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From: Christoph Hellwig <hch@lst.de>
To: Frederic Barrat <fbarrat@linux.ibm.com>,
	Andrew Donnellan <ajd@linux.ibm.com>,
	Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
	Maxime Ripard <mripard@kernel.org>,
	Thomas Zimmermann <tzimmermann@suse.de>,
	David Airlie <airlied@linux.ie>, Daniel Vetter <daniel@ffwll.ch>,
	Jessica Yu <jeyu@kernel.org>,
	Josh Poimboeuf <jpoimboe@redhat.com>,
	Jiri Kosina <jikos@kernel.org>, Miroslav Benes <mbenes@suse.cz>,
	Petr Mladek <pmladek@suse.com>,
	Joe Lawrence <joe.lawrence@redhat.com>
Cc: Masahiro Yamada <masahiroy@kernel.org>,
	Michal Marek <michal.lkml@markovi.net>,
	linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org,
	dri-devel@lists.freedesktop.org, live-patching@vger.kernel.org,
	linux-kbuild@vger.kernel.org
Subject: [PATCH 11/13] module: pass struct find_symbol_args to find_symbol
Date: Thu, 21 Jan 2021 08:49:57 +0100	[thread overview]
Message-ID: <20210121074959.313333-12-hch@lst.de> (raw)
In-Reply-To: <20210121074959.313333-1-hch@lst.de>

Simplify the calling convention by passing the find_symbol_args structure
to find_symbol instead of initializing it inside the function.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 kernel/module.c | 113 ++++++++++++++++++++++--------------------------
 1 file changed, 52 insertions(+), 61 deletions(-)

diff --git a/kernel/module.c b/kernel/module.c
index 644dda52dae38c..7a88b71736ff5c 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -536,12 +536,7 @@ static bool find_exported_symbol_in_section(const struct symsearch *syms,
  * Find an exported symbol and return it, along with, (optional) crc and
  * (optional) module which owns it.  Needs preempt disabled or module_mutex.
  */
-static const struct kernel_symbol *find_symbol(const char *name,
-					struct module **owner,
-					const s32 **crc,
-					enum mod_license *license,
-					bool gplok,
-					bool warn)
+static bool find_symbol(struct find_symbol_arg *fsa)
 {
 	static const struct symsearch arr[] = {
 		{ __start___ksymtab, __stop___ksymtab, __start___kcrctab,
@@ -561,19 +556,14 @@ static const struct kernel_symbol *find_symbol(const char *name,
 		  GPL_ONLY, true },
 #endif
 	};
-	struct find_symbol_arg fsa = {
-		.name = name,
-		.gplok = gplok,
-		.warn = warn,
-	};
 	struct module *mod;
 	unsigned int i;
 
 	module_assert_mutex_or_preempt();
 
 	for (i = 0; i < ARRAY_SIZE(arr); i++)
-		if (find_exported_symbol_in_section(&arr[i], NULL, &fsa))
-			goto found;
+		if (find_exported_symbol_in_section(&arr[i], NULL, fsa))
+			return true;
 
 	list_for_each_entry_rcu(mod, &modules, list,
 				lockdep_is_held(&module_mutex)) {
@@ -603,21 +593,12 @@ static const struct kernel_symbol *find_symbol(const char *name,
 			continue;
 
 		for (i = 0; i < ARRAY_SIZE(arr); i++)
-			if (find_exported_symbol_in_section(&arr[i], mod, &fsa))
-				goto found;
+			if (find_exported_symbol_in_section(&arr[i], mod, fsa))
+				return true;
 	}
 
-	pr_debug("Failed to find symbol %s\n", name);
-	return NULL;
-
-found:
-	if (owner)
-		*owner = fsa.owner;
-	if (crc)
-		*crc = fsa.crc;
-	if (license)
-		*license = fsa.license;
-	return fsa.sym;
+	pr_debug("Failed to find symbol %s\n", fsa->name);
+	return false;
 }
 
