summaryrefslogtreecommitdiff
path: root/include/linux
diff options
context:
space:
mode:
authorAlexey Dobriyan <adobriyan@sw.ru>2007-05-08 00:28:43 -0700
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-05-08 11:15:08 -0700
commit9d65cb4a1718a072898c7a57a3bc61b2dc4bcd4d (patch)
tree9e3fd1c9e61e8ed16959d115a9a3f6f7eb0bbf21 /include/linux
parentffb45122766db220d0bf3d01848d575fbbcb6430 (diff)
Fix race between cat /proc/*/wchan and rmmod et al
kallsyms_lookup() can go iterating over modules list unprotected which is OK for emergency situations (oops), but not OK for regular stuff like /proc/*/wchan. Introduce lookup_symbol_name()/lookup_module_symbol_name() which copy symbol name into caller-supplied buffer or return -ERANGE. All copying is done with module_mutex held, so... Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru> Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux')
-rw-r--r--include/linux/kallsyms.h7
-rw-r--r--include/linux/module.h6
2 files changed, 13 insertions, 0 deletions
diff --git a/include/linux/kallsyms.h b/include/linux/kallsyms.h
index 3e3b92dabe3b..ae0117a95cfd 100644
--- a/include/linux/kallsyms.h
+++ b/include/linux/kallsyms.h
@@ -30,6 +30,8 @@ extern int sprint_symbol(char *buffer, unsigned long address);
/* Look up a kernel symbol and print it to the kernel messages. */
extern void __print_symbol(const char *fmt, unsigned long address);
+int lookup_symbol_name(unsigned long addr, char *symname);
+
#else /* !CONFIG_KALLSYMS */
static inline unsigned long kallsyms_lookup_name(const char *name)
@@ -58,6 +60,11 @@ static inline int sprint_symbol(char *buffer, unsigned long addr)
return 0;
}
+static inline int lookup_symbol_name(unsigned long addr, char *symname)
+{
+ return -ERANGE;
+}
+
/* Stupid that this does nothing, but I didn't create this mess. */
#define __print_symbol(fmt, addr)
#endif /*CONFIG_KALLSYMS*/
diff --git a/include/linux/module.h b/include/linux/module.h
index 58d5a10cdf0d..099ae5932c68 100644
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -454,6 +454,7 @@ const char *module_address_lookup(unsigned long addr,
unsigned long *symbolsize,
unsigned long *offset,
char **modname);
+int lookup_module_symbol_name(unsigned long addr, char *symname);
/* For extable.c to search modules' exception tables. */
const struct exception_table_entry *search_module_extables(unsigned long addr);
@@ -525,6 +526,11 @@ static inline const char *module_address_lookup(unsigned long addr,
return NULL;
}
+static inline int lookup_module_symbol_name(unsigned long addr, char *symname)
+{
+ return -ERANGE;
+}
+
static inline int module_get_kallsym(unsigned int symnum, unsigned long *value,
char *type, char *name,
char *module_name, int *exported)