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authorRusty Russell <rusty@rustcorp.com.au>2008-07-22 19:24:25 -0500
committerRusty Russell <rusty@rustcorp.com.au>2008-07-22 19:24:26 +1000
commitdafd0940c96fec67974a88ed8e6b8ba3160394cd (patch)
tree616da8f0f283509ec71ff2d6e467fa4c6877edc6 /kernel
parentda39ba5e1d65e997a98f6eb93ba6e6eb505f6e3c (diff)
module: generic each_symbol iterator function
Introduce an each_symbol() iterator to avoid duplicating the knowledge about the 5 different sections containing symbols. Currently only used by find_symbol(), but will be used by symbol_put_addr() too. (Includes NULL ptr deref fix by Jiri Kosina <jkosina@suse.cz>) Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Jiri Kosina <jkosina@suse.cz>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/module.c244
1 files changed, 134 insertions, 110 deletions
diff --git a/kernel/module.c b/kernel/module.c
index 705e1d5d516c..c51c089c666e 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -152,156 +152,180 @@ extern const unsigned long __start___kcrctab_unused_gpl[];
#define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL)
#endif
-/* lookup symbol in given range of kernel_symbols */
-static const struct kernel_symbol *lookup_symbol(const char *name,
- const struct kernel_symbol *start,
- const struct kernel_symbol *stop)
-{
- const struct kernel_symbol *ks = start;
- for (; ks < stop; ks++)
- if (strcmp(ks->name, name) == 0)
- return ks;
- return NULL;
-}
-
-static bool always_ok(bool gplok, bool warn, const char *name)
-{
- return true;
-}
-
-static bool printk_unused_warning(bool gplok, bool warn, const char *name)
-{
- if (warn) {
- printk(KERN_WARNING "Symbol %s is marked as UNUSED, "
- "however this module is using it.\n", name);
- printk(KERN_WARNING
- "This symbol will go away in the future.\n");
- printk(KERN_WARNING
- "Please evalute if this is the right api to use and if "
- "it really is, submit a report the linux kernel "
- "mailinglist together with submitting your code for "
- "inclusion.\n");
- }
- return true;
-}
-
-static bool gpl_only_unused_warning(bool gplok, bool warn, const char *name)
-{
- if (!gplok)
- return false;
- return printk_unused_warning(gplok, warn, name);
-}
-
-static bool gpl_only(bool gplok, bool warn, const char *name)
-{
- return gplok;
-}
-
-static bool warn_if_not_gpl(bool gplok, bool warn, const char *name)
-{
- if (!gplok && warn) {
- printk(KERN_WARNING "Symbol %s is being used "
- "by a non-GPL module, which will not "
- "be allowed in the future\n", name);
- printk(KERN_WARNING "Please see the file "
- "Documentation/feature-removal-schedule.txt "
- "in the kernel source tree for more details.\n");
- }
- return true;
-}
-
struct symsearch {
const struct kernel_symbol *start, *stop;
const unsigned long *crcs;
- bool (*check)(bool gplok, bool warn, const char *name);
+ enum {
+ NOT_GPL_ONLY,
+ GPL_ONLY,
+ WILL_BE_GPL_ONLY,
+ } licence;
+ bool unused;
};
-/* Look through this array of symbol tables for a symbol match which
- * passes the check function. */
-static const struct kernel_symbol *search_symarrays(const struct symsearch *arr,
- unsigned int num,
- const char *name,
- bool gplok,
- bool warn,
- const unsigned long **crc)
+static bool each_symbol_in_section(const struct symsearch *arr,
+ unsigned int arrsize,
+ struct module *owner,
+ bool (*fn)(const struct symsearch *syms,
+ struct module *owner,
+ unsigned int symnum, void *data),
+ void *data)
{
- unsigned int i;
- const struct kernel_symbol *ks;
-
- for (i = 0; i < num; i++) {
- ks = lookup_symbol(name, arr[i].start, arr[i].stop);
- if (!ks || !arr[i].check(gplok, warn, name))
- continue;
+ unsigned int i, j;
- if (crc)
- *crc = symversion(arr[i].crcs, ks - arr[i].start);
- return ks;
+ for (j = 0; j < arrsize; j++) {
+ for (i = 0; i < arr[j].stop - arr[j].start; i++)
+ if (fn(&arr[j], owner, i, data))
+ return true;
}
- return NULL;
+
+ return false;
}
-/* Find a symbol, return value, (optional) crc and (optional) module
- * which owns it */
-static unsigned long find_symbol(const char *name,
- struct module **owner,
- const unsigned long **crc,
- bool gplok,
- bool warn)
+/* Returns true as soon as fn returns true, otherwise false. */
+static bool each_symbol(bool (*fn)(const struct symsearch *arr,
+ struct module *owner,
+ unsigned int symnum, void *data),
+ void *data)
{
struct module *mod;
- const struct kernel_symbol *ks;