 /*
@@ -1107,12 +1088,15 @@ static inline void print_unload_info(struct seq_file *m, struct module *mod)
 
 void __symbol_put(const char *symbol)
 {
-	struct module *owner;
+	struct find_symbol_arg fsa = {
+		.name	= symbol,
+		.gplok	= true,
+	};
 
 	preempt_disable();
-	if (!find_symbol(symbol, &owner, NULL, NULL, true, false))
+	if (!find_symbol(&fsa))
 		BUG();
-	module_put(owner);
+	module_put(fsa.owner);
 	preempt_enable();
 }
 EXPORT_SYMBOL(__symbol_put);
@@ -1381,19 +1365,22 @@ static int check_version(const struct load_info *info,
 static inline int check_modstruct_version(const struct load_info *info,
 					  struct module *mod)
 {
-	const s32 *crc;
+	struct find_symbol_arg fsa = {
+		.name	= "module_layout",
+		.gplok	= true,
+	};
 
 	/*
 	 * Since this should be found in kernel (which can't be removed), no
 	 * locking is necessary -- use preempt_disable() to placate lockdep.
 	 */
 	preempt_disable();
-	if (!find_symbol("module_layout", NULL, &crc, NULL, true, false)) {
+	if (!find_symbol(&fsa)) {
 		preempt_enable();
 		BUG();
 	}
 	preempt_enable();
-	return check_version(info, "module_layout", mod, crc);
+	return check_version(info, "module_layout", mod, fsa.crc);
 }
 
 /* First part is kernel version, which we ignore if module has crcs. */
@@ -1487,10 +1474,11 @@ static const struct kernel_symbol *resolve_symbol(struct module *mod,
 						  const char *name,
 						  char ownername[])
 {
-	struct module *owner;
-	const struct kernel_symbol *sym;
-	const s32 *crc;
-	enum mod_license license;
+	struct find_symbol_arg fsa = {
+		.name	= name,
+		.gplok	= !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)),
+		.warn	= true,
+	};
 	int err;
 
 	/*
@@ -1500,42 +1488,40 @@ static const struct kernel_symbol *resolve_symbol(struct module *mod,
 	 */
 	sched_annotate_sleep();
 	mutex_lock(&module_mutex);
-	sym = find_symbol(name, &owner, &crc, &license,
-			  !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)), true);
-	if (!sym)
+	if (!find_symbol(&fsa))
 		goto unlock;
 
-	if (license == GPL_ONLY)
+	if (fsa.license == GPL_ONLY)
 		mod->using_gplonly_symbols = true;
 
-	if (!inherit_taint(mod, owner)) {
-		sym = NULL;
+	if (!inherit_taint(mod, fsa.owner)) {
+		fsa.sym = NULL;
 		goto getname;
 	}
 
-	if (!check_version(info, name, mod, crc)) {
-		sym = ERR_PTR(-EINVAL);
+	if (!check_version(info, name, mod, fsa.crc)) {
+		fsa.sym = ERR_PTR(-EINVAL);
 		goto getname;
 	}
 
-	err = verify_namespace_is_imported(info, sym, mod);
+	err = verify_namespace_is_imported(info, fsa.sym, mod);
 	if (err) {
-		sym = ERR_PTR(err);
+		fsa.sym = ERR_PTR(err);
 		goto getname;
 	}
 
-	err = ref_module(mod, owner);
+	err = ref_module(mod, fsa.owner);
 	if (err) {
-		sym = ERR_PTR(err);
+		fsa.sym = ERR_PTR(err);
 		goto getname;
 	}
 
 getname:
 	/* We must make copy under the lock if we failed to get ref. */
-	strncpy(ownername, module_name(owner), MODULE_NAME_LEN);
+	strncpy(ownername, module_name(fsa.owner), MODULE_NAME_LEN);
 unlock:
 	mutex_unlock(&module_mutex);
-	return sym;
+	return fsa.sym;
 }
 
 static const struct kernel_symbol *
@@ -2296,16 +2282,19 @@ static void free_module(struct module *mod)
 
 void *__symbol_get(const char *symbol)
 {
-	struct module *owner;
-	const struct kernel_symbol *sym;
+	struct find_symbol_arg fsa = {
+		.name	= symbol,
+		.gplok	= true,
+		.warn	= true,
+	};
 
 	preempt_disable();
-	sym = find_symbol(symbol, &owner, NULL, NULL, true, true);
-	if (sym && strong_try_module_get(owner))
-		sym = NULL;
+	if (!find_symbol(&fsa) || !strong_try_module_get(fsa.owner)) {
+		preempt_enable();
+		return NULL;
+	}
 	preempt_enable();
-
-	return sym ? (void *)kernel_symbol_value(sym) : NULL;
+	return (void *)kernel_symbol_value(fsa.sym);
 }
 EXPORT_SYMBOL_GPL(__symbol_get);
 
