel.org, gregkh@linuxfoundation.org, jbaron@akamai.com Cc: Jim Cromie , Luis Chamberlain Subject: [PATCH 11/11] dyndbg: create and use struct _ddebug_info Date: Thu, 11 Aug 2022 11:35:41 -0600 Message-Id: <20220811173541.2901122-12-jim.cromie@gmail.com> X-Mailer: git-send-email 2.37.1 In-Reply-To: <20220811173541.2901122-1-jim.cromie@gmail.com> References: <20220811173541.2901122-1-jim.cromie@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" this new struct gathers the linker provided vectors/sections: descs - the vector of descriptors in __dyndbg section. num_descs - length of the data/section Use it as follows: In lib/dynamic_debug.c: Alter ddebug_add_module() params-list, replacing descriptor-table and its length with a single _ddebug_info object containing them. This future-proofs the function against the looming addition of class-map info, for either the builtin module set, or the loaded module. In dynamic_debug_init(): add & initialize an auto struct _ddebug_info var, and use it like a cursor / multi-part iterator. Re-initialize the var's component values before each call to ddebug_add_module(). This gives us an explicit by-module walk thru the built-in __dyndbgs data section. In kernel/module/{main.c,internal.h}: Embed a struct _ddebug_info into struct load_info, replacing the 2 fields it contains. Populate its members in find_module_sections. Also adjust dynamic_debug_setup/remove() to match the change to ddebug_add_module(). Note: this adds an include dynamic_debug, and might be prone to include loops, since its also smuggled in by printk.h. Nothing has puked in robot-land. cc: Luis Chamberlain Signed-off-by: Jim Cromie --- include/linux/dynamic_debug.h | 13 +++++++----- kernel/module/internal.h | 4 ++-- kernel/module/main.c | 18 ++++++++-------- lib/dynamic_debug.c | 40 +++++++++++++++++++++++++++-------- 4 files changed, 50 insertions(+), 25 deletions(-) diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h index 8d9eec5f6d8b..6a2001250da1 100644 --- a/include/linux/dynamic_debug.h +++ b/include/linux/dynamic_debug.h @@ -51,12 +51,16 @@ struct _ddebug { #endif } __attribute__((aligned(8))); =20 - +/* encapsulate linker provided built-in (or module) dyndbg data */ +struct _ddebug_info { + struct _ddebug *descs; + unsigned int num_descs; +}; =20 #if defined(CONFIG_DYNAMIC_DEBUG_CORE) =20 -int ddebug_add_module(struct _ddebug *tab, unsigned int n, - const char *modname); +int ddebug_add_module(struct _ddebug_info *dyndbg, const char *modname); + extern int ddebug_remove_module(const char *mod_name); extern __printf(2, 3) void __dynamic_pr_debug(struct _ddebug *descriptor, const char *fmt, ...); @@ -184,8 +188,7 @@ void __dynamic_ibdev_dbg(struct _ddebug *descriptor, #include #include =20 -static inline int ddebug_add_module(struct _ddebug *tab, unsigned int n, - const char *modname) +static inline int ddebug_add_module(struct _ddebug_info *dinfo, const char= *modname) { return 0; } diff --git a/kernel/module/internal.h b/kernel/module/internal.h index ec104c2950c3..ce42b5b8b4da 100644 --- a/kernel/module/internal.h +++ b/kernel/module/internal.h @@ -53,6 +53,7 @@ extern const struct kernel_symbol __stop___ksymtab_gpl[]; extern const s32 __start___kcrctab[]; extern const s32 __start___kcrctab_gpl[]; =20 +#include struct load_info { const char *name; /* pointer to module in temporary copy, freed at end of load_module() */ @@ -62,8 +63,7 @@ struct load_info { Elf_Shdr *sechdrs; char *secstrings, *strtab; unsigned long symoffs, stroffs, init_typeoffs, core_typeoffs; - struct _ddebug *debug; - unsigned int num_debug; + struct _ddebug_info dyndbg; bool