const struct symsearch arr[] = {
{ __start___ksymtab, __stop___ksymtab, __start___kcrctab,
- always_ok },
+ NOT_GPL_ONLY, false },
{ __start___ksymtab_gpl, __stop___ksymtab_gpl,
- __start___kcrctab_gpl, gpl_only },
+ __start___kcrctab_gpl,
+ GPL_ONLY, false },
{ __start___ksymtab_gpl_future, __stop___ksymtab_gpl_future,
- __start___kcrctab_gpl_future, warn_if_not_gpl },
+ __start___kcrctab_gpl_future,
+ WILL_BE_GPL_ONLY, false },
{ __start___ksymtab_unused, __stop___ksymtab_unused,
- __start___kcrctab_unused, printk_unused_warning },
+ __start___kcrctab_unused,
+ NOT_GPL_ONLY, true },
{ __start___ksymtab_unused_gpl, __stop___ksymtab_unused_gpl,
- __start___kcrctab_unused_gpl, gpl_only_unused_warning },
+ __start___kcrctab_unused_gpl,
+ GPL_ONLY, true },
};
- /* Core kernel first. */
- ks = search_symarrays(arr, ARRAY_SIZE(arr), name, gplok, warn, crc);
- if (ks) {
- if (owner)
- *owner = NULL;
- return ks->value;
- }
+ if (each_symbol_in_section(arr, ARRAY_SIZE(arr), NULL, fn, data))
+ return true;
- /* Now try modules. */
list_for_each_entry(mod, &modules, list) {
struct symsearch arr[] = {
{ mod->syms, mod->syms + mod->num_syms, mod->crcs,
- always_ok },
+ NOT_GPL_ONLY, false },
{ mod->gpl_syms, mod->gpl_syms + mod->num_gpl_syms,
- mod->gpl_crcs, gpl_only },
+ mod->gpl_crcs,
+ GPL_ONLY, false },
{ mod->gpl_future_syms,
mod->gpl_future_syms + mod->num_gpl_future_syms,
- mod->gpl_future_crcs, warn_if_not_gpl },
+ mod->gpl_future_crcs,
+ WILL_BE_GPL_ONLY, false },
{ mod->unused_syms,
mod->unused_syms + mod->num_unused_syms,
- mod->unused_crcs, printk_unused_warning },
+ mod->unused_crcs,
+ NOT_GPL_ONLY, true },
{ mod->unused_gpl_syms,
mod->unused_gpl_syms + mod->num_unused_gpl_syms,
- mod->unused_gpl_crcs, gpl_only_unused_warning },
+ mod->unused_gpl_crcs,
+ GPL_ONLY, true },
};
- ks = search_symarrays(arr, ARRAY_SIZE(arr),
- name, gplok, warn, crc);
- if (ks) {
- if (owner)
- *owner = mod;
- return ks->value;
+ if (each_symbol_in_section(arr, ARRAY_SIZE(arr), mod, fn, data))
+ return true;
+ }
+ return false;
+}
+
+struct find_symbol_arg {
+ /* Input */
+ const char *name;
+ bool gplok;
+ bool warn;
+
+ /* Output */
+ struct module *owner;
+ const unsigned long *crc;
+ unsigned long value;
+};
+
+static bool find_symbol_in_section(const struct symsearch *syms,
+ struct module *owner,
+ unsigned int symnum, void *data)
+{
+ struct find_symbol_arg *fsa = data;
+
+ if (strcmp(syms->start[symnum].name, fsa->name) != 0)
+ return false;
+
+ if (!fsa->gplok) {
+ if (syms->licence == GPL_ONLY)
+ return false;
+ if (syms->licence == WILL_BE_GPL_ONLY && fsa->warn) {
+ printk(KERN_WARNING "Symbol %s is being used "
+ "by a non-GPL module, which will not "
+ "be allowed in the future\n", fsa->name);
+ printk(KERN_WARNING "Please see the file "
+ "Documentation/feature-removal-schedule.txt "
+ "in the kernel source tree for more details.\n");
}
}
+ if (syms->unused && fsa->warn) {
+ printk(KERN_WARNING "Symbol %s is marked as UNUSED, "
+ "however this module is using it.\n", fsa->name);
+ printk(KERN_WARNING
+ "This symbol will go away in the future.\n");
+ printk(KERN_WARNING
+ "Please evalute if this is the right api to use and if "
+ "it really is, submit a report the linux kernel "
+ "mailinglist together with submitting your code for "
+ "inclusion.\n");
+ }
+
+ fsa->owner = owner;
+ fsa->crc = symversion(syms->crcs, symnum);
+ fsa->value = syms->start[symnum].value;
+ return true;
+}
+
+/* Find a symbol, return value, (optional) crc and (optional) module
+ * which owns it */
+static unsigned long find_symbol(const char *name,
+ struct module **owner,
+ const unsigned long **crc,
+ bool gplok,
+ bool warn)
+{
+ struct find_symbol_arg fsa;
+
+ fsa.name = name;
+ fsa.gplok = gplok;
+ fsa.warn = warn;
+
+ if (each_symbol(find_symbol_in_section, &fsa)) {
+ if (owner)
+ *owner = fsa.owner;
+ if (crc)
+ *crc = fsa.crc;
+ return fsa.value;
+ }
+
DEBUGP("Failed to find symbol %s\n", name);
return -ENOENT;
}
+/* lookup symbol in given range of kernel_symbols */
+static const struct kernel_symbol *lookup_symbol(const char *name,
+ const struct kernel_symbol *start,
+ const struct kernel_symbol *stop)
+{
+ const struct kernel_symbol *ks = start;
+ for (; ks < stop; ks++)
+ if (strcmp(ks->name, name) == 0)
+ return ks;
+ return NULL;
+}
+
/* Search for module by name: must hold module_mutex. */
static struct module *find_module(const char *name)
{