From mboxrd@z Thu Jan 1 00:00:00 1970 From: Suren Baghdasaryan Subject: [PATCH 14/40] lib: code tagging module support Date: Mon, 1 May 2023 09:54:24 -0700 Message-ID: <20230501165450.15352-15-surenb@google.com> References: <20230501165450.15352-1-surenb@google.com> Mime-Version: 1.0 Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20221208; t=1682960140; x=1685552140; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=Fsyg89/vfc29JJa9GS5YhCGnLnEPc8LoOfUR2xEk3nU=; b=XugZDvU8R0/s4xSWeFHluE62boWwkQ9CTbOENMFYQbMS3l2tyzUCtbQcKbwHigUJIJ OtnAHKBuBjvsP9/stYM2LN0tvR5v6TsP4w8c4UexO5Utfx0bFwgsYC7skVlENgpnJL9H sIxP6b1pDy/fBiWqF/8EcNcaUPUXV9QISrg+weQ/AP/7B06TvSpoas2EJfqmlc3VmYeD jr4T+ZByYleQx4KEZl+bfKD1sOEa1DJKK+WO7dY/hFTgLUuurZ1db5fCtz0miigMUxwU tm4S2IZOyKuiQL4O2pCNIbqdvFVKgmVq6GGIhg+Gt6k3Cilb/R8U19yQnyV0xS5Bv4tA iA/Q== In-Reply-To: <20230501165450.15352-1-surenb@google.com> List-ID: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: akpm@linux-foundation.org Cc: kent.overstreet@linux.dev, mhocko@suse.com, vbabka@suse.cz, hannes@cmpxchg.org, roman.gushchin@linux.dev, mgorman@suse.de, dave@stgolabs.net, willy@infradead.org, liam.howlett@oracle.com, corbet@lwn.net, void@manifault.com, peterz@infradead.org, juri.lelli@redhat.com, ldufour@linux.ibm.com, catalin.marinas@arm.com, will@kernel.org, arnd@arndb.de, tglx@linutronix.de, mingo@redhat.com, dave.hansen@linux.intel.com, x86@kernel.org, peterx@redhat.com, david@redhat.com, axboe@kernel.dk, mcgrof@kernel.org, masahiroy@kernel.org, nathan@kernel.org, dennis@kernel.org, tj@kernel.org, muchun.song@linux.dev, rppt@kernel.org, paulmck@kernel.org, pasha.tatashin@soleen.com, yosryahmed@google.com, yuzhao@google.com, dhowells@redhat.com, hughd@google.com, andreyknvl@gmail.com, keescook@chromium.org Add support for code tagging from dynamically loaded modules. Signed-off-by: Suren Baghdasaryan Co-developed-by: Kent Overstreet Signed-off-by: Kent Overstreet --- include/linux/codetag.h | 12 +++++++++ kernel/module/main.c | 4 +++ lib/codetag.c | 58 +++++++++++++++++++++++++++++++++++++++-- 3 files changed, 72 insertions(+), 2 deletions(-) diff --git a/include/linux/codetag.h b/include/linux/codetag.h index a9d7adecc2a5..386733e89b31 100644 --- a/include/linux/codetag.h +++ b/include/linux/codetag.h @@ -42,6 +42,10 @@ struct codetag_module { struct codetag_type_desc { const char *section; size_t tag_size; + void (*module_load)(struct codetag_type *cttype, + struct codetag_module *cmod); + void (*module_unload)(struct codetag_type *cttype, + struct codetag_module *cmod); }; struct codetag_iterator { @@ -68,4 +72,12 @@ void codetag_to_text(struct seq_buf *out, struct codetag *ct); struct codetag_type * codetag_register_type(const struct codetag_type_desc *desc); +#ifdef CONFIG_CODE_TAGGING +void codetag_load_module(struct module *mod); +void codetag_unload_module(struct module *mod); +#else +static inline void codetag_load_module(struct module *mod) {} +static inline void codetag_unload_module(struct module *mod) {} +#endif + #endif /* _LINUX_CODETAG_H */ diff --git a/kernel/module/main.c b/kernel/module/main.c index 044aa2c9e3cb..4232e7bff549 100644 --- a/kernel/module/main.c +++ b/kernel/module/main.c @@ -56,6 +56,7 @@ #include #include #include +#include #include #include #include "internal.h" @@ -1249,6 +1250,7 @@ static void free_module(struct module *mod) { trace_module_free(mod); + codetag_unload_module(mod); mod_sysfs_teardown(mod); /* @@ -2974,6 +2976,8 @@ static int load_module(struct load_info *info, const char __user *uargs, /* Get rid of temporary copy. */ free_copy(info, flags); + codetag_load_module(mod); + /* Done! */ trace_module_load(mod); diff --git a/lib/codetag.c b/lib/codetag.c index 7708f8388e55..4ea57fb37346 100644 --- a/lib/codetag.c +++ b/lib/codetag.c @@ -108,15 +108,20 @@ static inline size_t range_size(const struct codetag_type *cttype, static void *get_symbol(struct module *mod, const char *prefix, const char *name) { char buf[64]; + void *ret; int res; res = snprintf(buf, sizeof(buf), "%s%s", prefix, name); if (WARN_ON(res < 1 || res > sizeof(buf))) return NULL; - return mod ? + preempt_disable(); + ret = mod ? (void *)find_kallsyms_symbol_value(mod, buf) : (void *)kallsyms_lookup_name(buf); + preempt_enable(); + + return ret; } static struct codetag_range get_section_range(struct module *mod, @@ -157,8 +162,11 @@ static int codetag_module_init(struct codetag_type *cttype, struct module *mod) down_write(&cttype->mod_lock); err = idr_alloc(&cttype->mod_idr, cmod, 0, 0, GFP_KERNEL); - if (err >= 0) + if (err >= 0) { cttype->count += range_size(cttype, &range); + if (cttype->desc.module_load) + cttype->desc.module_load(cttype, cmod); + } up_write(&cttype->mod_lock); if (err < 0) { @@ -197,3 +205,49 @@ codetag_register_type(const struct codetag_type_desc *desc) return cttype; } + +void codetag_load_module(struct module *mod) +{ + struct codetag_type *cttype; + + if (!mod) + return; + + mutex_lock(&codetag_lock); + list_for_each_entry(cttype, &codetag_types, link) + codetag_module_init(cttype, mod); + mutex_unlock(&codetag_lock); +} + +void codetag_unload_module(struct module *mod) +{ + struct codetag_type *cttype; + + if (!mod) + return; + + mutex_lock(&codetag_lock); + list_for_each_entry(cttype, &codetag_types, link) { + struct codetag_module *found = NULL; + struct codetag_module *cmod; + unsigned long mod_id, tmp; + + down_write(&cttype->mod_lock); + idr_for_each_entry_ul(&cttype->mod_idr, cmod, tmp, mod_id) { + if (cmod->mod && cmod->mod == mod) { + found = cmod; + break; + } + } + if (found) { + if (cttype->desc.module_unload) + cttype->desc.module_unload(cttype, cmod); + + cttype->count -= range_size(cttype, &cmod->range); + idr_remove(&cttype->mod_idr, mod_id); + kfree(cmod); + } + up_write(&cttype->mod_lock); + } + mutex_unlock(&codetag_lock); +} -- 2.40.1.495.gc816e09b53d-goog