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authorRusty Russell <rusty@rustcorp.com.au>2013-01-21 17:17:39 +1030
committerRusty Russell <rusty@rustcorp.com.au>2013-01-21 17:17:57 +1030
commit373d4d099761cb1f637bed488ab3871945882273 (patch)
tree954bef7bc724aee105dd246d5f2b1ea04ed38b20 /kernel
parent64748a2c9062da0c32b59c1b368a86fc4613b1e1 (diff)
taint: add explicit flag to show whether lock dep is still OK.
Fix up all callers as they were before, with make one change: an unsigned module taints the kernel, but doesn't turn off lockdep. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/module.c26
-rw-r--r--kernel/panic.c34
-rw-r--r--kernel/sched/core.c2
-rw-r--r--kernel/sysctl.c2
4 files changed, 31 insertions, 33 deletions
diff --git a/kernel/module.c b/kernel/module.c
index e69a5a68766..cc000dd6e4a 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -197,9 +197,10 @@ static inline int strong_try_module_get(struct module *mod)
return -ENOENT;
}
-static inline void add_taint_module(struct module *mod, unsigned flag)
+static inline void add_taint_module(struct module *mod, unsigned flag,
+ enum lockdep_ok lockdep_ok)
{
- add_taint(flag);
+ add_taint(flag, lockdep_ok);
mod->taints |= (1U << flag);
}
@@ -727,7 +728,7 @@ static inline int try_force_unload(unsigned int flags)
{
int ret = (flags & O_TRUNC);
if (ret)
- add_taint(TAINT_FORCED_RMMOD);
+ add_taint(TAINT_FORCED_RMMOD, LOCKDEP_NOW_UNRELIABLE);
return ret;
}
#else
@@ -1138,7 +1139,7 @@ static int try_to_force_load(struct module *mod, const char *reason)
if (!test_taint(TAINT_FORCED_MODULE))
printk(KERN_WARNING "%s: %s: kernel tainted.\n",
mod->name, reason);
- add_taint_module(mod, TAINT_FORCED_MODULE);
+ add_taint_module(mod, TAINT_FORCED_MODULE, LOCKDEP_NOW_UNRELIABLE);
return 0;
#else
return -ENOEXEC;
@@ -2147,7 +2148,8 @@ static void set_license(struct module *mod, const char *license)
if (!test_taint(TAINT_PROPRIETARY_MODULE))
printk(KERN_WARNING "%s: module license '%s' taints "
"kernel.\n", mod->name, license);
- add_taint_module(mod, TAINT_PROPRIETARY_MODULE);
+ add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
+ LOCKDEP_NOW_UNRELIABLE);
}
}
@@ -2700,10 +2702,10 @@ static int check_modinfo(struct module *mod, struct load_info *info, int flags)
}
if (!get_modinfo(info, "intree"))
- add_taint_module(mod, TAINT_OOT_MODULE);
+ add_taint_module(mod, TAINT_OOT_MODULE, LOCKDEP_STILL_OK);
if (get_modinfo(info, "staging")) {
- add_taint_module(mod, TAINT_CRAP);
+ add_taint_module(mod, TAINT_CRAP, LOCKDEP_STILL_OK);
printk(KERN_WARNING "%s: module is from the staging directory,"
" the quality is unknown, you have been warned.\n",
mod->name);
@@ -2869,15 +2871,17 @@ static int check_module_license_and_versions(struct module *mod)
* using GPL-only symbols it needs.
*/
if (strcmp(mod->name, "ndiswrapper") == 0)
- add_taint(TAINT_PROPRIETARY_MODULE);
+ add_taint(TAINT_PROPRIETARY_MODULE, LOCKDEP_NOW_UNRELIABLE);
/* driverloader was caught wrongly pretending to be under GPL */
if (strcmp(mod->name, "driverloader") == 0)
- add_taint_module(mod, TAINT_PROPRIETARY_MODULE);
+ add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
+ LOCKDEP_NOW_UNRELIABLE);
/* lve claims to be GPL but upstream won't provide source */
if (strcmp(mod->name, "lve") == 0)
- add_taint_module(mod, TAINT_PROPRIETARY_MODULE);
+ add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
+ LOCKDEP_NOW_UNRELIABLE);
#ifdef CONFIG_MODVERSIONS
if ((mod->num_syms && !mod->crcs)
@@ -3197,7 +3201,7 @@ again:
"%s: module verification failed: signature and/or"
" required key missing - tainting kernel\n",
mod->name);
- add_taint_module(mod, TAINT_FORCED_MODULE);
+ add_taint_module(mod, TAINT_FORCED_MODULE, LOCKDEP_STILL_OK);
}
#endif
diff --git a/kernel/panic.c b/kernel/panic.c
index e1b2822fff9..7c57cc9eee2 100644
--- a/kernel/panic.c
+++ b/kernel/panic.c
@@ -259,26 +259,19 @@ unsigned long get_taint(void)
return tainted_mask;
}
-void add_taint(unsigned flag)
+/**
+ * add_taint: add a taint flag if not already set.
+ * @flag: one of the TAINT_* constants.
+ * @lockdep_ok: whether lock debugging is still OK.
+ *
+ * If something bad has gone wrong, you'll want @lockdebug_ok = false, but for
+ * some notewortht-but-not-corrupting cases, it can be set to true.
+ */
+void add_taint(unsigned flag, enum lockdep_ok lockdep_ok)
{
- /*
- * Can't trust the integrity of the kernel anymore.
- * We don't call directly debug_locks_off() because the issue
- * is not necessarily serious enough to set oops_in_progress to 1
- * Also we want to keep up lockdep for staging/out-of-tree
- * development and post-warning case.
- */
- switch (flag) {
- case TAINT_CRAP:
- case TAINT_OOT_MODULE:
- case TAINT_WARN:
- case TAINT_FIRMWARE_WORKAROUND:
- break;
-
- default:
- if (__debug_locks_off())
- printk(KERN_WARNING "Disabling lock debugging due to kernel taint\n");
- }
+ if (lockdep_ok == LOCKDEP_NOW_UNRELIABLE && __debug_locks_off())
+ printk(KERN_WARNING
+ "Disabling lock debugging due to kernel taint\n");
set_bit(flag, &tainted_mask);
}
@@ -421,7 +414,8 @@ static void warn_slowpath_common(const char *file, int line, void *caller,
print_modules();
dump_stack();
print_oops_end_marker();
- add_taint(taint);
+ /* Just a warning, don't kill lockdep. */
+ add_taint(taint, LOCKDEP_STILL_OK);
}
void warn_slowpath_fmt(const char *file, int line, const char *fmt, ...)
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 257002c13bb..662f3d51218 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -2785,7 +2785,7 @@ static noinline void __schedule_bug(struct task_struct *prev)
if (irqs_disabled())
print_irqtrace_events(prev);
dump_stack();
- add_taint(TAINT_WARN);
+ add_taint(TAINT_WARN, LOCKDEP_STILL_OK);
}
/*
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index c88878db491..f97f9d75cde 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -2006,7 +2006,7 @@ static int proc_taint(struct ctl_table *table, int write,
int i;
for (i = 0; i < BITS_PER_LONG && tmptaint >> i; i++) {
if ((tmptaint >> i) & 1)
- add_taint(i);
+ add_taint(i, LOCKDEP_STILL_OK);
}
}