@@ -2318,7 +2307,6 @@ EXPORT_SYMBOL_GPL(__symbol_get);
 static int verify_exported_symbols(struct module *mod)
 {
 	unsigned int i;
-	struct module *owner;
 	const struct kernel_symbol *s;
 	struct {
 		const struct kernel_symbol *sym;
@@ -2335,12 +2323,15 @@ static int verify_exported_symbols(struct module *mod)
 
 	for (i = 0; i < ARRAY_SIZE(arr); i++) {
 		for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) {
-			if (find_symbol(kernel_symbol_name(s), &owner, NULL,
-					NULL, true, false)) {
+			struct find_symbol_arg fsa = {
+				.name	= kernel_symbol_name(s),
+				.gplok	= true,
+			};
+			if (find_symbol(&fsa)) {
 				pr_err("%s: exports duplicate symbol %s"
 				       " (owned by %s)\n",
 				       mod->name, kernel_symbol_name(s),
-				       module_name(owner));
+				       module_name(fsa.owner));
 				return -ENOEXEC;
 			}
 		}
-- 
2.29.2


  parent reply	other threads:[~2021-01-21  7:57 UTC|newest]

Thread overview: 29+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-01-21  7:49 module loader dead code removal and cleanusp Christoph Hellwig
2021-01-21  7:49 ` [PATCH 01/13] powerpc/powernv: remove get_cxl_module Christoph Hellwig
2021-01-21  9:09   ` Andrew Donnellan
2021-01-21  7:49 ` [PATCH 02/13] module: add a module_loaded helper Christoph Hellwig
2021-01-21 10:00   ` Christophe Leroy
2021-01-21 17:11     ` Christoph Hellwig
2021-01-21 17:44       ` David Laight
2021-01-21  7:49 ` [PATCH 03/13] livepatch: refactor klp_init_object Christoph Hellwig
2021-01-27 12:58   ` Petr Mladek
2021-01-28 16:22     ` Christoph Hellwig
2021-01-28 16:24       ` Christoph Hellwig
2021-01-21  7:49 ` [PATCH 04/13] livepatch: move klp_find_object_module to module.c Christoph Hellwig
2021-01-21 21:45   ` Josh Poimboeuf
2021-01-26 14:25   ` Jessica Yu
2021-01-27 11:55     ` Petr Mladek
2021-01-21  7:49 ` [PATCH 05/13] kallsyms: refactor {,module_}kallsyms_on_each_symbol Christoph Hellwig
2021-01-21  7:49 ` [PATCH 06/13] kallsyms: only build {,module_}kallsyms_on_each_symbol when required Christoph Hellwig
2021-01-21  7:49 ` [PATCH 07/13] module: mark module_mutex static Christoph Hellwig
2021-01-21  7:49 ` [PATCH 08/13] drm: remove drm_fb_helper_modinit Christoph Hellwig
2021-01-21  8:25   ` Daniel Vetter
2021-01-21  8:28     ` Christoph Hellwig
2021-01-21  8:39       ` Daniel Vetter
2021-01-21  7:49 ` [PATCH 09/13] module: remove each_symbol_in_section Christoph Hellwig
2021-01-21  7:49 ` [PATCH 10/13] module: merge each_symbol_section into find_symbol Christoph Hellwig
2021-01-21  7:49 ` Christoph Hellwig [this message]
2021-01-21  7:49 ` [PATCH 12/13] module: remove EXPORT_SYMBOL_GPL_FUTURE Christoph Hellwig
2021-01-21  7:49 ` [PATCH 13/13] module: remove EXPORY_UNUSED_SYMBOL* Christoph Hellwig
2021-01-27 13:49   ` Jessica Yu
2021-01-28 16:09     ` Christoph Hellwig

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