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>
This commit is contained in:

committed by
Linus Torvalds

parent
ffb4512276
commit
9d65cb4a17
@@ -38,15 +38,12 @@ DECLARE_PER_CPU(struct hrtimer_cpu_base, hrtimer_bases);
|
||||
|
||||
static void print_name_offset(struct seq_file *m, void *sym)
|
||||
{
|
||||
unsigned long addr = (unsigned long)sym;
|
||||
char namebuf[KSYM_NAME_LEN+1];
|
||||
const char *sym_name;
|
||||
char symname[KSYM_NAME_LEN+1];
|
||||
|
||||
sym_name = kallsyms_lookup(addr, NULL, NULL, NULL, namebuf);
|
||||
if (sym_name)
|
||||
SEQ_printf(m, "%s", sym_name);
|
||||
else
|
||||
if (lookup_symbol_name((unsigned long)sym, symname) < 0)
|
||||
SEQ_printf(m, "<%p>", sym);
|
||||
else
|
||||
SEQ_printf(m, "%s", symname);
|
||||
}
|
||||
|
||||
static void
|
||||
|
Reference in New Issue
Block a user