sig_ok; #ifdef CONFIG_KALLSYMS unsigned long mod_kallsyms_init_off; diff --git a/kernel/module/main.c b/kernel/module/main.c index 0548151dd933..cfe10356793d 100644 --- a/kernel/module/main.c +++ b/kernel/module/main.c @@ -1593,16 +1593,16 @@ static void free_modinfo(struct module *mod) } } =20 -static void dynamic_debug_setup(struct module *mod, struct _ddebug *debug,= unsigned int num) +static void dynamic_debug_setup(struct module *mod, struct _ddebug_info *d= yndbg) { - if (!debug) + if (!dyndbg->num_descs) return; - ddebug_add_module(debug, num, mod->name); + ddebug_add_module(dyndbg, mod->name); } =20 -static void dynamic_debug_remove(struct module *mod, struct _ddebug *debug) +static void dynamic_debug_remove(struct module *mod, struct _ddebug_info *= dyndbg) { - if (debug) + if (dyndbg->num_descs) ddebug_remove_module(mod->name); } =20 @@ -2093,8 +2093,8 @@ static int find_module_sections(struct module *mod, s= truct load_info *info) if (section_addr(info, "__obsparm")) pr_warn("%s: Ignoring obsolete parameters\n", mod->name); =20 - info->debug =3D section_objs(info, "__dyndbg", - sizeof(*info->debug), &info->num_debug); + info->dyndbg.descs =3D section_objs(info, "__dyndbg", + sizeof(*info->dyndbg.descs), &info->dyndbg.num_descs); =20 return 0; } @@ -2783,7 +2783,7 @@ static int load_module(struct load_info *info, const = char __user *uargs, } =20 init_build_id(mod, info); - dynamic_debug_setup(mod, info->debug, info->num_debug); + dynamic_debug_setup(mod, &info->dyndbg); =20 /* Ftrace init must be called in the MODULE_STATE_UNFORMED state */ ftrace_module_init(mod); @@ -2845,7 +2845,7 @@ static int load_module(struct load_info *info, const = char __user *uargs, =20 ddebug_cleanup: ftrace_release_mod(mod); - dynamic_debug_remove(mod, info->debug); + dynamic_debug_remove(mod, &info->dyndbg); synchronize_rcu(); kfree(mod->args); free_arch_cleanup: diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c index 2e8ebef3bd0d..457ce936191a 100644 --- a/lib/dynamic_debug.c +++ b/lib/dynamic_debug.c @@ -923,14 +923,20 @@ static const struct proc_ops proc_fops =3D { * 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; =20 + 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 =3D kzalloc(sizeof(*dt), GFP_KERNEL); if (dt =3D=3D 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 i= nt n, * member of struct module, which lives at least as long as * this struct ddebug_table. */ - dt->mod_name =3D name; - dt->num_ddebugs =3D n; - dt->ddebugs =3D tab; + dt->mod_name =3D modname; + dt->ddebugs =3D di->descs; + dt->num_ddebugs =3D di->num_descs; + + INIT_LIST_HEAD(&dt->link); =20 mutex_lock(&ddebug_lock); list_add_tail(&dt->link, &ddebug_tables); mutex_unlock(&ddebug_lock); =20 - 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; } =20 +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; =20 + struct _ddebug_info di =3D { + .descs =3D __start___dyndbg, + .num_descs =3D __stop___dyndbg - __start___dyndbg, + }; + if (&__start___dyndbg =3D=3D &__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) =20 if (strcmp(modname, iter->modname)) { mod_ct++; - ret =3D ddebug_add_module(iter_mod_start, mod_sites, modname); + di.num_descs =3D mod_sites; + di.descs =3D iter_mod_start; + ret =3D __ddebug_add_module(&di, i, modname); if (ret) goto out_err; =20 @@ -1091,7 +1111,9 @@ static int __init dynamic_debug_init(void) iter_mod_start =3D iter; } } - ret =3D ddebug_add_module(iter_mod_start, mod_sites, modname); + di.num_descs =3D mod_sites; + di.descs =3D iter_mod_start; + ret =3D __ddebug_add_module(&di, i, modname); if (ret) goto out_err; =20 --=20 2.37.1