diff options
| author | Alexey Dobriyan <adobriyan@sw.ru> | 2007-05-08 09:28:43 +0200 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-05-08 20:15:08 +0200 |
| commit | 9d65cb4a1718a072898c7a57a3bc61b2dc4bcd4d (patch) | |
| tree | 9e3fd1c9e61e8ed16959d115a9a3f6f7eb0bbf21 /kernel/time | |
| parent | Simplify kallsyms_lookup() (diff) | |
| download | linux-9d65cb4a1718a072898c7a57a3bc61b2dc4bcd4d.tar.xz linux-9d65cb4a1718a072898c7a57a3bc61b2dc4bcd4d.zip | |
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 'kernel/time')
| -rw-r--r-- | kernel/time/timer_list.c | 11 | ||||
| -rw-r--r-- | kernel/time/timer_stats.c | 10 |
2 files changed, 8 insertions, 13 deletions
diff --git a/kernel/time/timer_list.c b/kernel/time/timer_list.c index fe9314a89f20..b734ca4bc75e 100644 --- a/kernel/time/timer_list.c +++ b/kernel/time/timer_list.c @@ -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 diff --git a/kernel/time/timer_stats.c b/kernel/time/timer_stats.c index 946ed45f7d2f..868f1bceb07f 100644 --- a/kernel/time/timer_stats.c +++ b/kernel/time/timer_stats.c @@ -257,14 +257,12 @@ void timer_stats_update_stats(void *timer, pid_t pid, void *startf, static void print_name_offset(struct seq_file *m, unsigned long addr) { - 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(addr, symname) < 0) seq_printf(m, "<%p>", (void *)addr); + else + seq_printf(m, "%s", symname); } static int tstats_show(struct seq_file *m, void *v) |